Type 1 diabetes in pre-school children - long-term metabolic control, associated autoimmunity and complications

Aims To identify clinical characteristics and co-morbidity rates of children diagnosed with Type 1 diabetes mellitus at younger than 6years of age. Methods Data were obtained from a retrospective chart review of 103 patients diagnosed with Type 1 diabetes at younger than 6years (study group) and 220 patients at older than 6years (comparison group). Measures of glycaemic control and occurrence of co-morbidities (coeliac disease, autoimmune thyroid disease, hypertension, nephropathy and retinopathy) were compared. Results The mean follow-up period was more than 8years. For the study group, mean HbA_1c levels ranged from 64mmol/mol to 66mmol/mol (8.0-8.2%) until age 10years, and then rose to 73mmol/mol (8.8%). The HbA_1c levels were higher in the study than in the comparison group for comparable ages (P=0.003). After adjustment for duration of diabetes this difference was not significant. The overall rate of severe hypoglycaemic events was greater in the study group than in the comparison group (P=0.03). Kaplan-Meier diagnosis rates of celiac disease, 10years after Type 1 diabetes diagnosis, were 14.4% and 4.2% in the study and comparison groups, respectively (P log-rank=0.03). There were no differences in rates of autoimmune thyroid disease, hypertension, nephropathy or retinopathy. Conclusions Children diagnosed with Type 1 diabetes before the age of 6years were in greater risk of developing celiac disease, compared with children diagnosed after the age of 6years. For children diagnosed with Type 1 diabetes aged under 6years, good metabolic control was achievable until age 10years, after which it deteriorated. Higher HbA_1c levels observed in children diagnosed before the age of 6years were associated with longer duration of disease.