Prevalence and Correlates of Chronic Kidney Disease in Patients with Hypertension in Rural Malawi.

Abstract

The prevalence of chronic kidney disease (CKD) in patients with hypertension is very high in Africa. We investigated the prevalence and correlates of CKD in patients with hypertension (defined as currently taking hypertension drugs at enrolment or systolic blood pressure ≥ 160 mmHg and / or diastolic blood pressure ≥ 110 mmHg) attending longitudinal care in rural Malawi, where currently no data on prevalence of CKD in patients with hypertension exists. We retrospectively reviewed medical records of all hypertensive patients who were screened for CKD between January 2018 and April 2019. Screening was done using serum creatinine, and CKD epidemiology formula was used to estimate the glomerular filtration rate (eGFR). We used Kidney Disease: Improving Global Outcomes definitions of renal insufficiency and CKD. Descriptive statistics were used to describe the variables and logistic regression analysis was used to identify correlates of CKD. During the study duration, 1197 patients with hypertension were screened for CKD. The mean creatinine and eGFR was 0.90 mg/dl (Confidence Interval (CI) 0.85–0.94 mg/dl) and 84.1 ml/min/1.73m2 (CI 82.7–85.4 ml/min/1.73m2) respectively. About half of the patients had a normal eGFR (48.3%, n = 578) and 36.3% (n = 435) had mildly decreased eGFR. The prevalence of renal insufficiency was 15.4% (CI 13.4–17.5, 184/1197) and the prevalence of CKD was 7.1% (CI 5.7–8.7%). By eGFR category in the CKD patients, 41.2% (n = 35), 31.8% (n = 27), 24.7% (n = 21) and 2.3% (n = 2) had CKD stage 3a, 3b, 4 and 5 respectively. CKD was strongly associated with age and diabetes. We found moderately high renal insufficiency and CKD in this cohort. We propose investing in screening for CKD in patients with hypertension in other clinics in Malawi.