Fabian and colleagues published their study in Lancet Global Health this month. They performed a systematic review to understand how kidney function was currently assessed on the African continent: many studies did not mention how creatinine was measured in the laboratory. The most commonly used formulae for estimating GFR were MDRD, CKD-EPI and Cockcroft-Gault, and USA-derived ethnicity co-efficients were often used.

Their study then looked at kidney function prospectively in patients in three countries (Malawi, South Africa and Uganda) by measuring creatinine and cystatin C as well as directly measuring GFR using the exogenous biomarker iohexol.

They found that, in all countries, equations estimating GFR using creatinine as one of the variables consistently over-estimated kidney function when compared to the measured GFR. Including ethnicity co-efficients in the MDRD and CKD-EPI formulae worsened the over-estimation.

Whilst further research is needed, this study highlights that traditionally used biomarkers for disease may not be universally applicable to all populations.

Read the full paper on The Lancet website.