Search Results (502)

Background/Objectives: Vitamin D is a nutrient involved not only in bone metabolism but also in metabolic functions, and deficiency is common during adolescence. This study aimed to describe the distribution of serum 25-hydroxyvitamin D levels among Korean adolescents and to examine their associations with metabolic syndrome and its individual components. Methods: We analyzed data from the 2022–2023 Korea National Health and Nutrition Examination Survey. Adolescents aged 10–18 years with serum 25-hydroxyvitamin D measurements were included (unweighted N = 880). Weighted analyses were performed by categorizing serum 25-hydroxyvitamin D levels into quartiles. Associations between vitamin D quartiles and anthropometric and metabolic parameters were examined using complex-sample general linear models, and odds ratios for metabolic syndrome and its individual components according to vitamin D deficiency were estimated using complex-sample logistic regression models. Results: Weighted prevalence of vitamin D deficiency (<20 ng/mL) was 62.4%, higher in females than males. Higher 25(OH)D quartiles were inversely associated with obesity-related indices, including BMI, waist circumference, and waist-to-height ratio, after full adjustment (p for trend < 0.05). No significant associations were observed for blood pressure, fasting glucose, or lipid parameters. In dichotomous analyses (<20 vs. ≥20 ng/mL), vitamin D deficiency was associated with higher odds of waist circumference ≥ 90th percentile (OR 2.59), waist-to-height ratio > 0.5 (OR 2.63), and BMI ≥ 95th percentile (OR 1.89), while metabolic syndrome was not significant. Conclusions: Vitamin D appears to play an important role in metabolic health in adolescents and was particularly associated with general and central obesity. Full article

Objective: This study aims to investigate the dietary assessment and trends of preschoolers aged 3 to 5 years in Korea from 2012 to 2021 and to provide basic data for early childhood dietary education and policy development. Methods: Data from the Korea National Health and Nutrition Examination Survey (KNHANES) from 2012 to 2021 were analyzed for 2510 children in the 3–5 age group. Dietary intake was assessed using a 24 h recall. Intakes of food groups, dishes, and nutrients were calculated, and trends across years were tested using generalized linear models adjusted for gender, age, household income, energy intake, mother’s age, and mother’s education. Results: Over the tenyear period, intakes of carbohydrates, phosphorus, iron, sodium, potassium, carotene, thiamine, niacin, and vitamin C, as well as the carbohydrate energy ratio, showed significant declines. Meanwhile, protein, fat, retinol, and riboflavin increased, as did the protein and fat energy ratios. Fruit intake decreased by approximately 42 g among food group intakes. Analysis of foods contributing to total food intake revealed that milk, white rice, apples, and eggs consistently accounted for a high proportion of total intake in all survey years. Average calcium intake was approximately 100 mg below the estimated average requirement. Conclusions: The results of this study showed that preschoolers exhibit insufficient intake of certain nutrients, such as calcium, and a decrease in fruit intake. Interventions are needed to establish regular meal patterns, promote plant food intake such as fruit, and improve calcium intake. These results provide valuable evidence for designing dietary education programs and dietary guidelines tailored to early childhood. Full article

