Kelly Bowden-Davies | Newcastle University (original) (raw)

Papers by Kelly Bowden-Davies

Cardiovascular Endocrinology & Metabolism

We conducted a systematic review and meta-analysis of randomized controlled trials examining the ... more We conducted a systematic review and meta-analysis of randomized controlled trials examining the effect of vitamin C and/or E on exercise-induced training adaptations. Medline, Embase and SPORTDiscus databases were searched for articles from inception until June 2019. Inclusion criteria was studies in adult humans where vitamin C and/or E had to be consumed alongside a supervised exercise training program of ≥4 weeks. Nine trials were included in the analysis of aerobic exercise adaptations and nine for resistance training (RT) adaptations. Vitamin C and/or E did not attenuate aerobic exercise induced improvements in maximal aerobic capacity (V̇O_2max) (SMD −0.14, 95% CI: −0.43 to 0.15, <i>P</i> = 0.35) or endurance performance (SMD −0.01, 95% CI: −0.38 to 0.36, <i>P</i> = 0.97). There were also no effects of these supplements on lean mass and muscle strength following RT (SMD −0.07, 95% CI: −0.36 to 0.23, <i>P</i> = 0.67) an...

Cardiovascular Endocrinology & Metabolism

Frontiers in Physiology, 2021

Objective This study examined the effects of a short-term reduction in physical activity, and sub... more Objective This study examined the effects of a short-term reduction in physical activity, and subsequent resumption, on metabolic profiles, body composition and cardiovascular (endothelial) function. Design Twenty-eight habitually active (≥10,000 steps/day) participants (18 female, 10 male; age 32 ± 11 years; BMI 24.3 ± 2.5 kg/m2) were assessed at baseline, following 14 days of step-reduction and 14 days after resuming habitual activity. Methods Physical activity was monitored throughout (SenseWear Armband). Endothelial function (flow mediated dilation; FMD), cardiorespiratory fitness (V.⁢O2 peak) and body composition including liver fat (dual-energy x-ray absorptiometry and magnetic resonance spectroscopy) were determined at each assessment. Statistical analysis was performed using one-way within subject’s ANOVA; data presented as mean (95% CI). Results Participants decreased their step count from baseline by 10,111 steps/day (8949, 11,274; P < 0.001), increasing sedentary time ...

Frontiers in Endocrinology, 2021

Purpose Elevated postprandial glycaemia [PPG] increases the risk of cardiometabolic complications... more Purpose Elevated postprandial glycaemia [PPG] increases the risk of cardiometabolic complications in insulin-resistant, centrally obese individuals. Therefore, strategies that improve PPG are of importance for this population. Consuming large doses of whey protein [WP] before meals reduces PPG by delaying gastric emptying and stimulating the secretion of the incretin peptides, glucose-dependent insulinotropic polypeptide [GIP] and glucagon-like peptide 1 [GLP-1]. It is unclear if these effects are observed after smaller amounts of WP and what impact central adiposity has on these gastrointestinal processes. Methods In a randomised-crossover design, 12 lean and 12 centrally obese adult males performed two 240 min mixed-meal tests, ~5–10 d apart. After an overnight fast, participants consumed a novel, ready-to-drink WP shot (15 g) or volume-matched water (100 ml; PLA) 10 min before a mixed-nutrient meal. Gastric emptying was estimated by oral acetaminophen absorbance. Interval blood s...

Molecular Biology Reports

We conducted a systematic review of human trials examining the effects of dietary phytochemicals ... more We conducted a systematic review of human trials examining the effects of dietary phytochemicals on Nrf2 activation. In accordance with the PRISMA guidelines, Medline, Embase and CAB abstracts were searched for articles from inception until March 2020. Studies in adult humans that measured Nrf2 activation (gene or protein expression changes) following ingestion of a phytochemical, either alone or in combination were included. The study was pre-registered on the Prospero database (Registration Number: CRD42020176121). Twenty-nine full-texts were retrieved and reviewed for analysis; of these, eighteen were included in the systematic review. Most of the included participants were healthy, obese or type 2 diabetics. Study quality was assessed using the Cochrane Collaboration Risk of Bias Assessment tool. Twelve different compounds were examined in the included studies: curcumin, resveratrol and sulforaphane were the most common (n = 3 each). Approximately half of the studies reported in...

