Association between Plasma Trimethylamine N-Oxide Levels and Type 2 Diabetes: A Case Control Study

Cardiovascular RiskCase-Control StudyDietary BiomarkersGut MicrobiotaHbA1c

Association between Plasma Trimethylamine N-Oxide Levels and Type 2 Diabetes: A Case Control Study

Why this matters for your gut health

Type 2 diabetes (T2D) prevalence is rising sharply in Saudi Arabia and globally, and prior research on the gut-microbiota metabolite TMAO and its link to diabetes has been inconsistent across populations. This study is the first to measure TMAO levels specifically in an Arabic population, helping clarify whether elevated TMAO is a meaningful, diet-modifiable risk marker for T2D, and whether ethnic/dietary differences explain conflicting results in earlier research.

Summary

This case-control study measured plasma TMAO in 297 Saudi participants (133 with T2D, 164 healthy controls) using UPLC-MS/MS, alongside diet (via a Saudi-validated FFQ), physical activity (IPAQ), and blood biomarkers. TMAO was significantly higher in diabetics than controls and correlated with fasting glucose, HbA1c, and triglycerides. After adjusting for age, BMI, education, physical activity, and diet, only the highest TMAO quartile (>6.40 µmol/L) remained significantly associated with T2D risk, and red meat intake was the main dietary driver of elevated TMAO.

Key findings

Median TMAO: 4.95 µmol/L (T2D) vs. 3.07 µmol/L (controls), p<0.001
Unadjusted model: OR=1.11 per unit TMAO increase (p<0.001)
Fully adjusted model (age, BMI, education, activity, diet): only highest TMAO quartile significant — OR=3.36, 95% CI [1.26–9.04], p=0.02
Positive correlations: TMAO with age (r=0.322), FPG (r=0.131), HbA1c (r=0.227), triglycerides (r=0.115)
Red meat consumption significantly associated with higher TMAO in T2D patients (p=0.014–0.025)
No significant TMAO association with BMI, LDL, HDL, or hs-CRP
First study reporting TMAO levels in an Arab population; comparable to US levels, not Chinese cohort levels

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Citation

Kalagi, N.A.; Thota, R.N.; Stojanovski, E.; Alburikan, K.A.; Garg, M.L. Association between Plasma Trimethylamine N-Oxide Levels and Type 2 Diabetes: A Case Control Study. Nutrients 2022, 14, 2093.