Borja Martínez Téllez - Academia.edu (original) (raw)
Papers by Borja Martínez Téllez
Obesity, 2021
This is an open access article under the terms of the Creat ive Commo ns Attri butio n-NonCo mmer... more This is an open access article under the terms of the Creat ive Commo ns Attri butio n-NonCo mmercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
Clinical Nutrition, 2021
Background: Harnessing cold-induced thermogenesis (CIT) and brown adipose tissue (BAT) activity h... more Background: Harnessing cold-induced thermogenesis (CIT) and brown adipose tissue (BAT) activity has been proposed as a means of counteracting a positive energy balance, and thus of combating obesity and its related comorbidities. However, it has remained unclear whether CIT and BAT activity show diurnal variation in humans-knowledge that might allow treatments based on these factors to be timeoptimized. Methods: A randomized crossover experiment was designed to examine whether CIT shows morning/ evening variation in young, healthy adults (n ¼ 14, 5 women). On the first experimental day, subjects' shivering thresholds were determined following a cooling protocol. After z96 h had elapsed, the subjects then returned on two further days (approx. 48 h apart) at 08:00 h or 18:00 in random order. On both the latter days, the resting energy expenditure (REE) was measured before the subjects underwent personalized cold exposure (i.e., according to their shivering threshold). CIT was then assessed for 60 min by indirect calorimetry. In an independent cross-sectional study (n ¼ 133, 88 women), subjects came to the laboratory between 8:00 and 18:00 h and their BAT 18 F-fluordeoxyglucose (18 F-FDG) uptake was assessed after personalized cold stimulation. Results: Both the REE and CIT were similar in the morning and evening (all P > 0.05). Indeed, 60 min of personalized-mild cold exposure in the morning or evening elicited a similar change in energy expenditure (16.8 ± 12.8 vs. 15.7 ± 15.1% increase above REE, P ¼ 0.72). BAT 18 F-FDG uptake was also similar in the morning, evening and afternoon (all P > 0.05). Conclusion: CIT does not appear to show morning/evening variation in young healthy adults, with the current study design and methodology. BAT 18 F-FDG uptake appears not to change across the day either, although experiments with a within-subject study design are needed to confirm these findings. Registered under ClinicalTrials.gov Identifier no. NCT02365129.
Proceedings of the Nutrition Society, 2020
Background:Eubiosis is the intestinal microbial ecosystem balance between human and microorganism... more Background:Eubiosis is the intestinal microbial ecosystem balance between human and microorganisms, whereas a disbalance in this intestinal microbial ecosystem is known as dysbiosis. The relationship between exercise with gut microbiota in humans is poorly studied, although it seems that one of the possible ways to restore eubiosis could be via exercise. This systematic review aimed to examine the scientific literature available on the influence of exercise in the gut microbiota of healthy adults.Methods:A systematic and comprehensive literature search was conducted in PubMed and Web of Science (WOS) from their inception to April 2019. Search terms used were: “Gastrointestinal Microbiome”, “Fecal Microbiota”, “Cecal Microbiota”, “Faecal Microbiota, “Exercises”, “Training” and “Human”.Results:The initial search retrieved 218 articles and 15 met the inclusion criteria of which 9 were cross-sectional, 3 acute and 3 chronic exercise interventions. Higher levels of physical activity or V...
Obesity, 2020
To describe the energy expenditure (EE) and macronutrient oxidation response to an individualized... more To describe the energy expenditure (EE) and macronutrient oxidation response to an individualized non-shivering cold exposure in young healthy adults. Methods: Two different groups of 44 (Study 1: 22.1±2.1 years old, 25.6±5.2 kg/m 2 , 34% men) and 13 young healthy adults (Study 2: 25.6±3.0 years old, 23.6±2.4 kg/m 2 , 54% men) participated in this study. We measured resting EE (RMR) and macronutrient oxidation rates, by indirect calorimetry under fasting conditions, in a warm environment (30-minutes) and in mild cold conditions (65-minutes, wearing a water perfused cooling vest set at an individualized temperature adjusted to the individuals' shivering threshold). Results: In study 1, EE increased in the initial stage of cold exposure and remained stable for the whole cold exposure (P<0.001). Mean CIT (9.56±7.9 Kcal/h) was 13.9±11.6 %RMR (Range:-14.8/39.9 %RMR). Carbohydrate oxidation decreased during the first 30 minutes of the cold exposure and later recovered up to the baseline values (P<0.01) in parallel to opposite changes in fat oxidation (P<0.01). Results were replicated in study 2. Conclusions: A 1-hour mild cold exposure individually adjusted to elicit maximum nonshivering thermogenesis induces a very modest increase in EE and a shift of macronutrient oxidation that may underlie a shift in thermogenic tissues activity.
Clinical and Translational Gastroenterology, 2020
To summarize the literature on the influence of exercise on the gut microbiota of healthy adults.... more To summarize the literature on the influence of exercise on the gut microbiota of healthy adults. METHODS: A systematic and comprehensive search in electronic database, including SciELO, Scopus, PubMed, and Web of Science up to July 5, 2019. Eligibility criterion was original studies conducted on healthy humans including exercise interventions or interventions involving any type of physical activity. RESULTS: The initial search retrieved 619 articles of which 18 met the inclusion criteria, 9 were observational, 4 reported very short-term exercise interventions, and 5 reported medium/long-term exercise interventions. Higher levels of physical activity or cardiorespiratory fitness were positively associated with fecal bacterial alpha diversity. Contrasting associations were detected between both the level of physical activity and cardiorespiratory fitness and fecal counts for the phyla Firmicutes, Bacteroidetes, and Proteobacteria. Higher levels of physical activity and cardiorespiratory fitness were positively associated with the fecal concentration of short-chain fatty acids. Reports on the effects of very shortterm and medium/long-term exercise interventions on the composition of the gut microbiota were inconsistent. DISCUSSION: Higher levels of physical activity and cardiorespiratory fitness are associated with higher fecal bacterial alpha diversity and with the increased representation of some phyla and certain short-chain fatty acids in the feces of healthy adults. Very short-term and medium/long-term exercise interventions seem to influence the fecal counts of some phyla. However, the heterogeneity between studies hampers any strong conclusions from being drawn. Better-designed studies are needed to unravel the possible mechanisms through which exercise might influence the composition and activity of the human gut microbiota.
