Protective Effect of Regular Physical Activity on Depression after Myocardial Infarction: the HUNT Study

Purpose To study if physical activity within the recommended level over time was associated with risk of developing depression after the first myocardial infarction in older adults. Methods Men (n= 143) and women (n=46) who had reached the age of 60 in 2006-08 who participated in the Nord-Trøndelag Health Study (HUNT1; 1984-86, HUNT2; 1995-97, HUNT3; 2006-08) without any mental illness or cardiovascular disease at baseline in HUNT2 and who experienced their first myocardial infarction before HUNT3 were included. Based on the patterns of physical activity from HUNT1 to HUNT2, the sample was divided into four groups: persistently inactive, from active to inactive, from inactive to active, and persistently active. The primary outcome, post myocardial infarction depression symptoms, was measured with the Hospital, Anxiety and Depression scale (HADS) in HUNT3. Results In HUNT3, 11 % of participants had depression. After multivariable adjustment those who were persistently active had significantly lower odds of being depressed (OR 0.28; 95% CI 0.08-0.98) compared with those who were persistently inactive. Additionally, a significant test for trend (P= .033) of lowering odds of depression was observed across all four categories of physical activity patterns at baseline. Conclusions In this small sample of initial healthy adults we observed a long-term protective effect of regular physical activity on the development of depression following myocardial infarction.