Relationship between physical activity and depressive symptoms in older Korean adults: moderation analysis of muscular strength.

BACKGROUND: This population-based cross-sectional study examined the associations between physical activity (PA) and lower body muscle strength (LBMS) with late-life depression in a representative sample of older Korean adults aged 65 years and older. METHODS: The data used in the current study (n = 10,097/60% women) were extracted from the 2020 Korea Longitudinal Study on Aging, which is a nationwide population-based survey conducted in Korea. Depressive symptoms were assessed with the Geriatric Depression Scale Short-Form. PA and LBMS were evaluated with a self-reported questionnaire and the 5 times sit-to-stand test, respectively. Covariates include age, gender, body mass index, education level, smoking status, alcohol intake, and comorbidity. RESULTS: Insufficient PA had higher odds of depression (odds ratio [OR] = 1.201, 95% confidence interval [CI] = 1.035-1.393, p = 0.016), even after adjustments for all covariates, compared to sufficient PA. Poor LBMS had higher odds of depression (OR = 2.173, 95% CI = 1.821-2.593, p < 0.001), even after adjustments for all covariates, compared to good LBMS. Particularly, a significant moderation effect of LBMS on the relationship between PA and depressive symptoms was observed (ß = 0.3514 and 95% CI = 0.1294 ~ 0.5733, p < 0.001). Individuals with poor LBMS had a greater odd of depression associated with physical inactivity compared to their counterparts with good LBMS. CONCLUSIONS: The results of this study support the importance of promoting muscular strength through regular exercise as a preventive strategy against late-life depression in Korean adults.

A Non-Randomized Combined Program of Walking and Low-Load Resistance Exercise Improves Cognitive Function and Cardiometabolic Risk Factors in Community-Dwelling Elderly Women.

Background: This study examines whether changes in cardiometabolic risk factors, functional fitness, and depressive symptoms following a six-month exercise intervention were associated with cognitive function in Korean women aged 65 years and older. Methods: A non-randomized study design was used to compare post-intervention changes in measured variables between control (n = 30) and exercise (n = 30) groups. The exercise intervention consisted of three days of low-load resistance exercise and two days of walking. Cognitive function and depressive symptoms were assessed with the Korean version of the Mini−Mental State Examination and the Korean version of the Geriatric Depression Scale, respectively. Functional fitness was measured using a senior fitness test battery. Results: The exercise group showed a significant improvement in cognitive function (p < 0.001) in conjunction with significant decreases in blood glucose (p = 0.052), triglycerides (p = 0.011), insulin (p = 0.002), tumor necrosis factor-α (p = 0.043), and depressive symptoms (p = 0.006) and an increase in interleukin-10 (p = 0.037), compared with the control group. Multivariate stepwise regression showed that changes in depressive symptoms (p < 0.001), insulin resistance (p < 0.001), and upper body muscle strength (p = 0.003) were positively associated with cognitive function. Conclusion: A six-month exercise intervention consisting of walking and low-load/high-repetition elastic band resistance exercise has the potential to improve cognitive function, as well as physical function and cardiometabolic risk factors, and to decrease depressive symptoms in older women.

Muscle Strength Moderates the Relationship between Nutritional Health Risk and Depression in Korean Older Adults.

Background: Little is known about the relationships between muscle strength and nutritional health risk with late-in-life depression. This study aimed to investigate the moderating effect of lower-extremity muscle strength on the relationship between nutritional health risk and depression in Korean older adults. Methods: Data obtained from 5949 women and 3971 men aged ≥ 65 years in the 2020 Korea Longitudinal Study on Aging were used in this study. Exposures included lower-extremity muscle strength and nutritional health risk. Lower-extremity muscle strength was measured with a modified sit-to-stand test. The nutritional health risk was assessed using a screening tool. Depression was defined as a score ≥ 8 points on the Geriatric Depression Scale (GDS). Results: Logistic regression analyses showed that depression was positively associated with nutritional health risk (p < 0.001) and inversely associated with lower-extremity muscle strength (p < 0.001). A moderation analysis with Andrew Hayes' PROCESS macro showed a significant moderating effect of lower-extremity muscle strength (ß = −0.119; 95% confidence interval, −0.172 to −0.066; p < 0.001) on the relationship between nutritional health risk and depression; the weaker was the muscle strength, the steeper was the slope of the GDS score for nutritional health risk. Conclusions: The current findings suggest the need for an intervention targeting both high nutritional risk and weak muscle strength as a therapeutic strategy against depression in Korean older adults.

