The effect of educational status on the relationship between obesity and risk of type 2 diabetes

OBJECTIVE: Obesity trends are likely to increase social disparities in diabetes. The magnitude of this effect depends on the strength of the relationship between obesity and diabetes across categories of disadvantage. This study aims to test the hypothesis that education level moderates the association between obesity and fasting plasma glucose (FPG), 2-h plasma glucose (2hPG), HbA1c level, and diabetes prevalence. METHODS: We used the baseline data from the Australian Obesity, Diabetes, and Lifestyle study in 2000 (n = 8646). We performed multiple linear regression analysis adjusted for confounding factors and stratified by education level. Body mass index (BMI) and waist circumference (WC) were positively associated with FPG, 2hPG, HbA1c and prevalence of diabetes. RESULTS: No moderating effect of education on these relationships was observed in the total population. In never smokers free of diagnosed diabetes at baseline the association of WC with 2hPG and HbA1c and of BMI with HbA1c was stronger in those with a lower level of education. CONCLUSIONS: Overall, these results suggest that the association between obesity and diabetes risk is independent of educational status. However, inconsistent results suggest that further analyses of an adequately powered longitudinal study of never smokers free of diabetes would be useful to further explore this hypothesis.