Investigation Of Renal Function Among Hypertensive Patients In Umuahia, South East Nigeria

ABSTRACT

The prevalence of chronic kidney disease (CKD) is on the increase globally. Hypertension, a cause and consequence of CKD, is one of the leading risk factors that contribute to increased prevalence of CKD. Understanding the burden of CKD in hypertensive individuals will help promote preventive strategies and initiate measures to reduce the progression of CKD to end stage renal disease (ESRD). Estimation of glomerular filtration rate (GFR) is one of the reliable means of investigating renal function in order to provide information regarding the functional status of the kidneys and identify persons at risk of CKD. Current guidelines advocate the use of CockcroftGault (CG), Modification of Diet in Renal Disease (MDRD) and the recently introduced Chronic Kidney Disease Epidemiology Collaboration equation (CKD- EPI). GFR estimated by these equations might differ with implications on staging, management, health and cost of kidney disease. The aim of this study was to investigate renal function in hypertensive patients and to compare the GFR values from CG, MDRD and CKD-EPI equations and their implication on staging of kidney disease in a tertiary hospital in Umuahia, South East Nigeria. Methodology: A cross sectional study involving 262 subjects aged 22-85 years comprising equal number of hypertensive and nonhypertensive was used. Questionnaires were administered; medical, socio-demographic and anthropometric profile was obtained. Blood samples were taken for creatinine determination and glomerular filtration rate was estimated using CG, MDRD and CKDEPI equations. Mean bias ± imprecision (±2SD) of the equations compared were calculated using the method of Bland and Altman. Results: The mean age of nonhypertensive subjects was 49.1±17.4 years and that of hypertensive was 59.0±14.6 years. SBP was 123.6±11.9mmHg and 161.6±20.0 mmHg for non-hypertensive and hypertensive subjects respectively while the mean DBP was 75.0±9.8 mmHg and 93.4±14.8mmHg and respectively. Among the hypertensive patients, mean GFR values were 73.6±38.0 mls/min/, 87.4 ±40.2 mls/min/1.73m2 and 90.3±28.9 mls/min/1.73m2 using CG, MDRD and CKD-Epi equations respectively. GFR values for CG showed that 29% were normal (stage 1), 28.2% had stage 2 while 42.6% had CKD (GFR< 60ml/min); MDRD values showed 39.7% normal, 30.5% stage 2 and 29.8% CKD (GFR