Increasing incidence of type 1 diabetes between 1986 and 2015 in Bauru, Brazil

Diabetes Res Clin Pract. 2017 May;127:198-204. doi: 10.1016/j.diabres.2017.03.014. Epub 2017 Mar 21.

Abstract

Aims: To assess temporal trends in the incidence of type 1 diabetes in Bauru, São Paulo State, Brazil from 1986 to 2015.

Research design and methods: The yearly incidence of type 1 diabetes (per 100,000/yr) from 1986 to 2015 was determined in children ≤14yr of age, using individual case notification and the capture and recapture method.

Results: During thirty years (1986-2015), 302 cases were diagnosed in our population. The overall incidence was of 12.8/100,000 (95% CI: 11.2-14.4), ranging from 2.8/100,000 in 1987 to 25.6/100,000 in 2013 with a 9.1-fold variation. It was non-significantly higher in girls [13.7 (95% CI: 11.4-16.1)] than in boys [12.0 (95% CI: 9.8-14.2)] (p=0.48) and significantly higher in the 5-9yr [14.6 (95% CI: 11.8-17.4)] and 10-14yr [15.8 (95% CI: 12.7-18.8)] age ranges compared to the 0-4yr [8.1 (95% CI: 6.0-10.2)] age range (p<0.001). The majority of diagnoses were made in colder months. The patterns of incidence were very high and high in 80.0% of the study-years.

Conclusions: The incidence of type1 diabetes in children ≤14yr has increased in Bauru, Brazil, in the last thirty years, in approximately 3.1% annually, with an absolute crude increase of 2.5-fold. These findings pose Brazil as a country with high incidence of type 1 diabetes. All Brazilian regions should be enrolled in future studies to determine the factors that contribute to the predisposition to type 1 diabetes in our population and to the steep rise in its incidence.

Keywords: Brazil; Childhood; Incidence; Type 1 diabetes.

Publication types

  • Historical Article

MeSH terms

  • Adolescent
  • Brazil / epidemiology
  • Child
  • Child, Preschool
  • Diabetes Mellitus, Type 1 / epidemiology*
  • Female
  • History, 20th Century
  • History, 21st Century
  • Humans
  • Incidence
  • Male