Dietary glycemic index in relation to metabolic risk factors and incidence of coronary heart disease: the Zutphen Elderly Study

Objective: To examine whether a high dietary glycemic index is associated with hyperinsulinemia, hyperglycemia, dyslipidemia and coronary heart disease (CHD) risk in elderly men. Design: Prospective study of incidence of major CHD (non-fatal myocardial infarction or death due to CHD) between 1985 and 1995 in 646 men, and a cross-sectional analysis of metabolic risk factors in 1990 in 394 men. Setting: Population based study in the Dutch town Zutphen. Subjects: Men aged 64-84y in 1985 without a history of CHD or diabetes, whose diet was assessed with the cross-check dietary history method. Results: The dietary glycemic index was positively correlated with consumption (g carbohydrate) of wheat bread (r = 0.47) and sugar products (r = 0.41) and inversely with fruit (r = -0.37) and milk (r = -0.40) consumption. During 4527 person-years of follow-up, 94 cases of CHD were documented. The risk ratio for CHD was 1.11 (95% CI, 0.66 - 1.87) for the highest as compared to the lowest tertile of glycemic index after correction for age, body mass index, physical activity, cigarette smoking, and dietary factors (P (trend) = 0.70). Furthermore, the glycemic index was not appreciably associated with blood concentrations of total cholesterol, HDL-cholesterol, triacylglycerols or (fasting or postload) insulin or glucose. Conclusions: Our findings do not support the hypothesis that a high-glycemic-index diet unfavorably affects metabolic risk factors or increases risk for CHD in elderly men without a history of diabetes or CHD.