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

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 characterise 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 7961 children and young adults diagnosed with type 1 diabetes by age 30 years from 2000-2019 and followed prospectively in the Australasian Diabetes Data Network (ADDN) until 31/12/2020. Linear mixed effect models related variables to HbA1c.

RESULTS

DKA at diagnosis was present in 2647 (33.2%) participants. Over a median 5.6 (IQR 3.2,9.4) years 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; [+2.5mmol/mol, 95% CI:1.4,3.6]; p<0.001) compared to 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; [-3.1mmol/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; [+15.0mmol/mol, 95% CI:12.6,17.4]; p<0.001), as was residing in postcodes of lower socioeconomic status (most versus least disadvantaged quintile +0.43%, 95% CI:0.34,0.52; [+4.7mmol/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 which was modified by use of CSII. Indigenous status and lower socioeconomic status were independently associated with higher long-term HbA1c.