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M Sénéchal1,2, H Arguin6, DR Bouchard4,5, AC Carpentier3, JL Ardilouze3, IJ Dionne1,2, M Brochu1,21Research Centre on Aging, Health and Social Services Centre, University Institute of Geriatrics of Sherbrooke, 2Faculty of Physical Education and Sports, University of Sherbrooke, 3Clinical Research Centre, Sherbrooke University Hospital Centre, Sherbrooke, QC; 4Faculty of Kinesiology and Recreation Management, University of Manitoba, Winnipeg, MB; 5Health, Leisure & Human Performance Research Institute, Winnipeg, MB; 6Division of Kinesiology, Department of Social and Preventive Medicine, Faculty of Medicine, Laval University, QC, CanadaObjective: To examine the association between weight gain since menopause and weight regain after a weight loss program.Methods: Participants were 19 obese women who participated in a 15-week weight loss program and a 12-month follow-up. Main outcomes were: body composition, resting metabolic rate, energy intake, energy expenditure, and weight regain at follow-up.Results: All body composition measures significantly decreased after intervention (all P ≤ 0.01) while all measures of fatness increased significantly after the 12-month follow-up (P ≤ 0.01). Body weight gain since menopause was associated with body weight regain (r = 0.65; P = 0.003) after follow-up even after adjustment for confounders.Conclusion: Weight gain since menopause is associated with body weight regain following the weight loss program. Therefore, weight gain since menopause should be considered as a factor influencing weight loss maintenance in older women.Keywords: obesity, body weight, weight regain, postmenopausal women, aging

This cross-sectional study examined the relationship between arm and leg muscle mass and isometric muscle strength in 465 well-functioning women and 439 well-functioning men from the NuAge cohort, age 67DS84 years. Leg and arm muscle mass and body fat were measured by dual-X-ray absorptiometry. Maximum voluntary isometric strength of knee extensors and elbow flexors was measured using the belt-resisted method and a handheld dynamometer, respectively. The regression model including leg muscle mass, physical activity level, age, height, and body fat explained 14% of the variance in quadriceps strength in men and 11% in women (p < .001), whereas the model including arm muscle mass and the same covariates elucidated 40% and 28%, respectively, of the variance in biceps strength (p < .001). These results suggest that muscle mass does not play a crucial role in the variations of isometric muscle strength in well-functioning elderly. [ABSTRACT FROM AUTHOR]

Hormone-replacement therapy (HRT) attenuates the menopause-associated alterations in body composition. It is not known, however, whether this effect is a result of a concomitant increase in energy expenditure. The authors examined whether women submitted to a long-term HRT treatment presented greater energy expenditure than women who had never used HRT. We compared 13 postmenopausal women using HRT (>1 yr) with 13 age- (±2 yr) and body-mass-index-matched (BMI; ±1.5kg/m2) postmenopausal women not using HRT. Resting energy expenditure (REE; indirect calorimetry), body composition, and daily (DEE) and physical activity (PAEE) energy expenditure (accelerometry) were obtained. Although BMI, fat mass, fat-free mass, DEE, and PAEE were similar between groups, the HRT group displayed a significantly greater REE than the no-HRT group (D +222 kcal/day). In conclusion, the authors observed that a long-term treatment with HRT is associated with a greater REE in postmenopausal women. These results need to be confirmed. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the effects of oral ß-hydroxy-ß-methylbutyrate (HMB) supplementation (3 g/d) on selected components of aerobic performance and body composition of active college students. Subjects were randomly assigned to either an HMB (n = 8) or a placebo (PLA) group (n = 8) for a 5-wk supplementation period during which they underwent interval training 3 times a week on a treadmill. Aerobic-performance components were measured using a respiratory-gas analyzer. Body composition was determined using dual-energy X-ray absorptiometry. After the intervention, there were significant differences (P < 0.05) between the 2 groups in gains in maximal oxygen consumption (+8.4% for PLA and +15.5% for HMB) and in respiratory-compensation point (+8.6% for PLA and +13.4% for HMB). Regarding body composition, there were no significant differences. The authors concluded that HMB supplementation positively affects selected components of aerobic performance in active college students. [ABSTRACT FROM AUTHOR]

BACKGROUND AND AIM: No study to date has documented the association between short sleep duration and the risk for obesity in older people. Therefore, the aim of this study was to examine crosssectional associations between short sleep duration and variations in body fat indices in older women. METHODS: Anthropometric and body composition measurements, resting energy expenditure, daily energy expenditure, daily energy intake, plasma lipid-lipoprotein profile, and self-reported sleep duration were determined in a sample of 90 women of 50 years and above. RESULTS: The odds ratios for overweight/obesity were comparable in subjects reporting <7 hours and >/=7 hours of sleep per day, with or without adjustment for age, daily energy expenditure and daily energy intake. The results did not permit to observe any significant difference between the two sleeper groups for all the variables investigated. The correlations between sleep duration and adiposity indices were also non significant. CONCLUSIONS: Short sleep duration does not predict an increased risk of being overweight/obese in older women. This observation, together with our previously reported results in younger subjects, suggests that the sleep-body fat relationship progressively becomes less detectable with increasing in age. [ABSTRACT FROM AUTHOR]