Aims: Low-carbohydrate diets (LCDs) are associated with metabolic benefits, but their long-term effects remain uncertain, particularly in Asian populations with traditionally high carbohydrate intake. This study examined LCD patterns and their association with metabolic syndrome (MetS) in Korean adults using nationally representative data from the 2022–2023 Korea National Health and Nutrition Examination Survey (KNHANES). Methods: Among 9617 adults aged ≥20 years with complete dietary and health data, LCD score was calculated from the percentage of energy derived from carbohydrates (reverse-scored), fats, and proteins, and participants were categorized into high-carbohydrate, moderate-carbohydrate, and low-carbohydrate groups. MetS was defined using an Adult Treatment Panel III and Korean criteria. Survey-weighted logistic regression was applied to assess associations between LCD score and MetS across sequentially adjusted models. Results: MetS prevalence differed significantly across LCD decile groups (LCD1: 9.6%, LCD2: 5.8%, LCD3: 9.7%; p < 0.001). In a minimally adjusted model, LCD decile 3 was associated with higher odds of MetS (OR, 1.14; 95% CI: 1.02–1.27). However, this association was attenuated and became non-significant after further adjustment for key metabolic risk factors. Obesity, blood pressure, fasting glucose, triglycerides, and high-density lipoprotein cholesterol were all strongly associated with MetS (all p < 0.001), and income-related disparities were evident, with lower-income groups showing higher carbohydrate and lower fat and protein intakes. Conclusions: These findings suggest that LCD patterns are not independently associated with MetS once underlying metabolic factors are considered. Public health strategies in Korea would be emphasized by improving nutrient quality, promoting balanced macronutrient intake, and reducing socioeconomic inequalities in diet to mitigate metabolic risk among adults. Full article

Nonalcoholic fatty liver disease (NAFLD) is a major public health concern with a global prevalence of approximately 32%. This study examined the association between the “weekend warrior”, other leisure-time physical activity patterns, and NAFLD in Korean adults. We included 44,264 individuals from the Korea National Health and Nutrition Examination Survey (2014–2023). Physical activity was measured using the Global Physical Activity Questionnaire (GPAQ), a self-reported instrument, and physical activity patterns were classified as inactive, weekend warrior (≥150 min/week of moderate-to-vigorous physical activity [MVPA] performed in 1–2 days), and regularly active. NAFLD was identified using the Hepatic Steatosis Index with a cutoff of >36. Weighted logistic regression was used to examine the association between physical activity patterns and NAFLD. The prevalence of NAFLD was 24%. After adjustment for sociodemographic and metabolic factors, both the weekend warrior (odds ratio [OR] = 0.80, 95% confidence interval [CI]: 0.64–0.99) and regularly active (OR = 0.83, 95% CI: 0.77–0.89) groups had significantly lower odds of NAFLD compared to the inactive group. When stratified by total MVPA level, both the weekend warrior and regularly active patterns with >300 min/week of MVPA showed even lower odds of NAFLD, compared to those with 150–300 min/week of MVPA. Both regularly active and weekend warrior patterns were associated with a lower prevalence of NAFLD, suggesting that the weekend warrior pattern may represent a feasible behavioral pattern associated with lower NAFLD prevalence for individuals with time constraints. Full article

Background/Objectives: Frailty represents a critical aging-related condition, but evidence on how different sources of vitamin C relate to frailty risk remains limited. Thus, this study aimed to examine the relationship between frailty risk and sources of vitamin C intake (dietary, including fruit and vegetable (FV) vs. supplemental) among Korean adults. Method: We analyzed data from 9478 adults in the Korea National Health and Nutrition Examination Survey (KNHANES 2018–2019). Frailty was assessed using a modified Fried phenotype. A multivariable logistic regression model was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for frailty according to vitamin C intake source. Results: More than 60% of participants had inadequate FV intake. Significant associations were observed primarily in women. Increased FV intake (OR = 0.44, 95% CI = 0.264–0.731, comparing the highest intake group (fourth quartile, Q4) vs. the lowest intake group (first quartile, Q1)) for dietary vitamin C intake (OR = 0.60, 95% CI = 0.393–0.914, Q4 vs. Q1) and vitamin C intake from FV (OR = 0.54, 95% CI = 0.348–0.851, Q4 vs. Q1), was significantly associated with a lower risk of frailty. Women with inadequate FV intake had a higher risk of frailty (OR = 2.06, 95% CI = 1.34–3.16) compared to those with adequate intake, regardless of vitamin C supplement use. In contrast, vitamin C supplementation was not significantly associated with frailty risk in either men or women. Conclusion: A higher intake of FV and dietary vitamin C, but not supplemental vitamin C, was associated with a lower risk of frailty, particularly among women. These findings suggest that improving overall diet quality through increased FV consumption may be more effective for frailty prevention than relying on single-nutrient supplementation. Full article

