A US prospective nested case-control study revealed that long-term increases in a gut-microbial metabolite, trimethylamine N-oxide (TMAO) were associated with higher risk of coronary heart disease (CHD), and repeated assessment of TMAO over 10 years improved the identification of people with a higher CHD risk. The study included 760 healthy women at baseline. Plasma TMAO levels were measured both at the first (1989 to 1990) and the second (2000 to 2002) blood collections; 10-year changes (Δ) in TMAO were calculated. Incident cases of CHD (n = 380) were identified after the second blood collection through 2016 and were matched to controls (n = 380). Increases in TMAO from the first to second blood collection were significantly associated with an increased CHD risk (relative risk [RR] in the top tertile: 1.58; RR per 1-SD increment: 1.33). Participants with elevated TMAO levels (the top tertile) at both time points showed the highest RR of 1.79 for CHD as compared with those with consistently low TMAO levels. Further, the ΔTMAO-CHD relationship was strengthened by unhealthy dietary patterns and was attenuated by healthy dietary patterns. Diet may modify the associations of ΔTMAO with CHD risk. Source: http://www.onlinejacc.org/
