Type 2 Diabetes Related Mitochondrial Defects in Peripheral Mononucleated Blood Cells from Overweight Postmenopausal Women.

Type 2 diabetes (T2D) is a multisystem disease that is the subject of many studies, but the earliest cause of the disease has yet to be elucidated. Mitochondrial impairment has been associated with diabetes in several tissues. To extend the association between T2D and mitochondrial impairment to blood cells, we investigated T2D-related changes in peripheral mononucleated blood cells' (PBMCs) mitochondrial function in two groups of women (CTRL vs. T2D; mean age: 54.1 ± 3.8 vs. 60.9 ± 4.8; mean BMI 25.6 ± 5.2 vs. 30.0 ± 5), together with a panel of blood biomarkers, anthropometric measurements and physiological parameters (VO2max and strength tests). Dual-energy X-ray absorptiometry (DXA) scan analysis, cardio-pulmonary exercise test and blood biomarkers confirmed hallmarks of diabetes in the T2D group. Mitochondrial function assays performed with high resolution respirometry highlighted a significant reduction of mitochondrial respiration in the ADP-stimulated state (OXPHOS; −30%, p = 0.006) and maximal non-coupled respiration (ET; −30%, p = 0.004) in PBMCs samples from the T2D group. The total glutathione antioxidant pool (GSHt) was significantly reduced (−38%: p = 0.04) in plasma samples from the T2D group. The fraction of glycated hemoglobin (Hb1Ac) was positively associated with markers of inflammation (C-reactive protein-CRP r = 0.618; p = 0.006) and of dyslipidemia (triglycerides-TG r = 0.815; p < 0.0001). The same marker (Hb1Ac) was negatively associated with mitochondrial activity levels (OXPHOS r = −0.502; p = 0.034; ET r = −0.529; p = 0.024). The results obtained in overweight postmenopausal women from analysis of PBMCs mitochondrial respiration and their association with anthropometric and physiological parameters indicate that PBMC could represent a reliable model for studying T2D-related metabolic impairment and could be useful for testing the effectiveness of interventions targeting mitochondria.

The Role of Obesity, Body Composition, and Nutrition in COVID-19 Pandemia: A Narrative Review.

The coronavirus disease 2019 (COVID-19) pandemic has spread worldwide, infecting nearly 500 million people, with more than 6 million deaths recorded globally. Obesity leads people to be more vulnerable, developing worse outcomes that can require hospitalization in intensive care units (ICU). This review focused on the available findings that investigated the link between COVID-19, body composition, and nutritional status. Most studies showed that not only body fat quantity but also its distribution seems to play a crucial role in COVID-19 severity. Compared to the body mass index (BMI), visceral adipose tissue and intrathoracic fat are better predictors of COVID-19 severity and indicate the need for hospitalization in ICU and invasive mechanical ventilation. High volumes of epicardial adipose tissue and its thickness can cause an infection located in the myocardial tissue, thereby enhancing severe COVID-related myocardial damage with impairments in coronary flow reserve and thromboembolism. Other important components such as sarcopenia and intermuscular fat augment the vulnerability in contracting COVID-19 and increase mortality, inflammation, and muscle damage. Malnutrition is prevalent in this population, but a lack of knowledge remains regarding the beneficial effects aimed at optimizing nutritional status to limit catabolism and preserve muscle mass. Finally, with the increase in patients recovering from COVID-19, evaluation and treatment in those with Long COVID syndrome may become highly relevant.

Exercise and physical performance in older adults with sarcopenic obesity: A systematic review.

