The association between body mass index and abdominal aortic aneurysm growth: a systematic review.

Diabetes, a state of relative insulin resistance, is negatively associated with both the presence and growth abdominal aortic aneurysms (AAA), which could suggest a protective role of obesity against AAA presence or growth. A recent meta-analysis demonstrated a trend toward a positive, though statistically non-significant, association between body mass index (BMI) and the presence of AAA. With respect to the association between obesity and AAA growth, however, the evidence had been very limited. To determine whether obesity (or BMI) is associated with AAA growth, we reviewed currently available studies with a systematic literature search. Our comprehensive search identified seven eligible studies reporting the association of BMI and AAA growth rates, which included data on a total of 3,768 AAA patients. All seven identified studies demonstrated no association between BMI and AAA growth. Despite a trend toward a positive association between BMI and AAA presence, the reason why BMI is not associated with AAA growth (suggested in the present review) is unclear. A discrepancy between associated comorbidities (coronary artery disease, peripheral artery disease, and chronic obstructive pulmonary disease) and AAA presence and between the same comorbidities and AAA growth, however, could be identified. Further investigations are required to elucidate why BMI is not associated with AAA growth despite the trend for a positive association with AAA presence.