Comparison of glomerular filtration rate estimation from serum creatinine and cystatin C in HNF1A-MODY and other types of diabetes

Introduction. we previously showed that in hnf1a-mody the cystatin c-based glomerular filtration rate (gfr) estimate is higher than the creatinine-based estimate. currently,we aimed to replicate this finding and verify its clinical significance. methods. the study included 72 patients with hnf1a-mody,72 with gck-mody,53 with type 1 diabetes (t1dm),70 with type 2 diabetes (t2dm),and 65 controls. serum creatinine and cystatin c levels were measured. gfr was calculated from creatinine and cystatin c using the ckd-epi creatinine equation (egrf-cr) and ckd-epi cystatin c equation (egfr-cys),respectively. results. cystatin c levels were lower (p<0.001) in the control (0.70±0.13 mg/l),hnf1a (0.75±0.21),and gck (0.72±0.16 mg/l) groups in comparison to those with either t1dm (0.87±0.15 mg/l) or t2dm (0.9±0.23 mg/l). moreover,egfr-cys was higher than egrf-cr in hnf1a-mody,gck-mody,and the controls (p=0.004; p=0.003; p<0.0001). this corresponded to 8.9 ml/min/1.73 m2,9.7 ml/min/1.73 m2,and 16.9 ml/min/1.73 m2 of difference. additionally,t1dm patients had higher egfr-cr than egfr-cys (11.6 ml/min/1.73 m2; p=0.0004); no difference occurred in t2dm (p=0.91). conclusions. we confirmed that egfr-cys values in hnf1a-mody patients are higher compared to egfr-cr. some other differences were also described in diabetic groups. however,none of them appears to be clinically relevant. © 2015 magdalena szopa et al.