Journal of Proteins and Proteomics

Aims To (1) explore and verify differences in the plasma proteome of white European (WE) and Sout... more Aims To (1) explore and verify differences in the plasma proteome of white European (WE) and South Asian (SA) adults with normal glycaemic control (NGC) or non-diabetic hyperglycaemia (NDH) and to (2) validate these findings using a separate WE and SA cohort at a high risk of NDH. Methods Mass spectrometry analysis was performed on fasted samples from 72 WE or SA men with NGC or NDH. These results were verified using specific biochemical assays and validated by repeating the analysis in an additional cohort of 30 WE and 30 SA adults. Proteomic results were analysed using independent samples t test and univariate analysis. The targeted assay results were analysed using generalised linear models with adjustment for appropriate covariates including age, BMI, fasting plasma glucose, high-density lipoprotein-cholesterol, triglycerides and sex. Results Only zinc-alpha-2-glycoprotein (ZAG) significantly differed between both ethnicities and glycaemic control groups. ZAG-specific biochemica...

European Journal of Endocrinology

Background Data suggest that metabolic health status, incorporating components of metabolic syndr... more Background Data suggest that metabolic health status, incorporating components of metabolic syndrome (MetS), predicts cardiovascular disease (CVD) risk better than BMI. This study explored the association of MetS and obesity with endothelial function, a prognostic risk factor for incident CVD. Methods Forty-four participants were phenotyped according to BMI as non-obese vs obese (<30 or >30 kg/m2) and according to the International Diabetes Federation criteria of MetS: ≤2 criteria MetS (MetS−) vs ≥3 criteria MetS (MetS+); (1.)non-obese MetS− vs (2.) non-obese MetS+ and (3.) obese MetS− vs (4.) obese MetS+. Flow-mediated dilation (FMD), body composition including liver fat (MRI and spectroscopy), dietary intake, intensities of habitual physical activity and cardio-respiratory fitness were determined. Variables were analysed using a one-factor between-groups ANOVA and linear regression; mean (95% CI) are presented. Results Individuals with MetS+ displayed lower FMD than those wi...

Frontiers in Nutrition

Mitigating postprandial hyperglycaemic excursions may be effective in not only enhancing glycaemi... more Mitigating postprandial hyperglycaemic excursions may be effective in not only enhancing glycaemic control for people with type 2 diabetes but also reducing the onset of diabetes-related complications. However, there are growing concerns over the long-term efficacy of anti-hyperglycaemic pharmacotherapies, which coupled with their rising financial costs, underlines the need for further non-pharmaceutical treatments to regulate postprandial glycaemic excursions. One promising strategy that acutely improves postprandial glycaemia for people with type 2 diabetes is through the provision of mealtime whey protein, owing to the slowing of gastric emptying and increased secretion of insulin and the incretin peptides. The magnitude of this effect appears greater when whey protein is consumed before, rather than with, a meal. Herein, this dietary tool may offer a simple and inexpensive strategy in the management of postprandial hyperglycaemia for people with type 2 diabetes. However, there are insufficient long-term studies that have investigated the use of mealtime whey protein as a treatment option for individuals with type 2 diabetes. The methodological approaches applied in acute studies and outcomes reported may also not portray what is achievable long-term in practice. Therefore, studies are needed to refine the application of this mealtime strategy to maximize its clinical potential to treat hyperglycaemia and to apply these long-term to address key components of successful diabetes care. This review discusses evidence surrounding the provision of mealtime whey protein to treat postprandial hyperglycaemia in individuals with type 2 diabetes and highlights areas to help facilitate its clinical application.

International Journal of Sport Nutrition and Exercise Metabolism

Purpose: This study examined whether a higher protein diet following strenuous exercise can alter... more Purpose: This study examined whether a higher protein diet following strenuous exercise can alter markers of muscle damage and inflammation in older adults. Methods: Using a double-blind, independent group design, 10 males and eight females (age 57 ± 4 years; mass 72.3 ± 5.6 kg; height 1.7 ± 6.5 m) were supplied with a higher protein (2.50 g·kg−1·day−1) or moderate protein (1.25 g·kg−1·day−1) diet for 48 hr after 140 squats with 25% of their body mass. Maximal isometric voluntary contractions, muscle soreness, creatine kinase, Brief Assessment of Mood Adapted, and inflammatory markers were measured preexercise, and 24 hr and 48 hr postexercise. Results: The maximal isometric voluntary contractions decreased postexercise (p = .001, ), but did not differ between groups (p = .822, ). Muscle soreness peaked at 24 hr post in moderate protein (44 ± 30 mm) and 48 hr post in higher protein (70 ± 46 mm; p = .005; ); however, no group differences were found (p = .585; ). Monocytes and lymphoc...

