Glomerular filtration rate: new age- and gender- specific reference ranges and thresholds for living kidney donation

BackgroundThere is a need for a large, contemporary, multi-centre series of measured glomerular filtration rates (mGFR) from healthy individuals to determine age- and gender-specific reference ranges for GFR. We aimed to address this and to use the ranges to provide age- and gender-specific advisory GFR thresholds considered acceptable for living kidney donation.MethodsIndividual-level data including pre-donation mGFR from 2974 prospective living kidney donors from 18 UK renal centres performed between 2003 and 2015 were amalgamated. Age- and gender-specific GFR reference ranges were determined by segmented multiple linear regression and presented as means two standard deviations.ResultsMales had a higher GFR than females (92.0 vs 88.1mL/min/1.73m(2), P<0.0001). Mean mGFR was 100mL/min/1.73m(2) until 35years of age, following which there was a linear decline that was faster in females compared to males (7.7 vs 6.6mL/min/1.73m(2)/decade, P=0.013); 10.5% of individuals aged >60years had a GFR <60mL/min/1.73m(2). The GFR ranges were used along with other published evidence to provide advisory age- and gender-specific GFR thresholds for living kidney donation.Conclusions These data suggest that GFR declines after 35years of age, and the decline is faster in females. A significant proportion of the healthy population over 60years of age have a GFR <60mL/min/1.73m(2) which may have implications for the definition of chronic kidney disease. Age and gender differences in normal GFR can be used to determine advisory GFR thresholds for living kidney donation.