Diabetic ketoacidosis at diagnosis of type 1 diabetes and glycemic control over time: The SEARCH for diabetes in youth study

Background The diagnosis of type 1 diabetes (T1D) in youth is often associated with diabetic ketoacidosis (DKA). We aimed to evaluate if the presence of DKA at diagnosis of T1D is associated with less favorable hemoglobin A1c (HbA1c) trajectories over time. Methods The SEARCH for Diabetes in Youth study of 1396 youth aged <20 years with newly diagnosed T1D were followed for up to 13 (median 8 [interquartile range or IQR 6-9]) years after diagnosis. Of these, 397 (28%) had DKA (bicarbonate level < 15 mmol/L and/or pH < 7.25 (venous) or < 7.30 (arterial or capillary) or mention of DKA in medical records) at diabetes onset. Longitudinal HbA1c levels were measured at each follow-up visit (average number of HbA1c measures 3.4). A linear piecewise mixed effects model was used to analyze the effect of DKA status at diagnosis of T1D on long-term glycemic control, adjusting for age at diagnosis, diabetes duration at baseline, sex, race/ethnicity, household income, health insurance status, time-varying insulin regimen and glucose self-monitoring, study site, and baseline fasting C-peptide level. Results At baseline, HbA1c levels were significantly higher in youth with T1D diagnosed in DKA vs those who were not (9.9% +/- 1.5% vs 8.5% +/- 1.4%, respectively). After the first year with diabetes, there was a significant difference in the rate of change in HbA1c levels by DKA status: HbA1c was 0.16% higher each year in youth with DKA compared to those without (interaction P-value<0.0001), after adjusting for aforementioned covariates. Conclusions DKA at T1D diagnosis is associated with worsening glycemic control over time, independent of demographic, socioeconomic, and treatment-related factors and baseline fasting C-peptide.