Associations of serum 25-hydroxyvitamin D with metabolic syndrome and its components in elderly men and women: the Korean Urban Rural Elderly cohort study

Background; Many studies have investigated the association between vitamin D and metabolic syndrome (MetS). However, few studies have investigated the association stratified by sex in the elderly. Therefore, we aimed to evaluate the association between vitamin D, MetS, and its components in Korean elderly men and women. Methods: A total of 987 men and 1949 women aged >= 65 years were recruited through Korean Urban Rural Elderly cohort study. Serum 25-hydroxyvitamin D (25(OH)D) levels were categorized into 4 quartiles and all data were analyzed separately by sex. MetS was defined by the revised criteria of the National Cholesterol Education Program Adult Treatment Panel III. Results: The participants in the lowest quartile of serum 25(OH)D showed a significant increase in the prevalence of high waist circumference, elevated triglyceride level, and low high-density lipoprotein cholesterol level, as well as MetS itself, in both men and women in a univariate analysis. After adjusting for potential confounders including age, smoking status, drinking status, exercise status, region of residence, seasonality, and parathyroid hormone level, the lowest 25(OH)D quartile group was associated with a higher risk of MetS (odds ratio [OR] 2.25, 95% confidence interval [CI] 1.48-3.43 in men and OR 1.65, 95% CI 1.27-2.16 in women) compared to the highest 25(OH)D quartile group as the reference group. However, no significant association was found between serum 25(OH)D levels and the prevalence of MetS components including hyperglycemia or hypertension in both men and women. Conclusions: Low 25(OH)D levels were associated with increased odds of MetS; in particular, they were associated with MetS components of high waist circumference, hypertriglyceridemia, and low high-density lipoprotein-cholesterol, after adjusting for age, smoking, alcohol, exercise, region of residency, and seasonality, in men and women over 65 years old.