Background: Sarcopenia and metabolic dysfunction share common physiological mechanisms, and insulin resistance has been recognized as a major contributor to muscle loss. However, the independent association between circulating fasting insulin and muscle strength remains unclear. Methods: We analyzed data from 8343 Korean adults aged ≥ 20 years who participated in the 2015 and 2019 Korea National Health and Nutrition Examination Surveys. Multivariate outliers were removed using the Mahalanobis distance, and sampling weights were applied to account for the complex survey design. Multivariable linear regression models were constructed with progressive adjustments for demographic and metabolic covariates, and stratified analyses were conducted by age, BMI category, and diabetes status. Results: Crude models showed a weak positive association between fasting insulin and handgrip strength in both sexes. However, after adjustment for age and BMI, the association became significantly inverse and remained consistent in fully adjusted models. The inverse association was most pronounced in individuals aged ≤ 65 years, with BMI < 23 kg/m², and without diabetes. Conclusions: Elevated fasting insulin levels were independently associated with lower handgrip strength in Korean adults. These findings suggest that hyperinsulinemia may reflect early metabolic changes linked to subclinical muscle weakness, warranting further longitudinal investigation. Full article

Background: The COVID-19 pandemic has substantially altered lifestyle behaviors, potentially affecting cardiovascular health. This study examined changes in lifestyle behaviors—specifically physical activity, smoking, and alcohol consumption—and cardiovascular disease (CVD) risk factors before and after the pandemic using nationally representative data from Korea. Methods: Data were obtained from the Korea National Health and Nutrition Examination Survey (KNHANES) from 2016 to 2023. Weighted analyses were conducted to ensure national representativeness. Descriptive and inferential statistics (t-tests, ANOVA, and correlation analyses) were used to compare health behaviors and CVD risk factors between pre-pandemic (2016–2019) and post-pandemic (2020–2023) periods. Results: Adherence to aerobic physical activity declined from 45.5% before the pandemic to 42.1% after the pandemic, and resistance exercise participation also decreased (p < 0.05). Average sedentary time increased from 8.1 ± 3.5 to 8.7 ± 3.4 h/day. Body mass index (BMI) increased from 23.9 ± 3.7 to 24.1 ± 3.5 kg/m², and triglyceride levels similarly increased (p < 0.05). In contrast, smoking prevalence decreased from 17.2% to 16.5%, and the average number of cigarettes smoked per day declined from 13 to 11–12. Alcohol intake per occasion also decreased significantly after the pandemic (p < 0.05). However, lipid indicators such as total cholesterol and LDL-C tended to be higher in the post-pandemic period, indicating unfavorable changes rather than improvement. Correlation analyses further showed that heavy drinking was associated with higher BMI, glucose, and triglyceride levels, whereas moderate drinking showed more favorable metabolic profiles. Conclusions: The COVID-19 pandemic exerted mixed effects on lifestyle behaviors and cardiovascular risk factors among Korean adults. While reductions in physical activity and increases in sedentary time may elevate long-term health risks, concurrent decreases in smoking and alcohol intake could have mitigated some negative outcomes. Nevertheless, adverse changes in lipid profiles—including increases in LDL-C, total cholesterol, and triglycerides—suggest that metabolic health worsened overall after the pandemic. These findings underscore the urgent need for tailored public health strategies to promote balanced lifestyle behaviors and mitigate cardiovascular risks in the post-pandemic era. Full article