Journal of Clinical Medicine, 2019
This 12-week randomized controlled trial investigates the effects of different training modalitie... more This 12-week randomized controlled trial investigates the effects of different training modalities on cardiometabolic risk in sedentary, middle-aged adults, and examines whether alterations in cardiometabolic risk are associated with changes in those health-related variables that are modifiable by exercise training. The study subjects were 71 middle-aged adults (~54 years old; ~50% women) who were randomly assigned to one of the following treatment groups: (1) no exercise (control group), (2) concurrent training based on international physical activity recommendations (PAR group), (3) high intensity interval training (HIIT) group, or (4) HIIT plus whole-body electromyostimulation (HIIT+EMS group). A cardiometabolic risk score was calculated based on the International Diabetes Federation’s clinical criteria. A significant reduction in cardiometabolic risk was observed for all exercise training groups compared to the control group (all p < 0.05), which persisted after adjusting pot...
Obesity, 2019
Objective: Brown adipose tissue (BAT) is a thermogenic tissue with potential as a therapeutic tar... more Objective: Brown adipose tissue (BAT) is a thermogenic tissue with potential as a therapeutic target in the treatment of obesity and related metabolic disorders. The most used technique for quantifying human BAT activity is the measurement of 18 F-fluorodeoxyglucose uptake via a positron emission tomography/computed tomography scan following exposure to cold. However, several studies have indicated the measurement of the supraclavicular skin temperature (SST) by infrared thermography (IRT) to be a less invasive alternative. This work reviews the state of the art of this latter method as a means of determining BAT activity in humans. Methods: The data sources for this review were PubMed, Web of Science, and EBSCOhost (SPORTdiscus), and eligible studies were those conducted in humans. Results: In most studies in which participants were first cooled, an increase in IRT-measured SST was noted. However, only 5 of 24 such studies also involved a nuclear technique that confirmed increased activity in BAT, and only 2 took into account the thickness of the fat layer when measuring SST by IRT. Conclusions: More work is needed to understand the involvement of tissues other than BAT in determining IRTmeasured SST; at present, IRT cannot determine whether any increase in SST is due to increased BAT activity.
![Research paper thumbnail of Distribution of Brown Adipose Tissue Radiodensity in Young Adults: Implications for Cold [18F]FDG-PET/CT Analyses](https://attachments.academia-assets.com/91865380/thumbnails/1.jpg)
](Molecular Imaging and Biology, 2019
Purpose: Nowadays, 2-deoxy-2-[ 18 F]fluoro-D-glucose ([ 18 F]FDG) positron emission tomography (P... more Purpose: Nowadays, 2-deoxy-2-[ 18 F]fluoro-D-glucose ([ 18 F]FDG) positron emission tomography (PET)/X-ray computed tomography (CT) is considered the best available technique to in vivo determination of human BAT volume. The most used Hounsfield unit (HU) threshold for BAT quantification is from-250 to − 50 HU. Therefore, the main objective of the present study is (i) to examine the influence of SUV and HU thresholds on BAT quantification by [ 18 F]FDG-PET/CT scan, (ii) to identify the proportion of BAT which is not detected by [ 18 F]FDG-PET/CT scan when limiting the range between − 10 and − 50 HU, and (iii) to describe the distribution of BAT radiodensity by weight status and sex in young healthy individuals. Procedures: We measured 125 individuals after a personalized cooling protocol with a static [ 18 F]FDG-PET/CT scan. We quantified BAT using different combination of threshold in every single HU for all participants. Results: We observed that the SUV threshold influences BAT quantification by [ 18 F]FDG-PET/ CT scans more than the HU range. We found that the range from − 50 to − 10 HU had the highest proportion of total BAT volume (43.2 %), which represents 41.4 % of the total BAT metabolic activity in our cohort. We also observed that BAT volume was not different between categories of body mass index, as well as BAT activity (SUV mean). In addition, BAT was less dense in women than in men, although the BAT activity (SUV mean) was higher in all ranges of HU. We also observed that the radiodensity of BAT located in the cervical area was mainly in the range from − 50 to − 10 HU. Conclusion: Therefore, all future human studies using static [ 18 F]FDG-PET/CT scans should include BAT in the radiodensity range from − 50 to − 10 HU.
Journal of Thermal Biology, 2019
Brown adipose tissue (BAT) thermogenic activity is commonly assessed with a positron emission tom... more Brown adipose tissue (BAT) thermogenic activity is commonly assessed with a positron emission tomography with computed tomography scan (PET/CT). This technique has several limitations and alternative techniques are needed. Supraclavicular skin temperature measured with iButtons and infrared thermography (IRT) has been proposed as an indirect marker of BAT activity. We studied the concurrent validity of skin temperature measured with iButtons vs. IRT and the association of supraclavicular skin temperature measured with iButtons and IRT with BAT. We measured skin temperature upon a shivering threshold test with iButtons and IRT in 6 different regions in 12 participants (n = 2 men). On a separate day, we determined supraclavicular skin temperature with an iButton and IRT after 2 h of a personalized cooling protocol. Thereafter, we quantified BAT volume and activity by PET/CT. We observed that the absolute differences between the devices were statistically different from 0 (all P < 0.05) after the shivering threshold test. Moreover, we did not find any association between supraclavicular skin temperature measured with iButtons or IRT and BAT 18 F-FDG activity (r = −0.213; P = 0.530 and r = −0.079; P = 0.817). However, we observed a negative association of supraclavicular skin temperature measured by IRT with BAT 18 F-FDG volume (r = −0.764; P = 0.006), but not with supraclavicular skin temperature measured with iButtons (r = −0.546; P = 0.082). In light of these results, we concluded that the measurement of skin temperature obtained by iButtons and IRT are not comparable. Furthermore, it seems that supraclavicular skin temperature is not associated with BAT 18 F-FDG activity, but it appears to be negatively associated with BAT 18 F-FDG volume in the case of IRT.
