The prevalence of renal impairment in individuals seeking HIV testing in Urban Malawi

Abstract

Background: Chronic kidney disease (CKD) poses a major health threat to people living in low- and middle-income countries, especially when it is combined with HIV, antiretroviral treatment (ART) or communicable and non-communicable diseases. Data about the prevalence of CKD and its association with other diseases is scarce, particularly in HIV-negative individuals. This study estimated the prevalence of CKD in individuals who were either HIV-positive (and ART-naïve) or HIV-negative in an urban Malawian population. Methods: This cross-sectional study was conducted at a HIV Testing and Counselling Centre in Lilongwe, Malawi. Consecutive clients who were ≥18 years and consented to participate were enrolled over a 3-month period. Clients were screened for potential renal disease and other conditions. Their blood pressure was measured, urine examined via dipstick and albumin/creatinine ratio and blood drawn for creatinine, cystatin C and sero-markers for schistosomiasis. Estimated glomerular filtration (EGFR) rate was calculated using a cystatin C-based formula and classified according to the matching CKD stages by K/DOQI (The National Kidney Foundation Kidney Disease Outcome Quality Initiative). We performed a descriptive analysis and compared differences between HIV-positive (and ART naïve) and -negative participants. Results: Out of 381 consecutive clients who were approached between January and March 2012, 366 consented and 363 (48% female; 32% HIV-positive) were included in the analysis. Reasons for exclusion were missing samples or previous use of ART. HIV-positive and negative clients did not differ significantly with regard to age, sex or medical history, but they did differ for BMI - 21.3 (±3.4) vs. 24 (±5.1), respectively (p < 0.001). Participants also differed with regard to serum cystatin C levels, but not creatinine. Reduced kidney function (according to CKD stages 2-5) was significantly more frequent 15.5 vs. 3.6%, respectively (p < 0.001) among HIV-positive clients compared to the HIV-negative group. Differences in renal function were most pronounced in the EGFR range 60-89 ml/min/1.73 m2 accompanied by proteinuria with results as 11.2% vs. 1.2%, respectively for clients who were HIV-positive vs. HIV-negative (p = 0.001). Conclusions: Reduced glomerular filtration and/or proteinuria occurred in 15.5% of HIV-positive, and 3.6% of HIV-negative patients in this urban Malawian cohort. Since generalized renal monitoring is not feasible in Malawi or other resource-limited countries, strategies to identify patients at risk for higher stages of CKD and appropriate preventive measures are needed for both HIV-positive and HIV-negative patients.