Recent incidence of type 1 diabetes mellitus in children 0–14 years in Newfoundland and Labrador, Canada climbs to over 45/100,000: a retrospective time trend study

BACKGROUND: To study and update the provincial incidence of type 1 diabetes mellitus (T1DM) in Newfoundland and Labrador (NL), a province of Canada with a very high incidence previously reported in 2006, and one of the highest incidences reported worldwide. This is a retrospective time trend study of the incidence of T1DM, in children aged 0–14 years from 1987–2010 inclusive. FINDINGS: Over the study period 931 children aged 0–14 years were diagnosed with T1DM. The incidence of T1DM in this population over the period 1987 – 2010 inclusive was 37.7 per 100,000 per year (95% CI 35. 3, 40.2) The incidence from 2007–2010 was 49.9 per 100,000 per year (95% CI 42.2, 57.6). The incidence over this 24 year period increased by a factor of 1.03 per 100,000 per year. CONCLUSION: NL has one of the highest incidences of T1DM reported worldwide. Potential reasons for the very high incidence could be related to the unique genetic background of the population, northern latitude and vitamin D insufficiency, low breastfeeding rates, and high rates of cesarean section.