Alcohol is a possible risk factor for abdominal aortic aneurysm (AAA), but evidence from individual studies is weak and inconsistent. Existing narrative reviews suggest the possibility of non-linear associations. A study aimed to quantify any association using a systematic literature review, followed by dose-response meta-analysis of prospective studies.
Research databases were searched to identify relevant prospective studies of alcohol consumption and AAA risk. Summary estimates of highest versus lowest levels of consumption, and linear and non-linear dose-response curves were quantified using random-effects models.
Eleven relevant cohorts were identified describing results from 3,580 individuals with AAA among 473, 092 participants. Data were extracted from ten cohorts for meta-analyses of high versus low levels of alcohol consumption (risk ratio for AAA 0·93, 95% CI (0·78 to 1·11). The linear dose-response risk ratio for AAA, derived from 11 cohorts, was 1·00 (0·97 to 1·04) per 8 g alcohol per day. Non-linear dose-response results showed a tick-shaped curve with lower risk up to 2 units/day, but increasing risk beyond that (P = 0·05). The increase in risk beyond 2 units/day was stronger in men than in women.
The authors conclude that although the linear dose-response analysis revealed little evidence of an association between alcohol consumption and AAA risk, a tick-shaped trend in the association was observed. This non-linear dose-response analysis revealed reduced risks for alcohol consumption below 2 units/day, masking increased risks for 2 or more units/day.
Source: Meta-analysis of the association between alcohol consumption and abdominal aortic aneurysm. Spencer SM, Trower AJ, Jia X, Scott DJA, Greenwood DC. Br J Surg. 2017 Sep 7. doi: 10.1002/bjs.10674.