Background. Little information is available about molecular markers for sarcopenia and osteoporosis in Asian populations.Objective. This study investigated the association of theACTN3polymorphism with sarcopenia and osteoporotic status in older Korean adults.Methods. Older Korean 62 men and 270 women (mean age 73.7 ± 6.6 years) participated in this study. Body mass index, percent body fatness, appendicular skeletal muscle mass, and bone mineral density of the lumbar spine, femur, and total body were analyzed with dual-energy X-ray absorptiometry.ACTN3R/X genotyping was determined using TaqMan probes.Results. Determination of odds ratios (ORs) and 95% confidence intervals (CIs) using binary logistic regression analyses showed that XX homozygotes were at a significantly higher risk of sarcopenia (OR=2.056,95% CI=1.024–4.127,p=0.043) and osteoporosis (OR=2.794,95% CI=1.208–5.461,p=0.016) than RR homozygotes (reference group,OR=1). The OR of XX homozygotes for having sarcopenia remained significant (OR=2.237,95% CI=1.044–4.836,p=0.038) after adjustments for age, gender, body fatness, and serum vitamin D. The OR of XX homozygotes for having osteoporosis was no longer significant (OR=2.682,95% CI=0.960–7.942,p=0.075) after adjustments for the covariates.Conclusion. Our findings suggest that theACTN3R577X genotype may influence decline in muscle and bone health phenotypes in older Korean adults.

Background. Obesity and physical inactivity are associated with higher prevalence of cardiovascular disease (CVD). Objective. This study investigated the association between obesity and carotid intima-media thickness (CIMT) stratified by physical activity (PA) in Korean office workers. Methods. Data obtained from 914 office workers aged 21-60 years (347 women) were used. Resting blood pressures, body mass index (BMI), and waist-to-height ratio (WHtR) were measured. PA was assessed using the international physical activity questionnaire. CIMT was assessed with a carotid artery ultrasonography. Logistic regression analysis was used to estimate the odds ratio (OR) and 95% confidence interval (CI) of obesity stratified by weekly PA for an abnormally increased CIMT. Results. Logistic regression analyses showed that those who were overall obese (OR=2.50, 95% CI=1.60-3.91, P<0.001) or central obese (OR=2.08, 95% CI=1.29-3.40, P=0.003) had significantly higher estimated risks of having an abnormally increased CIMT even after adjustments for age, sex, smoking, alcohol consumption, resting blood pressures, and history of hypertension, diabetes, and hyperlipidemia, as compared with those who were not overall or central obese (OR=1). A multivariate linear regression suggested that age (P<0.001), sex (P=0.002), hypertension (P=0.014), smoking (P=0.054), BMI (P<0.001), and physical activity (P=0.011) were important determinants of abnormally elevated CIMT in this study population. Conclusion. The current findings suggest that the risk of obesity for an abnormally increased CIMT is significantly modulated by demographics as well as lifestyle-related risk factors including smoking and physical inactivity in Korean office workers.

Background: The association between physical activity (PA) and all-cause mortality may be modulated by potential confounders. Aim: To investigate the association between weekly PA and all-cause mortality in a population-based prospective study. Subjects and methods: The study sample included Korean older adults aged 60 years and older who participated in baseline assessments (n = 15 416) in 2008 and completed follow-up visits in 2011 (n = 14,976). Primary outcome was 3-year all-cause mortality. Results: Compared with sufficiently active individuals (with Hazard Ratio (HR) = 1), completely inactive and insufficiently active individuals had a significantly higher risk of all-cause mortality (HR = 2.086, 95% CI = 1.639–2.655, p < 0.00 and HR = 1.644, 95% CI = 1.013–2.668, p = 0.044, respectively), even after adjustments for age and sex, health-related behaviour factors (i.e. smoking, alcohol intake and nutritional risk), cognitive impairment and components of frailty phenotype (i.e. involuntary weight loss, exhaustion and slowness). In addition, the inverse association between PA and all-cause mortality is differently modulated by potential confounders, including age, sex, smoking, depressive symptoms, cognitive impairment and involuntary weight loss. Conclusion: PA was inversely and independently associated with all-cause mortality in Korean older adults.