Hormonal replacement therapy (HRT) helps to prevent osteoporosis. The effect of short-term discontinuation of a long-term HRT on bone mineral density (BMD) in healthy post-menopausal women is unknown. Fifteen women on HRT (HRT users), 17 who never used HRT (non-users) and 8 former HRT users (past-HRT users) were recruited. BMD was measured by DXA. Our results allow to hypothesize that BMD may decline after short-term HRT discontinuation, which would increase the fracture risks. Indeed, our results show that past-HRT users are osteopenic just as non-users. However, these results should be re-examined using a prospective trial and a larger sample size. [ABSTRACT FROM AUTHOR]

Resistance training (RT) promotes skeletal muscle (Skm) hypertrophy, increases muscular strength, and improves metabolic health. Whether changes in fat-free mass (FFM; a surrogate marker of muscle hypertrophy) moderate RT-induced improvements in glucose homeostasis has not been determined, despite extensive research on the benefits of RT for health and performance. The aim of this meta-analysis is to examine whether RT-induced Skm hypertrophy drives improvements in glucose metabolism and to explore confounders, such as biological sex and training parameters. Random-effects meta-analyses were performed using variance random effects. Meta-regressions were performed for confounding factors depending on the heterogeneity ( I 2 ). Analyses from 33 intervention studies revealed significant within-study increases in FFM with a moderate effect size (within-studies: (effect size; ES = 0.24 [0.10; 0.39]; p  = 0.002; I 2  = 56%) and a tendency for significance when compared with control groups (ES = 0.42 [-0.04-0.88]; p  = 0.07). Within-study significant increases in glucose tolerance (2 h glucose: ES = -0.3 [-0.50; -0.11]; p  < 0.01; I 2  = 43%; glucose area under the curve (AUC): -0.40 [-0.66; -0.13] I 2  = 76.1%; p  < 0.01) and insulin sensitivity (ES = 0.38 [0.13; 0.62]; I 2  = 53.0%; p  < 0.01) were also apparent with RT. When compared to control groups, there was no significant difference in 2 h glucose, nor in glucose AUC from baseline in RT intervention groups. Meta-regression analyses failed to consistently reveal increases in FFM as a moderator of glucose homeostasis. Other mixed-effect models were also unsuccessful to unveil biological sex or training parameters as moderators of FFM increases and glucose homeostasis changes. Although Skm hypertrophy and improvements in glycemic control occur concurrently during RT, changes in these variables were not always related. Well-controlled trials including detailed description of training parameters are needed to inform RT guidelines for improving metabolic health. Registration and protocol number (Prospero): CRD42023397362., Competing Interests: The authors declare no conflicts of interest.

Background: Individuals affected by the post-covid condition (PCC) show an increased fatigue and the so-called post-exertion malaise (PEM) that led health professionals to advise against exercise although accumulating evidence indicates the contrary. The goal of this study is to determine the impact of a closely monitored 8-week mixed exercise program on physical capacity, symptoms, fatigue, systemic oxidative stress and plasma proteomic profiles of PCC cases., Methods: Twenty-five women and men with PCC were assigned sequentially to exercise ( n = 15) and non-exercise ( n = 10) groups. Individuals with no PCC served as a control group. The exercise program included cardiovascular and resistance exercises. Physical capacity, physical activity level and the presence of common PCC symptoms were measured before and after the intervention. Fatigue was measured the day following each exercise session. Plasma and PBMC samples were collected at the beginning and end of the training program. Glutathione and deoxyguanosine levels in PBMC and plasma proteomic profiles were evaluated., Results: Bicep Curl (+15% vs 4%; p = 0.040) and Sit-to-Stand test (STS-30 (+31% vs +11%; p = 0.043)) showed improvement in the exercise group when compared to the non-exercise group. An interaction effect was also observed for the level of physical activity ( p =0.007) with a positive effect of the program on their daily functioning and without any adverse effects on general or post-effort fatigue. After exercise, glutathione levels in PBMCs increased in women but remained unchanged in men. Discernable changes were observed in the plasma proteomics profile with certain proteins involved in inflammatory response decreasing in the exercise group., Conclusions: Supervised exercise adapted to the level of fatigue and ability is safe and effective in PCC patients in improving their general physical capacity and wellbeing. Systemic molecular markers that accompany physical improvement can be monitored by analyzing plasma proteomics and markers of oxidative stress. Large-scale studies will help identify promising molecular markers to objectively monitor patient improvement., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Chowdhury, Fontaine, Lord, Quenum, Limoges, Rioux-Perreault, Lucier, Cliche, Levesque, Boisvert, Cantin, Allard-Chamard, Menendez, Ilangumaran, Piché, Dionne and Ramanathan.)

