Which factors predict glycemic control in children diagnosed with type 1 diabetes before 6.5 years of age?

Predictors of long-term glycemic control and growth patterns in children diagnosed with type 1 diabetes (T1D) before 6.5 years of age were evaluated. One hundred seventy-three children (84 boys) with a mean diabetes duration of 4.9 ± 2.8 years participated in this observational study. Medical charts were reviewed for background, disease- and treatment-related parameters, and growth parameters. Study endpoints were HbA1c value, rates of severe hypoglycemia and diabetic ketoacidosis events, and growth patterns. Mean HbA1c for the total duration of diabetes (HbA1c-TDD) was 7.9 ± 0.8%. Comparison of the study variables between patients with HbA1c-TDD <7.5% (n = 53) or ≥7.5% yielded a significantly shorter duration of diabetes (P = 0.01) and lower rate of diabetic ketoacidosis (P = 0.02) in those with HbA1C-TDD <7.5%, without differences between these groups in age at diabetes onset, insulin regimens, daily glucose measurements, and rate of severe hypoglycemia. Factors significantly predicting achievement of the mean target HbA1c-TDD <7.5% were lower HbA1c at 0.5 years and 1 year after diabetes diagnosis (P = 0.002 and P < 0.001, respectively). Patients followed for at least 5 years (n = 48) showed a significant decrease in height-SDS (P < 0.001) and a significant increase in weight-SDS (P = 0.004) from diabetes diagnosis to the last follow-up visit, without a significant change in weight-SDS from 0.5 years after diagnosis to the last follow-up visit. Our results suggest that in patients with T1D diagnosed during the preschool-age, mean HbA1c level in the first year is a strong predictor of achieving target HbA1c level in the subsequent years, regardless the type of insulin regimen. This "metabolic tracking" emphasizes the importance of achieving early optimal control even in younger children.