Metformin therapy is not associated with the lower prevalence of ascending aortic aneurysm in diabetic patients

OBJECTIVES Metformin therapy has previously been associated with reduced abdominal aortic aneurysm growth rate in diabetic patients and shown to suppress the formation and progression of abdominal aortic aneurysm in normoglycemic mice. Here, we investigated the association between Metformin treatment and prevalence of aneurysm in the ascending aorta (AscAA). METHODS A total of 734 patients undergoing open-heart surgery for AscAA and/or aortic valve disease were studied. Diabetes status and medication use were self-reported by the patients in a systematic questionnaire. Aortic dilatation was defined as an aortic root or ascending aortic diameter >= 4.0 cm. High-sensitivity C-reactive protein levels were assessed as a measure of systemic inflammation. RESULTS We could confirm the inverse association between diabetes and AscAA prevalence (16% vs 43.9%, for diabetic and non-diabetic patients, respectively; Odds ratio 0.243; 95% CI, 0.129-0.460, P < 0.001). Furthermore, in diabetic patients, Metformin treatment was associated with lower high-sensitivity C-reactive protein levels. There was, however, no difference in the prevalence of AscAA among diabetic patients with and without Metformin treatment (16% vs 16% for treated and non-treated patients, respectively; OR 1.039; 95% CI 0.26-4.19, P = 0.957). CONCLUSIONS Our data do not support a protective effect of Metformin therapy in AscAA formation.