Obesity, 2019
This study aimed to examine whether brown adipose tissue (BAT) or skeletal muscle activity mediat... more This study aimed to examine whether brown adipose tissue (BAT) or skeletal muscle activity mediates the relationship between personal level of environmental temperature (Personal-ET) and wrist skin temperature (WT). Moreover, we examined whether BAT and skeletal muscle have a mediating role between Personal-ET and WT (as a proxy of peripheral vasoconstriction/vasodilation). Methods: The levels of BAT were quantified by cold-induced 18 F-fluorodeoxyglucose-positron emission tomography/computed tomography scan and measured the Personal-ET and WT by using iButtons (Maxim Integrated, Dallas, Texas) in 75 participants (74.6% women). Results: The study found that BAT volume and metabolic activity played a positive and significant role (up to 25.4%) in the association between Personal-ET and WT. In addition, at the coldest temperatures, the participants with lower levels of WT (inducing higher peripheral vasoconstriction) had higher levels of BAT outcomes, whereas in warm temperatures, participants with higher levels of WT (inducing higher peripheral vasodilation) had lower levels of BAT outcomes. The study did not find any mediating role of skeletal muscle activity. Conclusions: BAT volume and metabolic activity play a role in the relationship between Personal-ET and WT. Moreover, the data suggest that there are two distinct phenotypes: individuals who respond better to the cold, both through nonshivering thermogenesis and peripheral vasoconstriction, and individuals who respond better to the heat.
Journal of Thermal Biology, 2019
Currently, 18 [F]-Fluorodeoxyglucose (18 F-FDG) in combination with a positron emission tomograph... more Currently, 18 [F]-Fluorodeoxyglucose (18 F-FDG) in combination with a positron emission tomography/computed tomography (PET/CT) scan analysis is the most commonly used method to quantify human BAT volume and activity. However, this technique presents several drawbacks which negatively affect participant's health. The aim of the present work is to determine whether supraclavicular skin temperature can be used as an indirect marker of cold-induced BAT and skeletal muscle 18 F-FDG uptake in adults, while taking into account body composition. We performed a personalized cooling protocol just before an 18 F-FDG-PET/CT scan, and we measured supraclavicular skin temperature before (in warm conditions) and after the cooling protocol in 88 adults (n = 57 women, mean age: 21.9 ± 2.1 years old, body mass index: 24.5 ± 4.3 km/m 2). We found that supraclavicular skin temperature at the warm and cold periods was weakly and positively associated with BAT activity (SUV mean and SUV peak : β = 3.000; R 2 = 0.072; P = 0.022 and β = 2.448; R 2 = 0.060; P = 0.021), but not with skeletal muscle 18 F-FDG uptake, after controlling for body composition. We performed further analyses and the positive associations persisted only in the group of women. In conclusion, supraclavicular skin temperature in warm and cold conditions seems to be related with cold-induced 18 F-FDG uptake by BAT only in women, although the low explained variance of these associations means that there are other factors involved in the supraclavicular skin temperature.
Nutrients, 2019
Having valid and reliable resting energy expenditure (REE) estimations is crucial to establish re... more Having valid and reliable resting energy expenditure (REE) estimations is crucial to establish reachable goals for dietary and exercise interventions. However, most of the REE predictive equations were developed some time ago and, as the body composition of the current population has changed, it is highly relevant to assess the validity of REE predictive equations in contemporary young adults. In addition, little is known about the role of sex and weight status on the validity of these predictive equations. Therefore, this study aimed to investigate the role of sex and weight status in congruent validity of REE predictive equations in young adults. A total of 132 young healthy adults (67.4% women, 18–26 years old) participated in the study. We measured REE by indirect calorimetry strictly following the standard procedures, and we compared it to 45 predictive equations. The most accurate equations were the following: (i) the Schofield and the “Food and Agriculture Organization of the...
Frontiers in Physiology, 2018
Cold induced thermogenesis (CIT) in humans results mainly from the combination of both brown adip... more Cold induced thermogenesis (CIT) in humans results mainly from the combination of both brown adipose tissue (BAT) and skeletal muscle thermogenic activity. The relative contribution of both tissues to CIT and to cold induced nutrient oxidation rates (CI-NUTox) remains, however, to be elucidated. We investigated the association of BAT and skeletal muscle activity after a personalized cold exposure with CIT and CI-NUTox in 57 healthy adults (23.0 ± 2.4 years old; 25.1 ± 4.6 kg/m 2 ; 35 women). BAT and skeletal muscle (paracervical, sternocleidomastoid, scalene, longus colli, trapezius, parathoracic, supraspinatus, subscapular, deltoid, pectoralis major, and triceps brachii) metabolic activity were assessed by means of a 18 Fluorodeoxyglucose positron emission tomography-computed tomography scan preceded by a personalized cold exposure. The cold exposure consisted in remaining in a mild cold room for 2 h at 19.5-20 • C wearing a water perfused cooling vest set at 3.8 • C above the individual shivering threshold. On a separate day, we estimated CIT and CI-NUTox by indirect calorimetry under fasting conditions for 1 h of personalized cold exposure. There was no association of BAT volume or activity with CIT or CI-NUTox (all P > 0.2). Similarly, the skeletal muscle metabolic activity was not associated either with CIT or CI-NUTox (all P > 0.2). The results persisted after controlling for sex, the time of the day, and the date when CIT was assessed. Our results suggest that human BAT activity and skeletal muscle 18 F-FDG activity are not associated to CIT in young healthy adults. Inherent limitations of the available radiotracers for BAT detection and muscle activity quantification may explain why we failed to detect a physiologically plausible association.
Annals of Nutrition and Metabolism, 2015
Background: The energy-burning capacity of brown adipose tissue (BAT) makes it an attractive targ... more Background: The energy-burning capacity of brown adipose tissue (BAT) makes it an attractive target for use in anti-obesity therapies. Moreover, due to its ability to oxidize glucose and lipids, BAT activation has been considered a potential therapy to combat type 2 diabetes and atherogenesis. Summary: BAT is mainly regulated by the sympathetic nervous system (SNS); yet, recent findings have shown a group of novel activators that act independently of the stimulation of the SNS such as cardiac natriuretic peptides, irisin, interleukin-6, β-aminoisobutyric acid and fibroblast growth factor 21 that could influence BAT metabolism. Several strategies are being examined to activate and recruit BAT with no side effects. In this review, we postulate that exercise might activate and recruit human BAT through the activation of SNS, heart and skeletal muscle. Key Messages: Epidemiological and well-designed exercise-based randomized controlled studies are needed to clarify if exercise is able t...
