[Circadian rhythm of blood pressure in patients with chronic renal failure treated with hemodialysis].

In our study we tried to assess the abnormalities in circadian blood pressure variations in 20 patients with chronic renal failure treated with hemodialysis. In this group of patients we controlled blood pressure during 48-hours (including the dialytic and the interdialytic day). We used Oxford Medilog ABP equipment. As a control we included 40 healthy men, divided into two subgroups; men whose parents had or had not hypertension (20 men in each subgroup). To confirm the optimal HD parameters we controlled Kt/V and per. To evaluate circadian rhythms in blood pressure we used Cosinor analysis, and to assess the day-night blood pressure differences we used Student's t-test. We did not find that circadian rhythms in blood pressure in HD patients were existed. We found that in HD patients systolic blood pressure was higher at daytime of dialytic day, subsequently fell down to lower levels at night-time and next day, and returned to higher levels the next night (before the next hemodialysis). It can be connected with alterations in body fluid status during dialysis. Other disturbances in circadian rhythms in blood pressure can be explained as the results of other disturbances that existed in patients with chronic renal failure such as the lack of diurnal rhythm in secretion of atrial natriuretic factor, sympathetic overactivation, rHuEpo therapy and others.