Mitochondrial dysfunctions are thought to contribute to muscle atrophy and weakness that develop during ageing and mechanical unloading caused by immobilization, bed rest and microgravity. Older adults are at greater risk of developing muscle and mitochondrial dysfunctions in response to unloading. Although exercise is well known to promote muscle and mitochondrial health, its protective effect during mechanical unloading in older adults remains largely unexplored. Here, we investigated the impact of 14 days of head-down tilt bed rest (HDBR) with and without a multimodal exercise countermeasure in older men and women (55-65 years). Leg muscle volume was assessed using magnetic resonance imaging. Biopsies of the vastus lateralis were performed to assess markers of mitochondrial content, respiration, reactive oxygen species (ROS) production and calcium retention capacity (mCRC). Indices of mitochondrial quality control (MQC), including markers of fusion (MFN1 and 2), fission (Drp1), mitophagy (Parkin) and autophagy (p62 and LC3I and II) were measured using immunoblots. Muscle cross-sections were stained for neural cell adhesion molecule (NCAM, a marker of denervation). HDBR triggered muscle atrophy, decreased mitochondrial content and respiration and increased mitochondrial ROS production. HDBR had no impact on mCRC or MQC markers but increased markers of autophagy and denervation. Exercise prevented the deleterious effects of HDBR on leg muscle volume, mitochondrial ROS production and markers of autophagy and denervation. Exercise also increased mitochondrial content and respiration without altering mCRC and MQC markers. Collectively, our results indicate that an exercise countermeasure that can be performed in bed is effective in protecting muscle and mitochondrial health during HDBR in older adults. KEY POINTS: Conditions associated with muscle unloading, such as immobilization, bed rest or microgravity, result in muscle atrophy and weakness, particularly in older adults. Mitochondrial dysfunctions are thought to contribute to muscle atrophy caused by unloading and ageing. However, whether exercise can counteract the deleterious effects of unloading in older adults remains largely unexplored. Here, we report that older adults exposed to 14 days of head-down tilt bed rest (HDBR) displayed upper leg muscle atrophy, a decrease in mitochondrial content and respiration, an increase in H 2 O 2 emission, and an increase in autophagy and denervation markers. No impact of HDBR on mitochondrial quality control was observed. A multimodal exercise countermeasure prevented the deleterious effects of HDBR on upper leg muscle volume, mitochondrial reactive oxygen species emission, and markers of autophagy and denervation and increased mitochondrial content and respiration. These findings highlight the effectiveness of exercise in promoting muscle and mitochondrial health in older adults undergoing bed rest., (© 2024 The Author(s). The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.)

Weightlessness during spaceflight can harm various bodily systems, including bone density, muscle mass, strength and cognitive functions. Exercise appears to somewhat counteract these effects. A terrestrial model for this is head-down bedrest (HDBR), simulating gravity loss. This mirrors challenges faced by older adults in extended bedrest and space environments. The first Canadian study, backed by the Canadian Space Agency, Canadian Institutes of Health Research, and Canadian Frailty Network, aims to explore these issues. The study seeks to: (1) scrutinize the impact of 14-day HDBR on physiological, psychological and neurocognitive systems, and (2) assess the benefits of exercise during HDBR. Eight teams developed distinct protocols, harmonized in three videoconferences, at the McGill University Health Center. Over 26 days, 23 participants aged 55-65 underwent baseline measurements, 14 days of -6° HDBR, and 7 days of recovery. Half did prescribed exercise thrice daily combining resistance and endurance exercise for a total duration of 1 h. Assessments included demographics, cardiorespiratory fitness, bone health, body composition, quality of life, mental health, cognition, muscle health and biomarkers. This study has yielded some published outcomes, with more forthcoming. Findings will enrich our comprehension of HDBR effects, guiding future strategies for astronaut well-being and aiding bedrest-bound older adults. By outlining evidence-based interventions, this research supports both space travellers and those enduring prolonged bedrest., (© 2024 The Authors. Experimental Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.)

Background: Following SARS-CoV-2 infection a significant proportion of convalescent individuals develop the post-COVID condition (PCC) that is characterized by wide spectrum of symptoms encompassing various organs. Even though the underlying pathophysiology of PCC is not known, detection of viral transcripts and antigens in tissues other than lungs raise the possibility that PCC may be a consequence of aberrant immune response to the viral antigens. To test this hypothesis, we evaluated B cell and antibody responses to the SARS-CoV-2 antigens in PCC patients who experienced mild COVID-19 disease during the pre-vaccination period of COVID-19 pandemic., Methods: The study subjects included unvaccinated male and female subjects who developed PCC or not (No-PCC) after clearing RT-PCR confirmed mild COVID-19 infection. SARS-CoV-2 D614G and omicron RBD specific B cell subsets in peripheral circulation were assessed by flow cytometry. IgG, IgG3 and IgA antibody titers toward RBD, spike and nucleocapsid antigens in the plasma were evaluated by ELISA., Results: The frequency of the B cells specific to D614G-RBD were comparable in convalescent groups with and without PCC in both males and females. Notably, in females with PCC, the anti-D614G RBD specific double negative (IgD - CD27 - ) B cells showed significant correlation with the number of symptoms at acute of infection. Anti-spike antibody responses were also higher at 3 months post-infection in females who developed PCC, but not in the male PCC group. On the other hand, the male PCC group also showed consistently high anti-RBD IgG responses compared to all other groups., Conclusions: The antibody responses to the spike protein, but not the anti-RBD B cell responses diverge between convalescent males and females who develop PCC. Our findings also suggest that sex-related factors may also be involved in the development of PCC via modulating antibody responses to the SARS-CoV-2 antigens., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Limoges, Quenum, Chowdhury, Rexhepi, Namvarpour, Akbari, Rioux-Perreault, Nandi, Lucier, Lemaire-Paquette, Premkumar, Durocher, Cantin, Lévesque, Dionne, Menendez, Ilangumaran, Allard-Chamard, Piché and Ramanathan.)

