Relationship Between Sarcopenia, Obesity, Osteoporosis, and Cardiometabolic Health Conditions and Physical Activity Levels in Korean Older Adults

Sarcopenia risk in U.S. younger adults: the impact of physical activity intensity and occupational engagement-insights from a cross-sectional NHANES study

OBJECTIVE

This study aimed to investigate the associations between physical activity (PA) intensity, occupational PA engagement, and sarcopenia in younger adults.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) (from 2011 to 2018) were used for the study. PA data were extracted for the Global Physical Activity Questionnaire, and the ratio of limb muscle mass (ALM) to body mass index (BMI) was used to determine sarcopenia. Multiple logistic regression was performed, and dose-response curves were drawn to evaluate the associations.

RESULTS

Of the 8802 adults aged 20 to 59 years, 770 (8.7%) were identified as having sarcopenia. Compared to those in the reference group, the participants in the "low", "moderate", and "high" total METs groups had lower risks of sarcopenia (low: OR = 0.730, 95% CI = 0.583; 0.915; moderate: OR = 0.643, 95% CI = 0.485; 0.853; high: OR = 0.560, 95% CI = 0.457; 0.687). The risk of sarcopenia decreased in the high-intensity recreational PA group; however, such a significant association was observed only in the high-intensity occupational PA group. The relationship between total METs and sarcopenia showed a nonlinear U-shaped trend.

CONCLUSIONS

A greater intensity of PA is associated with a lower risk of sarcopenia among younger adults, regardless of whether moderate or vigorous PA is performed. Moreover, recreational PA may particularly advantageously contrast with occupational PA in lowering the risk of sarcopenia.

Association of physical behaviours with sarcopenia in older adults: a systematic review and meta-analysis of observational studies

BACKGROUND

Physical behaviours (ie, physical activity and sedentary behaviour) might have a role in the development of sarcopenia, although the evidence is unclear. We aimed to explore the association of total and intensity-specific levels of physical activity and sedentary behaviour with sarcopenia and its components (ie, muscle mass, muscle strength, and physical performance) in older adults.

METHODS

We conducted a systematic review and meta-analysis and searched MEDLINE (via PubMed), Scopus, and Web of Science from inception to July 26, 2022, for peer-reviewed, observational studies or baseline data from randomised clinical trials conducted in older adults (ie, individual age ≥60 years or mean age ≥65 years) and published in English that reported on the association of physical activity or sedentary behaviour or both with sarcopenia (or its determinants: muscle mass or strength, and physical performance). Physical activity and sedentary behaviour were measured by any method. The main outcome was sarcopenia, which could be diagnosed by any means. Estimates were extracted and pooled using Bayesian meta-analytic models and publication bias was assessed using the Egger's test. This study is registered with PROSPERO, CRD42022315865.

FINDINGS

We identified 15 766 records, of which 124 studies (230 174 older adults; 121 301 [52·7%] were female and 108 873 [47·3%] were male) were included in the systematic review. 86 studies were subsequently included in the meta-analysis. Higher levels of total physical activity were inversely associated with sarcopenia both cross-sectionally (21 studies, n=59 572; odds ratio 0·49, 95% credible interval 0·37-0·62) and longitudinally (four studies, n=7545; 0·51, 0·27-0·94). A protective association was also identified for moderate-to-vigorous physical activity in cross-sectional research (five studies, n=6787; 0·85, 0·71-0·99), whereas no association was identified for the remaining physical behaviours (ie, steps, light physical activity, or sedentary behaviour).

INTERPRETATION

Total and moderate-to-vigorous physical activity are inversely associated with sarcopenia. These findings might support the importance of moderate-to-vigorous, rather than light, intensity physical activity-based interventions to prevent sarcopenia.

FUNDING

None.

TRANSLATION

For the Spanish translation of the abstract see Supplementary Materials section.

Prevalence of sarcopenia and its association with diet and physical activity in older adults with type 2 diabetes: A cross-sectional study

This cross-sectional study explored the prevalence of sarcopenia in older adults with type 2 diabetes and investigated the effects of diet and physical activity on sarcopenia. In total, 577 older adults with diabetes were recruited from a teaching hospital in Taiwan. Diet and physical activity were assessed using self-rated questionnaires, including the Healthy Diet Inventory, the Mini Nutritional Assessment-Short Form, and the International Physical Activity Questionnaire-Short Form. Sarcopenia was defined in accordance with the Asian Working Group for Sarcopenia 2019 guidelines. In total, 51.12% of participants had either possible sarcopenia, sarcopenia, or severe sarcopenia. Participants who were female, old age, prolonged sedentary times, poor nutritional status, and lower level of moderate-to-vigorous physical activity were identified as risk factors for possible to severe sarcopenia. Older adults with diabetes and possible to severe sarcopenia had poor nutrition status and engaged in inadequate physical activity. The findings indicate that sarcopenia may be related to nutrition status and physical activity, especially in older adults with diabetes.

