The Effect of Active Vitamin D Administration on Muscle Mass in Hemodialysis Patients

Muscle wasting is common and insidious in end-stage renal disease (ESRD). Loss of muscle quantity and quality reduces quality of life and increases mortality in ESRD patients. Additionally, secondary hyperparathyroidism (SHPT) causes muscle atrophy. Meanwhile, vitamin D, which is used for SHPT treatment, plays an essential role in muscle growth. We prospectively investigated the effect of active vitamin D administration on muscle mass. We measured muscle mass based on bioelectrical impedance analysis in 68 hemodialysis patients. Patients were divided into a control group (without active vitamin D administration) and a VitD group (with active vitamin D administration). We compared muscle mass at the beginning of treatment and 1 year later. We also investigated health-related quality of life (HR-QOL) using the Medical Outcome Study Short Form-36 (SF-36). The VitD group experienced a significant increase in the amount of change in total muscle mass and muscle mass percentage in men (p = 0.025) but not in women (p = 0.945). By multivariable logistic regression analysis, active vitamin D administration was independently associated with increased muscle mass percentage in men only. In the SF-36, the physical functioning (PF) scores were significantly decreased at the end of the study in the patients without active vitamin D treatment, especially in women. Our results suggested that active vitamin D treatment was associated with increased muscle mass in men, and it might have a favorable effect on maintaining PF in HR-QOL in hemodialysis patients.