Association of plasma trimethylamine-N-oxide levels with post-stroke cognitive impairment: a 1-year longitudinal study

Background and aims Post-stroke cognitive impairment (PSCI) is a clinical condition arising from stroke and causes significant changes to memory, thinking, and behavior. Trimethylamine-N-oxide (TMAO), the metabolite produced by gut microbiota, has mechanistic relevance to atherosclerotic diseases. This study aimed to investigate whether an association existed between elevated plasma TMAO levels and PSCI. Methods Consecutive patients with acute ischemic stroke were prospectively enrolled during Jan. 2017 to Dec. 2017. TMAO concentration was measured within 24 h after admission. PSCI was assessed using the Mini-Mental State Examination (MMSE) score after 1 year and defined as MMSE score <= 26. Binary logistic regression analysis was used to determine the contribution of TMAO level in the prediction of PSCI. Results Of the 256 patients studied (age, 67.1 +/- 11.0 years; male, 54.3%), 86 (33.6%) patients were diagnosed as PSCI. The mean TMAO level was 5.6 +/- 2.4 mu M, with quartile level as follows: < 3.9 mu M (first quartile), 3.9-5.1 mu M (second quartile), 5.2-7.4 mu M (third quartile), and > 7.4 mu M (fourth quartile). After controlling for potential confounders, multivariable logistic analysis showed that higher level of plasma TMAO was an independent predictor for cognitive impairment in post-stroke patients (the quartile 1 was used as reference, the quartile 4 odds ratio, 3.304; 95% confidence intervals, 1.335-8.178; P = 0.010). Conclusions This study demonstrated that increasing plasma level of TMAO may be associated with PSCI.