Triglyceride to high-density lipoprotein cholesterol ratio was negatively associated with relative grip strength in older adults: a cross-sectional study of the NHANES database

Aim

This study aims to explore the association between triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio and relative grip strength in older adults in order to provide some references for the prevention and control of sarcopenia.

Methods

For this cross-sectional study, the demographic and clinical data of 1,404 individuals aged ≥60 years old were extracted from the National Health and Nutrition Examination Survey (NHANES) database in 2011-2014. The definition of relative grip strength was the sum of the largest reading from each hand/body mass index (BMI) ratio. We used weighted univariate linear regression and stepwise regression analysis to screen the covariates. Weighted univariate and multivariate linear regression analyses were used to explore the association between the TG/HDL-C ratio and the relative grip strength. We also explored this relationship in subgroups of gender, diabetes mellitus (DM), cardiovascular disease (CVD), and arthritis. The evaluation index was β with 95% confidence intervals (CIs).

Results

A total of 1,306 older adults were eligible. After adjusting for the covariates including age, gender, race, marital status, physical activity, DM, CVD, arthritis, and chronic kidney disease (CKD), we found that the TG/HDL-C ratio was negatively linked to the relative grip strength (all p < 0.05). Furthermore, the increased TG/HDL-C ratio was also related to the decreased relative grip strength in those who were women, not having DM, and having CVD (all p < 0.05).

Conclusion

With the increase in the TG/HDL-C ratio, the relative grip strength of older adults decreased significantly, indicating that the TG/HDL-C ratio could be closely monitored in the older adult population and may be associated with the prevention and control of sarcopenia.

Machine Learning for Sarcopenia Prediction in the Elderly Using Socioeconomic, Infrastructure, and Quality-of-Life Data

Since the WHO's 2021 aging redefinition emphasizes "healthy aging" by focusing on the elderly's ability to perform daily activities, sarcopenia, which is defined as the loss of skeletal muscle mass, is now becoming a critical health concern, especially in South Korea with a rapidly aging population. Therefore, we develop a prediction model for sarcopenia by using machine learning (ML) techniques based on the Korea National Health and Nutrition Examination Survey (KNHANES) data 2008-2011, in which we focus on the role of socioeconomic status (SES), social infrastructure, and quality of life (QoL) in the prevalence of sarcopenia. We successfully identify sarcopenia with approximately 80% accuracy by using random forest (RF) and LightGBM (LGB), CatBoost (CAT), and a deep neural network (DNN). For prediction reliability, we achieve area under curve (AUC) values of 0.831, 0.868, and 0.773 for both genders, males, and females, respectively. Especially when using only male data, all the models consistently exhibit better performance overall. Furthermore, using the SHapley Additive exPlanations (SHAP) analysis, we find several common key features, which mainly contribute to model building. These include SES features, such as monthly household income, housing type, marriage status, and social infrastructure accessibility. Furthermore, the causal relationships of household income, per capita neighborhood sports facility area, and life satisfaction are analyzed to establish an effective prediction model for sarcopenia management in an aging population.

Sarcopenia, sarcopenic obesity and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD), sarcopenia and sarcopenic obesity (SO) are highly prevalent conditions that may coexist, especially in the aging population, without any approved pharmacologic treatment for all of them. There are multiple pathophysiologic mechanisms suggested to explain an association between NAFLD and sarcopenia or SO, including alterations in the adipokines, cytokines, hepatokines and myokines, which may interplay with other factors, such as aging, diet and physical inactivity. In clinical terms, most observational studies support an association between NAFLD and sarcopenia or SO; importantly, there are few cohort studies indicating higher mortality in patients with NAFLD and sarcopenia. Their association also bears some treatment considerations: for example, pioglitazone or vitamin E, suggested as off label treatment for selected patients with nonalcoholic steatohepatitis, may be recommended in the coexistence of sarcopenia or SO, since limited evidence did not show adverse effects of them on sarcopenia and abdominal obesity. In this review, evidence linking sarcopenia and SO with NAFLD is summarized, with a special focus on clinical data. A synopsis of the major pathophysiological links between NAFLD and sarcopenia/SO is initially presented, followed by selected clinical studies and, finally, treatment considerations in patients with NAFLD and sarcopenia or SO are discussed.

