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 ≥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 ≥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 ≥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.