Background: Sarcopenic obesity is characterized by low muscle mass and high body fat; prevalence increases with age, particularly after age 65 years. For this systematic literature review we searched scientific databases for studies on exercise interventions for improving physical performance in adults with sarcopenic obesity; also, we identified potential gaps in clinical practice guidelines that need to be addressed. Methods: We followed the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The databases were searched for studies published through November 2021 that measured physical performance in adults with sarcopenic obesity. Results: Most of the studies applied a strength training protocol in which improvement was noted post-treatment on the Time Chair Rise (TCR), 30-s Chair Stand, and Single Leg Stance (SLS) tests. Discrepancies between the studies were observed when resistance training was combined with or without elastic bands or electromyostimulation, as measured with the Short Physical Performance Battery (SPPB), Physical Performance Test (PPT), Gait Speed, and Timed Up & Go (TUG) test. Post-intervention SPPB, PPT, and gait speed scores showed an increase or maintenance of performance, while TUG test scores were higher according to one study but lower according to another. Conclusions: Engagement in physical exercise, and resistance training in particular, can improve or maintain physical performance in adults with sarcopenic obesity. Study samples should include more men. A future area of focus should be the impact of different types of training (aerobic, power training, combined modalities). Finally, studies with longer intervention periods and follow-up periods are needed to gain a better understanding of the effectiveness of exercise on physical function in adults with sarcopenic obesity.

Is handgrip strength a marker of muscle and physical function of the lower limbs? Sex differences in older adults with obesity.

BACKGROUND AND AIMS: In this cross-sectional study we investigate the association between handgrip strength (HGS) and muscle function of the lower limbs and the predictors of the appendicular lean mass index (ALMI) in older adults with obesity of both sexes. METHODS AND RESULTS: Eighty-four older (67 ± 5 years) men (N = 44) and women (N = 40) with obesity (body mass index (BMI) 33 ± 4 kg/m2) performed: the HGS, isokinetic knee extensors (KE) and flexors (KF) muscle strength and power and Short Physical Performance Battery (SPPB). The correlation between HGS and lower limbs muscle function was evaluated, and four multiple hierarchical linear models were built to assess the contribution of each ALMI predictor (i.e., HGS, BMI, SPPB, muscle strength and power). In men, HGS was weakly-to-moderately associated (p < 0.05) with KE, KF muscle function and physical performance. In women, HGS showed a weak association (p < 0.05) with KE muscle function. The significant predictors of ALMI were only the BMI in women, whereas in the group of men BMI, KE maximal strength and power better explain the variance in ALMI than HGS alone. CONCLUSION: Our results suggest that HGS should not be used alone as a marker of lower muscle nor physical function. Sex differences exist with the BMI that is a contributor of ALMI both in men and women. However, at least in the group of men, markers related to strength and power of the lower limbs can better describe variations in ALMI compared to HGS in this kind of population. CLINICAL TRIAL REGISTRATION: NA.

Exploring the association between handgrip, lower limb muscle strength, and physical function in older adults: A narrative review.

Widely used in daily practice, handgrip strength (HGS) is a low cost, easy-to-use, and portable test to assess overall muscle and physical function. It can be used as a stand-alone or a first-line tool for evaluating muscle weakness, though controversy surrounds its use for assessing global or lower limb muscle function. Lower limb mobility and physical activity are reduced with advancing age. This decline is difficult to quantify with isokinetic or isometric devices in routine settings (hospital and nursing home). For this narrative review we explored and summarized the findings of studies that investigated the association between HGS, lower limb muscle strength, and physical performance in older adults. The review also provides directions for future research. We noted contrasting findings for an association between HGS, lower limb strength, and physical performance. We found insufficient evidence for endorsing the handgrip dynamometer as a definitive tool for measuring overall muscle strength and physical function. More evidence is needed from comparable studies involving larger samples of men and women and investigating other areas such as lifestyle, daily physical activity levels, and health-related disorders.

Knee flexor and extensor torque ratio in elderly men and women with and without obesity: a cross-sectional study.