Sarcopenia in Type 2 Diabetes Mellitus: Study of the Modifiable Risk Factors Involved

(1) Background: Sarcopenia has gained much interest in recent years due to an increase in morbidity. Sarcopenia is associated with type 2 diabetes mellitus (T2DM) and vice versa. There is a paucity of information regarding the prevalence and predictors of sarcopenia among T2DM individuals. The aim of the present study was to determine the prevalence and predictors of sarcopenia among T2DM individuals. (2) Methods: This study included 159 diabetics (cases) and 79 non-diabetics (controls) aged >50 years. The subjects were assessed for demographic and anthropometric parameters. Sarcopenia (according to the Asian Working Group for Sarcopenia 2019 criteria) was assessed using Jammer's hydraulic dynamometer for handgrip strength, dual-energy X-ray absorptiometry for muscle mass, and 6m gait speed. The biochemical investigations included glycated hemoglobin; fasting and prandial glucose; fasting insulin; lipid, renal, liver, and thyroid profiles; serum calcium; phosphorous; vitamin D; and parathyroid hormone (PTH). Appropriate statistical methods were used to determine the significance of each parameter, and a multivariate regression analysis was applied to determine the predictors. (3) Results: The prevalence of sarcopenia was significantly higher among the cases than the controls (22.5% vs. 8.86%, p-0.012). Body mass index (BMI) (OR-0.019, CI-0.001-0.248), physical activity (OR-0.45, CI-0.004-0.475), serum calcium levels (OR-0.155, CI-0.035-0.687), hypertension (OR-8.739, CI-1.913-39.922), and neuropathy (OR-5.57, CI-1.258-24.661) were significantly associated with sarcopenia following multivariate regression analysis. (4) Conclusions: T2DM individuals are prone to sarcopenia, especially those with a low BMI, low physical activity, hypertension, neuropathy, and low serum calcium levels. Hence, by modifying these risk factors among the elderly T2DM, sarcopenia can be prevented.

Correlation between bone mineral density and sarcopenia in US adults: a population-based study

INTRODUCTION

In the aging process of the body, in addition to changes in fat and muscle content, there is also bone loss, implying the possibility of a strong muscle-bone-lipid link. In this study, we initially investigated the relationship between lumbar BMD and low muscle mass and the relationship between "muscle-bone-lipid."

METHODS

The datasets from the National Health and Nutrition Examination Survey (NHANES) 2011-2018 were used in a cross-sectional investigation. BMD and appendicular skeletal muscle (ASM) were measured by dual-energy X-ray absorptiometry (DXA), and appendicular skeletal muscle was adjusted by body mass index (BMI) as a marker of sarcopenia. Weighted multivariate regression and logistic regression analysis were used to explore the independent relationship between lumbar BMD and sarcopenia. Fitted smoothing curves and threshold effect analysis were used to describe the nonlinear relationship.

RESULT

In 8386 participants with ages 20-59 years, there was a negative association between lumbar BMD and sarcopenia. In the fully adjusted model, the risk of developing sarcopenia decreased by 93% for each 1-unit increase in lumbar BMD (OR = 0.07, 95%CI 0.03-0.20). The risk of sarcopenia was 58% lower in participants in the highest quartile of lumbar BMD than in those in the lowest quartile (OR = 0.42, 95%CI 0.27-0.64). This negative association was more pronounced in the population of women with BMI ≥ 25.

CONCLUSION

Our findings suggest that lumbar BMD is negatively associated with sarcopenia in US adults. The dynamic balance between "muscle-bone-lipid" is likely to be related to the pathogenesis of bone loss.

Deep-learning model for predicting physical fitness in possible sarcopenia: analysis of the Korean physical fitness award from 2010 to 2023

Introduction

Physical fitness is regarded as a significant indicator of sarcopenia. This study aimed to develop and evaluate a deep-learning model for predicting the decline in physical fitness due to sarcopenia in individuals with potential sarcopenia.