Diabetes

Background: The consumption of large (∼50g) doses of whey protein [WP] before meals (i.e., preloa... more Background: The consumption of large (∼50g) doses of whey protein [WP] before meals (i.e., preload) has been shown to improve postprandial glycemic [PPG] excursions in people with type 2 diabetes [T2D]. Yet, studies to date have not accounted for treatment palatability, the energy associated with large WP doses, or the burden allied with preload preparation, limiting its ecological translation. Herein, we examined the PPG responses to a mixed-meal tolerance test [MMTT] following prior consumption of a low dose of WP from a novel, pre-made shot in people with T2D. Methods: Nine adults with T2D (8M/1F; HbA1c 57.6±10.1 mmol∙mol) attended the laboratory on two occasions, ∼14d apart. After an overnight fast, subjects randomly consumed a bespoke, ready-to-drink WP (15g) or placebo [PLA] shot (100ml) 10min prior to a 4hr MMTT (387kcal; 58% CHO). At 4hr, a further shot was consumed 10min before an ad libitum lunch. Subjective appetite and preload palatability were assessed by visual analog ...

Reviews in Endocrine and Metabolic Disorders

To systematically review the current literature investigating associations between zinc-alpha2-gl... more To systematically review the current literature investigating associations between zinc-alpha2-glycoprotein (ZAG) and dysglycaemia (including type 2 diabetes (T2DM), poly-cystic-ovary syndrome (PCOS), pre-diabetes or insulin resistance). This included relationships between ZAG and continuous measures of insulin and glucose. Additionally, we performed a meta-analysis to estimate the extent that ZAG differs between individuals with or without dysglycaemia; whilst examining the potential influence of adiposity. A systematic search was performed on four databases for studies on circulating ZAG concentrations in adult human populations, comparing healthy controls to individuals with dysglycaemia. Key characteristics, including the mean ZAG concentrations (mg∙L−1), and any correlational statistics between ZAG and continuous measures of glucose, glycated haemoglobin (HbA1c) or insulin were extracted. Meta-analyses were performed to compare metabolically healthy controls to cases, and on st...

Critical Reviews in Food Science and Nutrition

Abstract We conducted a systematic review and meta-analysis of randomized controlled trials exami... more Abstract We conducted a systematic review and meta-analysis of randomized controlled trials examining the effect of vitamin C and/or E on exercise-induced training adaptations. Medline, Embase and SPORTDiscus databases were searched for articles from inception until June 2019. Inclusion criteria was studies in adult humans where vitamin C and/or E had to be consumed alongside a supervised exercise training program of ≥4 weeks. Nine trials were included in the analysis of aerobic exercise adaptations and nine for resistance training (RT) adaptations. Vitamin C and/or E did not attenuate aerobic exercise induced improvements in maximal aerobic capacity (O2max) (SMD −0.14, 95% CI: −0.43 to 0.15, P = 0.35) or endurance performance (SMD −0.01, 95% CI: −0.38 to 0.36, P = 0.97). There were also no effects of these supplements on lean mass and muscle strength following RT (SMD −0.07, 95% CI: −0.36 to 0.23, P = 0.67) and (SMD −0.15, 95% CI: −0.16 to 0.46, P = 0.35), respectively. There was also no influence of age on any of these outcomes (P > 0.05). These findings suggest that vitamin C and/or E does not inhibit exercise-induced changes in physiological function. Studies with larger sample sizes and adequate power are still required.

Therapeutic Advances in Endocrinology and Metabolism

Background: Although the health benefits of regular physical activity and exercise are well estab... more Background: Although the health benefits of regular physical activity and exercise are well established and have been incorporated into national public health recommendations, there is a relative lack of understanding pertaining to the harmful effects of physical inactivity. Experimental paradigms including complete immobilization and bed rest are not physiologically representative of sedentary living. A useful ‘real-world’ approach to contextualize the physiology of societal downward shifts in physical activity patterns is that of short-term daily step reduction. Results: Step-reduction studies have largely focused on musculoskeletal and metabolic health parameters, providing relevant disease models for metabolic syndrome, type 2 diabetes (T2D), nonalcoholic fatty liver disease (NAFLD), sarcopenia and osteopenia/osteoporosis. In untrained individuals, even a short-term reduction in physical activity has a significant impact on skeletal muscle protein and carbohydrate metabolism, ca...