British journal of sports medicine, Jan 3, 2015
ABSTRACT 2 Brown adipose tissue (BAT) has the ability to oxidise glucose and lipids, and dissipat... more ABSTRACT 2 Brown adipose tissue (BAT) has the ability to oxidise glucose and lipids, and dissipate energy in the form of heat. 1 Thus, it could provide one method to influence energy balance—and therefore, be a player in the fight against obesity and type 2 diabetes. BAT is highly regulated by the sympathetic nervous system (SNS) to increase body temperature when mammals are exposed to cold. The heat production is mediated by uncoupling protein 1 (UCP-1), an inner-membrane mitochondrial protein exclusively expressed in BAT. 1 Dogma was that BAT was only present in newborns. However, radiologists using the radiotracer 18 F-fluorodeoxyglucose in positron emission tomography (PET)/computed tomog-raphy to detect metabolically active tumours, found competing areas in the supraclavicular, thoracic spine and neck regions with high rates of glucose uptake. The significance of BAT for human physiology was recognised in 2007. 2 Recently, another type of cells called brown-in-white (BRITE) or beige cells, in white adipose tissue (WAT) have been found. 3 BRITE cells possess a multilocular morphology, enriched mitochondria and express the brown adipocyte-specific UCP-1. IMPORTANCE OF ACTIVATING BAT A potential clinical implication of activating BAT relates to the stimulation of resting energy expenditure and diet-induced thermogenesis. In humans, the thermogenic response to a meal is higher in those possessing BAT. It has been estimated that 50 g of activated BAT might translate to increase ∼5% of resting energy expenditure. A 5% chronic increase in resting energy expenditure turns to ∼75–100 kcal/day, which over the course of a year might translate into a loss of ∼4–4.7 kg of fat. SYMPATHETIC NERVOUS SYSTEM
Revista Andaluza de Medicina del Deporte, 2015
Objetivo. Los objetivos del presente estudio fueron evaluar la fuerza resistencia de la musculatu... more Objetivo. Los objetivos del presente estudio fueron evaluar la fuerza resistencia de la musculatura extensora del tronco y analizar la relación existente entre la resistencia de la musculatura extensora del tronco y la presencia de dolor lumbar en alumnos de Educación Secundaria Obligatoria y post-obligatoria. Método. La muestra estuvo compuesta por 69 estudiantes de 12a18años (35 chicos y 34 chicas) de un instituto de la Región de Murcia. Para la toma de datos se emplearon dos instrumentos: una prueba para determinar la resistencia muscular de los extensores del tronco (Test de Biering-Sorensen) y un cuestionario para valorar la incidencia y factores de riesgo asociados con el dolor de espalda denominado "Encuesta sobre el dolor de espalda en adolescentes". Resultados. Los resultados mostraron que las chicas mantenían más tiempo la posición horizontal en la realización del test que los chicos con una media de 183,35 ± 72,32 segundos y 135,74 ± 65,23 segundos, respectivamente. Con respecto a la presencia de dolor de espalda en relación con la resistencia de la musculatura extensora del tronco, se observó en todos los casos una mayor duración del test en los estudiantes que declararon no padecer dolor con una media de 172,65 ± 93,495 segundos frente a los que presentaban dolor con una media de 154,70 ± 62,742 segundos. Aunque, las diferencias no fueron estadísticamente significativas. Conclusión. Los chicos y las chicas tienen diferentes perfiles de resistencia en la musculatura extensora del tronco, presentando las chicas una mayor resistencia que los chicos. Los estudiantes que declararon padecer dolor de espalda durante el pasado año aguantaron menos tiempo en la realización de Test de Biering-Sorensen.
Revista Andaluza de Medicina del Deporte, 2015
futuras investigaciones qué variables metodológicas pueden influir en el nivel de actividad físic... more futuras investigaciones qué variables metodológicas pueden influir en el nivel de actividad física realizado por los escolares dentro de las clases de Educación Física.
Revista Andaluza de Medicina del Deporte, 2015
las propuestas que los maestros de EF llevarían a cabo para mejorar los hábitos físico-deportivos... more las propuestas que los maestros de EF llevarían a cabo para mejorar los hábitos físico-deportivos de los alumnos. Métodos. Participaron 10 maestros de EF de 4 CEIPs del municipio de Soria, con una experiencia media de 25,86 (±9,12) años trabajados en la docencia. Se administró un cuestionario de diez preguntas abiertas y cerradas. Una vez recogidos los cuestionarios se transcribieron las respuestas y se procedió al análisis cualitativo a través del software científico ATLAS.ti. Resultados. El 50% de los maestros considera que existe relación entre la práctica de actividad físico-deportiva extraescolar de los alumnos y su desarrollo madurativo, el 30% no responde a la pregunta y el 20% dice que existe cierta relación. El 60% de los maestros no trabaja específicamente la adquisición de hábitos de práctica físico-deportiva por parte de los alumnos, el 10% no responde, el 10% responde afirmativamente pero no concreta la manera en que lo hace, y el otro 10% sí lo concreta. El 10% de los maestros participantes no formula ninguna propuesta con el objetivo de que los niños adquirieran hábitos saludables de práctica físico-deportiva, frente al 90% que sí lo considera oportuno. Conclusiones. El 90% del profesorado considera que los alumnos que practican actividad físico-deportiva extraescolar tienen un nivel de desarrollo mayor. El 20% de los maestros trabaja específicamente la adquisición de hábitos saludables de práctica físico-deportiva. El 90% de los docentes cree conveniente realizar algún tipo de propuesta para mejorar el nivel de práctica de actividad física saludable de los alumnos, y que principalmente sea promovida a nivel institucional.
Revista Andaluza de Medicina del Deporte, 2015
Objective. Menopause is characterized by the presence of emotional instability and greater dissat... more Objective. Menopause is characterized by the presence of emotional instability and greater dissatisfaction with life. Therefore, we aimed to analyze the effects of an exercise intervention on quality of life and optimism in perimenopausal women. Method. Fourteen perimenopausal women (54.1 ± 3.2 years) participated in a 9 weeks (60 minutes/session, 3 days/week) moderate-vigorous intensity (12-16 rating of perceived effort) exercise intervention (aerobic and resistance exercise mainly). Health-related quality of life and general optimism and pessimism were evaluated by means of the Short-Form Health Survey (SF-36) and the Revised Life Orientation Test, respectively. Nonparametric Wilcoxon signed ranks test for paired samples was used. Results. The exercise program improved physical function by 12% (P < 0.05) and emotional role by 18% (P = 0.05). No statistically significant differences were found for the remaining SF-36 dimensions. After the exercise intervention participants' general optimism improved 21% (P < 0.05). Conclusion. An exercise intervention program is successful by improving the physical functioning and general optimism of perimenopausal women. Because of the small sample size, the results must be taken cautiously. Future studies with greater sample sizes should confirm the present results.