Background: Homocysteine (Hcy) has been associated with several health problems, including reduced physical capacity. No study appears to have looked at the role of Hcy values longitudinally on physical capacity deterioration in older adults. The objective is to examine cross-sectional and prospective associations between Hcy values and frailty in the elderly and investigate Hcy potential association with the onset of frailty., Methods: 769 community-dwelling older adults from the MAPT study were recruited for this study. Total Hcy was measured at baseline. Frailty was evaluated at 5 different collection timepoints: baseline, 6-month, 1-, 2-, and 3-year using a frailty index (FI) composed of 19 items. Linear regressions adjusted for all the confounders (age, gender, educational level, MAPT group allocation and Omega-3) were performed to examine the cross-sectional associations of homocysteine values with the FI. A cox model was used to test the association of Hcy with the onset of frailty., Results: Mean Hcy values (15.9 ± 5.6 μmol\L) were obtained from 769 community-dwelling adults (75.7 ± 4.6 years old). After adjustments, a significant (β = 0.002, (00002-0.003)) and positive association between baseline Hcy values and FI was found (ß = 0.002). Additionally, higher values of Hcy were associated with a worsening of FI after 3 years (ß = 0.002, p = 0.003). A significant association between baseline Hcy values and the likelihood of developing frailty was discovered by incident event analysis (HR: 1.04 (1.01-1.06), p = 0.004)., Conclusion: High levels of Hcy are associated with the fragility process in community-dwelling older adults., Competing Interests: Declaration of competing interest None., (Crown Copyright © 2022. Published by Elsevier Inc. All rights reserved.)

Introduction: Head-down bed rest (HDBR) has long been used as an analog to microgravity, and it also enables studying the changes occurring with aging. Exercise is the most effective countermeasure for the deleterious effects of inactivity. The aim of this study was to investigate the efficacy of an exercise countermeasure in healthy older participants on attenuating musculoskeletal deconditioning, cardiovascular fitness level, and muscle strength during 14 days of HDBR as part of the standard measures of the Canadian Space Agency., Methods: Twenty-three participants (12 males and 11 females), aged 55-65 years, were admitted for a 26-day inpatient stay at the McGill University Health Centre. After 5 days of baseline assessment tests, they underwent 14 days of continuous HDBR followed by 7 days of recovery with repeated tests. Participants were randomized to passive physiotherapy or an exercise countermeasure during the HDBR period consisting of 3 sessions per day of either high-intensity interval training (HIIT) or low-intensity cycling or strength exercises for the lower and upper body. Peak aerobic power (V̇O2peak) was determined using indirect calorimetry. Body composition was assessed by dual-energy X-ray absorptiometry, and several muscle group strengths were evaluated using an adjustable chair dynamometer. A vertical jump was used to assess whole-body power output, and a tilt test was used to measure cardiovascular and orthostatic challenges. Additionally, changes in various blood parameters were measured as well as the effects of exercise countermeasure on these measurements., Results: There were no differences at baseline in main characteristics between the control and exercise groups. The exercise group maintained V̇O2peak levels similar to baseline, whereas it decreased in the control group following 14 days of HDBR. Body weight significantly decreased in both groups. Total and leg lean masses decreased in both groups. However, total body fat mass decreased only in the exercise group. Isometric and isokinetic knee extension muscle strength were significantly reduced in both groups. Peak velocity, flight height, and flight time were significantly reduced in both groups with HDBR., Conclusion: In this first Canadian HDBR study in older adults, an exercise countermeasure helped maintain aerobic fitness and lean body mass without affecting the reduction of knee extension strength. However, it was ineffective in protecting against orthostatic intolerance. These results support HIIT as a promising approach to preserve astronaut health and functioning during space missions, and to prevent deconditioning as a result of hospitalization in older adults., (© 2023 The Author(s). Published by S. Karger AG, Basel.)

Aging and family history of type 2 diabetes (T2D) are known risk factors of T2D. Younger first-degree relatives (FDR) of T2D patients have shown early metabolic alterations, which could limit exercise's ability to prevent T2D. Thus, the objective was to determine whether exercise metabolism was altered during submaximal exercise in FDR postmenopausal women. Nineteen inactive postmenopausal women (control: 10, FDR: 9) aged 60 to 75 years old underwent an incremental test on a cycle ergometer with intensity ranging from 40 to 70% of peak power output. Participants consumed 50 mg of 13 C-palmitate 2 h before the test. At the end of each stage, glucose, lactate, glycerol, non-esterified fatty acids and 13 C-palmitate were measured in plasma, and 13 CO 2 was measured in breath samples. Gas exchanges and heart rate were both monitored continuously. There were no between-group differences in substrate oxidation, plasma substrate concentrations or 13 C recovered in plasma or breath. Interestingly, despite exercising at a similar relative intensity to control, FDR were consistently at a lower percentage of heart rate reserve. Overall, substrate plasma concentration and oxidation are not affected by family history of T2D in postmenopausal women and therefore not a participating mechanism in the altered response to exercise previously reported. More studies are required to better understand the mechanisms involved in this response.

