Physical Activity and the Risk of Aortic Dissection: Results from the UK Biobank

We investigated the association between physical activity and the risk of aortic dissection in the UK Biobank. The analytical dataset included 452,994 participants aged mainly between 40 and 69 years, recruited from 2006 to 2010. Cox proportional hazards models were used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between physical activity and the risk of aortic dissection. During 12.3 years follow-up, 331 aortic dissection cases were identified. No clear association was observed between the highest vs. lowest quintile of frequency of leisure-time physical activity (HR, 95% CIs: 0.84, 95% CI: 0.59–1.19; Ptrend = 0.88), moderate physical activity (1.11, 0.71–1.72, Ptrend = 0.51), or vigorous physical activity (1.06, 0.76–1.48, Ptrend = 0.74) and risk of aortic dissection. A suggestive inverse U-shaped association was observed for moderate vs. low levels of walking and aortic dissection risk with HRs (95% CIs) of 1.00 (reference), 0.80 (0.53–1.20), 0.63 (0.41–0.97), 0.63 (0.39–1.02) and 0.78 (0.55–1.11) for walking 2, 4, 5, 6, and 7 times/week, respectively. This association was slightly strengthened after exclusion of participants with prevalent CVD, cancer and respiratory disease at baseline. In analyses using MET-hours/week as the metric, a suggestive inverse association was observed for vigorous physical activity (0.66, 0.43–0.99; Ptrend = 0.09), but not for other physical activity domains. Overall, we found little evidence of a clear association between physical activity and aortic dissection in the current study. Potential U-shaped inverse associations between frequency of walking and the risk of aortic dissection, and between MET-hours/week of vigorous physical activity and aortic dissection need further study in additional large cohort studies.