Falls are a major cause of morbidity in aging populations; this study examined physical, psychological, and lifestyle correlates of falls among older Korean adults. Using 2022 KNHANES data, we conducted a cross-sectional analysis of adults aged ≥65 years (n = 612). Fall in the past year was the outcome; multivariable logistic regression and ROC analyses evaluated candidate predictors. Lower weekly working hours (<12) (OR = 3.11, 95% CI 1.23–7.88), insufficient physical activity (<150 min/week) (2.49, 1.03–5.99), reduced grip strength (<15 kg) (2.23, 1.14–4.35), low diastolic blood pressure (<69 mmHg) (2.06, 1.09–3.89), elevated LDL cholesterol (≥150 mg/dL) (3.06, 1.49–6.28), and depressive symptoms (PHQ-9 ≥ 3) (3.02, 1.52–6.00) were independently associated with higher fall odds. Age ≥ 75 years, alcohol use, anxiety (GAD-7 ≥ 3), vitamin D ≤ 3 ng/mL, and vitamin E ≤ 7 mg/L were not significant in adjusted models. Discrimination was modest across individual markers (AUCs 0.55–0.65); model fit was acceptable (Nagelkerke R² = 0.262; Hosmer–Lemeshow p = 0.318). These findings suggest that screening for low muscle strength, depressive symptoms, hypotension, and high LDL cholesterol—alongside promoting physical activity and social engagement through work—may help identify and manage fall risk in community-dwelling older adults. Causal inference is not supported due to the cross-sectional design. Full article

Background/Objectives: This study investigated the association between physical activity (PA) levels and the risk of chronic diseases in Korean adults with sleep deficiency (SD). Methods: Data were obtained from the Korea National Health and Nutrition Examination Survey (2016–2021; n = 31,338). SD was defined as less than 7 h of sleep per night. The PA levels were categorized as low, moderate, or high. Multivariable logistic regression was used to estimate odds ratios (OR) with 95% confidence intervals (CI) for various chronic diseases, adjusting for demographic and lifestyle covariates. Results: High PA levels were associated with lower odds of abdominal obesity (OR = 0.855, 95% CI = 0.782–0.934, p < 0.001), hypertension (OR = 0.787, 95% CI = 0.657–0.942, p < 0.01), diabetes mellitus (OR = 0.743, 95% CI = 0.622–0.887, p < 0.01), and metabolic syndrome (OR = 0.706, 95% CI = 0.586–0.850, p < 0.001). Moderate PA showed similar but weaker associations. Conversely, high PA levels were associated with higher odds of depression (OR = 1.474, 95% CI = 1.123–1.935, p < 0.01). Subgroup analyses indicated that the protective effects of PA were stronger among women, non-smokers, and individuals with obesity. Conclusions: Among adults with SD, moderate-to-vigorous PA is associated with a lower odds of several metabolic disorders, including abdominal obesity, diabetes, and metabolic syndrome. This highlights the importance of regular PA in maintaining metabolic health. However, a positive association between high PA and depression should warrant further investigation, as reverse causality or residual confounding may explain this association. Full article

Background/Objectives: Cardiometabolic risk clustering (CMRC), the coexistence of multiple risk factors, markedly increases the risk of cardiovascular disease and diabetes. While obesity is central, the independent roles of vitamin D status and systemic inflammation remain unclear. This study examined determinants of CMRC in middle-aged Korean adults, focusing on vitamin D and C-reactive protein (CRP). Methods: Cross-sectional data were analyzed from 2062 adults aged 40–64 years in the 2023 Korea National Health and Nutrition Examination Survey. CMRC was defined as ≥3 of abdominal obesity, hypertension, diabetes, hypertriglyceridemia, and low high-density lipoprotein cholesterol. Serum 25-hydroxyvitamin D [25(OH)D], CRP, lifestyle behaviors, and covariates were assessed. Complex-sample logistic regression identified factors associated with CMRC. Results: CMRC prevalence was 16.5%. Older age (OR = 1.04, 95% CI: 1.02–1.06), current smoking (OR = 1.76, 95% CI: 1.26–2.45), elevated CRP (1–3 mg/L: OR = 1.40, 95% CI: 1.04–1.87; ≥3 mg/L: OR = 1.63, 95% CI: 1.00–2.66), and obesity (OR = 8.29, 95% CI: 6.12–11.21) increased CMRC risk. Protective factors included male sex (OR = 0.60, 95% CI: 0.45–0.81), sufficient vitamin D (≥20 ng/mL: OR = 0.76, 95% CI: 0.58–0.99), and meeting World Health Organization physical activity guidelines (OR = 0.71, 95% CI: 0.55–0.92). Conclusions: These survey-weighted associations may help identify at-risk mid-life adults at the population level and motivate longitudinal evaluation of vitamin D deficiency and inflammation in risk assessment and targeted prevention. Full article

