Blood pressure control and kidney damage in hypertension: Results of a three-center cross-sectional study in North Central Nigeria

Background: Hypertension is one of the commonest cause of chronic kidney disease (CKD) in Nigerians. We describe blood pressure (BP) control and kidney disease markers in patients with hypertension as part of measures to curb the burden of this chronic debilitating disease. Methods: Patients with hypertension in the main tertiary hospitals in three states in north central Nigeria were evaluated for indicators of CKD, including proteinuria and estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m2. Patients had their early morning first void urine tested for proteinuria using Combi-10 test strips. eGFR was estimated using the MDRD equation. Results: A total of 1063 subjects (63.1% females and 36.8% males) with a mean age of 55 +/- 11 years were studied. Diabetes mellitus (DM) was present in 214 (20.6%) and 422 (39.7%) had optimal BP control. The median duration of hypertension was 6 years (range 1-44 years). Proteinuria occurred in 130 (12.2%), while 212 (19.9%) had reduced eGFR and 46 (4.3%) had proteinuria and reduced eGFR. The use of calcium channel blockers [adjusted odds ratio (AOR): 0.70, 95% Confidence Interval (CI) 0.50-0.99] and the use of more than two antihypertensive medications (AOR: 0.62, 95% CI 0.40-0.96) were associated with reduced odds of optimal BP control. Male sex (AOR: 1.75, 95% CI 1.14-2.70) and the use of renin-angiotensin-aldosterone system blocking medications (AOR: 2.07, 95% CI 1.18-3.64) were independently associated with proteinuria while DM (AOR: 1.69, 95% CI 1.06-2.55) and treatment with more than two medications (AOR: 1.86, 95% CI 1.09-3.17) were more likely to have reduced eGFR. Conclusion: A large proportion of hypertensive patients in north-central Nigeria have poorly controlled BP. Kidney damage is common among these patients.