Diabetes as a risk factor for myocardial infarction: population and gender perspectives

OBJECTIVES: To investigate diabetes as a risk factor for acute myocardial infarction (AMI) from a population perspective in a region with high cardiovascular disease (CVD) risk. DESIGN: Population screenings for diabetes and a population-based AMI register. SETTING: Northern Sweden MONICA area. SUBJECTS: Representative sample (Norrbotten and Västerbotten counties) of 2432 men and women 35-64 years was investigated 1990 and 1994. All patients with AMI aged 35-64 years were included, in total 3031 between 1989 and 1993. RESULTS: The prevalence of diabetes was 5% in men and 4.4% in women. The relative risk (RR) in diabetic men was 2.9; 95% confidence interval (CI) 2.6-3.4, and in diabetic women, RR 5.0; CI 3.9-6.3. The risk for re-infarction was about twice as large in patients with diabetes as in patients without diabetes. In both sexes the overall 28 day case fatality (CF) was significantly higher in diabetic compared to non-diabetic subjects. When compared to the non-diabetic population, the overall mortality from AMI in the diabetic population was 4 times higher among men and 7 times higher among women. The population attributable risk (PAR), a crude estimate of all AMIs ascribed to diabetes, was 11% in men and 17% in women. CONCLUSIONS: Diabetes increases the risk for AMI attack rate, incidence, case-fatality, recurrence and mortality and is an important contributor to all AMIs in middle-aged people.