Coffee consumption and risk of cardiovascular events and all-cause mortality among women with type 2 diabetes.

AIMS/HYPOTHESIS: Coffee has been linked to both beneficial and harmful health effects, but data on its relationship with cardiovascular disease and mortality in patients with type 2 diabetes are sparse.

METHODS: This was a prospective cohort study including 7,170 women with diagnosed type 2 diabetes but free of cardiovascular disease or cancer at baseline. Coffee consumption was assessed in 1980 and then every 2-4 years using validated questionnaires. A total of 658 incident cardiovascular events (434 coronary heart disease and 224 stroke) and 734 deaths from all causes were documented between 1980 and 2004.

RESULTS: After adjustment for age, smoking and other cardiovascular risk factors, the relative risks were 0.76 (95% CI 0.50-1.14) for cardiovascular diseases (p trend = 0.09) and 0.80 (95% CI 0.55-1.14) for all-cause mortality (p trend = 0.05) for the consumption of >or=4 cups/day of caffeinated coffee compared with non-drinkers. Similarly, multivariable RRs were 0.96 (95% CI 0.66-1.38) for cardiovascular diseases (p trend = 0.84) and 0.76 (95% CI 0.54-1.07) for all-cause mortality (p trend = 0.08) for the consumption of >or=2 cups/day of decaffeinated coffee compared with non-drinkers. Higher decaffeinated coffee consumption was associated with lower concentrations of HbA(1c) (6.2% for >or=2 cups/day versus 6.7% for <1 cup/month; p trend = 0.02).

CONCLUSIONS: These data provide evidence that habitual coffee consumption is not associated with increased risk of cardiovascular diseases or premature mortality among diabetic women.