Eating Speed, Physical Activity, and Cardiorespiratory Fitness Are Independent Predictors of Metabolic Syndrome in Korean University Students.

BACKGROUND: Little is known regarding the role of eating quickly, physical inactivity, and poor cardiorespiratory fitness (CRF) in assessing the onset of metabolic syndrome (Mets) in Korean young adults. OBJECTIVES: This study examined the association between the three risk factors and Mets in 1891 Korean university students (30% female) aged 18-29 years. METHODS: Eating speed (slow vs. fast) and physical activity (active vs. inactive) were assessed with a standardized questionnaire. Maximal oxygen uptake as an indicator of CRF was assessed with graded exercise testing. Components of Mets were waist circumference, systolic and diastolic blood pressures, fasting blood glucose (FBG), triglycerides (TG), and high-density lipoprotein cholesterol (HDLC). RESULTS: All the three exposures were positively associated with abdominal obesity, elevated blood pressures, elevated FBG, elevated TG, and decreased HDLC. Logistic regression analysis showed that the odds ratio (OR) of Mets was incremental in the order of physical inactivity (odds ratio, OR = 1.666; 95% confidence interval, CI = 1.024-2.708; p = 0.040), fast eating (OR = 1.687; 95% CI = 1.094-2.601; p = 0.018), and poor CRF (OR = 5.378; 95% CI = 3.475-8.325; p < 0.001). CONCLUSIONS: The current findings suggest that a multifaceted intervention targeting at promotion of physical activity and CRF in concert with healthy eating behaviors should be implemented as a preventive strategy against Mets in Korean university students.

The Relationship of Lifestyle Risk Factors and Depression in Korean Adults: A Moderating Effect of Overall Nutritional Adequacy.

BACKGROUND: Little is known regarding the role of nutrition in determining the associations between lifestyle risk factors and depression. OBJECTIVES: This study examined whether or not nutritional adequacy modulates the relationship between depression and lifestyle risk factors in Korean adults aged 18-65 years (n = 7446). METHODS: Data were obtained from the 2016 and 2018 Korea National Health and Examination Survey. Depression, smoking, at-risk alcohol consumption, physical inactivity, sleep deprivation, and mean adequacy ratio (MAR) were assessed. RESULTS: Individuals with two (OR = 1.960, p < 0.001), three (OR = 4.237, p < 0.001), or four (OR = 5.312, p < 0.001) risk factors had a significantly higher risk of depression compared to individuals with one or zero risk factor. In contrast, individuals with moderate MAR (OR = 0.607, p < 0.001) and high (OR = 0.698, p < 0.001) MAR had a lower depression risk compared to individuals with low MAR. Moderation analysis showed a moderating effect of MAR (coefficient = -0.220, p = 0.007) on the relationship between risk factors and depression. CONCLUSIONS: The current findings suggest that overall nutritional adequacy plays a modulating role in determining the relationship between depression and lifestyle risk factors in Korean adults.

Predictors of Changes in Cognitive Function in Older Korean Adults: The 2006-2018 Korean Longitudinal Study of Aging.

Cognitive decline with normal aging varies widely among individuals. This study aimed to investigate predictors of longitudinal changes in cognitive function in community-dwelling Korean adults aged 65 years and older. Data from 727 older adults who participated in the Korean Longitudinal Study of Aging (KLoSA) survey from 2006 (baseline) until 2018 (seventh wave) were used. Cognitive performance was assessed with the Korean Mini-Mental State Examination. The participants were retrospectively classified into normal cognition, mild cognitive impairment, and moderate/severe cognitive impairment. Education, income, religion, living area, alcohol intake, smoking, physical activity, handgrip strength, functional dependency, depression, comorbidity, medications, fall experience, and unintentional weight loss were included as covariates. A linear mixed regression analysis showed that a steeper decline in cognitive function over time was significantly associated with parameters of poor socio-economic status, health conditions, and unhealthy behaviors. Individuals with mild cognitive impairment or moderate/severe cognitive impairment were likely to have steeper cognitive declines compared with individuals with normal cognition. The current findings of the study showed that age-related cognitive decline was multifactorial in older Korean adults.

A Long-Term Exercise Intervention Reduces Depressive Symptoms in Older Korean Women.

