Factors that Influence Growth Rates of Abdominal Aortic Aneurysms. Analysis of a Mexican Cohort.

Objective: Abdominal Aortic Aneurysms (AAA) growth remains a process not fully understood. The objective of this study was to analyze risk factors associated with changes in AAA diameter in a Mexican cohort.

Methods: An observational study in which we analyzed the entirely of patients in which an AAA was reported in a Computed Tomography (CT) study from 2014 to 2021 who had a follow-up CT. We divided them by groups depending on the diagnosis of type 2 diabetic mellitus and pharmacological history (diabetic vs non-diabetic, metformin vs non-metformin intake and statin vs non-statin intake). We compared pre and post follow-up AAA diameters using paired t-tests. A multivariate analysis was performed in order to identify independent variables associated with an increased growth rate. Statistical analysis was performed on Stata 17.

Results: During the studied period 72 (39.77%) patients had a follow-up CT. Mean age was 75 years (±9.05) and 52 (72.22%) were men. When comparing infra-renal largest diameter through time based on metformin intake, a significant difference was found only in the metformin non-intake group (42.05 ± 12.54 vs45.34 ± 12.06 [P = 0.02]), in contrast the metformin intake group measures were non-significantly different (36.13 ± 7.04 vs 37.00 ± 4.51; P = 0.57) through follow-up. In the multivariate analysis AAA largest diameter at diagnosis correlated with significantly increased growth rate (coeff = 0.06, P < 0.05).

Conclusions: AAA diameters appear to change through time in a non-linear pattern influenced by different epidemiological and clinical factors. Metformin intake appears to promote a stability in AAA diameter growth in our studied population.