BACKGROUND: With aging and obesity lower limb torque deteriorates. Importantly, the ratio between knee flexor (KF) and extensor (KE) torque is an indicator of joint stability. AIMS: We compared KF torque and KF/KE ratio in older subjects of both sexes with obesity (OB) or without (NOB) obesity. METHODS: The maximal torque during KE and KF isokinetic contractions were evaluated at: 60, 90, 150, 180 and 210 deg/s in 89 elderly (68 ± 5 years) subjects with NOB (BMI < 30 kg/m2) and OB (BMI ≥ 30 kg/m2). Values were normalised for body weight (BW) and leg lean mass (i.e., muscle quality). RESULTS: At all speeds men had higher absolute KF values (P < 0.001). When values were normalised for BW, sex differences remain in favour of men (P < 0.001) with lower values in both groups with OB than NOB (P < 0.001). Muscle quality and KF/KE ratio were lower in OB than NOB (P < 0.001). CONCLUSIONS: The KF torque and KF/KE ratio decline with aging and with OB. In all groups, the KF/KE ratio was below the joint stability threshold. Thus, exercise physiologists should include exercises designed to train both KE and KF in older subjects with OB.

Full characterisation of knee extensors' function in ageing: effect of sex and obesity.

BACKGROUND/OBJECTIVES: Muscle function is a marker of current and prospective health/independence throughout life. The effects of sex and obesity (OB) on the loss of muscle function in ageing remain unresolved, with important implications for the diagnosis/monitoring of sarcopenia. To characterise in vivo knee extensors' function, we compared muscles torque and power with isometric and isokinetic tests in older men (M) and women (W), with normal range (NW) of body mass index (BMI) and OB. SUBJECTS/METHODS: In 70 sedentary older M and W (69 ± 5 years), NW and OB (i.e. BMI < 30 kg m-2 and ≥30 kg m-2, respectively) we tested the right knee's extensor: (i) isometric torque at 30°, 60°, 75° and 90° knee angles, and (ii) isokinetic concentric torque at 60, 90, 150, 180 and 210° s-1 angular speeds. Maximal isometric T-angle, maximal isokinetic knee-extensor torque-velocity, theoretical maximal shortening velocity, maximal power, optimal torque and velocity were determined in absolute units, normalised by body mass (BM) and right leg lean mass (LLMR) and compared over sex, BMI categories and angle or angular speeds by three-way ANOVA. RESULTS: In absolute units, relative to BM and LLMR, sex differences were found in favour of M for all parameters of muscle function (main effect for sex, p < 0.05). OB did not affect either absolute or relative to LLMR isometric and isokinetic muscle function (main effect for BMI, p > 0.05); however, muscle function indices, when adjusted for BM, were lower in both M and W with OB compared to NW counterparts (p < 0.05). CONCLUSIONS: We confirmed sex differences in absolute, relative to BM and LLMR muscle function in favour of men. While overall muscle function and muscle contractile quality is conserved in individuals with class I OB, muscle function normalised for BM, which defines the ability to perform independently and safely the activities of daily living, is impaired in comparison with physiological ageing.

Prolonged unsupervised Nordic walking and walking exercise following six months of supervision in adults with overweight and obesity: A randomised clinical trial.

BACKGROUND AND AIMS: This study is a randomized trial that examined the effects of 6 months of unsupervised Nordic walking (NW) and walking (W) exercise following 6 months of supervised training in overweight/obese adults. METHODS AND RESULTS: After a 6-month program of diet and supervised training participants (n = 27) of NW (66 ± 7 yrs, body mass index (BMI) 34 ± 5) and W (66 ± 8 yrs, BMI 32 ± 5) group continue the training without supervision for other 6 months. Steps count and mean heart rate (HRmean) were performed in each session; anthropometric and body composition, aerobic capacity and strength of the upper and lower limbs were evaluated at baseline, after 6 months of supervised and 6 months of unsupervised training. In the unsupervised training, monthly sessions and steps count decreased over time in both groups (p < 0.05), with no significant changes in HRmean. Compared to the supervised phase, adherence decreased significantly only in the W group in the last 3 months of unsupervised training. Compared to baseline in both groups BMI did not change, but W group lost total fat; only the NW group maintained (p < 0.05) the gains in arm curl (33%) and chair stand (31%); both groups improved in six-minute walking test (p < 0.05). CONCLUSION: Despite unsupervised training was not effective for a further increase in performance, participants, especially in NW, maintained some of the improvements achieved during the supervision. However, the presence of instructor that guides training, may enhance adherence and health benefits of NW and W exercise. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT03212391 (July 11, 2017).

