The impact of diabetes mellitus on mortality from all causes and coronary heart disease in women - 20 years of follow-up

Background: Few data are available on the long-term impact of type 2 diabet es mellitus on total mortality and fatal coronary heart disease (CHD) in wo men. Methods: We examined prospectively the impact of type 2 diabetes and histor y of prior CHD on mortality from all causes and CHD among 121046 women aged 30 to 55 years with type 2 diabetes in the Nurses' Health Study who were f ollowed up for 20 years from 1976 to 1996. Results: During 20 years of follow-up, we documented 8464 deaths from all c auses, including 1239 fatal CHD events. Compared with women with no diabete s or CHD at baseline, age-adjusted relative risks (RRs) of overall mortalit y were 3.39 (95% confidence interval [CI], 3.08-3.73) for women with a hist ory of diabetes and no CHD at baseline, 3.00 (95% CI, 2.50-3.60) for women with a history of CHD and no diabetes at baseline, and 6.84 (95% CI, 4.71-9 .95) for women with both conditions at base- line. The corresponding age-ad justed RRs of fatal CHD across these 4 groups were 1.0, 8.70, 10.6, and 24. 8, respectively. Multivariate adjustment for body mass index and other coro nary risk factors only modestly attenuated the RRs. Compared with nondiabet ic persons, the multivariate RRs of fatal CHD across categories of diabetes duration (less than or equal to5, 6-10, 11-15, 16-25, > 25 years) were 2.7 5,.3.63, 5.51, 6.38, and 11.9 (P < .001 for trend), respectively. The combi nation of prior CHD and a long duration of clinical diabetes tie, > 15 year s) was associated with a 30-fold (95% CI, 20.7-43.5) increased risk of fata l CHD. Conclusions: Our data indicate that among women, history of diabetes is ass ociated with dramatically increased risks of death from all causes and fata l CHD. :The combination of diabetes and prior CHD identifies particularly h igh-risk women.