Causes for nondipper hypertension in chronical hemodialisis patients

Hypertension (HT) is a common problem in hemodialisis (HD). The aim of this study is to investigate the causes for nondipper HT in chronical HD patients and to explore their impact on risk factors for cardio-vascular diseases. 57 chronical HD patients with an average age of 50 ± 18 and 19 healthy individuals with an average age of 47 ± 13 were included in the study. Blood pressure parameters were measured by applying Ambulatory Blood Pressure Monitorization (ABPM) on the arm without fistula for the period between two HD sessions. Left Ventricle Mass Index (LVMI) Carotid Intima-Media Thickness (IMT), and vein compliance was measured by echocardiogramm. Bioimpedance analysis was applied before and immediately after the HD. Routine heamatological and biochemical analysis were performed in all cases, and high sensitive C - reactive protein (hsCRP), von Willebrand Factor (vWF), and homosisteine levels were measured. Statistically, the average Sistolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) was found significantly higher in patients compared to the control group, however sistolic decrease rates were found lower (p<0.001). The average extracellular fluid/kg (ECL/kg) rate, LVMI, arteria carotis IMT, and hsCRP levels were significantly higher in the patient group (p<0.05). When classified according to nondipper and dipper patients, both groups showed similar average total SBP and DBP, ans similar average day SBP and DBP (p>0.05). average night SBP and DBP was found significantly higher in the nondipper group (p<0.05). ECL/kg and ECL/kg2 rates, LVMI, arteria carotis IMT, and hsCRP levels were significantly higher in the nondipper patient group, however the hemoglobin levels were lower (p<0.05). A negative relation was determined between the sistolic decrease rate and LVMI, ECL/kg, ECL/kg2, hsCRP and arteria carotis IMT (r:-0.23, r:-0.39, r:-0.41, r:-0.38, r:-0.32, r:-0.39, p<0.05, respectively). Using Stepwise linear regretion analysis it was shown that ECL/kg, hsCRP and arteria carotis IMT were the factors influencing the sistolic decrease. We showed that increase in ECL/kg, LVMI, and arteria carotis IMT, and hsCRP may be the causes for nondipper HT. We determined that a salt-poor diet and strict volume control is necessary to control HT in chronical HD patients. However, keeping patients normotensive with strict volume control does not necessarily mean a decrease in cardiovascular mortality and morbidity, but it is required that the patients are dipper in nocturnal blood pressure, too.