Type 2 diabetes in Canada: concentration of risk among most disadvantaged men but inverse social gradient across groups in women

AIMS: To assess sex-specific associations of educational and income levels with Type 2 diabetes mellitus. METHODS: Logistic regression analyses (Canadian Community Health Survey, cross-sectional) adjusted for ethnicity, immigration, urban/rural, overweight/obesity, physical inactivity, smoking, chronic conditions and regular physician. RESULTS: Compared to women with some post-secondary education, Type 2 diabetes was more likely in both high school graduates without post-secondary education odds ratio (OR) 1.27, 95% confidence interval (CI) 1.07-1.51 and high school non-completers (OR 1.73, 95% CI 1.47-2.04); among men, definitive conclusions in high school graduates without post-secondary education could not be drawn (OR 0.93, 95% CI 0.78-1.12), but Type 2 diabetes was more likely in high school non-completers (OR 1.26, 95% CI 1.08-1.48). Compared to women with the highest income, Type 2 diabetes was three times more likely in the lowest income group (OR 2.90, 95% CI 2.25-3.73), 2.53 times more likely in the low middle income group (OR 2.53, 95% CI 1.98-3.24) and 55% more likely in the high middle income group (OR 1.55, 95% CI 1.20-2.01). Among men, Type 2 diabetes was approximately 40% more likely in both the lowest (OR 1.41, 95% CI 1.10-1.80) and low middle income groups (OR 1.39, 95% CI 1.12-1.71); definitive conclusions in the high middle income group could not be drawn (OR 1.05, 95% CI 0.87-1.28). CONCLUSIONS: In women, Type 2 diabetes increased monotonically with lower educational and income levels; in men, Type 2 diabetes was concentrated in the least educated and least affluent. Our findings support the need for policies and practices that lower diabetes risk among the most disadvantaged women and men and moderately disadvantaged women.