Obesity, 2021
This is an open access article under the terms of the Creat ive Commo ns Attri butio n-NonCo mmer... more This is an open access article under the terms of the Creat ive Commo ns Attri butio n-NonCo mmercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
Clinical Nutrition, 2021
Background: Harnessing cold-induced thermogenesis (CIT) and brown adipose tissue (BAT) activity h... more Background: Harnessing cold-induced thermogenesis (CIT) and brown adipose tissue (BAT) activity has been proposed as a means of counteracting a positive energy balance, and thus of combating obesity and its related comorbidities. However, it has remained unclear whether CIT and BAT activity show diurnal variation in humans-knowledge that might allow treatments based on these factors to be timeoptimized. Methods: A randomized crossover experiment was designed to examine whether CIT shows morning/ evening variation in young, healthy adults (n ¼ 14, 5 women). On the first experimental day, subjects' shivering thresholds were determined following a cooling protocol. After z96 h had elapsed, the subjects then returned on two further days (approx. 48 h apart) at 08:00 h or 18:00 in random order. On both the latter days, the resting energy expenditure (REE) was measured before the subjects underwent personalized cold exposure (i.e., according to their shivering threshold). CIT was then assessed for 60 min by indirect calorimetry. In an independent cross-sectional study (n ¼ 133, 88 women), subjects came to the laboratory between 8:00 and 18:00 h and their BAT 18 F-fluordeoxyglucose (18 F-FDG) uptake was assessed after personalized cold stimulation. Results: Both the REE and CIT were similar in the morning and evening (all P > 0.05). Indeed, 60 min of personalized-mild cold exposure in the morning or evening elicited a similar change in energy expenditure (16.8 ± 12.8 vs. 15.7 ± 15.1% increase above REE, P ¼ 0.72). BAT 18 F-FDG uptake was also similar in the morning, evening and afternoon (all P > 0.05). Conclusion: CIT does not appear to show morning/evening variation in young healthy adults, with the current study design and methodology. BAT 18 F-FDG uptake appears not to change across the day either, although experiments with a within-subject study design are needed to confirm these findings. Registered under ClinicalTrials.gov Identifier no. NCT02365129.
Proceedings of the Nutrition Society, 2020
Background:Eubiosis is the intestinal microbial ecosystem balance between human and microorganism... more Background:Eubiosis is the intestinal microbial ecosystem balance between human and microorganisms, whereas a disbalance in this intestinal microbial ecosystem is known as dysbiosis. The relationship between exercise with gut microbiota in humans is poorly studied, although it seems that one of the possible ways to restore eubiosis could be via exercise. This systematic review aimed to examine the scientific literature available on the influence of exercise in the gut microbiota of healthy adults.Methods:A systematic and comprehensive literature search was conducted in PubMed and Web of Science (WOS) from their inception to April 2019. Search terms used were: “Gastrointestinal Microbiome”, “Fecal Microbiota”, “Cecal Microbiota”, “Faecal Microbiota, “Exercises”, “Training” and “Human”.Results:The initial search retrieved 218 articles and 15 met the inclusion criteria of which 9 were cross-sectional, 3 acute and 3 chronic exercise interventions. Higher levels of physical activity or V...
Obesity, 2020
To describe the energy expenditure (EE) and macronutrient oxidation response to an individualized... more To describe the energy expenditure (EE) and macronutrient oxidation response to an individualized non-shivering cold exposure in young healthy adults. Methods: Two different groups of 44 (Study 1: 22.1±2.1 years old, 25.6±5.2 kg/m 2 , 34% men) and 13 young healthy adults (Study 2: 25.6±3.0 years old, 23.6±2.4 kg/m 2 , 54% men) participated in this study. We measured resting EE (RMR) and macronutrient oxidation rates, by indirect calorimetry under fasting conditions, in a warm environment (30-minutes) and in mild cold conditions (65-minutes, wearing a water perfused cooling vest set at an individualized temperature adjusted to the individuals' shivering threshold). Results: In study 1, EE increased in the initial stage of cold exposure and remained stable for the whole cold exposure (P<0.001). Mean CIT (9.56±7.9 Kcal/h) was 13.9±11.6 %RMR (Range:-14.8/39.9 %RMR). Carbohydrate oxidation decreased during the first 30 minutes of the cold exposure and later recovered up to the baseline values (P<0.01) in parallel to opposite changes in fat oxidation (P<0.01). Results were replicated in study 2. Conclusions: A 1-hour mild cold exposure individually adjusted to elicit maximum nonshivering thermogenesis induces a very modest increase in EE and a shift of macronutrient oxidation that may underlie a shift in thermogenic tissues activity.
Clinical and Translational Gastroenterology, 2020
To summarize the literature on the influence of exercise on the gut microbiota of healthy adults.... more To summarize the literature on the influence of exercise on the gut microbiota of healthy adults. METHODS: A systematic and comprehensive search in electronic database, including SciELO, Scopus, PubMed, and Web of Science up to July 5, 2019. Eligibility criterion was original studies conducted on healthy humans including exercise interventions or interventions involving any type of physical activity. RESULTS: The initial search retrieved 619 articles of which 18 met the inclusion criteria, 9 were observational, 4 reported very short-term exercise interventions, and 5 reported medium/long-term exercise interventions. Higher levels of physical activity or cardiorespiratory fitness were positively associated with fecal bacterial alpha diversity. Contrasting associations were detected between both the level of physical activity and cardiorespiratory fitness and fecal counts for the phyla Firmicutes, Bacteroidetes, and Proteobacteria. Higher levels of physical activity and cardiorespiratory fitness were positively associated with the fecal concentration of short-chain fatty acids. Reports on the effects of very shortterm and medium/long-term exercise interventions on the composition of the gut microbiota were inconsistent. DISCUSSION: Higher levels of physical activity and cardiorespiratory fitness are associated with higher fecal bacterial alpha diversity and with the increased representation of some phyla and certain short-chain fatty acids in the feces of healthy adults. Very short-term and medium/long-term exercise interventions seem to influence the fecal counts of some phyla. However, the heterogeneity between studies hampers any strong conclusions from being drawn. Better-designed studies are needed to unravel the possible mechanisms through which exercise might influence the composition and activity of the human gut microbiota.