Medicine & Science in Sports & Exercise

To investigate whether (a) lower levels of daily physical activity (PA) and greater sedentary tim... more To investigate whether (a) lower levels of daily physical activity (PA) and greater sedentary time accounted for contrasting metabolic phenotypes (higher liver fat/presence of metabolic syndrome [METS+] vs lower liver fat/absence of metabolic syndrome [METSj]) in individuals of similar body mass index and (b) the association of sedentary time on metabolic health and liver fat. Methods: Ninety-eight habitually active participants (53 female, 45 male; age, 39 T 13 yr; body mass index 26.9 T 5.1 kgIm j2), underwent assessments of PA (SenseWear armband; wear time~98%), cardiorespiratory fitness (V O 2 peak), body composition (magnetic resonance imaging and magnetic resonance spectroscopy) and multiorgan insulin sensitivity (oral glucose tolerance test). We undertook a) cross-sectional analysis comparing four groups: nonobese or obese, with and without metabolic syndrome (METS+ vs METSj) and b) univariate and multivariate regression for sedentary time and other levels of PA in relation to liver fat. Results: Light, moderate, and vigorous PA did not account for differences in metabolic health between individuals, whether nonobese or obese, although METS+ individuals were more sedentary, with a higher number, and prolonged bouts (~1-2 h). Overall, sedentary time, average daily METS and V O 2 peak were each independently associated with liver fat percentage. Each additional hour of daily sedentary time was associated with a 1.15% (95% confidence interval, 1.14%-1.50%) higher liver fat content. Conclusions: Greater sedentary time, independent of other levels of PA, is associated with being metabolically unhealthy; even in habitually active people, lesser sedentary time, and higher cardiorespiratory fitness and average daily METS is associated with lower liver fat.

Diabetologia, Jun 1, 2018

Low physical activity levels and sedentary behaviour are associated with obesity, insulin resista... more Low physical activity levels and sedentary behaviour are associated with obesity, insulin resistance and type 2 diabetes. We investigated the effects of a short-term reduction in physical activity with increased sedentary behaviour on metabolic profiles and body composition, comparing the effects in individuals with first-degree relatives with type 2 diabetes (FDR+ve) vs those without (FDR-ve). Forty-five habitually active participants (16 FDR+ve [10 female, 6 male] and 29 FDR-ve [18 female, 11 male]; age 36 ± 14 years) were assessed at baseline, after 14 days of step reduction and 14 days after resuming normal activity. We determined physical activity (using a SenseWear armband), cardiorespiratory fitness ([Formula: see text]), body composition (dual-energy x-ray absorptiometry/magnetic resonance spectroscopy) and multi-organ insulin sensitivity (OGTT) at each time point. Statistical analysis was performed using a two-factor between-groups ANCOVA, with data presented as mean ± SD o...

PROTEOMICS, 2015

Divergent selection has created rat phenotypes of high-and low-capacity runners (HCR and LCR, res... more Divergent selection has created rat phenotypes of high-and low-capacity runners (HCR and LCR, respectively) that have differences in aerobic capacity and correlated traits such as adiposity. We analyzed visceral adipose tissue of HCR and LCR using label-free high-definition MS (elevated energy) profiling. The running capacity of HCR was ninefold greater than LCR. Proteome profiling encompassed 448 proteins and detected 30 significant (p <0.05; false discovery rate <10%, calculated using q-values) differences. Approximately half of the proteins analyzed were of mitochondrial origin, but there were no significant differences in the abundance of proteins involved in aerobic metabolism. Instead, adipose tissue of LCR rats exhibited greater abundances of proteins associated with adipogenesis (e.g. cathepsin D), ER stress (e.g. 78 kDa glucose response protein), and inflammation (e.g. Ig gamma-2B chain C region). Whereas the abundance antioxidant enzymes such as superoxide dismutase [Cu-Zn] was greater in HCR tissue. Putative adipokines were also detected, in particular protein S100-B, was 431% more abundant in LCR adipose tissue. These findings reveal low running capacity is associated with a pathological profile in visceral adipose tissue proteome despite no detectable differences in mitochondrial protein abundance.

We investigated whether diurnal differences in muscle force output are associated with the post-t... more We investigated whether diurnal differences in muscle force output are associated with the post-translational state of muscle proteins. Ten physically active men (mean ± SD; age 26.7 ± 3.7 y) performed experimental sessions in the morning (08:00 h) and evening (17:00 h), which were counterbalanced in order of administration and separated by at least 72 h. Knee extensor maximal voluntary isometric contraction (MVIC) force and peak rate of force development (RFD) were measured, and samples of vastus lateralis were collected immediately after exercise. MVIC force was greater in the evening (mean difference of 67 N, 10.2%; p < 0.05). Two-dimensional (2D) gel analysis encompassed 122 proteoforms and discovered 6 significant (p < 0.05; false discovery rate [FDR] = 10%) diurnal differences. Phosphopeptide analysis identified 1693 phosphopeptides and detected 140 phosphopeptides from 104 proteins that were more (p < 0.05, FDR = 22%) phosphorylated in the morning. Myomesin 2, muscle...

