Dietary glycemic index, dietary glycemic load and mortality among men with established cardiovascular disease

In men with established cardiovascular disease, the effect of diets with high glycemic index (GI) and glycemic load (GL) is unknown. We tested the hypothesis that diets with higher GI and GL are associated with increased mortality in men with established cardiovascular disease.

We measured dietary GI and GL using food-frequency questionnaires in 4617 men, 45-79 years old, with a history of cardiovascular disease. The men were followed for cardiovascular mortality (6-year follow-up, 608 cases) and all-cause mortality (8-year follow-up, 1303 cases) using the Swedish cause-of-death and death registers. We used Cox models with age as the timescale and adjusted for body mass index, physical activity, history of hypertension and diabetes, family history of myocardial infarction, aspirin use, cigarette smoking and dietary factors to estimate incidence rate ratios (RRs).

Comparing top to bottom quartiles of dietary GI, the RR for cardiovascular mortality was 0.86 (95% confidence interval (CI) 0.67-1.10, P for linear trend=0.21), and the RR for all-cause mortality was 1.00 (95% CI 0.85-1.19, P for linear trend=0.87). Compared to quartile 1, the RR for men with dietary GL in quartile 4 was 1.02 (95% CI 0.70-1.49, P for linear trend=0.81) for cardiovascular and 1.15 (95% CI 0.89-1.49, P for linear trend=0.20) for all-cause mortality.

In this population of men with prior cardiovascular disease, dietary GI and GL were not associated with cardiovascular or all-cause mortality.