Diabetic Ketoacidosis at Diagnosis of Type 1 Diabetes Predicts Poor Long-term Glycemic Control

Abstract

OBJECTIVE This study tested the hypothesis that diabetic ketoacidosis (DKA) at diagnosis of type 1 diabetes in children predicts poor long-term glycemic control independently of established risk factors. RESEARCH DESIGN AND METHODS This was a prospective cohort study of 3,364 Colorado residents diagnosed with type 1 diabetes before 18 years of age, in 1998–2012, and monitored for up to 15 years. Of those, 1,297 (39%) had DKA at diagnosis (blood glucose >250 mg/dL, and venous pH <7.3 or bicarbonate <15 mEq/L). Severity of DKA was further classified as mild/moderate (pH 7.10–7.29 or bicarbonate 5–14 mEq/L) or severe (pH <7.10 or bicarbonate <5 mEq/L). HbA1c levels were measured an average of 2.8 times/year (median 20 HbA1c values/patient). A linear mixed model was used to examine the effect of DKA on long-term HbA1c levels, adjusting for age, race/ethnicity, sex, family history of diabetes, health insurance, and insulin pump use. RESULTS DKA at diagnosis predicted persistently elevated HbA1c levels. Compared with children without DKA, HbA1c tracked 1.4% (15.3 mmol/mol) higher in those with severe DKA (P < 0.0001) and 0.9% (9.8 mmol/mol) higher in those with mild/moderate DKA at diagnosis (P < 0.0001). These effects were independent of ethnic minority status or lack of health insurance at diagnosis that predicted higher HbA1c by 0.5% (5.5 mmol/mol; P < 0.0001) and 0.2% (2.2 mmol/mol; P < 0.0001), respectively. Insulin pump use or having a parent or sibling with type 1 diabetes predicted lower long-term HbA1c by, respectively, 0.4% (4.4 mmol/mol; P < 0.0001) and 0.2% (2.2 mmol/mol; P = 0.01). CONCLUSIONS DKA at diagnosis of type 1 diabetes in children predicts poor long-term glycemic control, independent of demographic and socioeconomic factors.