Despite its prevalence and significance, late life depression is underrecognized and undertreated. This study aimed to investigate the effect of a long-term exercise intervention on depressive symptoms in older Korean women. Thirty older women were assigned to exercise (n = 15, age of 80.8 ± 3.8 years) or control group (n = 15, age of 78.6 ± 3.2 years). The exercise group underwent a resistance exercise plus walking two times weekly on nonconsecutive days for 6 months. Post-intervention change in depressive symptoms was regarded as the primary outcome. Secondary outcomes included changes in body composition and physical performance. Repeated measures analysis of variance showed significant group by time interactions for depressive symptoms (F(1,23) = 37.540, p < 0.001), percent body fat (F(1,23) = 6.122, p = 0.021), lean body mass (F(1,23) = 5.662, p = 0.026), waist circumference (F(1,23) = 4.330, p = 0.049), handgrip strength (F(1,23) = 10.114, p = 0.005), 6-min walking (F(1,23) = 28.988, p < 0.001), and 2.44-m Up & Go (F(1,23) = 28.714, p < 0.001). The current findings support regular exercise as a therapeutic strategy to promote overall and mental health in older Korean women with depressive symptoms.

Handgrip strength, depression, and all-cause mortality in Korean older adults.

BACKGROUND: Decreased muscle strength and/or depression with aging are emerging as important public health concerns in both developed and developing countries. This study investigated the effects of low handgrip strength (HGS) and depression on the risk of all-cause mortality in Korean older adults. METHODS: Data from 13,901 Korean adults (57% women) who participated in the 2008 baseline survey and completed the 2011 follow-up assessments were used. RESULTS: In total, the current findings showed that individuals with depression only and individuals with low HGS plus depression had significantly higher risks of all-cause mortality (hazard ratio (HR) = 1.366, 95% confidence interval (CI) = 1.033-1.807, p = 0.029 and HR = 1.961, 95% CI = 1.409-2.736, p < 0.001, respectively) even after adjustments for all the measured covariates, compared with individuals with high HGS plus no depression (HR = 1). Gender-stratified analysis showed that men with depression only and men with depression plus low HGS had significantly higher risks of all-cause mortality (HR = 1.376, 95% CI =1.029-1.841, p = 0.031 and HR = 1.861, 95% CI = 1.306-2.651, p = 0.001, respectively) even after adjustments for all the measured covariates, compared with individuals with no depression plus high HGS (HR = 1). In women, however, the joint effect of depression and low HGS only remained significant at borderline (HR = 2.603, 95% CI = 0.981-6.908, p = 0.055) when adjusted for all the confounders. CONCLUSION: The current finding suggested that depression and low HGS were significantly and synergistically associated with the increased risk of premature death from all causes in the Korean geriatric population.

Sarcopenia Is Associated with Cognitive Impairment and Depression in Elderly Korean Women.

BACKGROUND: Sarcopenia has been implicated in the increased risk for cognitive impairment and depression associated with aging. In this cross-sectional study, we investigated the relationship of sarcopenia with cognitive impairment (MCI) and depression in a sample of 201 community-dwelling Korean women (mean age of 74.0±6.8 yr) between 2014 and 2015. METHODS: The Korean version of mini-mental state examination and the center for epidemiologic studies depression scale was used to assess cognitive performance and depression, respectively. Grp strength was measured with a dynamometer. Demographics, body composition, education, alcohol consumption, and history of cardiovascular diseases were assessed as covariates. RESULTS: Odds ratio (OR) and 95% confidence interval (95% CI) of MCI and depression were calculated according to sarcopenia status. Compared to non-sarcopenic, pre-sarcopenic and sarcopenic women had the ORs of 2.160 (95% CI of 0.840 - 5.554, P=0.030) and of 5.493 (95% CI of 1.854 - 16.270, P=0.002) for MCI. The OR of pre-sarcopenia for MCI remained significant (P=0.030) even after adjustments for age, body mass index (BMI), lean body mass, and education, while the OR of sarcopenia for MCI was no longer significant (P=0.084) when adjusted for the covariates. Compared to non-sarcopenic, pre-sarcopenic and sarcopenic women had the ORs of 3.750 (95% CI of 1.137 - 12.370, P=0.030) and of 4.687 (95% CI of 1.127-19.505, P=0.034) for depression. The ORs of pre-sarcopenia and sarcopenia for depression remained statistically significant (P=0.020 and P=0.042, respectively) even after adjusted for the covariates. CONCLUSION: Sarcopenia was significantly associated with MCI and depression in otherwise healthy community dwelling elderly Korean women.

