Effects of reduced energy availability on bone metabolism in women and men (original) (raw)
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Bone, 2018
We aimed to explore the effects of low energy availability (EA)[15 kcal·kg lean body mass (LBM)·d] achieved by diet or exercise on bone turnover markers in active, eumenorrheic women. By using a crossover design, ten eumenorrheic women (VO: 48.1 ± 3.3 ml·kg·min) completed all three, 3-day conditions in a randomised order: controlled EA (CON; 45 kcal·kgLBM·d), low EA through dietary energy restriction (D-RES; 15 kcal·kgLBM·d) and low EA through increasing exercise energy expenditure (E-RES; 15 kcal·kgLBM·d), during the follicular phase of three menstrual cycles. In CON, D-RES and E-RES, participants consumed diets providing 45, 15 and 45 kcal·kgLBM·d. In E-RES only, participants completed supervised running sessions (129 ± 10 min·d) at 70% of their VO that resulted in an exercise energy expenditure of 30 kcal·kg LBM·d. Blood samples were collected at baseline (BASE) and at the end of the 3-day period (D6) and analysed for bone turnover markers (β-CTX and P1NP), markers of calcium met...
Bone, 2008
Background: Bone loss in amenorrheic athletes has been attributed to energy deficiency-related suppression of bone formation, but not increased resorption despite hypoestrogenism. Objective: To assess the independent and combined effects of energy deficiency and estrogen deficiency on bone turnover markers in exercising women. Design: PINP, osteocalcin, U-CTX-I, TT 3 , leptin, and ghrelin were measured repeatedly, and bone mineral density (BMD) was measured once in 44 exercising women. Resting energy expenditure (REE) was used to determine energy status (deficient or replete) and was corroborated with measures of metabolic hormones. Daily levels of urinary estrone and pregnanediol glucuronides (E1G, PdG), were assessed to determine menstrual and estrogen status. Volunteers were then retrospectively categorized into 4 groups: 1) Energy Replete + Estrogen Replete (EnR + E 2 R), (n = 22), 2) Energy Replete + Estrogen Deficient (EnR + E 2 D), (n = 7), 3) Energy Deficient + Estrogen Replete (EnD + E 2 R), (n = 7), and 4) Energy Deficient + Estrogen Deficient (EnD + E 2 D), (n = 8). Results: The groups were similar (p N 0.05) with respect to age (24.05 ± 1.75 yrs), weight (57.7 ± 2.2 kg), and BMI (21.05 ± 0.7 kg/m 2 ). By design, REE/FFM (p = 0.028) and REE:pREE (p b 0.001) were lower in the EnD vs. EnR group, and the E 2 D group had a lower REE:pREE (p = 0.005) compared to the E 2 R group. The EnD + E 2 D group had suppressed PINP (p = 0.034), and elevated U-CTX-I (p = 0.052) and ghrelin (p = 0.028) levels compared to the other groups. These same women also had convincing evidence of energy conservation, including TT 3 levels that were 29% lower (p = 0.057) and ghrelin levels that were 44% higher (p = 0.028) than that observed in the other groups. Energy deficiency was associated with suppressed osteocalcin, and TT 3 (p b 0.05), whereas estrogen deficiency was associated with decreased E1G (p b 0.02), and lower L2-L4 BMD (p = 0.033). Leptin was significant in predicting markers of bone formation, but not markers of bone resorption. Conclusions: When the energy status of exercising women was adequate (replete), there were no apparent perturbations of bone formation or resorption, regardless of estrogen status. Estrogen deficiency in exercising women, in the presence of an energy deficiency, was associated with bone loss and involved suppressed bone formation and increased bone resorption. These findings underscore the importance of avoiding energy deficiency, which is associated with hypoestrogenism, to avoid bone health problems.
