Nondipping heart rate and associated factors in patients with chronic kidney disease

Background: Nondipping heart rate (NHR) is a condition reported to be associated with cardiovascular events and cardiovascular mortality recently. We aimed to search whether there is difference among hypertensive patients with and without chronic kidney disease (CKD) in terms of NHR pattern and the factors associated with NHR in patients with CKD. Methods: The study included 133 hypertensive patients with normal kidney functions, 97 hypertensive patients with predialysis CKD, and 31 hypertensive hemodialysis patients. Heart rate, blood pressure and pulse wave velocity (PWV) were measured by 24-h ambulatory blood pressure monitorization. NHR was defined as a decrease of less than 10% at night mean heart rate when compared with daytime values. Results: NHR pattern was established as 26.3% in non-CKD hypertensive group, 43.3% in predialysis group and 77.4% in dialysis group. Among patients with CKD, when NHR group was compared with dipper heart rate group, it was seen that they were at older age, there were higher prevalence of diabetes mellitus and more female sex, and while the value of urea, creatinine, phosphorus, intact parathyroid hormone, and PWV were significantly higher, the value of hemoglobin, albumin and calcium were significantly lower. By multivariate analysis, hemoglobin [odds ratio (OR) 0.661; 95% CI 0.541–0.806; p < 0.001] and PWV (OR 1.433; 95% CI 1.107–1.853; p = 0.006) were established as independent determinants of NHR pattern. Conclusions: NHR pattern is significantly more frequently seen in hypertensive CKD patients than in hypertensive patients with non-CKD. Anemia and increased arterial stiffness are seen independently associated with NHR in CKD patients.