Journal of Clinical Medicine, 2019
This 12-week randomized controlled trial investigates the effects of different training modalitie... more This 12-week randomized controlled trial investigates the effects of different training modalities on cardiometabolic risk in sedentary, middle-aged adults, and examines whether alterations in cardiometabolic risk are associated with changes in those health-related variables that are modifiable by exercise training. The study subjects were 71 middle-aged adults (~54 years old; ~50% women) who were randomly assigned to one of the following treatment groups: (1) no exercise (control group), (2) concurrent training based on international physical activity recommendations (PAR group), (3) high intensity interval training (HIIT) group, or (4) HIIT plus whole-body electromyostimulation (HIIT+EMS group). A cardiometabolic risk score was calculated based on the International Diabetes Federation’s clinical criteria. A significant reduction in cardiometabolic risk was observed for all exercise training groups compared to the control group (all p < 0.05), which persisted after adjusting pot...
Obesity, 2019
Objective: Brown adipose tissue (BAT) is a thermogenic tissue with potential as a therapeutic tar... more Objective: Brown adipose tissue (BAT) is a thermogenic tissue with potential as a therapeutic target in the treatment of obesity and related metabolic disorders. The most used technique for quantifying human BAT activity is the measurement of 18 F-fluorodeoxyglucose uptake via a positron emission tomography/computed tomography scan following exposure to cold. However, several studies have indicated the measurement of the supraclavicular skin temperature (SST) by infrared thermography (IRT) to be a less invasive alternative. This work reviews the state of the art of this latter method as a means of determining BAT activity in humans. Methods: The data sources for this review were PubMed, Web of Science, and EBSCOhost (SPORTdiscus), and eligible studies were those conducted in humans. Results: In most studies in which participants were first cooled, an increase in IRT-measured SST was noted. However, only 5 of 24 such studies also involved a nuclear technique that confirmed increased activity in BAT, and only 2 took into account the thickness of the fat layer when measuring SST by IRT. Conclusions: More work is needed to understand the involvement of tissues other than BAT in determining IRTmeasured SST; at present, IRT cannot determine whether any increase in SST is due to increased BAT activity.
Molecular Imaging and Biology, 2019
Purpose: Nowadays, 2-deoxy-2-[ 18 F]fluoro-D-glucose ([ 18 F]FDG) positron emission tomography (P... more Purpose: Nowadays, 2-deoxy-2-[ 18 F]fluoro-D-glucose ([ 18 F]FDG) positron emission tomography (PET)/X-ray computed tomography (CT) is considered the best available technique to in vivo determination of human BAT volume. The most used Hounsfield unit (HU) threshold for BAT quantification is from-250 to − 50 HU. Therefore, the main objective of the present study is (i) to examine the influence of SUV and HU thresholds on BAT quantification by [ 18 F]FDG-PET/CT scan, (ii) to identify the proportion of BAT which is not detected by [ 18 F]FDG-PET/CT scan when limiting the range between − 10 and − 50 HU, and (iii) to describe the distribution of BAT radiodensity by weight status and sex in young healthy individuals. Procedures: We measured 125 individuals after a personalized cooling protocol with a static [ 18 F]FDG-PET/CT scan. We quantified BAT using different combination of threshold in every single HU for all participants. Results: We observed that the SUV threshold influences BAT quantification by [ 18 F]FDG-PET/ CT scans more than the HU range. We found that the range from − 50 to − 10 HU had the highest proportion of total BAT volume (43.2 %), which represents 41.4 % of the total BAT metabolic activity in our cohort. We also observed that BAT volume was not different between categories of body mass index, as well as BAT activity (SUV mean). In addition, BAT was less dense in women than in men, although the BAT activity (SUV mean) was higher in all ranges of HU. We also observed that the radiodensity of BAT located in the cervical area was mainly in the range from − 50 to − 10 HU. Conclusion: Therefore, all future human studies using static [ 18 F]FDG-PET/CT scans should include BAT in the radiodensity range from − 50 to − 10 HU.
Journal of Thermal Biology, 2019
Brown adipose tissue (BAT) thermogenic activity is commonly assessed with a positron emission tom... more Brown adipose tissue (BAT) thermogenic activity is commonly assessed with a positron emission tomography with computed tomography scan (PET/CT). This technique has several limitations and alternative techniques are needed. Supraclavicular skin temperature measured with iButtons and infrared thermography (IRT) has been proposed as an indirect marker of BAT activity. We studied the concurrent validity of skin temperature measured with iButtons vs. IRT and the association of supraclavicular skin temperature measured with iButtons and IRT with BAT. We measured skin temperature upon a shivering threshold test with iButtons and IRT in 6 different regions in 12 participants (n = 2 men). On a separate day, we determined supraclavicular skin temperature with an iButton and IRT after 2 h of a personalized cooling protocol. Thereafter, we quantified BAT volume and activity by PET/CT. We observed that the absolute differences between the devices were statistically different from 0 (all P < 0.05) after the shivering threshold test. Moreover, we did not find any association between supraclavicular skin temperature measured with iButtons or IRT and BAT 18 F-FDG activity (r = −0.213; P = 0.530 and r = −0.079; P = 0.817). However, we observed a negative association of supraclavicular skin temperature measured by IRT with BAT 18 F-FDG volume (r = −0.764; P = 0.006), but not with supraclavicular skin temperature measured with iButtons (r = −0.546; P = 0.082). In light of these results, we concluded that the measurement of skin temperature obtained by iButtons and IRT are not comparable. Furthermore, it seems that supraclavicular skin temperature is not associated with BAT 18 F-FDG activity, but it appears to be negatively associated with BAT 18 F-FDG volume in the case of IRT.