The Journal of Physiology

Cardiovascular Endocrinology & Metabolism

We conducted a systematic review and meta-analysis of randomized controlled trials examining the ... more We conducted a systematic review and meta-analysis of randomized controlled trials examining the effect of vitamin C and/or E on exercise-induced training adaptations. Medline, Embase and SPORTDiscus databases were searched for articles from inception until June 2019. Inclusion criteria was studies in adult humans where vitamin C and/or E had to be consumed alongside a supervised exercise training program of ≥4 weeks. Nine trials were included in the analysis of aerobic exercise adaptations and nine for resistance training (RT) adaptations. Vitamin C and/or E did not attenuate aerobic exercise induced improvements in maximal aerobic capacity (V̇O_2max) (SMD −0.14, 95% CI: −0.43 to 0.15, <i>P</i> = 0.35) or endurance performance (SMD −0.01, 95% CI: −0.38 to 0.36, <i>P</i> = 0.97). There were also no effects of these supplements on lean mass and muscle strength following RT (SMD −0.07, 95% CI: −0.36 to 0.23, <i>P</i> = 0.67) an...

Cardiovascular Endocrinology & Metabolism

Frontiers in Physiology, 2021

Objective This study examined the effects of a short-term reduction in physical activity, and sub... more Objective This study examined the effects of a short-term reduction in physical activity, and subsequent resumption, on metabolic profiles, body composition and cardiovascular (endothelial) function. Design Twenty-eight habitually active (≥10,000 steps/day) participants (18 female, 10 male; age 32 ± 11 years; BMI 24.3 ± 2.5 kg/m2) were assessed at baseline, following 14 days of step-reduction and 14 days after resuming habitual activity. Methods Physical activity was monitored throughout (SenseWear Armband). Endothelial function (flow mediated dilation; FMD), cardiorespiratory fitness (V.⁢O2 peak) and body composition including liver fat (dual-energy x-ray absorptiometry and magnetic resonance spectroscopy) were determined at each assessment. Statistical analysis was performed using one-way within subject’s ANOVA; data presented as mean (95% CI). Results Participants decreased their step count from baseline by 10,111 steps/day (8949, 11,274; P < 0.001), increasing sedentary time ...

Frontiers in Endocrinology, 2021

Purpose Elevated postprandial glycaemia [PPG] increases the risk of cardiometabolic complications... more Purpose Elevated postprandial glycaemia [PPG] increases the risk of cardiometabolic complications in insulin-resistant, centrally obese individuals. Therefore, strategies that improve PPG are of importance for this population. Consuming large doses of whey protein [WP] before meals reduces PPG by delaying gastric emptying and stimulating the secretion of the incretin peptides, glucose-dependent insulinotropic polypeptide [GIP] and glucagon-like peptide 1 [GLP-1]. It is unclear if these effects are observed after smaller amounts of WP and what impact central adiposity has on these gastrointestinal processes. Methods In a randomised-crossover design, 12 lean and 12 centrally obese adult males performed two 240 min mixed-meal tests, ~5–10 d apart. After an overnight fast, participants consumed a novel, ready-to-drink WP shot (15 g) or volume-matched water (100 ml; PLA) 10 min before a mixed-nutrient meal. Gastric emptying was estimated by oral acetaminophen absorbance. Interval blood s...

Molecular Biology Reports

We conducted a systematic review of human trials examining the effects of dietary phytochemicals ... more We conducted a systematic review of human trials examining the effects of dietary phytochemicals on Nrf2 activation. In accordance with the PRISMA guidelines, Medline, Embase and CAB abstracts were searched for articles from inception until March 2020. Studies in adult humans that measured Nrf2 activation (gene or protein expression changes) following ingestion of a phytochemical, either alone or in combination were included. The study was pre-registered on the Prospero database (Registration Number: CRD42020176121). Twenty-nine full-texts were retrieved and reviewed for analysis; of these, eighteen were included in the systematic review. Most of the included participants were healthy, obese or type 2 diabetics. Study quality was assessed using the Cochrane Collaboration Risk of Bias Assessment tool. Twelve different compounds were examined in the included studies: curcumin, resveratrol and sulforaphane were the most common (n = 3 each). Approximately half of the studies reported in...

