A Comparison of three Methods to Estimate the Glomerular Filtration Rate in Diabetic Patients at the Ngaoundere Regional Hospital (Cameroon)

Abstract

Estimation of Glomerular Filtration Rate (GFR) can be done using different methods. The cheaper and most available are those with formulas to determine the estimated GFR. The majority of these formulas have been developed among extra- African populations. In Sub-Saharan Africa, 3 formulas are almost used to estimate GFR which are MDRD, CG and CKD-EPI. This present study was conducted to assess the importance of these formulas as estimators of GFR for diabetic among African Populations. The study was conducted at the Ngaoundere Regional Hospital. Only diabetics from 30 to 78 years attending the regional hospital were enrolled in the study. After enrolment, diabetics with very high values of urea and/or creatinine were excluded. We evaluated CG, MDRD and CKD–EPI as estimators of GFR. Creatinine clearance of 24 hours has been considered as gold standard method. 60 participants were included for sex ratio (M/F) 1.5. The average eGFR of diabetics with high Blood Pressure was lower (91.2 ml / min) than diabetics with lower Blood Pressure (102 ml / min) according to ClCr24. A significant correlation (0.975) between MDRD and CKD-EPI was found when measuring eGFR. It was less significant between CG and MDRD (0.663) and; between CG and CKD-EPI (0.729). A strong similarity was noticed between MDRD and CKD-EPI (92%) while it was smaller between MDRD and CG (55%) and between CKD-EPI and CG (63%) when estimating the stage of kidney diseases. Compared to ClCr24, similarity in half results was found with MDRD (50%) and less than half with CKD-EPI (48%) and CG (38%). The study shown higher value of fasting blood glucose of diabetics attending the Ngaoundere Regional Hospital (212.1 ± 83.0 mg / dl) than the normal recommandation (127-144 mg / dl) for diabetic patients. The average value of the eGFR with MDRD (76.6 ± 20.0 mL / min) was closer to CKD-EPI (78.8 ± 20.4 ml / min) (P<0,001 ; X2=0,976). eGFR was lower in diabetics with high Blood Pressure compared to diabetics with low Blood Pressure. Estimation of CKD stages using MDRD and CKD shown significant similarity. In conclusion, CKD-EPI and MDRD estimated better the GFR. MDRD presented values that were closer to the Creatinine clearance of 24 hours. Further studies are needed with more participants to evaluate the best formula between MDRD and CKD-EPI for the estimation of GFR in Sub-Saharan diabetic population.