Smoking, Smoking Cessation, And Risk Of Abdominal Aortic Aneurysm: The Atherosclerosis Risk In Communities Study

Introduction: Smoking is the strongest risk factor for abdominal aortic aneurysm (AAA), and male ever smokers who are recommended for one-time screening for AAA with ultrasonography at age of 65 to 75 years. However, the proportion of eligible individuals who receive this screening remains small (~1%). Few studies have evaluated the association of key smoking parameters with incident AAA by sex. Methods: In 14,889 ARIC participants free of a history of AAA at baseline (1987-89), we quantified the associations of smoking parameters (pack-years, duration, and intensity [pack/day]) with incident AAA (hospitalizations with AAA diagnosis [ICD code: 441.3, 441.4, 38.44, 39.71] or a death certificate ICD code: 441.3, 441.4, I71.3, I71.4) using Cox models. Years since quitting in former smokers were explored as time-varying variables. Results: Over a median follow-up of 20 years, there were 567 cases of AAA. The incident rate of AAA was 5.98 per 1,000 person-years in male current smokers and 2.65 per 1,000 person-years in female current smokers. Pack-years was significantly associated with incident AAA (HR 7.31 [95% CI 5.48-9.74] for those smoked ≥40 pack-years vs. never smokers) and the association was stronger in women than men (8.53 [5.03-14.45] vs. 5.97 [4.21-8.47], p-for-interaction =0.02). Both smoking duration and intensity showed significant associations with AAA. Smoking cessation demonstrated a graded association with lower risk of AAA in both sexes, but significantly increased risk lasted longer in men (2.16 [1.39-3.36] in 30-<40 years after cessation) than in women (1.84 [0.76-4.46] in 20-<30 years after cessation) (Table). Conclusions: All smoking parameters tested consistently show significant associations with incident AAA in both sexes. After cessation, the residual risk lasted at least 40 years in men and 20 years in women. Our results further emphasize the importance of smoking prevention and early cessation for preventing AAA and the potential need of AAA screening in female current smokers and recent quitters.