Background/Objectives: Ultra-processed food (UPF) consumption is increasingly implicated in metabolic diseases; however, evidence for non-alcoholic fatty liver disease (NAFLD) and potential sex differences remains limited. Thus, this study aimed to examine the relationship between UPF consumption and NAFLD stratified by sex in Korean adults. Methods: This was a cross-sectional analysis of Korean adults from the Korea National Health and Nutrition Examination Survey 2013–2021 (n = 24,587). UPF intake was quantified as the percentage of NOVA Group 4 items consumed in total daily food weight based on a 24 h recall. The participants were grouped into quartiles of UPF intake. NAFLD was defined using the hepatic steatosis index. Survey-weighted models were used to summarize the characteristics and estimated odds ratios (ORs) for NAFLD across the UPF quartiles with adjustment for factors associated with both NAFLD and dietary intake. Linear trend tests across quartiles and continuous analyses of UPF intake were performed, with sex-stratified models to assess potential effect modification. Results: NAFLD prevalence increased as UPF intake quartile increased, from 19.1% in Q1 to 24.1% in Q4. With Q1 as reference, the fully adjusted OR for Q4 was 1.24 (95% CI, 1.10–1.41, p for trend = 0.001). In the sex-stratified analyses, the association was only significant in women (Q4 vs. Q1: OR, 1.52, 95% CI, 1.28–1.81; p for trend < 0.001). When UPF intake was modeled as a continuous variable, NAFLD risk showed a modest overall increase, with a nearly flat pattern in men and a clear linear increase in women. Conclusions: Higher UPF intake is associated with a greater risk of NAFLD in Korean adults, with a more pronounced association in women. Thus, UPF consumption is a feasible modifiable target for liver health. Full article

Background: Oral health is increasingly recognized as a determinant of overall well-being, but its role in mental health remains underexplored. Chewing difficulty and tooth loss can impair nutrition, social interaction, and quality of life, thereby contributing to psychological distress. Objectives: This study examined the association between oral health indicators and anxiety among Korean adults. Methods: Data were obtained from 4746 adults aged ≥19 years who participated in the 2023 Korea National Health and Nutrition Examination Survey (KNHANES). Anxiety was assessed using the Generalized Anxiety Disorder-7 (GAD-7), a validated 7-item self-report questionnaire with responses on a 4-point Likert scale (0 = not at all to 3 = nearly every day). Anxiety severity was categorized into four levels. Severity was categorized into four levels using the GAD-7. Oral health predictors included the number of remaining teeth and self-reported chewing difficulty, along with toothache experience, toothbrushing frequency, and unmet dental care needs. Complex survey-weighted ordinal logistic regression models were applied, adjusting for sociodemographic, behavioral, and clinical covariates. Results: Overall, 15.3% of adults reported mild, 3.1% moderate, and 1.6% severe anxiety. Chewing difficulty, fewer than 20 remaining teeth, overweight status, high stress, depressive symptoms, and unmet dental care needs were significantly associated with greater anxiety severity. Conclusions: The number of remaining teeth retention and chewing function were closely related to anxiety. Preserving functional dentition and ensuring timely access to dental care may be effective public health measures to reduce the psychological burden in the general population. Full article

