Vitamin D Metabolites, Body Composition, and Nutritional Status in Patients in the Long Term After Kidney Transplantation.

BACKGROUND The aim of the study was to assess the relationship between body composition and nutritional status with the level of vitamin D metabolites 25(OH)D and 1,25(OH)2D in patients in the long term after kidney transplantation (KTx). MATERIAL AND METHODS During 2 routine outpatient visits in summer and winter, the anthropometric and body composition measurements and laboratory data from 105 stable KTx patients were taken and the annual averages were analyzed. RESULTS Data of 64 patients (26 F, 38 M) at mean age 49.3±12.2 years and 5.6±2.7 years after KTx with mean BMI 26.9 kg/m² were included for final analysis. Mean annual 25(OH)D concentration was 18.76±6.32 ng/dl and 1,25(OH)2D 86.65±18.0 pg/ml. A reverse relationship between 25(OH)D level and fat tissue index was observed (r=-0.26; P=0.039). 25(OH)D level increased together with body cell mass (r=0.30, P=0.017) and lean tissue mass values (r=0.30, P=0.015). The body weight and BMI were not associated with 25(OH)D or 1,25(OH)2D level. A reverse relationship was found between: 25(OH)D and total cholesterol (r=-0.31, P=0.012) and LDL level (r=-0.25, P=0.049), and between 1,25(OH)2D and HDL level (r=-0.25, P=0.046). No significant correlations between biochemical nutritional parameters, graft function and 25(OH)D or 1,25(OH)2D were noted. CONCLUSIONS Body composition is one of the factors affecting the vitamin D status in KTx patients. Fat tissue index is a negative predictor of 25(OH)D level in patients in the long term after KTx. A low level of 25(OH)D predisposes to lipids disturbances in KTx recipients.