Background: It is well established that body composition influences metabolic health, but emerging data are conflicting with the largely purported idea that a large fat-free mass (FFM) has a protective effect on health. A potential explanation for these discrepancies is the way FFM is represented. The first objective is to determine the association between the metabolic syndrome (MetS) and FFM when the latter was represented in three different ways: 1-absolute FFM; 2-relative to squared height (FFMi); and 3-relative to body weight (FFM%). The second objective is to assess the impact of FFM on the relative risk of having the MetS after taking fat mass, physical activity, and sociodemographic variables into account., Methods: A total of 5274 individuals from the National Health and Nutrition Examination Survey database were studied. Age-specific and sex-specific quartiles of the three representations of FFM were defined, and the prevalence of MetS was determined in each of them. Quartiles of FFMi (kg/m 2 ) were used to calculate the odds ratios of having the MetS independently of FM, physical activity levels, and sociodemographic variables., Results: The prevalence of MetS decreased with increasing quartiles of whole-body FFM% (Q1: 40%; Q4: 10%) but grew with increasing quartiles of absolute FFM (Q1: 13%; Q4: 40%) and FFMi (Q1: 10%; Q4: 44%). Similar results were observed for appendicular and truncal FFM. The odds ratios of having the MetS, independently of fat mass, physical activity, and sociodemographic variables, were significantly greater in the fourth quartile of FFMi when compared with the first quartiles of each specific subgroup [Q4 vs. Q1: younger men: 4.16 (1.99-8.68); younger women: 5.74 (2.46-13.39); older men: 1.98 (1.22-3.22); older women: 2.88 (1.69-4.90); all P ≤ 0.01]., Conclusions: These results support the notion that the representation of FFM significantly influences its association with MetS and that a larger FFM, whether absolute or relative to height, is associated with alterations in cardiometabolic health., (© 2021 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of Society on Sarcopenia, Cachexia and Wasting Disorders.)

Background and Aims: To compare the effect of a low-volume walking high-intensity interval training (HIIT) to moderate-intensity continuous training (MICT) on risk of cardiovascular diseases and physical capacity in older women with type 2 diabetes (T2D)., Methods: Thirty inactive older women with T2D were randomized into either HIIT (75 min/week) or MICT (150 min/week). Cardiovascular risk profile (lipid profile; waist circumference and fat mass; resting, post-exercise and ambulatory blood pressure [BP]; VO 2 peak; UKPDS score; ABC's) and physical capacity were assessed before and after a 12-week intervention., Results: While resting systolic and diastolic BP (all p ≤ 0.01) were reduced, ambulatory BP (p ≥ 0.49) and lipid profile (p ≥ 0.40) remained unchanged after the intervention. Although VO 2 peak increased to a similar extent in both groups (p = 0.015), the distance covered during the 6MWT (p = 0.01) and grip strength (p = 0.02) increased to a greater extend in HIIT. The UKPDS risk score decreased in both groups after the intervention (p = 0.03) and 31% of the participants reached the ABC's compared to 24% at baseline., Conclusion: Low-volume walking HIIT is an efficient exercise intervention for older women with T2D as it improved some CVD risk factors and physical capacity. Nevertheless, neither low-volume HIIT nor MICT is sufficient to affect ambulatory blood pressure in T2D patients., Competing Interests: Declaration of competing interest The present manuscript is not under consideration elsewhere, has not previously been published, and has been approved by all authors. Moreover, the authors declare no conflict of interest. The authors declare no conflict of interest., (Copyright © 2021 Diabetes India. Published by Elsevier Ltd. All rights reserved.)

Intradialytic exercise is feasible and yields substantial clinical benefits in middle-aged patients. However, evidence is scarce in older hemodialysis patients., Objective: To assess the feasibility and clinical benefits of supervised, intradialytic exercise in older patients., Methods: Multicenter one-arm feasibility study. The main outcome was feasibility (ease of recruitment, dropout rate, adherence, affective valence, and adverse events). The secondary outcomes were physical capacity (five-repetition sit-to-stand, 60-s sit-to-stand tests, and grip strength), quality of life (36-Item Short-Form Health Survey), quality of sleep (Pittsburgh Sleep Quality Index), depressive symptoms (Beck Depression Inventory), and dialysis efficacy (Kt/V and urea reduction ratio)., Results: About 79% of the screened patients agreed to participate (n = 25, 73 [66-77] years). The dropout rate was high (32%), but adherence remained high among the participants who completed the study (94%). Improvements were found in the five-repetition sit-to-stand (p < .001), 60-s sit-to-stand tests (p = .028), 36-Item Short-Form Health Survey mental component score (p = .008), depressive symptoms (p = .006), and quality of sleep (p = .035)., Conclusion: Supervised intradialytic exercise seems safe and beneficial in older patients.

