Patterns of wave reflection in black African ancestry patients with chronic kidney disease in Cameroon

Abstract

Background: Increased augmentation index (AI), a surrogate measure of arterial stiffness (AS) and a direct index of wave reflection is an independent predictor of cardiovascular events in chronic kidney disease (CKD) patients. This study aimed to assess the patterns of wave reflection among blacks Cameroonian patients with CKD.

Methods: 150 CKD patients (Mean age: 52±15 years, 57% males) were enrolled in this cross-sectional study performed at the Douala General Hospital, between November 2015 and May 2016. Sociodemographic, biologic variables, medical history and current medication, weight, height, waist circumference, blood pressures (BP), heart rate (HR) and AI corrected for HR (Aix) were recorded in all participants. Estimated brachial and aortic AIx, pulse pressure (systolic minus diastolic BP) (PP) were measured using a Mobil-O-Graph automatic brachial oscillometric device.

Results: Age, sex and height-adjusted AIx was similar between in non-dialysed (n = 90) and in hemodialysed (n = 60) patients: 22.6 ±4.5% vs 22.2 ±3.7 (P = 0.51). AIx ≥ 30%, suggestive of subclinical aorta damage, was higher in non-dialysis than in hemodialysed patients, especially in post-dialysis: 27.8% vs 18.3%, P = 0.002. Importantly, hemodialysis acutely decreased markedly brachial PP, another surrogate measure of AS, by 6 mmHg (P = 0.008) in patients on maintenance dialysis. Multivariable regression analysis showed that male gender was inversely, while MAP and stage 5 CKD were positively associated with AIx in the whole study group (RR 0.230, P<0.0001). In non-dialysis dwellers taken separately, male gender was inversely, and MAP was positively retaled to AIx (RR = 0.19, P = 0.0002), while only MAP was independently and positively associated with AIx in hemodialysed patients in pre-dialysis (RR 0.15, P = 0.045).

Conclusions: This study reveals comparable magnitude of wave reflection and AS assessed by AIx and pulse pressure among non-dialysis and hemodialysed CKD Cameroonian patients. Decrease of brachial pulse pressure in patients on maintenance hemodialysis suggests improvement of function following dialysis. Our findings suggest that assessment of AS may represent an important tool to monitor arterial damage progression and therapeutic responses in black African patients with CKD.

Keywords: Arterial stiffness, chronic kidney disease, augmentation index, Douala, Cameroon