Sports Medicine, 2020
Endurance athletes expend large amounts of energy in prolonged high-intensity exercise and, due to the weight-sensitive nature of most endurance sports, often practice periods of dietary restriction. The Female Athlete Triad and Relative Energy Deficiency in Sport models consider endurance athletes at high-risk for suffering from low energy availability and associated health complications, including an increased chance of bone stress injury. Several studies have examined the effects of low energy availability on various parameters of bone structure and markers of bone (re)modelling; however, there are differences in findings and research methods and critical summaries are lacking. It is difficult for athletes to reduce energy expenditure or increase energy intake (to restore energy availability) in an environment where performance is a priority. Development of an alternative tool to help protect bone health would be beneficial. High-impact exercise can be highly osteogenic and energ...
Bone, 2004
Physical activity is an important factor in attaining bone mass. Our aim was to investigate if low to moderate intensity exercise affects bone resorption [serum tartrate-resistant acid phosphatase (TRAP) 5b activity] and formation (serum osteocalcin concentration) in a randomized controlled exercise intervention trial in Finnish middle-aged men. In addition, the relations of these bone turnover markers with bone mineral density (BMD) and serum sex hormone concentrations [circulating testosterone (T), estradiol (E 2 ), and sex hormone-binding globulin (SHBG) concentrations] were evaluated. Serum TRAP 5b activity and osteocalcin concentration were measured at randomization and after 1 and 4 years of the exercise intervention. BMDs of the lumbar spine (L2 -L4), femoral neck, and total proximal femur were measured with a dual-energy X-ray absorptiometry (DXA). At randomization, TRAP 5b activity was strongly correlated with the osteocalcin concentration (Spearman r = 0.541, P < 0.0001). In addition, TRAP 5b activity was significantly correlated with proximal femur BMD values (r = À0.201, P = 0.018) and osteocalcin concentration with femoral neck and proximal femur BMD values (r = À0.187, P = 0.028; r = À0.240, P = 0.005, respectively). Serum E 2 , free E 2 , and free T concentrations were inversely correlated with both bone turnover markers.
Physical Activity and Bone Turnover Markers: A Cross-Sectional and a Longitudinal Study
Calcified Tissue International, 2008
Strenuous physical activity in young individuals has an important effect on both bone mass and bone turnover but the effect of moderate physical activity in adults remains uncertain. In a large cohort (N = 530) of healthy premenopausal women, bone formation markers (osteocalcin and N-terminal propeptide of type 1 procollagen [P1NP]), but not serum C-telopeptide of type 1 collagen (sCTX), were found to be significantly associated with the level of physical activity, and this association remained significant after adjusting the data (ANCOVA) by age and body mass index. Mean spine and hip bone mineral density (BMD) values were positively associated with physical activity but this was statistically significant (P = 0.050) only for adjusted values of spine BMD.
Bone Metabolism Markers and their Correlation with Body Mass Index in Aerobic Physical Activity
SCRIPTA MEDICA, 2018
Introduction: Bone formation marker osteocalcin (OC) and bone resorption marker C-terminal telopeptide of type 1 collagen (CTX) can be used to detect or to monitor the early responses of the skeleton to physical activity. Literature suggests that it is likely that higher body mass index (BMI) has positive effect on bones and can postpone onset of osteoporosis.Aim of the Study: The aim of this study is to:1.Determine the effect of aerobic physical acitivity on OC and CTX in young women2.Investigate correlation of OC, CTX and BMI in young women engaged into structured aerobic excerciseMaterial and methods: Study included 64 healthy young women, aged 19 to 25 years, devided into two groups: intervention group (n=32) and control group (n=32). The study duration was six weeks with follow-up period of four weeks. The intervention group underwent structured aerobic physical activity program for six weeks, but the control group did not receive such program. Level of OC, CTX and BMI were mea...
The Bone Metabolic Response to Exercise and Nutrition
Exercise and Sport Sciences Reviews, 2020
Bone (re)modelling markers can help determine how bone responds to different types, intensities and durations of exercise. They might also help predict those at risk of bone injury. We synthesised evidence on the acute and chronic bone metabolic responses to exercise, along with how nutritional factors can moderate this response. Recommendations to optimise future research efforts are made. IN BRIEF: Bone (re)modelling markers elucidate the dynamic bone response to exercise and if used appropriately have large potential to progress understanding.
