Počki (Feb 2020)
Clinical assessment of disorders of the melatonin-forming function of the pineal gland and anemia in patients with chronic kidney disease stage 5 undergoing hemodialysis
Abstract
Background. The results of a number of studies have proved the relationship between the functional state of the pineal gland and renal function. However, violations of the melatonin-forming function (MFF) of the pineal gland in patients with chronic kidney disease (CKD) undergoing hemodialysis and its relationship with the development of anemia in this population is a poorly understood issue. The purpose: to conduct a clinical assessment of anemia in patients with stage 5 CKD who are treated with hemodialysis depending on clinical and demographic parameters, and to determine its correlation with the violation of MFF. Materials and methods. We examined 130 people (50 % of men) with stage 5 CKD undergoing hemodialysis treatment. Based on the level of melatonin in saliva, patients treated with hemodialysis were divided into two groups: group I — 110 individuals with impaired MFF, group II — 20 people with normal MFF. The control group included 20 healthy individuals matched for age and gender. All patients underwent clinical and laboratory studies: general and biochemical blood tests with determination of all indicators of blood iron metabolism, lipid profile, blood pressure measurement, body mass index calculation, evaluation of the salivary melatonin concentration at different periods of the day, as well as parathyroid hormone. Results. A significant prevalence of MFF disturbance was found in patients with stage 5 CKD, which are treated with hemodialysis, and its relationship with the development of anemia. Analysis of circadian melatonin levels depending on the severity of anemia demonstrated their profound impairment in patients with moderate severity of anemia, in which a significant difference was determined by the level of melatonin at night (p = 0.004). Correlation analysis showed a weak negative correlation between the level of hemoglobin and the duration of hemodialysis (r = –0.217; p < 0.05) that may indicate the progression of anemia with an increase in the duration of renal replacement treatment. Positive correlations were established between hemoglobin concentration and the level of daytime melatonin (r = 0.193; p < 0.05), and closer relationship — with the level of nighttime melatonin (r = 0.278; p < 0.05), which reflects the correlation between the violation of MFF and hemoglobin synthesis. A negative correlation was demonstrated between ferritin and hemoglobin level (r = –0.31; p < 0.05), as well as with serum iron concentration (r = –0.202; p < 0.05) and the level of transferrin (r = –0.234; p < 0.05). A negative correlation is determined between the level of ferritin and the daytime salivary melatonin (r = –0.202; p < 0.05), and the relationship of average strength — with salivary melatonin at night (r = –0.396; p < 0.05). When analyzing the level of transferrin, we determined the positive correlation of the latter with the daytime melatonin (r = –0.332; p < 0.05), and average correlation — with melatonin level at night (r = 0.447; p < 0.05). The inverse weak correlation was found between transferrin concentration and hemodialysis duration (r = –0.191; p < 0.05). Conclusions. A high frequency of MFF disturbance was demonstrated (84.6 %), which is associated with a significant prevalence of anemia and iron deficiency in patients with stage 5 CKD undergoing hemodialysis treatment. In people receiving renal replacement treatment, a relationship was established between the degree of pineal gland dysfunction and the severity of anemia; at that, it increases with an increase in the duration of hemodialysis treatment and the duration of hypertension. In hemodialysis patients, the concentration of ferritin reflects the activity of inflammation that increases with a violation of MFF. Pineal gland dysfunction and anemia have age-dependent nature: they are most severe in old age.
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