Obesity, 2019
This study aimed to examine whether brown adipose tissue (BAT) or skeletal muscle activity mediat... more This study aimed to examine whether brown adipose tissue (BAT) or skeletal muscle activity mediates the relationship between personal level of environmental temperature (Personal-ET) and wrist skin temperature (WT). Moreover, we examined whether BAT and skeletal muscle have a mediating role between Personal-ET and WT (as a proxy of peripheral vasoconstriction/vasodilation). Methods: The levels of BAT were quantified by cold-induced 18 F-fluorodeoxyglucose-positron emission tomography/computed tomography scan and measured the Personal-ET and WT by using iButtons (Maxim Integrated, Dallas, Texas) in 75 participants (74.6% women). Results: The study found that BAT volume and metabolic activity played a positive and significant role (up to 25.4%) in the association between Personal-ET and WT. In addition, at the coldest temperatures, the participants with lower levels of WT (inducing higher peripheral vasoconstriction) had higher levels of BAT outcomes, whereas in warm temperatures, participants with higher levels of WT (inducing higher peripheral vasodilation) had lower levels of BAT outcomes. The study did not find any mediating role of skeletal muscle activity. Conclusions: BAT volume and metabolic activity play a role in the relationship between Personal-ET and WT. Moreover, the data suggest that there are two distinct phenotypes: individuals who respond better to the cold, both through nonshivering thermogenesis and peripheral vasoconstriction, and individuals who respond better to the heat.
Journal of Thermal Biology, 2019
Currently, 18 [F]-Fluorodeoxyglucose (18 F-FDG) in combination with a positron emission tomograph... more Currently, 18 [F]-Fluorodeoxyglucose (18 F-FDG) in combination with a positron emission tomography/computed tomography (PET/CT) scan analysis is the most commonly used method to quantify human BAT volume and activity. However, this technique presents several drawbacks which negatively affect participant's health. The aim of the present work is to determine whether supraclavicular skin temperature can be used as an indirect marker of cold-induced BAT and skeletal muscle 18 F-FDG uptake in adults, while taking into account body composition. We performed a personalized cooling protocol just before an 18 F-FDG-PET/CT scan, and we measured supraclavicular skin temperature before (in warm conditions) and after the cooling protocol in 88 adults (n = 57 women, mean age: 21.9 ± 2.1 years old, body mass index: 24.5 ± 4.3 km/m 2). We found that supraclavicular skin temperature at the warm and cold periods was weakly and positively associated with BAT activity (SUV mean and SUV peak : β = 3.000; R 2 = 0.072; P = 0.022 and β = 2.448; R 2 = 0.060; P = 0.021), but not with skeletal muscle 18 F-FDG uptake, after controlling for body composition. We performed further analyses and the positive associations persisted only in the group of women. In conclusion, supraclavicular skin temperature in warm and cold conditions seems to be related with cold-induced 18 F-FDG uptake by BAT only in women, although the low explained variance of these associations means that there are other factors involved in the supraclavicular skin temperature.
Nutrients, 2019
Having valid and reliable resting energy expenditure (REE) estimations is crucial to establish re... more Having valid and reliable resting energy expenditure (REE) estimations is crucial to establish reachable goals for dietary and exercise interventions. However, most of the REE predictive equations were developed some time ago and, as the body composition of the current population has changed, it is highly relevant to assess the validity of REE predictive equations in contemporary young adults. In addition, little is known about the role of sex and weight status on the validity of these predictive equations. Therefore, this study aimed to investigate the role of sex and weight status in congruent validity of REE predictive equations in young adults. A total of 132 young healthy adults (67.4% women, 18–26 years old) participated in the study. We measured REE by indirect calorimetry strictly following the standard procedures, and we compared it to 45 predictive equations. The most accurate equations were the following: (i) the Schofield and the “Food and Agriculture Organization of the...
Frontiers in Physiology, 2018
Cold induced thermogenesis (CIT) in humans results mainly from the combination of both brown adip... more Cold induced thermogenesis (CIT) in humans results mainly from the combination of both brown adipose tissue (BAT) and skeletal muscle thermogenic activity. The relative contribution of both tissues to CIT and to cold induced nutrient oxidation rates (CI-NUTox) remains, however, to be elucidated. We investigated the association of BAT and skeletal muscle activity after a personalized cold exposure with CIT and CI-NUTox in 57 healthy adults (23.0 ± 2.4 years old; 25.1 ± 4.6 kg/m 2 ; 35 women). BAT and skeletal muscle (paracervical, sternocleidomastoid, scalene, longus colli, trapezius, parathoracic, supraspinatus, subscapular, deltoid, pectoralis major, and triceps brachii) metabolic activity were assessed by means of a 18 Fluorodeoxyglucose positron emission tomography-computed tomography scan preceded by a personalized cold exposure. The cold exposure consisted in remaining in a mild cold room for 2 h at 19.5-20 • C wearing a water perfused cooling vest set at 3.8 • C above the individual shivering threshold. On a separate day, we estimated CIT and CI-NUTox by indirect calorimetry under fasting conditions for 1 h of personalized cold exposure. There was no association of BAT volume or activity with CIT or CI-NUTox (all P > 0.2). Similarly, the skeletal muscle metabolic activity was not associated either with CIT or CI-NUTox (all P > 0.2). The results persisted after controlling for sex, the time of the day, and the date when CIT was assessed. Our results suggest that human BAT activity and skeletal muscle 18 F-FDG activity are not associated to CIT in young healthy adults. Inherent limitations of the available radiotracers for BAT detection and muscle activity quantification may explain why we failed to detect a physiologically plausible association.
Annals of Nutrition and Metabolism, 2015
Background: The energy-burning capacity of brown adipose tissue (BAT) makes it an attractive targ... more Background: The energy-burning capacity of brown adipose tissue (BAT) makes it an attractive target for use in anti-obesity therapies. Moreover, due to its ability to oxidize glucose and lipids, BAT activation has been considered a potential therapy to combat type 2 diabetes and atherogenesis. Summary: BAT is mainly regulated by the sympathetic nervous system (SNS); yet, recent findings have shown a group of novel activators that act independently of the stimulation of the SNS such as cardiac natriuretic peptides, irisin, interleukin-6, β-aminoisobutyric acid and fibroblast growth factor 21 that could influence BAT metabolism. Several strategies are being examined to activate and recruit BAT with no side effects. In this review, we postulate that exercise might activate and recruit human BAT through the activation of SNS, heart and skeletal muscle. Key Messages: Epidemiological and well-designed exercise-based randomized controlled studies are needed to clarify if exercise is able t...
