Nighttime Blood Pressure Abnormalities in Iranian CKD Patients: Necessity to Perform Ambulatory Blood Pressure Monitoring

Abstract

Introduction. Ambulatory blood pressure monitoring (ABPM) is a valuable tool for detecting abnormalities in nighttime blood pressure (BP), including non-dipping and nighttime hypertension. These abnormalities are independent predictors of a poor prognosis in patients with chronic kidney disease (CKD). The aim of our study  was to analyze ABPM data and evaluate nighttime BP abnormalities in an Iranian CKD population.

Methods. This cross-sectional study was conducted on sixty two patients at stages III and IV of CKD who were referred to a nephrology clinic in Tehran, Iran. The patients were classified as either dippers (19.4%) or non-dippers (80.6%), as well as nighttime normotensives (38.7%) or hypertensives (61.3%), based on ABPM  data and in accordance with 2023 ESC/ESH guidelines. We compared demographic data, estimated glomerular filtration rate (eGFR), and daytime BP levels among these groups.

Results. The mean age of patients was 56.34 years, with 61.1% of them being male. Daytime pulse pressure was significantly greater in non-dippers compared to dippers (52.67 vs. 44 mmHg, P = .02). We found a significant correlation between the extent of BP dipping and eGFR (R = 0.281, P = .02). Systolic and diastolic daytime BP levels were significantly higher in individuals with nighttime hypertension. Diabetic patients were more likely to be non-dippers and have nighttime hypertension. After adjusting for age, diabetes mellitus, and daytime pulse pressure in a multivariable model, we determined that eGFR independently predicted the 
extent of BP dipping.

Conclusion. Our results showed that both non-dipping and nighttime hypertension are highly prevalent in CKD patients, but they have distinct contributing factors. The eGFR was identified as an independent predictor of BP dipping, whereas nighttime BP levels were primarily determined by daytime BP levels.

DOI: 10.52547/ijkd.7559