Reversed gender distribution of diabetes in Northern Canada

To determine age and gender distributions of prevalent diabetes and related risk factors for Northern Canadians.

Cross-sectional study.

The data used were from 78,549 people aged 40 years or more (including 1148 from Northern Canada) who participated in a national survey in 2005. The study questionnaire covered the information on diabetes and potential risk factors. Multiple classification analysis and a logistic regression model were used for multivariate analysis.

In Northern Canada, the prevalence of diabetes tended to increase with age more rapidly in women (P=0.013), while the opposite was true for Southern Canada (P<0.001). Compared with women aged 40-54 years, the adjusted odds ratio for diabetes was 3.31 [95% confidence interval (CI) 1.06-10.4] for women aged 55-69 years and 6.39 (95%CI 1.42-22.8) for women aged 70+ years living in Northern Canada. The corresponding odds ratios for men living in Northern Canada were 1.58 (95%CI 0.53-4.71) and 4.30 (95%CI 0.81-22.9), respectively. The prevalence of obesity was higher for women (28.2%) than men (22.5%) in Northern Canada (P=0.041).

The gender and age distribution of diabetes is unusual in Northern Canada, where the prevalence increases with age more rapidly in women than in men. Further study is required in order to gain an understanding of the possible genetic, cultural and other reasons for this pattern.