Methods

This study used the 2010-2023 Korean National Physical Fitness Award data. The data comprised exercise- and health-related measurements in Koreans aged >65 years and included body composition and physical fitness variables. Appendicular muscle mass (ASM) was calculated as ASM/height2 to define normal and possible sarcopenia. The deep-learning model was created with EarlyStopping and ModelCheckpoint to prevent overfitting and was evaluated using stratified k-fold cross-validation (k = 5). The model was trained and tested using training data and validation data from each fold. The model's performance was assessed using a confusion matrix, receiver operating characteristic curve, and area under the curve. The average performance metrics obtained from each cross-validation were determined. For the analysis of feature importance, SHAP, permutation feature importance, and LIME were employed as model-agnostic explanation methods.

Results

The deep-learning model proved effective in distinguishing from sarcopenia, with an accuracy of 87.55%, precision of 85.57%, recall of 90.34%, and F1 score of 87.89%. Waist circumference (WC, cm), absolute grip strength (kg), and body fat (BF, %) had an influence on the model output. SHAP, LIME, and permutation feature importance analyses revealed that WC and absolute grip strength were the most important variables. WC, figure-of-8 walk, BF, timed up-and-go, and sit-and-reach emerged as key factors for predicting possible sarcopenia.

Conclusion

The deep-learning model showed high accuracy and recall with respect to possible sarcopenia prediction. Considering the need for the development of a more detailed and accurate sarcopenia prediction model, the study findings hold promise for enhancing sarcopenia prediction using deep learning.

Older adults physically inactive in occupational and commuting domains have a higher risk for osteopenia and osteoporosis: A 12-month prospective study

The relationship between different domains of physical activity (PA) and bone health in older adults needs to be further investigated. We evaluated 379 Brazilian older adults and observed that the risk of osteopenia is higher in older adults who are physically inactive in occupational domain and for osteoporosis the risk is higher in physically inactive in commuting domain and total habitual PA.

PURPOSE

Bone mineral density (BMD) usually decreases with age, and the risk of osteometabolic diseases, such as osteopenia and osteoporosis, increases in older adults. PA is strictly related to BMD. However, the relationship between different domains of PA and bone health in older adults is still unclear, and needs to be further investigated, aiming at the implementation of preventative health measures for this population. Thus, the aim of the current study was to analyze the association between different domains of PA and the risk for osteopenia and osteoporosis in older adults in a 12-month follow-up.

METHODS

Prospective study that included 379 Brazilian community-dwelling older adults, aged ≥ 60 years (70 ± 7 years, 69% women). Areal bone mineral density (aBMD) total, proximal femur, and lumbar spine were measured by dual energy X-ray absorptiometry (DXA), and PA was self-reported. Binary logistic regression analysis and 95%CI were used to analyze the association between the practice of PA in different domains (at baseline and follow-up) and risk for osteopenia and osteoporosis (follow-up).

RESULTS

The risk for osteopenia (total proximal femur or lumbar spine) is higher in older adults who are physically inactive in the occupational domain (OR:3.25; 95%CI:1.24-8.55). In addition, older adults who are physically inactive in the commuting domain (OR:3.43; 95%CI:1.09-10.82) and total PA (OR:5.58; 95%CI:1.57-19.88) present a higher risk for osteoporosis (total proximal femur or lumbar spine) compared to physically active older adults.

CONCLUSION

The risk of osteopenia is higher in older adults who are physically inactive in occupational domain and for osteoporosis the risk is higher in physically inactive in commuting domain and total habitual PA.

Sarcopenia Prediction for Elderly People Using Machine Learning: A Case Study on Physical Activity

Sarcopenia is a well-known age-related disease that can lead to musculoskeletal disorders and chronic metabolic syndromes, such as sarcopenic obesity. Numerous studies have researched the relationship between sarcopenia and various risk factors, leading to the development of predictive models based on these factors. In this study, we explored the impact of physical activity (PA) in daily life and obesity on sarcopenia prediction. PA is easier to measure using personal devices, such as smartphones and watches, or lifelogs, than using other factors that require medical equipment and examination. To demonstrate the feasibility of sarcopenia prediction using PA, we trained various machine learning models, including gradient boosting machine (GBM), xgboost (XGB), lightgbm (LGB), catboost (CAT), logistic regression, support vector classifier, k-nearest neighbors, random forest (RF), multi-layer perceptron, and deep neural network (DNN), using data samples from the Korea National Health and Nutrition Examination Survey. Among the models, the DNN achieved the most precise accuracy on average, 81%, with PA features across all data combinations, and the accuracy increased up to 90% with the addition of obesity information, such as total fat mass and fat percentage. Considering the difficulty of measuring the obesity feature, when adding waist circumference to the PA features, the DNN recorded the highest accuracy of 84%. This model accuracy could be improved by using separate training sets according to gender. As a result of measurement with various metrics for accurate evaluation of models, GBM, XGB, LGB, CAT, RF, and DNN demonstrated significant predictive performance using only PA features including waist circumference, with AUC values at least around 0.85 and often approaching or exceeding 0.9. We also found the key features for a highly performing model such as the quantified PA value and metabolic equivalent score in addition to a simple obesity measure such as body mass index (BMI) and waist circumference using SHAP analysis.

