Background: Diabetic kidney disease (DKD) is one of the leading causes of CKD and ESRD. Decline in eGFR represents an early marker of DKD that may precede microalbuminuria. The optimal eGFR formula during transition from adolescence into adulthood remains unclear.

Objective: To assess longitudinal change in eGFR in youth with T1D transitioning to young adulthood using CKiDU25 creatinine-sex-adjusted (CKiDU25-1) , CKiDU25 combined-creatinine-cystatin (CKiDU25-2) , and CKDEPI40 eGFR formulas.

Methods: eGFR was calculated at four time points. Subsequently, linear mixed effect model was used to calculate subject specific eGFR slopes. The percentage of decliners, defined as eGFR slope </= -3ml/min/1.73m2/year, corresponding to larger eGFR decline was determined. Relationships between eGFR slope and average A1C, ACR, sex, and diabetes duration was assessed using linear regression.

Results: There were 99 participants, of which 45% were male, assessed over an average of 7.4 ± 1 years, beginning at 14 ±1.7 to 21.3 ± 2.1 years. Mean eGFR for CKiDU25-1 was 108.1 ± 13.1, slope of -2.9 ± 2.9, and 44% decliners. Mean eGFR for CKiDU25-2 was 104.8 ± 11.9, slope of -2.7 ± 2.2 and 42% decliners. Mean eGFR for CKDEPI40 was 114.8 ± 6.9, slope of 0.8 ± 0.9 and no eGFR decliners. Comparison of all three eGFRs and slopes showed no significant difference between CKiD-1 and CKiD-2, however there was significant differences between CKDEPI40 and both CKiDU25 eGFR and slopes. There was a significant relationship between sex and eGFR slope with males having greater decline in eGFR with all formulae. No significant relationship was found between eGFR slope and ACR, A1C and diabetes duration.

Conclusion: CKiDU25-1 and CKiDU25-2 formulae provide similar eGFRs and eGFR slopes while the CKDEPI40 had a higher mean eGFR and no change in eGFR over time. If cystatin-C is not available, CKiDU25-1 provides a suitable alternative for assessment of eGFR changes in youth with type 1 diabetes transitioning into early adulthood.


F.Babalola: None. E.B.Sochett: None. J.Curtis: None. R.Moineddin: None. Y.T.Elia: None. J.W.Scholey: n/a. D.Cherney: Other Relationship; AbbVie Inc., AstraZeneca, Bayer AG, Boehringer Ingelheim International GmbH, Janssen Research & Development, LLC, Lilly, Maze, BMS, CSL-Behring, Merck, Otsuka, Novartis and Novo-Nordisk , Mitsubishi Tanabe Pharma Corporation, Sanofi, Research Support; Boehringer Ingelheim-Lilly, Merck, Janssen, Sanofi, AstraZeneca and Novo-Nordisk. C.A.White: None. F.H.Mahmud: None.

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