Characteristics of melatonin-forming disorders of the epiphysis in hemodialysis patients depending on clinical and demographic parameters

Current scientific studies' results have shown the relationship between the epiphysis functional state and the kidneys function. However, the impaired of the epiphysis melatonin-forming function (MFE) in patients with chronic kidney disease (CKD) undergoing hemodialysis (HD) is a poorly understood issue. Methods. 130 HD patients (50% of men) were examined in this study. Based on the melatonin level, the patients were allocated into 2 groups: group I included 110 HD patients with impaired MFE and group II consisted of 20 HD patients with preserved MFE. 20 healthy individuals were included in the control group. Results. The melatonin level was significantly lower in HD patients compared to the control group at daytime and night (p <0.001). MFE disorder were diagnosed in 84.6% HD patients. The group I patients had significantly higher BMI (p = 0.01), waist volume (p = 0.04), duration of HD treatment (p = 0.01) and arterial pressure (p <0.001) compared with the second group. Moreover, the increased level of C-reactive protein (p <0.001), total cholesterol (p < 0.05), triglycerides (p <0.05) and a lower serum albumin level (p <0.01) were observed in the patients of group I compared with the second one. The melatonin levels at daytime and night were significantly correlated with the patients' age (r = -0.42; p <0.001 and r = -0.40; p <0.001), HD treatment duration (r = -0.64; p <0.001 and r = -0.65; p <0.001), BMI (r = -0.22; p = 0.006 and r = -0.33; p <0.001) and arterial pressure (r = -0.66; p <0.001 and r = -0.84; p <0.001). In addition, albumin, hemoglobin and serum uric acid concentration were associated with the melatonin level. Conclusions. The violation of MFE was diagnosed in 84.6% of HD patients and determined by the duration of the dialysis treatment, the blood pressure, body weight, hemoglobin level, the degree of impaired protein and purine metabolism.