The Association Between Trimethylamine N-Oxide (Tmao) and Kynurenine (Kyn) and Atherogenic Indices and Body Composition in Adults: A Cross-Sectional Study Publisher



Mirzababaei A ; Mahmoodi M ; Abaj F ; Ebrahimi S ; Samadi M ; Khalili P ; Mohamadi A ; Zarrinvafa Z ; Mirzaei K
Source: Nutrire Published:2025

Abstract

Background: Cardiovascular disease (CVD) is the leading cause of mortality and morbidity Worldwide. Changes in the gut microbiome’s composition have been linked to CVD. Atherogenic indices are increasingly used as the marker of plasma atherogenicity. This study aims to examine associations between gut microbiota metabolites trimethylamine N-Oxide (TMAO) and kynurenine (KYN) and the atherogenic indices and body composition. Methods: This cross-sectional study included 250 adults from the Tehran University of Medical Sciences (TUMS) Employee’s Cohort study (TEC) aged between 20 and 50 years. Anthropometric data and body composition were measured using a bioelectrical impedance analyzer (BIA). Serum profiles were measured based on the standard protocols and atherogenicity has been assessed using several indices, including Atherogenic Index of Plasma (AIP), Coronary Risk Indexes (CRI-I and CRI-II), Atherogenic Coefficient (AC), Cholesterol Index, and the TyG index. Serum concentrations of KYN and TMAO were measured using commercial kits. Result: A positive correlation between TMAO and KYN and hip circumference (HC), waist circumference (WC) and atherogenic indices was observed. In the adjusted model, higher TMAO (≥ 30.39 pg/ml) was associated with higher Atherogenic index of plasma (AIP) (β: 0.13, 95% CI: 0.01, 0.32, P = 0.03), the triglyceride-glucose index (TyG) (β: 0.21, 95% CI: 0.01,0.27, P = 0.04) and waist circumference (WC) (β: 0.12, 95% CI: 4.61,57.57, P = 0.05). Furthermore, after adjusting for confounders, a significant positive association between KYN levels and CHOLINDEX (β: 0.11, 95% CI: 7.66,12.18, P = 0.02) and HC levels (β: 0.15, 95% CI: 2.02–48.84, P = 0.03) was found. Conclusion: These findings demonstrate a possible role of TMAO and KYN as biomarkers of anthropometric measurements and atherogenic index disorder in adults. Further studies are needed to confirm the causality of these associations and potential mediating pathways. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.