Utility of estimated glomerular filtration rate equations in Nigerians with stable chronic kidney disease

Chronic kidney disease (CKD) is a global public health problem. The incidence and prevalence are increasing worldwide, while the outcomes remain poor and treatment cost high. Unfortunately, CKD in Sub-Sahara Africa is usually diagnosed late and supported with limited treatment facility.

This study aimed at filling the gap created by late diagnosis by assessing utility of estimated glomerular filtration rate (eGFR) in Nigerians and possibly proposing routine reporting of eGFR for earlier diagnosis of CKD.

This study was carried out among patients with established and stable chronic kidney disease (CKD) from the renal unit of the University of Ilorin Teaching Hospital. A total of 64 patients with CKD, comprising 48 males and 16 females were selected by simple random sampling technique for the study. Their creatinine clearance using 24-hour urine collection method, the Cockcroft and Gault [CG] formula and Modification of Diet in Renal Disease (MDRD) formula was determined. Creatinine clearance from CG formula and endogenous creatinine clearance were corrected to 1.73m2 body surface area.

The mean creatinine clearance from 24-hour urine collection was 21.75ml/min/1.73m2. We obtained 32.18 ml/min/ 1.73m2 from Cockcroft and Gault and 26.56 ml/min/ 1.73m2 from MDRD formulae respectively. There was no statistically significant difference between the mean creatinine clearance values obtained from the 24- hour urine collection when compared with those obtained from the Cockcroft-Gault formula (p >0.5) and the MDRD formula (p > 0.5). Also, when creatinine clearance from 24-hour urine collection was subjected to correlation analysis; correlation coefficients of 0.905 and 0.904 were obtained for Cockcroft-Gault and MDRD formula respectively.

Our results thus show that the formula method (eGFR) for calculating clearance is 95% reliable in patients with chronic kidney disease in this environment. To promote early detection of CKD which is usually amenable to treatment we recommend routine reporting of eGFR.