Nutrients
Suppression of insulin-like growth factor 1 (IGF-1) and leptin secondary to low energy availability (LEA) may contribute to adverse effects on bone health. Whether a high-protein diet attenuates these effects has not been tested. Seven men completed three five-day conditions operationally defined as LEA (15 kcal kg fat-free mass (FFM)−1·day−1) with low protein (LEA-LP; 0.8 g protein·kg body weight (BW)−1), LEA with high protein (LEA-HP; 1.7 g protein·kg BW−1) and control (CON; 40 kcal·kg FFM−1·day−1, 1.7 g protein·kg BW−1). In all conditions, participants expended 15 kcal·kg FFM−1·day−1 during supervised cycling sessions. Serum samples were analyzed for markers of bone turnover, IGF-1 and leptin. The decrease in leptin during LEA-LP (−65.6 ± 4.3%) and LEA-HP (−54.3 ± 16.7%) was greater than during CON (−25.4 ± 11.4%; p = 0.02). Decreases in P1NP (p = 0.04) and increases in CTX-I (p = 0.04) were greater in LEA than in CON, suggesting that LEA shifted bone turnover in favour of bone r...
British Journal of Sports Medicine, 2005
Objective: To evaluate the effect of strenuous exercise on bone metabolism and related hormones in elderly subjects. Methods: Twenty one active elderly subjects (11 men and 10 women; mean age 73.3 years) showing a mean theoretical Vo 2max of 151.4% participated. Concentrations of plasma ionised calcium (iCa), serum intact parathyroid hormone (iPTH), 25-hydroxyvitamin D (25(OH)D), and 1.25-dihydroxy-vitamin D3 (1.25(OH) 2 D3), as well as the bone biochemical markers type I collagen C-telopeptide for bone resorption and osteocalcin and bone alkaline phosphatase for bone formation, were analysed before and after a maximal incremental exercise test. Results: At basal level, iPTH was positively correlated with age (r = 0.56, p,0.01) and negatively correlated with 25(OH)D (r = 20.50; p,0.01) and 1.25(OH) 2 D3 (r = 20.47; p,0.05). Moreover, 25(OH)D and 1.25(OH) 2 D3 levels were negatively correlated with age (r = 20.50, p,0.01 and r = 20.53, p,0.01, respectively). After exercise, iCa and 25(OH)D decreased (p,0.001 and p = 0.01, respectively) while iPTH increased (p,0.001). The levels of 1.25(OH) 2 D3, bone biochemical markers, haematocrit, and haemoglobin were unchanged. The variations in iCa and 25(OH)D were not related to age and/or sex. The iPTH variation was directly related to basal iPTH levels (p,0.01) and indirectly related to age. Conclusions: In active elderly subjects, strenuous exercise disturbed calcium homeostasis and bone related hormones without immediate measurable effect on bone turnover. Although an increase in iPTH could have an anabolic action on bone tissue, our findings from our short term study did not allow us to conclude that such action occurred.
Zahedan Journal of Research in Medical Sciences
Background: Estrogen deficiency and increasing its reabsorption are determining factors in reducing bone density in postmenopausal women. Objectives: The purpose of this study was to investigate the response threshold of alkaline phosphatase (ALP) and parathyroid hormone (PTH) to resistance training along with Calcium and vitamin D intake in postmenopausal women. Methods: In the present study, 17 postmenopausal women (50 - 60 years old) in Zahedan were randomly selected and divided into two groups, exercise + supplement (n = 9) and control (n = 8). The exercise + supplement group received 1,500 mg of Calcium and 600 IU daily of vitamin D. Each of them performed resistance training movements in three sets with eight repetitions, with an intensity of 55% 1RM in the first week to 65% 1RM in the fourth week for three sessions/week during four weeks. Sampling was performed before the first training session and 24 hours after the last session from the first to fourth weeks. Data were anal...