Diabetes mellitus and risk of fatal ischaemic heart disease by gender: 18 years follow-up of 74 914 individuals in the HUNT 1 Study

AIM: To study long-term mortality from ischaemic heart disease (IHD) in subjects with and without diabetes and how the association between diabetes and fatal IHD is influenced by gender and established cardiovascular disease (CVD). METHODS AND RESULTS: In 1984-86, all inhabitants aged 20 years or older in Nord-Trøndelag County, Norway were invited to the HUNT Study. A total of 74,914 participated in our study, 2100 of them with prevalent diabetes. During 18 years of follow-up, 19,967 persons died. Among people without diabetes or CVD at baseline, men had twice (HR 2.20, CI 2.00-2.41) the rate of fatal IHD compared with women. With diabetes present, the gender gap was substantially reduced (HR 1.25, CI 0.9-1.72), and if both diabetes and CVD were present, IHD mortality in men and women was identical (HR 1.1, CI 0.79-1.64). Gender specific analyses showed a stronger association of diabetes with IHD mortality in women (HR 2.71, CI 2.33-3.16) compared with men (HR 1.98, CI 1.70-2.30, test for interaction, P < 0.01). CONCLUSION: Diabetes is a stronger predictor for IHD mortality in women than in men, and diabetes attenuates the usual gender gap in IHD mortality. With both diabetes and established CVD present, the gender gap is fully attenuated.