British journal of sports medicine, Jan 3, 2015
ABSTRACT 2 Brown adipose tissue (BAT) has the ability to oxidise glucose and lipids, and dissipat... more ABSTRACT 2 Brown adipose tissue (BAT) has the ability to oxidise glucose and lipids, and dissipate energy in the form of heat. 1 Thus, it could provide one method to influence energy balance—and therefore, be a player in the fight against obesity and type 2 diabetes. BAT is highly regulated by the sympathetic nervous system (SNS) to increase body temperature when mammals are exposed to cold. The heat production is mediated by uncoupling protein 1 (UCP-1), an inner-membrane mitochondrial protein exclusively expressed in BAT. 1 Dogma was that BAT was only present in newborns. However, radiologists using the radiotracer 18 F-fluorodeoxyglucose in positron emission tomography (PET)/computed tomog-raphy to detect metabolically active tumours, found competing areas in the supraclavicular, thoracic spine and neck regions with high rates of glucose uptake. The significance of BAT for human physiology was recognised in 2007. 2 Recently, another type of cells called brown-in-white (BRITE) or beige cells, in white adipose tissue (WAT) have been found. 3 BRITE cells possess a multilocular morphology, enriched mitochondria and express the brown adipocyte-specific UCP-1. IMPORTANCE OF ACTIVATING BAT A potential clinical implication of activating BAT relates to the stimulation of resting energy expenditure and diet-induced thermogenesis. In humans, the thermogenic response to a meal is higher in those possessing BAT. It has been estimated that 50 g of activated BAT might translate to increase ∼5% of resting energy expenditure. A 5% chronic increase in resting energy expenditure turns to ∼75–100 kcal/day, which over the course of a year might translate into a loss of ∼4–4.7 kg of fat. SYMPATHETIC NERVOUS SYSTEM
Revista Andaluza de Medicina del Deporte, 2015
Objetivo. Los objetivos del presente estudio fueron evaluar la fuerza resistencia de la musculatu... more Objetivo. Los objetivos del presente estudio fueron evaluar la fuerza resistencia de la musculatura extensora del tronco y analizar la relación existente entre la resistencia de la musculatura extensora del tronco y la presencia de dolor lumbar en alumnos de Educación Secundaria Obligatoria y post-obligatoria. Método. La muestra estuvo compuesta por 69 estudiantes de 12a18años (35 chicos y 34 chicas) de un instituto de la Región de Murcia. Para la toma de datos se emplearon dos instrumentos: una prueba para determinar la resistencia muscular de los extensores del tronco (Test de Biering-Sorensen) y un cuestionario para valorar la incidencia y factores de riesgo asociados con el dolor de espalda denominado "Encuesta sobre el dolor de espalda en adolescentes". Resultados. Los resultados mostraron que las chicas mantenían más tiempo la posición horizontal en la realización del test que los chicos con una media de 183,35 ± 72,32 segundos y 135,74 ± 65,23 segundos, respectivamente. Con respecto a la presencia de dolor de espalda en relación con la resistencia de la musculatura extensora del tronco, se observó en todos los casos una mayor duración del test en los estudiantes que declararon no padecer dolor con una media de 172,65 ± 93,495 segundos frente a los que presentaban dolor con una media de 154,70 ± 62,742 segundos. Aunque, las diferencias no fueron estadísticamente significativas. Conclusión. Los chicos y las chicas tienen diferentes perfiles de resistencia en la musculatura extensora del tronco, presentando las chicas una mayor resistencia que los chicos. Los estudiantes que declararon padecer dolor de espalda durante el pasado año aguantaron menos tiempo en la realización de Test de Biering-Sorensen.
Revista Andaluza de Medicina del Deporte, 2015
futuras investigaciones qué variables metodológicas pueden influir en el nivel de actividad físic... more futuras investigaciones qué variables metodológicas pueden influir en el nivel de actividad física realizado por los escolares dentro de las clases de Educación Física.
Revista Andaluza de Medicina del Deporte, 2015
las propuestas que los maestros de EF llevarían a cabo para mejorar los hábitos físico-deportivos... more las propuestas que los maestros de EF llevarían a cabo para mejorar los hábitos físico-deportivos de los alumnos. Métodos. Participaron 10 maestros de EF de 4 CEIPs del municipio de Soria, con una experiencia media de 25,86 (±9,12) años trabajados en la docencia. Se administró un cuestionario de diez preguntas abiertas y cerradas. Una vez recogidos los cuestionarios se transcribieron las respuestas y se procedió al análisis cualitativo a través del software científico ATLAS.ti. Resultados. El 50% de los maestros considera que existe relación entre la práctica de actividad físico-deportiva extraescolar de los alumnos y su desarrollo madurativo, el 30% no responde a la pregunta y el 20% dice que existe cierta relación. El 60% de los maestros no trabaja específicamente la adquisición de hábitos de práctica físico-deportiva por parte de los alumnos, el 10% no responde, el 10% responde afirmativamente pero no concreta la manera en que lo hace, y el otro 10% sí lo concreta. El 10% de los maestros participantes no formula ninguna propuesta con el objetivo de que los niños adquirieran hábitos saludables de práctica físico-deportiva, frente al 90% que sí lo considera oportuno. Conclusiones. El 90% del profesorado considera que los alumnos que practican actividad físico-deportiva extraescolar tienen un nivel de desarrollo mayor. El 20% de los maestros trabaja específicamente la adquisición de hábitos saludables de práctica físico-deportiva. El 90% de los docentes cree conveniente realizar algún tipo de propuesta para mejorar el nivel de práctica de actividad física saludable de los alumnos, y que principalmente sea promovida a nivel institucional.
Revista Andaluza de Medicina del Deporte, 2015
Objective. Menopause is characterized by the presence of emotional instability and greater dissat... more Objective. Menopause is characterized by the presence of emotional instability and greater dissatisfaction with life. Therefore, we aimed to analyze the effects of an exercise intervention on quality of life and optimism in perimenopausal women. Method. Fourteen perimenopausal women (54.1 ± 3.2 years) participated in a 9 weeks (60 minutes/session, 3 days/week) moderate-vigorous intensity (12-16 rating of perceived effort) exercise intervention (aerobic and resistance exercise mainly). Health-related quality of life and general optimism and pessimism were evaluated by means of the Short-Form Health Survey (SF-36) and the Revised Life Orientation Test, respectively. Nonparametric Wilcoxon signed ranks test for paired samples was used. Results. The exercise program improved physical function by 12% (P < 0.05) and emotional role by 18% (P = 0.05). No statistically significant differences were found for the remaining SF-36 dimensions. After the exercise intervention participants' general optimism improved 21% (P < 0.05). Conclusion. An exercise intervention program is successful by improving the physical functioning and general optimism of perimenopausal women. Because of the small sample size, the results must be taken cautiously. Future studies with greater sample sizes should confirm the present results.