The Mini Sarcopenia Risk Assessment (MSRA) Questionnaire score as a predictor of skeletal muscle mass loss.

BACKGROUND: Previous studies showed a strong relationship between reduction of appendicular muscle mass and worsening disability; hence, accuracy in assessing muscle mass is considered a key feature for a sarcopenia screening tool. AIM: The aim of the study was to evaluate if the 7 items of Mini Sarcopenia Risk Assessment (MSRA) questionnaire predict muscle mass loss in a population of community-dwelling elderly subjects over a 5.5-y follow-up. METHODS: The study included 159 subjects, 92 women and 67 men aged 71.5 ± 2.2 years and with mean body mass index of 26.7 ± 4.0 kg/m2. Appendicular skeletal muscle mass (ASMM) as measured with Dual-Energy X-ray absorptiometry (DXA), was obtained at baseline and after 2 and 5.5 years of follow-up where the skeletal muscle index (SMI) was calculated. RESULTS: A significant reduction of ASMM and SMI was observed at two and 5.5 years of follow-up, in both, men and women. Repeated-measures analysis of variance (ANOVA) found a significant time effect on ASMM for both subjects with MSRA > 30 and ≤ 30 (P < 0.01 and P < 0.001). The group × time interaction was significant (P < 0.001), after even considering separately subjects with normal muscle mass and low muscle mass at baseline (P < 0.05 and P = 0.005). Similar results were obtained for SMI. Considering only the subjects with normal SMI at baseline, subjects with MSRA questionnaire ≤ 30 showed 5.7 (95% CI 1.73-19.03) higher risk of exceeding the low muscle mass threshold. CONCLUSION: In a population of community-dwelling elderly men and women, MSRA score of 30 is predictive of a steeper decline in ASMM and SMI and of a higher risk of exceeding the low muscle mass EWGSOP threshold.

Worsening Disability and Hospitalization Risk in Sarcopenic Obese and Dynapenic Abdominal Obese: A 5.5 Years Follow-Up Study in Elderly Men and Women.

Background/Objectives: A general lack of studies comparing the effect of both dynapenic abdominal obesity and sarcopenic obesity on worsening disability and hospitalization risk should be recognized. The aim of the current study was to evaluate, with a 5.5-year follow-up, the prognostic value of sarcopenic obesity and dynapenic abdominal obesity definitions on worsening disability and hospitalization risk in a sample of older adults. Subjects/Methods: In 177 women and 97 men aged 68-78 years, the following outcomes were evaluated at baseline: appendicular skeletal muscle mass (ASMM), percent fat mass (FM%), leg isometric strength, body mass index (BMI), lipid profile, vitamin D3, albumin, fibrinogen, glycemia, physical activity level, income, smoking status, and comorbidities. The rate of reported disabilities and hospitalization were also assessed at baseline, 1, 2, 3, and 5.5-years follow-up. The study population was classified into: (i) non-sarcopenic/obese (NS/O), sarcopenic/non-obese (S/NO), sarcopenic/obese (S/O), non-sarcopenic/non-obese (NS/NO, reference category) according to relative ASMM/FM% tertiles; (ii) non-dynapenic/abdominal obese (ND/AO), dynapenic/non-abdominal obese (D/NAO), dynapenic/abdominal obese (D/AO), non-dynapenic/non-abdominal obese (ND/NAO, reference category) according to muscle strength/waist circumference tertiles. Results: The prevalence of D/AO and S/O was 12.0 and 8.0%, respectively. Only 2 subjects were both D/NAO and S/O (0.8%). D/NAO subjects showed a worsening disability risk of 1.69 times (95% CI: 1.11-2.57), ND/AO subjects showed a 2-fold increased risk (95% CI: 1.34-2.98), while being D/AO more than trebled the risk, even after adjustment for confounding factors (HR: 3.39, 95%; CI: 1.91-6.02). By dividing the study population according to the relative ASMM/FM% tertiles, no groups showed an increased risk of worsening disability. The hospitalization risk, even after adjustment for potential confounders, was 1.84 (95% CI: 1.06-3.19) for D/AO. Dividing the study population according to the relative ASMM/FM% tertiles, no groups showed increased risk of hospitalization. Conclusions: Our results showed that dynapenic abdominal obesity and sarcopenic obesity seem to indicate two distinct phenotypes associated with different health risk profiles. The distribution of participants in waist circumference and muscle strength tertiles allowed for a more accurate risk stratification for worsening disability and hospitalization.

