Use of antidiabetic and antidepressant drugs is associated with increased risk of myocardial infarction: a nationwide register study

AIMS: To explore the gender- and age-specific risk of developing a first myocardial infarction in people treated with antidiabetic and/or antidepressant drugs compared with people with no pharmaceutical treatment for diabetes or depression. METHODS: A cohort of all Swedish residents aged 45-84 years (n = 4 083 719) was followed for a period of 3 years. Data were derived from three nationwide registers. The prescription and dispensing of antidiabetic and antidepressant drugs were used as markers of disease. All study subjects were reallocated according to treatment and the treatment categories were updated every year. Data were analysed using a Cox regression model with a time-dependent variable. The outcome of interest was first fatal or non-fatal myocardial infarction. RESULTS: During follow-up, 42 840 people had a first myocardial infarction, 3511 of which were fatal. Women aged 45-64 years, receiving both antidiabetic and antidepressant drugs had a hazard ratio for myocardial infarction of 7.4 (95% CI 6.3-8.6) compared with women receiving neither. The corresponding hazard ratio for men was 3.1 (95% CI 2.8-3.6). CONCLUSIONS: The combined use of antidiabetic and antidepressant drugs was associated with a higher risk of myocardial infarction compared with use of either group of drugs alone. The increase in relative risk was greater in middle-aged women than in middle-aged men.