Abstract P374: Greater Burden Of Chronic Kidney Disease Is Associated With Hypertension Prevalence And Management In South Africa

Abstract

Introduction: Complications e.g., chronic kidney disease (CKD) are frequent with longstanding hypertension, particularly if poorly managed. Hypothesis: We assessed the hypothesis that prevalence and associations of CKD differed by hypertension prevalence, awareness, treatment and control in South Africa using five CKD estimates. Methods: In this randomly selected cross-sectional study, glomerular filtration rate (GFR) was estimated by CKD Epidemiology Collaboration (CKD-EPI) equations [CKD-EPI creatinine (CKD-EPIcr), CKD-EPI cystatin C, CKD-EPI creatinine-cystatin C], Modification of Diet in Renal Disease (MDRD) and Cockcroft-Gault formula (CGF). Blood pressures were measured, and history of hypertension management collected. Results: Among 1092 participants, mean age 43.5 years, 64% women, the prevalence of hypertension was 42% with similar rates in men (41%) and women (43%). In participants with hypertension (n=460), awareness, treatment and control were 61.5% (283/460), 47.2% (217/460) and 27.0% (124/460), with better rates in women compared with men (p<0.001). CKD prevalence (GFR<60 mL/min/1.73m 2 ) was 2.0-5.9% overall using 5 formulae, and significantly higher in participants with (3.9-10.2%) compared to without hypertension (0.6-2.7%) (p<0.001). In participants with hypertension, CKD was higher in those aware (5.7-13.8%) vs unaware (1.1-4.5%) of their diagnosis (p≤0.015), on treatment (6.9-14.3%) vs none (1.2-6.6%) (p≤0.016), and those with controlled (BP<140/90 mmHg) vs uncontrolled hypertension (6.5-15.1% vs. 3-8%, p≤0.096). In models adjusted for age, sex and obesity, higher hypertension prevalence and awareness were significantly (p<0.05) associated with CKD by CKD-EPIcr and MDRD equations; hypertension treatment was significantly associated with CKD by CKD-EPIcr, MDRD and CGF formulae, while hypertension control was not associated with CKD. Conclusions: This study highlights the higher prevalence and greater likelihood of CKD in participants with hypertension and those who were diagnosed and receiving treatment, likely due to the longer duration of their hypertension compared with their counterparts. Higher CKD in the diagnosed and treated reinforces the need for optimal control, which was low in this cohort.