Increasing incidence of type 2 diabetes in New Zealand children <15 years of age in a regional-based diabetes service, Auckland, New Zealand.

Aim: It is important to understand whether type 2 diabetes mellitus (T2DM) is increasing in childhood for health-care planning and clinical management. The aim of this study is to examine the incidence of T2DM in New Zealand children, aged <15 years from a paediatric diabetes centre, Auckland, New Zealand.

Methods: Retrospective analysis of prospectively collected data from a population-based referral cohort from 1995 to 2015.

Results: Hundred and four children presented with T2DM over the 21-year period. The female:male ratio was 1.8:1, at mean (standard deviation) age 12.9 (1.9) years, body mass index standard deviation score +2.3 (0.5), blood sugar 15.3 (8.5) mmol/L, HbA1c 76 (28) mmol/mol. At diagnosis, 90% had acanthosis nigricans and 48% were symptomatic. In all, 33% were Maori, 46% Pacific Island, 15% Asian/Middle Eastern and 6% European. There was a progressive secular increase of 5% year on year in incidence. The overall annual incidence of T2DM <15 years of age was 1.5/100 000 (1.2-1.9) (95% confidence interval), with higher rates in Pacific Island (5.9/100 000) and Maori (4.1/100 000).

Conclusions: The incidence of T2DM in children <15 years of age in New Zealand has increased progressively at 5%/year over the last 21 years. The risk was disproportionately associated with girls and children from high-risk ethnic groups.