Journal of Proteins and Proteomics

Aims To (1) explore and verify differences in the plasma proteome of white European (WE) and Sout... more Aims To (1) explore and verify differences in the plasma proteome of white European (WE) and South Asian (SA) adults with normal glycaemic control (NGC) or non-diabetic hyperglycaemia (NDH) and to (2) validate these findings using a separate WE and SA cohort at a high risk of NDH. Methods Mass spectrometry analysis was performed on fasted samples from 72 WE or SA men with NGC or NDH. These results were verified using specific biochemical assays and validated by repeating the analysis in an additional cohort of 30 WE and 30 SA adults. Proteomic results were analysed using independent samples t test and univariate analysis. The targeted assay results were analysed using generalised linear models with adjustment for appropriate covariates including age, BMI, fasting plasma glucose, high-density lipoprotein-cholesterol, triglycerides and sex. Results Only zinc-alpha-2-glycoprotein (ZAG) significantly differed between both ethnicities and glycaemic control groups. ZAG-specific biochemica...

European Journal of Endocrinology

Background Data suggest that metabolic health status, incorporating components of metabolic syndr... more Background Data suggest that metabolic health status, incorporating components of metabolic syndrome (MetS), predicts cardiovascular disease (CVD) risk better than BMI. This study explored the association of MetS and obesity with endothelial function, a prognostic risk factor for incident CVD. Methods Forty-four participants were phenotyped according to BMI as non-obese vs obese (<30 or >30 kg/m2) and according to the International Diabetes Federation criteria of MetS: ≤2 criteria MetS (MetS−) vs ≥3 criteria MetS (MetS+); (1.)non-obese MetS− vs (2.) non-obese MetS+ and (3.) obese MetS− vs (4.) obese MetS+. Flow-mediated dilation (FMD), body composition including liver fat (MRI and spectroscopy), dietary intake, intensities of habitual physical activity and cardio-respiratory fitness were determined. Variables were analysed using a one-factor between-groups ANOVA and linear regression; mean (95% CI) are presented. Results Individuals with MetS+ displayed lower FMD than those wi...

Frontiers in Nutrition

Mitigating postprandial hyperglycaemic excursions may be effective in not only enhancing glycaemi... more Mitigating postprandial hyperglycaemic excursions may be effective in not only enhancing glycaemic control for people with type 2 diabetes but also reducing the onset of diabetes-related complications. However, there are growing concerns over the long-term efficacy of anti-hyperglycaemic pharmacotherapies, which coupled with their rising financial costs, underlines the need for further non-pharmaceutical treatments to regulate postprandial glycaemic excursions. One promising strategy that acutely improves postprandial glycaemia for people with type 2 diabetes is through the provision of mealtime whey protein, owing to the slowing of gastric emptying and increased secretion of insulin and the incretin peptides. The magnitude of this effect appears greater when whey protein is consumed before, rather than with, a meal. Herein, this dietary tool may offer a simple and inexpensive strategy in the management of postprandial hyperglycaemia for people with type 2 diabetes. However, there are insufficient long-term studies that have investigated the use of mealtime whey protein as a treatment option for individuals with type 2 diabetes. The methodological approaches applied in acute studies and outcomes reported may also not portray what is achievable long-term in practice. Therefore, studies are needed to refine the application of this mealtime strategy to maximize its clinical potential to treat hyperglycaemia and to apply these long-term to address key components of successful diabetes care. This review discusses evidence surrounding the provision of mealtime whey protein to treat postprandial hyperglycaemia in individuals with type 2 diabetes and highlights areas to help facilitate its clinical application.

International Journal of Sport Nutrition and Exercise Metabolism

Purpose: This study examined whether a higher protein diet following strenuous exercise can alter... more Purpose: This study examined whether a higher protein diet following strenuous exercise can alter markers of muscle damage and inflammation in older adults. Methods: Using a double-blind, independent group design, 10 males and eight females (age 57 ± 4 years; mass 72.3 ± 5.6 kg; height 1.7 ± 6.5 m) were supplied with a higher protein (2.50 g·kg−1·day−1) or moderate protein (1.25 g·kg−1·day−1) diet for 48 hr after 140 squats with 25% of their body mass. Maximal isometric voluntary contractions, muscle soreness, creatine kinase, Brief Assessment of Mood Adapted, and inflammatory markers were measured preexercise, and 24 hr and 48 hr postexercise. Results: The maximal isometric voluntary contractions decreased postexercise (p = .001, ), but did not differ between groups (p = .822, ). Muscle soreness peaked at 24 hr post in moderate protein (44 ± 30 mm) and 48 hr post in higher protein (70 ± 46 mm; p = .005; ); however, no group differences were found (p = .585; ). Monocytes and lymphoc...

