Association between chronic kidney disease stages and changes in ambulatory blood pressure monitoring parameters

Introduction: Blood pressure (BP) assessment affects the management of arterial hypertension (AH) in chronic kidney disease (CKD). CKD patients have specific patterns of BP behavior during ambulatory blood pressure monitoring (ABPM). Objectives: The aim of the current study was to evaluate the associations between progressive stages of CKD and changes in ABPM. Methodology: This is a cross-sectional study with 851 patients treated in outpatient clinics of a university hospital who underwent ABPM examination from January 2004 to February 2012 in order to assess the presence and control of AH. The outcomes considered were the ABPM parameters. The variable of interest was CKD staging. Confounding factors included age, sex, body mass index, smoking, cause of CKD, and use of antihypertensive drugs. Results: Systolic BP (SBP) was associated with CKD stages 3b and 5, irrespective of confounding variables. Pulse pressure was only associated with stage 5. The SBP coefficient of variation was progressively associated with stages 3a, 4 and 5, while the diastolic blood pressure (DBP) coefficient of variation showed no association. SBP reduction was associated with stages 2, 4 and 5, and the decline in DBP with stages 4 and 5. Other ABPM parameters showed no association with CKD stages after adjustments. Conclusion: Advanced stages of CKD were associated with lower nocturnal dipping and greater variability in blood pressure.