RELATIONSHIPS BETWEEN SHORT-TERM BLOOD PRESSURE VARIABILITY AND EARLY RENAL DYSFUNCTION IN HYPERTENSION

Abstract

The prognostic significance of short–term blood pressure (BP) variability (STBPV), expressed as standard deviation (SD) of blood pressures (BP) intermittently recorded over 24 hours, is debated. Recently, indices of STBPV other than SD have been proposed. Among these, the 24-h BP Average Real Variability (ARV) seems to be associated more consistently than SD with an enhanced cardiovascular risk. The relationship between mild-to-moderate renal dysfunction (MMRD) and ARV was not investigated. Our study was aimed to analyse, in a large group of untreated essential hypertensives, the relationships between ARV, and other STBV indices, with MMRD. We enrolled 329 essential hypertensive patients, with an eGFR > 30 ml/min/1.73 m2. All the subjects were untreated for hypertension and underwent a 24-h ambulatory blood pressure monitoring. Ninety-six of the participants belonged to the first III stages of 2012 KDIGO classification of chronic kidney diseases (CKD) and were considered to have MMRD. Among the STBV indices evaluated [ARV of 24 h BP; Weighted SD of 24 h BP, SD of daytime and nightime BP] only ARV of 24 h systolic BP differed in subjects with MMRD [9.93 (8.57-11.18) mmHg] compared to the hypertensives with normal renal function [9.1 (8-10.2) mmHg; p = 0.001]. This association held (p < 0.03) in multiple logistic regression analysis after adjustment for 24 h average systolic BP, age, gender and other confounding factors. Our results seem to suggest that in essential hypertensive patients, ARV of 24 h systolic BP, but not other STBPV indices, is significantly associated with MMRD.