Lifestyle factors and risk of migraine and tension-type headache. Follow-up data from the Nord-Trøndelag Health Surveys 1995-1997 and 2006-2008.

Aims The aim of this population-based historical cohort study was to investigate the influence of lifestyle factors on the risk of developing migraine or tension-type headache (TTH). Methods Data from the Nord-Trøndelag Health Study performed in 1995-1997 and 2006-2008 was used. A total of 15,276 participants without headache at baseline were included. A Poisson regression was used to evaluate the associations between lifestyle factors and risk ratios (RRs) of migraine and TTH 11 years later. Precision of the estimates was assessed by 95% confidence interval (CIs). Results Increased risk of migraine (RR 1.30, 95% CI 1.11-1.52) was found in smokers (past or current) compared to those who had never smoked. Hard physical exercise 1-2 hours per week reduced the risk of migraine (OR 0.71, 95% CI 0.54-0.94) compared to inactivity, and the risk of migraine was also lower among those who consumed alcohol (RR 0.73, 95% CI 0.57-0.94) compared to abstainers. No association was found between smoking, physical activity, alcohol use and risk of TTH. Conclusions The main finding was that current and previous smoking was associated with increased risk of migraine, but not of TTH.