Skeletal muscle (SM) tissue has been repetitively shown to play a major role in whole-body glucose homeostasis and overall metabolic health. Hence, SM hypertrophy through resistance training (RT) has been suggested to be favorable to glucose homeostasis in different populations, from young healthy to type 2 diabetic (T2D) individuals. While RT has been shown to contribute to improved metabolic health, including insulin sensitivity surrogates, in multiple studies, a universal understanding of a mechanistic explanation is currently lacking. Furthermore, exercised-improved glucose homeostasis and quantitative changes of SM mass have been hypothesized to be concurrent but not necessarily causally associated. With a straightforward focus on exercise interventions, this narrative review aims to highlight the current level of evidence of the impact of SM hypertrophy on glucose homeostasis, as well various mechanisms that are likely to explain those effects. These mechanistic insights could provide a strengthened rationale for future research assessing alternative RT strategies to the current classical modalities, such as low-load, high repetition RT or high-volume circuit-style RT, in metabolically impaired populations., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Paquin, Lagacé, Brochu and Dionne.)

Menopause transition is associated with detrimental changes in physical activity, body composition, and metabolic profile. Although physical activity energy expenditure (PAEE) is inversely associated with metabolic syndrome (MetS) in individuals at higher risk of cardiovascular disease, the association is unknown in low-risk individuals. The aim of the study was to investigate the association between PAEE and MetS (prevalence and severity) in inactive overweight or obese postmenopausal women with a low Framingham Risk Score (<10%). Cross-sectional data of 126 participants were divided into quartiles based on PAEE (Quartile (Q)1 = lowest PAEE) while fat-free mass (FFM) and fat mass were measured by dual-energy X-ray absorptiometry. MetS prevalence was significantly different between Q1 and Q4 (37.9% vs 13.3%, p = 0.03). After controlling for potential confounders, MetS severity was negatively associated with PAEE (B = -0.057, p < 0.01) and positively with FFM (B = 0.038, p < 0.001). Moderation analyses indicated that a greater FFM exacerbated the association between PAEE and MetS severity in Q1 and Q2 (PAEE × FFM; B = -0.004; p = 0.1). Our results suggest that displaying a low FRS and lower PAEE increase MetS prevalence and severity. In addition, greater FFM interacts with lower PAEE to worsens MetS severity, while higher PAEE lessened this effect. Novelty: Inactive individuals displaying higher daily PAEE also have a lower MetS prevalence. Greater FFM is associated with a worse MetS severity where a higher PAEE mitigated this deleterious effect in our cohort.

Objectives: First, to establish the respective ability of body mass index (BMI), waist circumference (WC), and relative fat mass index (RFM), to estimate body fat (BF%) measured by DXA (DXA-BF%) and correctly identify postmenopausal women living with obesity (BF% > 35). Second, to identify the best indicator of successful weight-loss intervention in postmenopausal women living with obesity., Methods: A total of 277 women (age: 59.8 ± 5.3 y; BF%: 43.4 ± 5.3) from five weight-loss studies with complete data for anthropometric measurements [BMI = weight/height (kg/m2); WC (cm)] and BF% were pooled together. Statistical performance indicators were determined to assess ability of RFM [64-(20 × height/waist circumference) + (12 × sex)], BMI and WC to estimate BF% before and after weight-loss intervention and to correctly identify postmenopausal women living with obesity., Results: Compared with RFM (r = 0.51; r2 = 0.27; RMSE = 4.4%; Lin's CCC = 0.46) and WC (r = 0.49; r2 = 0.25; RMSE = 4.8%; Lin's CCC = 0.41), BMI (r = 0.73; r2 = 0.52; RMSE = 3.7%; Lin's CCC = 0.71) was the best anthropometric index to estimate DXA-BF% and correctly identify postmenopausal women living with obesity (sensitivity + specificity: BMI = 193; RFM = 152; WC = 158), with lower misclassification error, before weight-loss intervention. After weight-loss, the change in BMI was strongly correlated with change in DXA-BF%, indicating that the BMI is the best indicator of success weight-loss intervention., Conclusion: In the absence of more objective measures of adiposity, BMI is a suitable proxy measure for BF% in postmenopausal women, for whom a lifestyle intervention is relevant. Furthermore, BMI can be used as an indicator to assess success of weight-loss intervention in this subpopulation., Competing Interests: Financial disclosure/conflicts of interest: None reported., (Copyright © 2021 by The North American Menopause Society.)

Sarcopenic obesity is associated with several negative health outcomes. However, the prevalence of this condition - and the relationship to physical performance parameters - varies across definitions. The aim of this cross-sectional investigation was to describe the prevalence of sarcopenic obesity using different published definitions and their relationship with handgrip strength and walking speed in older Canadian adults. Individuals aged 65+ in the Canadian Longitudinal Study on Aging ( n = 11,803; 49.6% male, 50.4% female) were included. Body composition was measured using dual X-ray absorptiometry. Sarcopenic obesity was defined using 29 definitions. Low handgrip strength was identified as < 27 kg in males and < 16 kg in females and poor physical performance was defined as gait speed ≤ 0.8 m/s. The prevalence of sarcopenic obesity ranged from 0.1 to 85.3% in males, and from 0 to 80.4% in females. Sarcopenic obesity was frequently associated with low handgrip strength ( p < 0.05) in both males (14/17 definitions, 82.4%) and females (21/29 definitions, 72.4%). In very few definitions, sarcopenic obesity was associated with slow gait speed (males: 1/17 definitions [6.7%]; females: 2/29 [6.9%]). In conclusion, the prevalence of sarcopenic obesity varied greatly according to definitions and sarcopenic obesity was frequently associated with low handgrip strength., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Purcell, Mackenzie, Barbosa-Silva, Dionne, Ghosh, Siervo, Ye and Prado.)

