Body Mass Index and Mortality From Aortic Aneurysm and Dissection

Aims: Reports on an association between body mass index and aortic disease, which remains controversial. This study investigated the association between body mass index and mortality from aortic disease. Methods: We conducted the Japan Collaborative Cohort Study, a prospective study of 103,972 Japanese men and women aged 40-79 years. Body mass index was calculated on the basis of self-reported height and weight, and the participants were followed up from 1988-89 through 2009. Sex-specific hazard ratios (95% confidence intervals) of mortality from aortic disease according to quintiles of body mass index were analyzed using the Cox proportional hazards model. Results: During the median 18.8 years of follow-up, we documented 139 deaths due to aortic aneurysm (including 51 thoracic and 74 abdominal aortic aneurysms) and 134 deaths due to aortic dissection. We observed positive associations of body mass index with mortality from aortic aneurysm among men: the multivariable hazard ratios (95% confidence intervals) for highest versus lowest quintiles of body mass index were 4.48 (2.10-9.58), P for trend <0.0001 for aortic aneurysm; 6.52 (1.33-32.02), P=0.005 for thoracic aortic aneurysm; 3.81 (1.39-10.49), P=0.01 for abdominal aortic aneurysm; and 2.71 (1.59-4.62), P= 0.001 for total aortic disease. No association was found for aortic dissection. Among ever-smokers (men >= 90%) but not never-smokers (women 84%), an association between body mass index and aortic disease mortality was observed regardless of sex, which may explain the sex difference (P for sex-interaction = 0.046). Conclusions: We found a positive association between body mass index and mortality from aortic aneurysm among Japanese men and smokers.