Background/Objectives: Dynapenia, characterized by an age-related decline in muscle strength, has recently gained attention as a major public health concern. While prior studies identified individual risk factors, little is known about how these factors cluster differently by sex. This study investigated sex-specific risk factors and their combinations associated with dynapenia among Korean middle-aged and older adults. Methods: We analyzed 22,850 participants aged ≥ 40 years from the 2014–2019 Korea National Health and Nutrition Examination Survey. Dynapenia was defined as handgrip strength < 28 kg in men and <18 kg in women. Sex-stratified multivariable logistic regression identified independent predictors, and association rule mining (ARM) detected synergistic risk factor combinations. Results: Dynapenia was more prevalent in women (13.9%) than in men (8.5%). Advancing age, physical inactivity, lack of resistance exercise, and a high incidence of diabetes and stroke were consistent risk factors in both sexes. However, ARM revealed distinct clustering patterns: behavioral factors predominated in men, whereas socioeconomic disadvantage and metabolic comorbidities were more relevant in women with dynapenia. Conclusions: These findings emphasize the need for sex-specific prevention strategies for dynapenia, promoting resistance exercise among men and addressing both inactivity and socioeconomic barriers in women. Full article

Background: Studies on the relationship between unmet healthcare needs and depression in older adults are limited in Asia. This study aimed to investigate the relationship between unmet healthcare needs and the risk of depression in older adults aged ≥65 years in Korea. Methods: This cross-sectional study used data from the Korean National Health and Nutrition Examination Survey in 2014, 2016, and 2018. Three models were constructed using a weighted multivariate logistic regression analysis to account for the complex survey design. Model 1 is adjusted for sex and age. Model 2 was further adjusted for household income, education level, marital status, and private health insurance. Model 3 was further adjusted for alcohol use, cigarette use, weekly walking activity, hypertension, dyslipidemia, and diabetes mellitus. Subgroup analyses were performed to assess the stability and robustness of the association between unmet healthcare needs and depression. Results: In total, this study included 4062 participants aged ≥65 years, with 3749 and 313 individuals in the non-depression and depression groups, respectively. In the unadjusted models, individuals with unmet healthcare needs had a greater likelihood of depression than those without unmet needs. This association remained significant across all three sequentially adjusted models. Subgroup analyses supported these findings. Conclusions: Unmet healthcare needs are significantly associated with depressive symptoms in older adults. Therefore, a multidimensional approach is required when addressing mental health issues in this population, and addressing unmet healthcare needs may be crucial for promoting mental health. Full article

Background/Objectives: Although vitamin D has been associated with sarcopenia in older adults, evidence across age groups remains limited. This study evaluated the relationship between vitamin D deficiency (VDD) and muscle health in Korean adults aged ≥19 years. Methods: Data utilized in this study were obtained from the 2022 Korea National Health and Nutrition Examination Survey IX-1. Serum 25-hydroxyvitamin D [25(OH)D] levels were analyzed in relation to appendicular skeletal muscle mass (ASM), grip strength, and sarcopenia using multivariable regression models. Results: Among 3,920 participants, 46.5% had VDD, with the highest prevalence observed in younger adults. After adjusting for age, body mass index, energy intake, and other confounding factors, serum 25(OH)D levels showed a positive association with ASM in middle-aged men (β = 0.005; p = 0.007) and with maximal handgrip strength in young men (β = 0.097; p = 0.048). Among older men, those with VDD had significantly higher odds of low muscle mass (OR = 1.82; 95% CI: 1.10–3.02) and sarcopenia (OR = 2.30; 95% CI: 1.03–5.16) than those without VDD, after adjusting for potential confounders. No significant associations were observed in women. Conclusions: These results suggest that maintaining adequate vitamin D levels may benefit muscle health in men. Further prospective or interventional studies are needed to more accurately assess the effects of vitamin D on muscle health. Full article