Maria Inês Barreto Silva1, Vanessa Vicente de Souza Cavalieri2, Carla Cavalheiro da Silva Lemos3, Márcia Regina Simas Torres Klein4, Rachel Bregman3. 1. Department of Applied Nutrition, Nutrition Institute, Rio de Janeiro State University, Rio de Janeiro, Brazil. Electronic address: Mibsab@terra.com.br. 2. Postgraduation Program in Medical Science, Rio de Janeiro State University, Rio de Janeiro, Brazil. 3. Nephrology Division, Rio de Janeiro State University, Rio de Janeiro, Brazil. 4. Department of Applied Nutrition, Nutrition Institute, Rio de Janeiro State University, Rio de Janeiro, Brazil.
Abstract
OBJECTIVES: The association of vitamin D status with high body adiposity is poorly investigated in the chronic kidney disease (CKD) population. The aim of the present study was to describe vitamin D status and to identify body adiposity predictors of vitamin D deficiency, in a nondialyzed CKD population inhabiting a tropical city. METHODS: This cross-sectional study included patients with CKD, defined as estimated glomerular filtration rate (eGFR) <60 mL/min, regularly treated by an interdisciplinary team in an outpatient university clinic, set in a Brazilian city (latitude: 22°54'S; 43°12'W). Adiposity parameters analyzed were body mass index (BMI), total body adiposity (dual-energy x-ray absorptiometry [DXA] and body adiposity index [BAI]), and central body adiposity (DXA-trunk fat and waist-to-height ratio [WHtR]). Laboratory parameters included serum concentrations of 25-hydroxyvitamin D, phosphate, parathyroid hormone, and insulin (insulin resistance [IR evaluation: homeostasis model assessment; HOMA]). RESULTS: We studied 244 patients (54.9% men; n = 134) with median eGFR = 29.1 mL/min and BMI 26.1 kg/m2, comprising 58.2% (n = 142) with overweight/obesity. The vitamin D status was sufficient (≥30 ng/dL) in 43%, insufficient (20-30 ng/dL) in 37%, and deficient (<20 ng/dL) in 20%. Total body adiposity was the independent predictor of vitamin D deficiency (DXA: odds ratio [OR], 2.3; 95% confidence interval [CI], 1.1-5; P = 0.03; BAI: OR, 1.9; 95% CI, 1-3.8; P = 0.02), whereas BMI, DXA-trunk fat, and WHtR showed no correlation. Higher serum phosphorus and hyperparathyroidism were related (P < 0.05) to vitamin D deficiency. IR was not independently associated with 25-hydroxyvitamin D concentration. CONCLUSIONS: Just under half of the CKD population presented sufficient concentration of 25-hydroxyvitamin D. Total body adiposity, independent of age and eGFR, regardless if evaluated by DXA or BAI, was the predictor of vitamin D deficiency, which in turn was associated with higher serum phosphorus and hyperparathyroidism, but not with IR. Copyright Â
OBJECTIVES: The association of vitamin D status with high body adiposity is poorly investigated in the chronic kidney disease (CKD) population. The aim of the present study was to describe vitamin D status and to identify body adiposity predictors of vitamin D deficiency, in a nondialyzed CKD population inhabiting a tropical city. METHODS: This cross-sectional study included patients with CKD, defined as estimated glomerular filtration rate (eGFR) <60 mL/min, regularly treated by an interdisciplinary team in an outpatient university clinic, set in a Brazilian city (latitude: 22°54'S; 43°12'W). Adiposity parameters analyzed were body mass index (BMI), total body adiposity (dual-energy x-ray absorptiometry [DXA] and body adiposity index [BAI]), and central body adiposity (DXA-trunk fat and waist-to-height ratio [WHtR]). Laboratory parameters included serum concentrations of 25-hydroxyvitamin D, phosphate, parathyroid hormone, and insulin (insulin resistance [IR evaluation: homeostasis model assessment; HOMA]). RESULTS: We studied 244 patients (54.9% men; n = 134) with median eGFR = 29.1 mL/min and BMI 26.1 kg/m2, comprising 58.2% (n = 142) with overweight/obesity. The vitamin D status was sufficient (≥30 ng/dL) in 43%, insufficient (20-30 ng/dL) in 37%, and deficient (<20 ng/dL) in 20%. Total body adiposity was the independent predictor of vitamin D deficiency (DXA: odds ratio [OR], 2.3; 95% confidence interval [CI], 1.1-5; P = 0.03; BAI: OR, 1.9; 95% CI, 1-3.8; P = 0.02), whereas BMI, DXA-trunk fat, and WHtR showed no correlation. Higher serum phosphorus and hyperparathyroidism were related (P < 0.05) to vitamin D deficiency. IR was not independently associated with 25-hydroxyvitamin D concentration. CONCLUSIONS: Just under half of the CKD population presented sufficient concentration of 25-hydroxyvitamin D. Total body adiposity, independent of age and eGFR, regardless if evaluated by DXA or BAI, was the predictor of vitamin D deficiency, which in turn was associated with higher serum phosphorus and hyperparathyroidism, but not with IR. Copyright Â