Reambulation following hindlimb unloading attenuates disuse-induced changes in murine fracture healing

Patients with bone and muscle loss from prolonged disuse have higher risk of falls and subsequent fragility fractures. In addition, fracture patients with continued disuse and/or delayed physical rehabilitation have worse clinical outcomes compared to individuals with immediate weight-bearing activity following diaphyseal fracture. However, the effects of prior disuse followed by physical reambulation on fracture healing cellular processes and adjacent bone and skeletal muscle recovery post-injury remains poorly defined. To bridge this knowledge gap and inform future treatment and rehabilitation strategies for fractures, a preclinical model of fracture healing with a history of prior unloading with and without reambulation was employed. First, skeletally mature male and female C57BL/6J mice (18 weeks) underwent hindlimb unloading by tail suspension (HLU) for 3 weeks to induce significant bone and muscle loss modeling enhanced bone fragility. Next, mice had their right femur fractured by open surgical dissection (stabilized with 24-gauge pin). The, mice were randomly assigned to continued HLU or allowed normal weight-bearing reambulation (HLU + R). Mice given normal cage activity throughout the experiment served as healthy age-matched controls. All mice were sacrificed 4-days (DPF4) or 14-days (DPF14) following fracture to assess healing and uninjured hindlimb musculoskeletal properties (6-10 mice per treatment/biological sex). We found that continued disuse following fracture lead to severely diminished uninjured hindlimb skeletal muscle mass (gastrocnemius and soleus) and femoral bone volume adjacent to the fracture site compared to healthy age-matched controls across mouse sexes. Furthermore, HLU led to significantly decreased periosteal expansion (DPF4) and osteochondral tissue formation by DPF14, and trends in increased osteoclastogenesis (DPF14) and decreased woven bone vascular area (DPF14). In contrast, immediate reambulation for 2 weeks after fracture, even following a period of prolonged disuse, was able to increase hindlimb skeletal tissue mass and increase osteochondral tissue formation, albeit not to healthy control levels, in both mouse sexes. Furthermore, reambulation attenuated osteoclast formation seen in woven bone tissue undergoing disuse. Our results suggest that weight-bearing skeletal loading in both sexes immediately following fracture may improve callus healing and prevent further fall risk by stimulating skeletal muscle anabolism and decreasing callus resorption compared to minimal or delayed rehabilitation regimens.

Does an Association among Sarcopenia and Metabolic Risk Factors Exist in People Older Than 65 Years? A Systematic Review and Meta-Analysis of Observational Studies

Sarcopenia is defined as the generalized and progressive loss of skeletal muscle strength and mass that may be affected by metabolic factors, although this relationship has been poorly studied. The aim of this review and meta-analysis was to analyze the relationship among the different metabolic risk factors and sarcopenia in people older than 65 years. Following the PRISMA 2020 guide, we searched for articles that studied the relationship among sarcopenia and metabolic risk factors in adults over 65 years of age, published between 2012 and 2022 in four databases: PubMed, Web of Science, Cochrane Plus, and CINAHL. A total of 370 articles were identified in the initial search, of which 13 articles were selected for inclusion in this review. It was observed that metabolic risk factors such as Body Mass Index, systolic and diastolic blood pressure, glucose, cholesterol, or triglycerides had a significant association with sarcopenia. There is evidence of the association of different metabolic risk factors with sarcopenia in adults over 65 years of age, so it is necessary to carry out studies that investigate different strategies that reduce the appearance of sarcopenia, and with it, the incidence of metabolic diseases.

Cross-sectional and longitudinal associations between body flexibility and sarcopenia

BACKGROUND

The associations between body flexibility and sarcopenia were not well understood. This study aimed to explore the cross-sectional and longitudinal associations of flexibility with sarcopenia.

