Relative role of major risk factors for Type 2 diabetes development in the historical cohort of the Brisighella Heart Study: an 8-year follow-up

Abstract

Aim: The aim of this study was to evaluate and quantify the role of different risk factors in the long-term development of Type 2 diabetes mellitus in a rural Italian population.

Methods: The Brisighella Heart Study (BHS; 1972-2003) is a prospective, population-based longitudinal epidemiological cohort involving 2939 randomly selected subjects, aged 14-84 years, resident in the rural Italian town of Brisighella. For this study, we randomly selected 1441 adult subjects representative of the Brisighella population; consecutively visited during three BHS surveys. A step-wise Cox regression analysis determined the prognostic significance of each independent risk factor for the development of Type 2 diabetes in the 8-year long follow-up.

Results: Blood pressure, high-density lipoprotein cholesterol, triglycerides, physical activity, total energy intake, and drug treatment had no effect on the incidence of diabetes. Age was a significant predictor of Type 2 diabetes when inserted alone in the model (P = 0.007), but irrelevant when adjusted for baseline body mass index (BMI) and or fasting plasma glucose. Among these with impaired fasting glucose (IFG), the diabetes incidence/year was estimated to be 6.6% for men and 11.2% for women (P < 0.001). Basal glycaemia under 6.1 mmol/l were not significant long-term predictors of diabetes development, while higher basal glycaemia and each level BMI were.

Conclusion: Our findings confirm that IFG and BMI predict Type 2 diabetes development in our population. This should help to identify effective approaches to prevention.