Background: The incidence of type 2 diabetes mellitus (T2DM) is increasing in adolescents in most western countries. The time-course of glycemic control and impact of early treatment remain poorly understood.
Objectives: To determine the change in incidence of T2DM, and the time-course of glycemic control in a regional pediatric cohort with T2DM.
Methods: Retrospective analysis of prospectively collected data on 52 patients with T2DM from a population-based treatment referral cohort from 1 January 1995 to 31 December 2007.
Results: The annual incidence of new cases of T2DM in children <15 yr increased fivefold in the Auckland region of New Zealand from 1995 [0.5/100,000; 95% confidence interval (CI) 0.0–2.2] to 2007 (2.5/100,000; 95% CI 1.0–5.5). The average annual incidence per 100,000 over the entire period was 1.3 (95% CI 1.0–1.8) overall, 0.1 (0.0–0.4) in Europeans, and 3.4 in both Maori (2.0–5.3) and Pacifica (2.2–5.0). Fifty-seven percent of children were symptomatic at presentation. Fifty-eight percent of patients were treated with insulin from diagnosis, most of whom were symptomatic (p = 0.003). Follow-up data were available for 48 patients with a mean of 2.4 yr. Although insulin therapy was associated with a greater fall in HbA1c values in the first 12 months of treatment (to a nadir of 7.1 vs. 8.1%, p < 0.05), there was a rapid deterioration after 12 months, and subsequent mean HbA1c values were >9% in both groups. Therapy did not affect body mass index standard deviation score (BMI SDS).
Conclusions: The incidence of T2DM in childhood or adolescence increased markedly over a 13-yr period in the Auckland region. Long-