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

<bold>Aims: </bold>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).<bold>Methods: </bold>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).<bold>Results: </bold>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.<bold>Conclusions: </bold>The main finding was that current and previous smoking was associated with increased risk of migraine, but not of TTH. [ABSTRACT FROM AUTHOR]