Introduction: This study aimed to investigate the association of smoking and physical activity (PA) with metabolic syndrome (MetS) in adult men in Korea.Methods: This study analyzed data of 7,229 adult men aged 19–64 years obtained from the 2014–2021 Korea National Health and Nutrition Examination Survey (KNHANES). Information on smoking habits was obtained using KNHANES data, while that on total PA (TPA), leisure-time PA (LTPA), and occupational PA (OPA) was collected using the Global Physical Activity Questionnaire. Smoking status was classified into non-smokers and smokers, and PA was categorized into three groups (total, leisure time, and occupational) according to the time spent engaging in moderate or high-intensity PA areas. The diagnosis of MetS was based on the Adult Treatment Program III of the National Cholesterol Education Program and Koreans’ waist circumference criteria.Results: Logistic regression revealed that the risk of MetS was significantly lower in non-smokers than in smokers, even after adjusting for all covariates. The risk of MetS was significantly lower in individuals who engaged in at least 150 min of moderate- and high-intensity TPA or LTPA per week than in those who did not engage in PA. Furthermore, smokers who engaged in at least 150 min of moderate- to high-intensity TPA and LTPA per week had a significantly lower risk of MetS than those who did not engage in PA. Meanwhile, OPA was not associated with MetS.Conclusion: The findings suggest that engaging in moderate- to high-intensity TPA or LTPA for at least 150 min per week attenuates the risk of MetS caused by smoking.

Background. Little is known regarding the effects of socioeconomic status (SES) and frailty on mortality in Korea. Objective. This study investigated the combined impact of low SES and frailty on all-cause mortality in Korean older adults. Methods. Study sample at baseline comprised 7,960 community-dwelling adults (56.8% women) aged 65 years and older. The Cox proportional hazards model was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) of low SES and frailty for all-cause mortality. Results. Overall, low SES plus frailty resulted in an increased risk of all-cause mortality (HR = 1.56, 95% CI = 1.09–2.23, P=0.015) even after adjustments for all the measured covariates, as compared with high SES plus nonfrailty (HR = 1). Among older adults aged 65–75 years, the increased mortality risk of either low SES plus nonfrailty (HR = 1.37, 95% CI = 1.02–1.84, P=0.038) or high SES plus frailty (HR = 2.09, 95% CI = 1.12–3.91, P=0.021) remained significant even after adjustments for all the covariates, as compared with high SES plus nonfrailty (HR = 1). Conclusion. The current findings suggest that either low SES or frailty is significantly associated with increased all-cause mortality in Korean older adults.

OBJECTIVES: This study investigated whether the lower extremity muscle mass index (LMI) mediates the relationship between general obesity, central obesity, and knee osteoarthritis in middle-aged and elderly women in Korea.METHODS: Data of 2,843 women aged ≥50 years were collected from the Korean National Health and Nutrition Examination Survey conducted between 2009 and 2011. General obesity and central obesity were evaluated based on body mass index (BMI) and waist circumference (WC), calculated through anthropometric measurements and body composition assessments. LMI was calculated by dividing the muscle mass in both legs—measured using the dual-energy X-ray absorptiometry—by body weight. Knee osteoarthritis was defined as a Kellgren-Lawrence scale (KL) grade of ≥2 as assessed through radiographic images.RESULTS: Knee osteoarthritis prevalence, indicated by KL grades, was significantly higher in the general obesity and central obesity groups compared to the normal group, and conversely, lower with varying LMI levels. Using mediation analysis with bootstrapping and adjusting for covariates, we found that LMI mediated the relationship between BMI and KL (β, 0.005; 95% confidence interval [CI], 0.000 to 0.010) and WC and KL grade (β, 0.002; 95% CI, 0.001 to 0.003), explaining 4.8% and 6.7% of the total effects of BMI and WC on KL grade, respectively.CONCLUSIONS: The study suggested that LMI partially mediates the link between general obesity and/or central obesity and knee osteoarthritis, proposing that a higher proportion of lower limb muscle mass relative to body weight can alleviate the increased risk of knee osteoarthritis caused by obesity.