Higher TMAO Levels Linked to Greater Risk of Abdominal Aortic Aneurysm

Higher blood levels of the gut microbiome-derived metabolite trimethylamine N-oxide (TMAO) were independently associated with an increased risk of developing abdominal aortic aneurysms (AAAs) and experiencing serious AAA-related events in apparently healthy older adults. Researchers measured plasma TMAO levels in 4,442 community-dwelling adults aged 65 years or older from the US Cardiovascular Health Study and followed them prospectively with ultrasound screening. Higher baseline TMAO levels were associated with larger infrarenal aortic diameter and a greater likelihood of AAA. During a median follow-up of 12.2 years (54,402 person-years), 79 participants experienced major AAA events, including aneurysm repair, rupture, or AAA-related death. After adjusting for traditional cardiovascular risk factors, kidney function, socioeconomic status, and cardiometabolic lifestyle factors, elevated TMAO remained independently associated with a significantly higher risk of adverse AAA outcomes, whether analyzed as a continuous measure, by tertiles, or using a clinical threshold of ≥6.2 μM. These findings identify TMAO as a novel risk factor for AAA and suggest it may represent a potential therapeutic target for preventing AAA development and progression. Source: https://academic.oup.com/eurheartj/