The evaluation of relationship between vitamin d and muscle power by micro manual muscle tester in end-stage renal disease patients

Abstract EN

Muscle force of lower limb is a major factor for sustaining physical activity.

Decreased muscle force can limit physical activity, which can increase mortality and morbidity in end-stage renal disease (ESRD) patients.

Muscle force depends on several factors.

One of the most important factors is 25-hydroxy vitamin D (25-OHD) that affects muscle function in both uremic and non-uremic patients.

The aim of this study was to investigate the association between serum level of 25-OHD and muscle force of lower extremities in hemodialysis patients estimated by a Micro Manual Muscle Tester, a digital instrument that measures muscle force in kilograms.

This cross-sectional study was performed on 135 adult patients, 69 male (51 %) and 66 female (69 %) (mean : 1.4, standard deviation : 0.5), undergoing hemodialysis.

Standard biochemistry parameters were measured before hemodialysis, including 25-OHD, calcium, albumin, parathyroid hormone and C-reactive protein (CRP).

Based on the result of serum level of 25-OHD, patients were classified into the following three groups : 85 patients (63 %) were 25-OHD deficient (25-OHD < 30), 43 patients (32 %) had a normal level of 25-OHD (30-70) and seven patients (5 %) had a toxic level of 25-OHD (> 70) (mean : 1.42, standard deviation : 0.59).

Also, based on the result of muscle force, patients were classified into the following three groups : 84 / 133 patients (62 %) had weak muscle force (< 5 kg), 46 / 133 patients (34 %) had normal muscle force (5-10 kg) and three patients (21 %) had strong muscle force (> 10 kg) (mean : 1.39, standard deviation : 0.53).

There was a significant relation between 25-OHD level and muscle force (P = 0.02), between age and muscle force (P = 0.002) and between gender and muscle force (P < 0.001).

In our opinion, 25-OHD can be a useful drug in ESRD patients to improve muscle force and physical activity.