Serum creatinine and estimated glomerular filtration rates in HIV positive and negative adults in Ethiopia

BACKGROUND: Glomerular filtration rate estimating equations using serum creatinine are not validated in most African settings. We compared serum creatinine and estimated glomerular filtration rate (eGFR) in HIV positive and negative adults and assessed the performance of eGFR equations ((Cockcroft and Gault (CG), Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI)) compared to 24-hour creatinine clearance in HIV positive adults. METHODS: Data were collected on demographic, anthropometric, body composition, clinical parameters and serum creatinine in HIV positive and negative adults. 24-hour urine was collected from some of the HIV positive adults who volunteered. Bias was calculated as mean difference between 24-hr creatinine clearance and eGFR (eGFR– 24 hour creatinine clearance) and the accuracy of each eGFR equation was calculated as the percentage of estimates within 30% of creatinine clearance. RESULTS: A total of 340 HIV positive and 100 HIV negative adults were included in this study. Creatinine clearance was determined for 46 of HIV positive adults. Serum creatinine increased with increasing age, weight, height, body surface area, fat free mass and grip strength in both HIV positive and negative adults (P<0.05). No difference was observed in eGFR between HIV positive and HIV negative adults. For all eGFR equations, the correlation between eGFR and 24-hr creatinine clearance was 0.45–0.53 and the accuracy within 30% of 24-hr creatinine clearance was 24–46%. Removing ethnic coefficient reduced the bias and improved accuracy of the CKD-EPI and the MDRD estimates. CONCLUSION: Ethiopian HIV positive adults in the present study had good kidney function at the initiation of antiretroviral treatment. However, all eGFR equations overestimated 24-hr creatinine clearance in the study population. Creatinine based eGFR equations that accounts for low muscle mass and body surface area are needed.