Diabetic Ketoacidosis at Onset of Type 1 Diabetes and Long-term HbA1c in 7,961 Children and Young Adults in the Australasian Diabetes Data Network
Helen Clapin, Arul Earnest, Peter G. Colman, Elizabeth A. Davis, Craig Jefferies, Kym Anderson, Melissa J. Chee, Philip Bergman, Martin de Bock, Kung‐Ting Kao, P. Gerry Fegan, D. Jane Holmes–Walker, Stephanie Johnson, Bruce R. King, Meng Tuck Mok, Kruthika Narayan, Alexia Peña, Richard Sinnott, Benjamin J. Wheeler, Anthony Zimmermann, Maria E. Craig, Jennifer Couper, the ADDN Study Group, Geoffrey Ambler, Sof Andrikopoulos, Helen L. Barrett, Jenny Batch, Fergus Cameron, Louise Conwell, Andrew Cotterill, Chris Cooper, Kim C. Donaghue, Jan Fairchild, Spiros Fourlanos, Sarah J. Glastras, Peter W Goss, Leonie Gray, Shane Hamblin, Paul L. Hofman, Tony Huynh, Steven James, Timothy W. Jones, Antony Lafferty, Michelle Martin, Robert McCrossin, Kris Neville, Mark Pascoe, Ryan Paul, Dorota Pawlak, Liza Phillips, Darrell Price, Christine Rodda, David Simmons, Carmel E. Smart, Monique Stone, Steve Stranks, Elaine Tham, Glenn M. Ward, Helen Woodhead
Abstract
OBJECTIVE: The relationship between diabetic ketoacidosis (DKA) at diagnosis of type 1 diabetes and long-term glycemic control varies between studies. We aimed, firstly, to characterize the association of DKA and its severity with long-term HbA1c in a large contemporary cohort, and secondly, to identify other independent determinants of long-term HbA1c. RESEARCH DESIGN AND METHODS: Participants were 7,961 children and young adults diagnosed with type 1 diabetes by age 30 years from 2000 to 2019 and followed prospectively in the Australasian Diabetes Data Network (ADDN) until 31 December 2020. Linear mixed-effect models related variables to HbA1c. RESULTS: DKA at diagnosis was present in 2,647 participants (33.2%). Over a median 5.6 (interquartile range 3.2, 9.4) years of follow-up, participants with severe, but not moderate or mild, DKA at diagnosis had a higher mean HbA1c (+0.23%, 95% CI 0.11,0.28; [+2.5 mmol/mol, 95% CI 1.4,3.6]; P < 0.001) compared with those without DKA. Use of continuous subcutaneous insulin infusion (CSII) was independently associated with a lower HbA1c (-0.28%, 95% CI -0.31, -0.25; [-3.1 mmol/mol, 95% CI -3.4, -2.8]; P < 0.001) than multiple daily injections, and CSII use interacted with severe DKA to lower predicted HbA1c. Indigenous status was associated with higher HbA1c (+1.37%, 95% CI 1.15, 1.59; [+15.0 mmol/mol, 95% CI 12.6, 17.4]; P < 0.001), as was residing in postcodes of lower socioeconomic status (most vs. least disadvantaged quintile +0.43%, 95% CI 0.34, 0.52; [+4.7 mmol/mol, 95% CI 3.4, 5.6]; P < 0.001). CONCLUSIONS: Severe, but not mild or moderate, DKA at diagnosis was associated with a marginally higher HbA1c over time, an effect that was modified by use of CSII. Indigenous status and lower socioeconomic status were independently associated with higher long-term HbA1c.