While poor glycemic control increases the risk of diabetic kidney disease (DKD) , its impact on renal function decline among those with established DKD is unclear. To examine this, we tested the relationship between baseline HbA1c and renal outcomes in the 3-year Preventing Early Renal Loss (PERL) trial (n=530) , which included persons with type 1 diabetes (T1D) and early-to-moderate DKD (eGFR 40-100 ml/min/1.73m2 and persistent albuminuria and/or ongoing GFR decline) . In Cox regression models, baseline HbA1c was associated (p<0.0001) with a higher risk of progression to ESKD or serum creatinine doubling (HR 1.87 per HbA1c unit increment, 95% CI 1.42-2.47) , and in mixed-effects linear regression models, with 0.87 and 0.51 ml/min/1.73m2/year higher rates of estimated glomerular filtration rate (eGFR) and iohexol GFR decline (p<0.00for both) . Baseline albumin excretion rate (AER) was a modifier of the HbA1c-GFR slope relationships (p for interaction <0.05) , such that HbA1c was associated with a higher rate of GFR decline among those with AER≥200 μg/min than among those with AER<20 or 20≤AER<200 (Fig.1) . Thus, worse glycemic control in PERL was a major determinant of GFR decline and ESKD risk after DKD onset, especially in persons with overt proteinuria. Efforts to normalize HbA1c should continue among such persons.
H.Shah: None. J.B.Mcgill: Advisory Panel; Gilead Sciences, Inc., Lilly Diabetes, MannKind Corporation, Novo Nordisk A/S, Provention Bio, Inc., Salix Pharmaceuticals, Consultant; Bayer AG, Boehringer Ingelheim International GmbH, Research Support; Dexcom, Inc., Novo Nordisk. I.B.Hirsch: Consultant; Abbott Diabetes, Bigfoot Biomedical, Inc., GWave, Roche Diabetes Care, Research Support; Beta Bionics, Inc., Insulet Corporation, Medtronic. C.Wu: None. A.Galecki: None. M.Mauer: None. A.Doria: Research Support; Novo Nordisk Foundation. Perl consortium: n/a.
National Institutes of Health UC4DK101108Juvenile Diabetes Research Foundation 17-2012-377The Leona M. and Harry B. Helmsley Charitable Trust 2018PG-T1D014