METHODS

Our study selected participants aged 50-80 from the WELL-China cohort and the Lanxi cohort. Participants from the urban area of the Lanxi cohort were followed up 4 years later. Body flexibility was measured by the sit-and-reach test. Muscle mass was evaluated by dual-energy X-ray absorptiometry. Muscle strength was evaluated using handgrip strength. Sarcopenia was defined as having both low muscle mass and low muscle strength. We used multivariable logistic regressions to assess the cross-sectional associations of body flexibility with low muscle mass, low muscle strength and sarcopenia. We also used multivariable logistic regressions to explore the associations of baseline flexibility and 4-year changes in flexibility with incident low muscle mass, low muscle strength and sarcopenia.

RESULTS

A total of 9453 participants were enrolled in the cross-sectional study, and 1233 participants were included in the longitudinal analyses. In the cross-sectional analyses, compared with low body flexibility, high body flexibility was inversely associated with low muscle mass (odds ratio [OR], 0.58; 95% confidence interval [CI], 0.50-0.68; P < 0.001), low muscle strength (OR, 0.62; 95% CI, 0.55-0.69; P < 0.001) and sarcopenia (OR, 0.52; 95% CI, 0.41-0.65; P < 0.001), and these associations did not differ in different age groups, sex or physical activity levels. In the longitudinal analyses, compared with participants with low body flexibility, participants with high body flexibility had lower risk of the incident low muscle strength (OR, 0.53; 95% CI, 0.38-0.74; P < 0.001) and sarcopenia (OR, 0.36; 95% CI, 0.21-0.61; P < 0.001), but not incident low muscle mass (OR, 0.59; 95% CI, 0.33-1.06; P = 0.076). Every 1-cm increase in flexibility during 4 years was associated with reduced risk of incident low muscle mass (OR, 0.96; 95% CI, 0.93-1.00; P = 0.025), low muscle strength (OR, 0.96; 95% CI, 0.94-0.98; P = 0.002) and sarcopenia (OR, 0.96; 95% CI, 0.93-0.99; P = 0.007).

CONCLUSIONS

High flexibility was associated with reduced risk of incident low muscle strength and sarcopenia. Increases in flexibility were associated with reduced risk of incident low muscle mass, low muscle strength and sarcopenia. Flexibility exercises and monitoring the dynamic change of flexibility might be helpful in preventing sarcopenia among adults aged 50 years or over.

Effects of Omega-3 Supplementation Alone and Combined with Resistance Exercise on Skeletal Muscle in Older Adults: A Systematic Review and Meta-Analysis

Sarcopenia negatively affects skeletal muscle mass and function in older adults. Omega-3 (ω-3) fatty acid supplementation, with or without resistance exercise training (RET), is suggested to play a role as a therapeutic component to prevent or treat the negative effects of sarcopenia. A systematic review and meta-analysis were conducted on the impact of ω-3 fatty acid supplementation with or without RET on measures of muscle mass and function in older adults (≥55 y). The data sources included SPORTDiscus, PubMed, and Medline. All the study types involving ω-3 fatty acid supplementation on measures of muscle mass and function in older adults (without disease) were included. The mean differences (MDs) or standardized mean differences (SMDs) with 95% confidence intervals were calculated and pooled effects assessed. Sixteen studies (1660 females, 778 males) met our inclusion criteria and were included in the meta-analysis. ω-3 fatty acid supplementation did not impact lean tissue mass (SMD 0.09 [-0.10, 0.28]). Benefits were observed for lower body strength (SMD 0.54 [0.33, 0.75]), timed-up-and-go (MD 0.29 [0.23, 0.35]s), and 30-s sit-to-stand performance (MD 1.93 [1.59, 2.26] repetitions) but not walking performance (SMD -0.01 [-0.10, 0.07]) or upper body strength (SMD 0.05 [-0.04, 0.13]). Supplementing with ω-3 fatty acids may improve the lower-body strength and functionality in older adults.

Associations of physical activity with sarcopenia and sarcopenic obesity in middle-aged and older adults: the Louisiana osteoporosis study

BACKGROUND

This study examined the associations between physical activity, obesity, and sarcopenia in middle-aged and older adults.

