Very high and increasing incidence of type 1 diabetes mellitus in Newfoundland and Labrador, Canada

Abstract

Objective: To determine the incidence of type 1 diabetes mellitus (T1DM) among children aged 0–14 yr inclusive in the Canadian province of Newfoundland and Labrador (NL). Methods: Prospective and retrospective cohort study of the incidence of T1DM in children aged 0–14 yr from 1987 to 2005. Identified cases during this time period were ascertained from several sources and verified using the capture–recapture technique. Results: Over the study period, 732 children aged 0–14 yr were diagnosed with T1DM. The incidence of T1DM in this population over the period 1987–2005 inclusive was 35.08 per 100 000 (95% confidence interval: 32.54, 37.62). The incidence over this period increased linearly at the rate of 0.78 per 100 000 per year. There was a significant difference between the incidence of 31.61 per 100 000 for boys in the 0–4‐yr age‐group and 19.05 per 100 000 for girls in the 0–4‐yr age‐group (p = 0.001). The incidence was very high throughout the entire province. Conclusions/Interpretation: The province of NL has one of the highest incidences of T1DM reported worldwide. The incidence is increasing over the 19‐yr study period.