Diabetes

Background: The consumption of large (∼50g) doses of whey protein [WP] before meals (i.e., preloa... more Background: The consumption of large (∼50g) doses of whey protein [WP] before meals (i.e., preload) has been shown to improve postprandial glycemic [PPG] excursions in people with type 2 diabetes [T2D]. Yet, studies to date have not accounted for treatment palatability, the energy associated with large WP doses, or the burden allied with preload preparation, limiting its ecological translation. Herein, we examined the PPG responses to a mixed-meal tolerance test [MMTT] following prior consumption of a low dose of WP from a novel, pre-made shot in people with T2D. Methods: Nine adults with T2D (8M/1F; HbA1c 57.6±10.1 mmol∙mol) attended the laboratory on two occasions, ∼14d apart. After an overnight fast, subjects randomly consumed a bespoke, ready-to-drink WP (15g) or placebo [PLA] shot (100ml) 10min prior to a 4hr MMTT (387kcal; 58% CHO). At 4hr, a further shot was consumed 10min before an ad libitum lunch. Subjective appetite and preload palatability were assessed by visual analog ...

Reviews in Endocrine and Metabolic Disorders

To systematically review the current literature investigating associations between zinc-alpha2-gl... more To systematically review the current literature investigating associations between zinc-alpha2-glycoprotein (ZAG) and dysglycaemia (including type 2 diabetes (T2DM), poly-cystic-ovary syndrome (PCOS), pre-diabetes or insulin resistance). This included relationships between ZAG and continuous measures of insulin and glucose. Additionally, we performed a meta-analysis to estimate the extent that ZAG differs between individuals with or without dysglycaemia; whilst examining the potential influence of adiposity. A systematic search was performed on four databases for studies on circulating ZAG concentrations in adult human populations, comparing healthy controls to individuals with dysglycaemia. Key characteristics, including the mean ZAG concentrations (mg∙L−1), and any correlational statistics between ZAG and continuous measures of glucose, glycated haemoglobin (HbA1c) or insulin were extracted. Meta-analyses were performed to compare metabolically healthy controls to cases, and on st...

Critical Reviews in Food Science and Nutrition

Abstract We conducted a systematic review and meta-analysis of randomized controlled trials exami... more Abstract We conducted a systematic review and meta-analysis of randomized controlled trials examining the effect of vitamin C and/or E on exercise-induced training adaptations. Medline, Embase and SPORTDiscus databases were searched for articles from inception until June 2019. Inclusion criteria was studies in adult humans where vitamin C and/or E had to be consumed alongside a supervised exercise training program of ≥4 weeks. Nine trials were included in the analysis of aerobic exercise adaptations and nine for resistance training (RT) adaptations. Vitamin C and/or E did not attenuate aerobic exercise induced improvements in maximal aerobic capacity (O2max) (SMD −0.14, 95% CI: −0.43 to 0.15, P = 0.35) or endurance performance (SMD −0.01, 95% CI: −0.38 to 0.36, P = 0.97). There were also no effects of these supplements on lean mass and muscle strength following RT (SMD −0.07, 95% CI: −0.36 to 0.23, P = 0.67) and (SMD −0.15, 95% CI: −0.16 to 0.46, P = 0.35), respectively. There was also no influence of age on any of these outcomes (P > 0.05). These findings suggest that vitamin C and/or E does not inhibit exercise-induced changes in physiological function. Studies with larger sample sizes and adequate power are still required.

Therapeutic Advances in Endocrinology and Metabolism

Background: Although the health benefits of regular physical activity and exercise are well estab... more Background: Although the health benefits of regular physical activity and exercise are well established and have been incorporated into national public health recommendations, there is a relative lack of understanding pertaining to the harmful effects of physical inactivity. Experimental paradigms including complete immobilization and bed rest are not physiologically representative of sedentary living. A useful ‘real-world’ approach to contextualize the physiology of societal downward shifts in physical activity patterns is that of short-term daily step reduction. Results: Step-reduction studies have largely focused on musculoskeletal and metabolic health parameters, providing relevant disease models for metabolic syndrome, type 2 diabetes (T2D), nonalcoholic fatty liver disease (NAFLD), sarcopenia and osteopenia/osteoporosis. In untrained individuals, even a short-term reduction in physical activity has a significant impact on skeletal muscle protein and carbohydrate metabolism, ca...

