Association between visceral obesity and sarcopenia and vitamin D deficiency in older Koreans: The Ansan geriatric study

OBJECTIVES: To investigate whether vitamin D levels are independently associated with visceral obesity, sarcopenia, or sarcopenic obesity. DESIGN: Cross-sectional. SETTING: Population-based sample of elderly adults living in Ansan, Korea. PARTICIPANTS: Two hundred sixteen men and 268 women aged 65 and older. MEASUREMENTS: Serum 25-hydroxyvitamin D (25(OH)D) levels, visceral fat area (VFA) according to abdominal computed tomography scanning, and body composition (body fat percentage, appendicular skeletal muscle mass (ASM)) using dual-energy X-ray absorptiometry. Visceral obesity was defined as VFA of 100 cm ² or greater and sarcopenia as ASM/height ² more than 1 standard deviation (SD) below the sex-specific mean of a young reference group. RESULTS: The adjusted 25(OH)D level for men was negatively associated with systolic blood pressure, VFA, and body fat percentage but positively associated with ASM. In women, waist circumference, triglyceride levels, and VFA were negatively correlated with 25(OH)D levels. In the joint regression model, VFA and ASM were independently associated with 25(OH)D levels (β = -0.078, P = .01 and b = 0.087, P = .02, respectively) per 1SD difference in VFA and ASM in men but not women. When participants were categorized according to four visceral obesity and sarcopenia categories, adjusted mean 25(OH)D level was lower in men with visceral obesity than in men without but was not affected by the presence or absence of sarcopenia. CONCLUSION: Greater visceral fat and lower muscle mass were associated with lower 25(OH)D levels in elderly Korean men, suggesting that screening for vitamin D deficiency may be appropriate in older Koreans with visceral obesity or sarcopenia. Sarcopenic obesity as defined according to prespecified criteria did not have an additive association with 25(OH)D levels.