The effects of exercise and diet program in overweight people - Nordic walking versus walking.

PURPOSE: Nordic walking (NW) has been recommended as a form of exercise for clinical populations. Despite intervention programs designed to face a clinical status may last several months, no longitudinal studies have compared the effect of NW to another usual form of exercise, like walking (W). We evaluated the effects of diet combined with a long-supervised NW versus W training on body composition, aerobic capacity and strength in overweight adults. PATIENTS AND METHODS: Thirty-eight participants, randomized into a NW (n=19, 66±7 years, body mass index (BMI) 33±5)) and a W (n=19, 66±8 years, BMI 32±5) group, followed a diet and a supervised training routine 3 times/week for 6 months. The variables assessed at baseline, after 3 and 6 months were: anthropometric indexes (ie, BMI and waist circumference (WC)), body composition, aerobic capacity (oxygen consumption (VO2peak), peak power output (PPO), 6-min walking test (6MWT)) and strength (maximal voluntary contraction of biceps brachialis (MVCBB) and quadriceps femoris (MVCQF), chair stand and arm curl (AC)). RESULTS: After 6 months both NW and W group decreased significantly BMI (6% and 4%, respectively) and WC (8% and 4%, respectively), but only the NW group reduced (P<0.05) total body fat (8%), android fat (14%) and leg fat (9%). After 6 months, PPO increased (P<0.05) in both groups, but VO2peak improved (P<0.05) only in the NW group (8%). After 6 months, 6MWT increased (P<0.001) in both groups and only the NW group improved (P<0.05) in MVCBB (14%), MVCQF (17%) and AC (35%). CONCLUSION: Our results suggest that NW can give in some relevant health parameters, greater and faster benefits than W. Thus, NW can be a primary tool to counteract the obesity and overweight state in middle-aged adults.

Sprint running: how changes in step frequency affect running mechanics and leg spring behaviour at maximal speed.

The purpose of this study was to investigate the changes in selected biomechanical variables in 80-m maximal sprint runs while imposing changes in step frequency (SF) and to investigate if these adaptations differ based on gender and training level. A total of 40 athletes (10 elite men and 10 women, 10 intermediate men and 10 women) participated in this study; they were requested to perform 5 trials at maximal running speed (RS): at the self-selected frequency (SFs) and at SF ±15% and ±30%SFs. Contact time (CT) and flight time (FT) as well as step length (SL) decreased with increasing SF, while kvert increased with it. At SFs, kleg was the lowest (a 20% decrease at ±30%SFs), while RS was the largest (a 12% decrease at ±30%SFs). Only small changes (1.5%) in maximal vertical force (Fmax) were observed as a function of SF, but maximum leg spring compression (ΔL) was largest at SFs and decreased by about 25% at ±30%SFs. Significant differences in Fmax, Δy, kleg and kvert were observed as a function of skill and gender (P < 0.001). Our results indicate that RS is optimised at SFs and that, while kvert follows the changes in SF, kleg is lowest at SFs.