METHODS

We analyzed the data of 8, 919 study participants aged between 45 to 97 (mean age = 57.2 ± 8.8) from a Southern state in the United States. Self-reported physical activity was classified to regular exercise ≥ 3 times/week, < 3 times/week, and no regular exercise. Associations between physical activity, obesity and sarcopenia were explored with generalized linear models and ordinal logistic regressions stratified by age (middle-aged and older adults) and gender adjusting for covariates.

RESULTS

In middle-aged and older adults, all examined obesity related traits (e.g., body mass index, waist circumference) were inversely associated with physical activity levels (p < 0.01) in both genders. Exercising ≥ 3 times/week was negatively associated with lean mass indicators (e.g., appendicular lean mass) in middle-aged and older females (p < 0.01), while the negative associations become positive after adjusting for weight. Positive associations between physical activity and grip strength were only found in middle-aged males (p < 0.05). Ordinal logistic regression revealed that those exercising ≥ 3 times/week were less likely to have obesity, sarcopenia, and sarcopenia obesity in all groups (p < 0.01), except for sarcopenia in older males and females (p > 0.05). Positive associations of exercising < 3 times/week with sarcopenia and sarcopenia obesity were only found in middled adults.

CONCLUSION

The associations of exercise frequency with obesity and sarcopenia vary considerably across gender and age groups. Exercise programs need to be individualized to optimize health benefits. Future research exploring physical activity strategies to balance weight reduction and lean mass maintaining is warranted in middle-aged and especially older adults.

Comparison of Vascular Function, Cardiometabolic Parameters, Hemorheological Function, and Cardiorespiratory Fitness Between Middle-Aged Korean Women With and Without Obesity—A Pilot Study

This study aimed to compare vascular function, cardiometabolic parameters, hemorheological function, and cardiorespiratory fitness in middle-aged Korean women according to obesity defined using body mass index (BMI). A total of 32 Korean women aged between 34 and 60 years (16 without obesity, mean age 46.31 ± 7.49 years and 16 with obesity, mean age 49.68 ± 6.69 years) participated in this study. Obesity was defined as BMI ≥ 25 kg/m2. The body composition, vascular function, cardiometabolic parameters, hemorheological function, and cardiorespiratory fitness of all participants were measured. Statistical differences in the dependent parameters between individuals with and without obesity were analyzed, and the correlations between BMI and the dependent variables were verified. The obese group showed significantly worse results (p &lt; 0.05) for body composition (significantly higher weight, BMI, fat mass, and percent body fat), vascular function [significantly higher branchial ankle pulse wave velocity (baPWV) and lower flow-mediated vasodilation (FMD)], cardiometabolic parameters [significantly higher insulin and homeostatic model assessment for insulin resistance (HOMA-IR)], hemorheological function (significantly lower erythrocyte deformability and higher aggregation), and cardiorespiratory fitness [significantly lower maximal oxygen uptake (VO2max)] compared to the non-obese group. In addition, BMI showed a significant positive correlation (p &lt; 0.05) with baPWV (r = 0.430); total cholesterol (r = 0.376), triglyceride (r = 0.411), low-density lipoprotein cholesterol (r = 0.462), and insulin (r = 0.477) levels; HOMA-IR (r = 0.443); and erythrocyte aggregation (r = 0.406), and a significant negative correlation (p &lt; 0.05) with VO2max (r = −0.482) and FMD (r = −0.412). Our study confirmed that obesity is a major determinant for deterioration of vascular function, cardiometabolic parameters, hemorheological function, and cardiorespiratory fitness.

Physical activities mediate the correlations between serum creatinine and bone mineral density in Chinese

BACKGROUND

The relationship between serum creatinine (CR) and osteoporosis under normal renal function and the possible mediating effects mediated by physical activity (PA) are largely unknown.

METHODS

A total of 4,137 elderly Chinese subjects were recruited. Three models including different covariates were established. Correlation analysis and multiple linear regression analysis were used to evaluate the relationship between CR and bone mineral density (BMD) and also under different PA pattern. Logistic regression was used to investigate the interaction between CR*PA with osteoporosis. PA was used as a moderating variable to investigate the relationship between CR and BMD.

RESULTS

As we expected, the association between CR and BMD remained significant after adjusting covariates in all models. The relationship between CR and BMD showed changeable pattern in case of different physical activity. Specially, the moderating effects of PA on serum creatinine and BMD were significant for all models only in the case of medium physical activity (PA3).

CONCLUSIONS

In Chinese elderly under normal renal function, serum CR is positively correlated with BMD, and medium physical activity has mediation effect on such correlation.