Increased Serum Trimethylamine N-Oxide Level in Type 2 Diabetic Patients with Mild Cognitive Impairment

Cardiovascular biomarkerChronic inflammationCognitive decline biomarkerDiabetic complicationsGut microbiota metabolite

Increased Serum Trimethylamine N-Oxide Level in Type 2 Diabetic Patients with Mild Cognitive Impairment

Why this matters for your gut health

Type 2 diabetes (T2DM) carries a well-known risk of cognitive decline, but there’s no reliable early biomarker to flag which diabetic patients are heading toward mild cognitive impairment (MCI) before it becomes more serious. TMAO — a gut-microbiota-derived metabolite already linked to cardiovascular and kidney disease — had never been examined for its connection to cognition in diabetics. Identifying it as a marker could open the door to earlier screening and possibly gut-microbiome-targeted interventions to protect brain health in diabetic patients.

Summary

Die Studie verglich die TMAO-Serumspiegel bei 253 hospitalisierten T2DM-Patienten (74 mit MCI, 179 ohne) und 150 gesunden Kontrollpersonen in Shanghai, wobei der kognitive Status anhand der MoCA-Werte und die TMAO-Konzentration mittels HPLC-MS/MS bestimmt wurden. Die Diabetiker wiesen deutlich höhere TMAO-Werte auf als die gesunden Kontrollpersonen, und innerhalb der Diabetikergruppe hatten diejenigen mit MCI sogar noch höhere TMAO-Werte als diejenigen ohne MCI. Statistische Modellierungen zeigten, dass TMAO neben Bildungsniveau, Diabetesdauer, Hyperlipidämie und Entzündungsmarkern (hs-CRP) ein unabhängiger Prädiktor für das MCI-Risiko war.

Key findings

Serum TMAO was significantly higher in T2DM patients (12.28 μmol/L) vs healthy controls (5.10 μmol/L), P < 0.001
Among T2DM patients, MCI group had higher TMAO (14.16 μmol/L) than non-MCI group (11.75 μmol/L), P < 0.001
TMAO positively correlated with age, BMI, diabetes duration, HbA1c, triglycerides, creatinine, and hs-CRP (all P < 0.05)
TMAO negatively correlated with HDL-C, BDNF, and MoCA score
Multivariate logistic regression: TMAO was an independent risk factor for MCI (OR = 1.404, 95% CI 1.255–1.571, P < 0.001)
ROC analysis identified optimal TMAO cutoff of 14.14 μmol/L (sensitivity 70.3%, specificity 78.8%, AUC = 0.785)
Study limitations: single cognitive test (MoCA) used, cross-sectional design (no longitudinal tracking), assessment done within 7 days of admission (mood/mental state may confound results)

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Citation

Xu N, Wan J, Wang C, Liu J, Qian C, Tan H. Increased Serum Trimethylamine N-Oxide Level in Type 2 Diabetic Patients with Mild Cognitive Impairment. Diabetes Metab Syndr Obes. 2022;15:2197–2205.