Medicine & Science in Sports & Exercise

To investigate whether (a) lower levels of daily physical activity (PA) and greater sedentary tim... more To investigate whether (a) lower levels of daily physical activity (PA) and greater sedentary time accounted for contrasting metabolic phenotypes (higher liver fat/presence of metabolic syndrome [METS+] vs lower liver fat/absence of metabolic syndrome [METSj]) in individuals of similar body mass index and (b) the association of sedentary time on metabolic health and liver fat. Methods: Ninety-eight habitually active participants (53 female, 45 male; age, 39 T 13 yr; body mass index 26.9 T 5.1 kgIm j2), underwent assessments of PA (SenseWear armband; wear time~98%), cardiorespiratory fitness (V O 2 peak), body composition (magnetic resonance imaging and magnetic resonance spectroscopy) and multiorgan insulin sensitivity (oral glucose tolerance test). We undertook a) cross-sectional analysis comparing four groups: nonobese or obese, with and without metabolic syndrome (METS+ vs METSj) and b) univariate and multivariate regression for sedentary time and other levels of PA in relation to liver fat. Results: Light, moderate, and vigorous PA did not account for differences in metabolic health between individuals, whether nonobese or obese, although METS+ individuals were more sedentary, with a higher number, and prolonged bouts (~1-2 h). Overall, sedentary time, average daily METS and V O 2 peak were each independently associated with liver fat percentage. Each additional hour of daily sedentary time was associated with a 1.15% (95% confidence interval, 1.14%-1.50%) higher liver fat content. Conclusions: Greater sedentary time, independent of other levels of PA, is associated with being metabolically unhealthy; even in habitually active people, lesser sedentary time, and higher cardiorespiratory fitness and average daily METS is associated with lower liver fat.

Diabetologia, Jun 1, 2018

Low physical activity levels and sedentary behaviour are associated with obesity, insulin resista... more Low physical activity levels and sedentary behaviour are associated with obesity, insulin resistance and type 2 diabetes. We investigated the effects of a short-term reduction in physical activity with increased sedentary behaviour on metabolic profiles and body composition, comparing the effects in individuals with first-degree relatives with type 2 diabetes (FDR+ve) vs those without (FDR-ve). Forty-five habitually active participants (16 FDR+ve [10 female, 6 male] and 29 FDR-ve [18 female, 11 male]; age 36 ± 14 years) were assessed at baseline, after 14 days of step reduction and 14 days after resuming normal activity. We determined physical activity (using a SenseWear armband), cardiorespiratory fitness ([Formula: see text]), body composition (dual-energy x-ray absorptiometry/magnetic resonance spectroscopy) and multi-organ insulin sensitivity (OGTT) at each time point. Statistical analysis was performed using a two-factor between-groups ANCOVA, with data presented as mean ± SD o...

PROTEOMICS, 2015

Divergent selection has created rat phenotypes of high-and low-capacity runners (HCR and LCR, res... more Divergent selection has created rat phenotypes of high-and low-capacity runners (HCR and LCR, respectively) that have differences in aerobic capacity and correlated traits such as adiposity. We analyzed visceral adipose tissue of HCR and LCR using label-free high-definition MS (elevated energy) profiling. The running capacity of HCR was ninefold greater than LCR. Proteome profiling encompassed 448 proteins and detected 30 significant (p <0.05; false discovery rate <10%, calculated using q-values) differences. Approximately half of the proteins analyzed were of mitochondrial origin, but there were no significant differences in the abundance of proteins involved in aerobic metabolism. Instead, adipose tissue of LCR rats exhibited greater abundances of proteins associated with adipogenesis (e.g. cathepsin D), ER stress (e.g. 78 kDa glucose response protein), and inflammation (e.g. Ig gamma-2B chain C region). Whereas the abundance antioxidant enzymes such as superoxide dismutase [Cu-Zn] was greater in HCR tissue. Putative adipokines were also detected, in particular protein S100-B, was 431% more abundant in LCR adipose tissue. These findings reveal low running capacity is associated with a pathological profile in visceral adipose tissue proteome despite no detectable differences in mitochondrial protein abundance.

We investigated whether diurnal differences in muscle force output are associated with the post-t... more We investigated whether diurnal differences in muscle force output are associated with the post-translational state of muscle proteins. Ten physically active men (mean ± SD; age 26.7 ± 3.7 y) performed experimental sessions in the morning (08:00 h) and evening (17:00 h), which were counterbalanced in order of administration and separated by at least 72 h. Knee extensor maximal voluntary isometric contraction (MVIC) force and peak rate of force development (RFD) were measured, and samples of vastus lateralis were collected immediately after exercise. MVIC force was greater in the evening (mean difference of 67 N, 10.2%; p < 0.05). Two-dimensional (2D) gel analysis encompassed 122 proteoforms and discovered 6 significant (p < 0.05; false discovery rate [FDR] = 10%) diurnal differences. Phosphopeptide analysis identified 1693 phosphopeptides and detected 140 phosphopeptides from 104 proteins that were more (p < 0.05, FDR = 22%) phosphorylated in the morning. Myomesin 2, muscle...

The Journal of Physiology