Phenotypes of body composition and their associations with vitamin D deficiency in hemodialysis patients

Abstract

Purpose The coexistence of excess adiposity, reduced muscle strength, and decreased muscle mass may be associated with vitamin D deficiency. This association has not been previously studied in hemodialysis (HD) patients. Aim This study aimed to identify whether sarcopenia and obesity, separately and combined, are associated with vitamin D deficiency in HD patients. Methods This cross-sectional study enrolled 237 individuals aged 18 years or older, of both sexes, on maintenance HD. Vitamin D deficiency was defined as a 25(OH)D level<20 ng/dL. Sarcopenia was defined as the presence of both diminished muscle strength and low muscle mass. Obesity was classified by body mass index (BMI)>30 kg/m2 . The participants were classified as non- sarcopenic non-obese, sarcopenic, obese without sarcopenia and sarcopenic obesity. Results A total of 237 patients were analyzed, mean age was 59 (48–68) years, and 56.9% were men. The prevalence of patients non- sarcopenic non-obese, sarcopenic, obese without sarcopenia, and sarcopenic obesity was 53.6% (n=127), 23.6% (n=56), 11.4% (n=27), and 11.4% (n=27), respectively. Vitamin D concentrations were 28.9 (19.5–39.6) ng/mL, and 26.6% (n=63) of the patients were considered deficient. In the adjusted logistic regression model, sarcopenia (OR=4.02, 95% CI: 1.700–9.486, p=0.002), obesity (OR=2.85, 95% CI: 1.008–8.040, p=0;048) and sarcopenic obesity (OR=3.05, 95% CI: 1.119–8.326, p=0.029) were significantly associated with increased odds of vitamin D deficiency. Conclusions Sarcopenia, obesity, and sarcopenic obesity were associated with an increased risk of vitamin D deficiency. Notably, patients with sarcopenia alone showed the strongest association, suggesting that muscle loss may play a major role in relation to excess weight on vitamin D status.