Depression mediates the association between physical inactivity and cognitive impairment in Korean older adults.

BACKGROUND: This study investigated the association between physical activity and cognitive impairment in older adults. METHODS: Data from 10245 Korean adults (4428 men and 5817 women) who participated in the 2008 baseline survey of the living profiles of older people survey were used for this analysis. Compared with low PA men, moderate PA men only had significantly lower odds-ratio (OR) and 95% confidence interval (95% CI) (OR=0.795, 95% CI: 0.654~0.965, P=0.021) for having cognitive impairment even after adjusting for measured covariates, which was no longer significant when additionally adjusted for depressive symptoms (OR=0.862, 95% CI: 0.707~1.051, P=0.143). RESULTS: Compared with low PA women, moderate- and high PA women had significantly lower risks of cognitive impairment (OR=0.830, 95% CI: 0.712~0.969, P=0.018 and OR=0.784, 95% CI: 0.651~0.943, P=0.010, respectively) even after adjusted for the measured covariates, which was no longer significant when additionally adjusted for depressive symptoms (OR=0.897, 95% CI: 0.776~1.049, P=0.173 and OR=0.919, 95% CI: 0.761~1.111, P=0.385, respectively). CONCLUSIONS: These findings suggest that depression mediates the inverse relationship between physical activity and cognitive decline among older adults.

Physical inactivity and cognitive impairment in Korean older adults: gender differences in potential covariates.

BACKGROUND: Physical inactivity is one major lifestyle risk factor of mild cognitive impairment with ageing. AIM: To investigate whether or not potential covariates modulate the association between physical activity (PA) and cognitive impairment in older adults. SUBJECTS AND METHODS: Data from 10 245 Korean older adults (5817 women) were used. RESULTS: High PA older adults were younger and longer educated and had lower comorbidity and depression than low PA older adults. Compared with low PA men, moderate PA men only had a significantly lower odds-ratio (OR) and 95% confidence interval (95% CI) (OR = 0.795, 95% CI = 0.654 ∼ 0.965, p = 0.021) for having cognitive impairment, even after adjusting for measured covariates, which was no longer significant when additionally adjusted for comorbidity (OR = 0.862, 95% CI = 0.707 ∼ 1.051, p = 0.143). Compared with low PA women, moderate and high PA women had significantly lower risks of cognitive impairment (OR = 0.830, 95% CI = 0.712 ∼ 0.969, p = 0.018 and OR = 0.784, 95% CI = 0.651 ∼ 0.943, p = 0.010, respectively), even after adjusting for the measured covariates including comorbidity, which was no longer significant when additionally adjusted for depression (OR = 0.897, 95% CI = 0.776 ∼ 1.049, p = 0.173 and OR = 0.919, 95% CI = 0.761 ∼ 1.111, p = 0.385, respectively). CONCLUSION: These findings suggest that gender differences in the covariates modulate the relationship between physical activity and cognitive decline in older Korean adults.

Insulin Resistance and Its Association with Metabolic Syndrome in Korean Children.

BACKGROUND: This study investigated the association between insulin resistance (IR) and metabolic syndrome (MetS) in children. METHODS: A cross-sectional study involving 1036 healthy children aged between 7 and 13 years was conducted. Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated as an index of IR. Participants were classified according to the HOMA-IR quartiles. RESULTS: Incremental, linear trends were found in age (p < 0.001), body mass index (BMI) (p < 0.001), body fat (p < 0.001), waist circumference (p < 0.001), resting blood pressures (BP) (p < 0.001), triglycerides (TG) (p < 0.001), total cholesterol (TC) (p < 0.001), high density lipoprotein-cholesterol (HDL-C) (p < 0.001), FBG (p < 0.001), and insulin (<0.001) according to incremental HOMA-IR categories (from the 1st to 4th quartile). Compared with children in the 1st HOMA-IR quartile, children in the 4th HOMA-IR quartile had significantly higher odd ratios (ORs) of abnormalities in systolic (p = 0.051) and diastolic BP (p = 0.005), FBG (p < 0.001), TG (p < 0.001), TC (p = 0.016), and HDL-C (p = 0.006) even after adjustments for age, gender, BMI, and body fat percentage. Children in the 3rd HOMA-IR quartile had significant abnormalities in FBG (p < 0.001), TG (p = 0.001), and HDL-C (p = 0.010) even after adjustments for the covariates. CONCLUSION: The current findings suggest that IR is significantly associated with the clustering of MetS risk factors in children in Korea.