Objectives: Sarcopenia is a debilitating condition affecting millions of individuals worldwide and is defined with different criteria. The objective of this study was to determine the prevalence of sarcopenia in older Canadians using three internationally accepted criteria., Design: Observational cohort study., Settings and Participants: Data from 12,592 subjects [6,314 males (50.1%), 6,278 females (49.9%)] ≥65 years old in the Canadian Longitudinal Study on Aging were included., Measurements: Appendicular lean mass (ALM; kg) and appendicular lean mass index (ALM kg/height in m2) were collected from dual X-ray absorptiometry measurements. Physical performance was assessed using the 4-m gait speed test, and muscle strength was measured by hand dynamometry. Sarcopenia was defined according to criteria put forth by the International Working Group on Sarcopenia (IWGS), Foundation for the National Institutes of Health (FNIH) Sarcopenia Project, and revised European Working Group on Sarcopenia in Older People (EWGSOP). Positive and negative percent agreements and Cohen's kappa (κ) described the agreement among sarcopenia definitions., Results: Among the evaluated criteria, gait speed ≤ 1.0 m/s (IWGS definition of slowness) was the most frequently identified deficit (56.8% males, 57.2% females). The prevalence of sarcopenia ranged from 1.4 to 5.2% in males and 1.6 to 7.2 % in females among the different definitions. Positive percent agreement values among criteria were generally low (range: 1.5 - 55.3%) and corresponded to κ indicating none to minimal agreement (0.01 - 0.23). Negative percent agreement values were ≥ 95%., Conclusion: Sarcopenia prevalence was relatively low in older Canadian adults and current definitions had poor agreement in diagnosing individuals as sarcopenic., Competing Interests: The authors have no conflicts of interests to declare.

Background: Aging, cancer and its treatment all contribute to increase the risk of deconditioning and sedentary behaviors. Mixed exercise is recognized to counteract the effects of aging and deconditioning as well as improving physical capacity during cancer treatment in adults., Aims: To determine the impact of a mixed exercise program (MXEP) to improve physical capacity and decrease sedentary behavior time (SBT) in older adults during cancer treatment., Methods: Fourteen participants (68.8 ± 3.4 years) completed 12 weeks of a mixed exercise program (MEXP) (n = 6) or stretching (n = 8) while they were under cancer treatment. Five tests of the Senior Fitness Test (Chair Stand, 8-Foot Up & Go, Arm Curl, Sit & Reach, 6 min Walk Test), two maximal strength tests (leg press and handgrip) and a Global Physical Capacity Score (GPCS) were used to assess physical capacity. For the amount of SBT (min/day), we used question 1 of the Physical Activity Scale for the Elderly., Results: Both groups presented significant pre- vs post-intervention differences for the Chair Stand, Arm Curl, 6 min Walk Tests and also GPCS. Nevertheless, this difference was significantly greater in the MEXP group only for the Chair Stand Test (4.3 ± 2.2 vs 1.0 ± 1.3 reps; p = 0.01) and the GPCS (4.0 ± 0.6 vs 1.5 ± 2.3 points; p = 0.047). A tend to display a greater decrease in SBT (- 295 ± 241 min/week vs - 11 ± 290 min/week; p = 0.079) was observed in favor of MEXP., Conclusion: A 12-week mixed exercise program led to significant improvements in physical capacity and may reduce SBT.

Background: The aim of this study was to identify modifiable risk factors associated with isolated impaired fasting glucose (IFG), isolate impaired glucose tolerance (IGT), or combined IFG-IGT in men and women aged 50 years and older., Methods: Cross-sectional analyses were performed in 703 men and women aged between 50 and 80 years old from NHANES (2007-2008). Outcome variables: IFG and IGT (ADA 2003), estimated body composition, cardiometabolic profile, and socio-demographic, dietary, and lifestyle factors., Results: First, 235 had normal glucose tolerance (men = 38.3%, women = 61.7%), 243 had IFG (men = 61.7%, women = 38.3%), 67 had IGT (men = 40.3%, women = 59.7%) and 158 had both conditions (men = 57.0%, women = 43.0%). The only common determinant of both IFG and IGT was triglyceride levels. High total fat mass index (FMI) and high total fat-free mass index (FFMI) were independently associated with IFG; while high C-reactive protein (CRP) levels were independently associated with IGT. Finally, combined IFG-IGT was associated with inadequate fiber intake, high FMI, FFMI, and CRP levels., Conclusions: Middle-age and older individuals presented different modifiable risk factors depending on whether they had IFG or IGT. IFG was associated with deteriorated body composition and lipids, whereas IGT was associated with deteriorated lipids and inflammatory factors. IFG-IGT, on the other hand, was associated with a larger number of risk factors, including worsen body composition, cardiometabolic and dietary factors. To prevent the transition to type 2 diabetes, specific clinical interventions targeting these risk factors should be considered., Competing Interests: Conflict of interest statement: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Body mass index (BMI) is often criticised since it doesn't consider sex, age and ethnicity, which may affect the height scaling exponent of the equation. Aims: First, to identify specific height scaling exponents (α) based on sex, age and ethnicity. Second, to assess the performance of the current vs the proposed BMI equations (1) to predict total fat mass (TFM) and metabolic syndrome (MetS) severity and (2) to correctly identify obese individuals and those having MetS. Methods: In total, 41,403 individuals aged 20-80 years (NHANES, 1999-2014) were studied. Specific "α" were identified using the Benn formula. Various statistical approaches were performed to assess performances of the current vs the proposed-BMIs. Results: The proposed "α" varies from 1.2 to 2.5, after considering sex, age and ethnicity. BMIs calculated using the proposed "α" showed a similar capacity to predict TFM and MetS severity and to correctly identify obese individuals and those having MetS compared to the current BMI. Conclusions: Despite sex, age and ethnicity modulating the height scaling exponent of the BMI equation, using these proposed exponents in the BMI equation didn't improve the capacity to predict TFM and MetS severity, suggesting that the current BMI remains a valid clinical tool.

Obesity in older adults results from several interacting factors. Consequently, interventions have shown mitigated effects. We determined (a) the different subgroups of older adults with obesity based on clusters of associated comorbidities and (b) the trajectory of these clusters to assess their stability over 3 years and factors contributing to transitions. Obese men (n = 193; body mass index [BMI] = 33.15 ± 2.69 kg/m 2 ) and women (n = 220; BMI = 33.71 ± 3.71 kg/m 2 ) aged between 68 and 82 years were studied. Outcome variables were body composition, strength, physical capacity (PC), nutrition, psychological and physical health and social participation. Cluster analyses, stratified by sex, were used to identify obesity profiles at baseline and follow-up. Three profiles were identified, based on general health (GH), psychological health (PH) and PC: Cluster 1: healthy obese (GH+, PH+, PC+); Cluster 2: obese with low PC (GH+/-, PH+/-, PC-); Cluster 3: unhealthy obese (GH-, PH-, PC-). After 3 years, 61.2% and 70.2% of men and women remained in their initial cluster, compared to 20.4% and 13.7% who transitioned towards a worse health cluster and 18.3% and 16.0% who transitioned towards a more favourable cluster, partly explained by changes in physical health for men and physical health and PH for women. The results of this study show that targeting physical function in men and physical health and PH functions in women could prevent further health decline in older adults with obesity. Further studies are needed to investigate the role of these clusters in the prediction of cardiometabolic complications and mortality., (© 2019 World Obesity Federation.)

Background: A greater fat-free mass (FFM) is purported to be associated with protective effects on insulin resistance (IR). However, recent studies suggested negative associations between FFM and IR., Objectives: (1) To explore the direction of the association between FFM and IR in a large heterogeneous sample after controlling for confounding factors. (2) To determine cut off values of FFM associated with an increased risk of IR., Methods: Outcome variables were measured in 7044 individuals (48.6% women, 20-79 years; NHANES, 1999-2006): body composition [fat mass (FM), FFM and appendicular FFM (aFFM); DXA], FFM index [FFMI: FFM/height (kg/m 2 )], appendicular FFMI [aFFM/height (kg/m 2 )] and insulin resistance (HOMA-IR). Multivariate regression analyses were performed to determine the independent predictors of HOMA-IR in younger (20-49 years) and older (50-79 years) men and women. ROC analyses were used to determine FFM cut-offs to identify a higher risk of insulin resistance (HOMA-IR > 75th percentile)., Results: aFFMI was an independent predictor of IR in younger (men: β = 0.21; women: β = 0.31; all p ≤ 0.001) and older (men: β = 0.11; women: β = 0.37; all p ≤ 0.001) individuals. Thresholds for aFFMI at which the risk of IR was significantly increased were 8.96 and 8.39 kg/m 2 in younger and older men, and 7.22 and 6.64 kg/m 2 in younger and older women, respectively., Conclusion: Independently of age, a greater aFFMI was an independent predictor of IR. These results suggest revisiting how we envision the link between FFM and IR and explore potential mechanisms.

We aimed to longitudinally assess the relationship between changing brain energy metabolism (glucose and acetoacetate) and cognition during healthy aging. Participants aged 71 ± 5 year underwent cognitive evaluation and quantitative positron emission tomography (PET) and magnetic resonance imaging (MRI) scans at baseline ( N = 25) and two ( N = 25) and four ( N = 16) years later. During the follow-up, the rate constant for brain extraction of glucose (K glc ) declined by 6%-12% mainly in the temporo-parietal lobes and cingulate gyri ( p ≤ 0.05), whereas brain acetoacetate extraction (Kacac) and utilization remained unchanged in all brain regions ( p ≥ 0.06). Over the 4 years, cognitive results remained within the normal age range but an age-related decline was observed in processing speed. K glc in the caudate was directly related to performance on several cognitive tests ( r = +0.41 to +0.43, all p ≤ 0.04). Peripheral insulin resistance assessed by the homeostasis model assessment of insulin resistance (HOMA-IR) was significantly inversely related to K glc in the thalamus ( r = -0.44, p = 0.04) and in the caudate ( r = -0.43, p = 0.05), and also inversely related to executive function, attention and processing speed ( r = -0.45 to -0.53, all p ≤ 0.03). We confirm in a longitudinal setting that the age-related decline in K glc is directly associated with declining performance on some tests of cognition but does not significantly affect Kacac.