From Gut to Vessel Wall: TMAO and Carotid Ultrasound in Pediatric Obesity
Author Block: A. Borlea, D. I. Stoian, S. MIHUTA, A. BENA, C. Paul; Timisoara/RO
Purpose: PURPOSE. To investigate the relationship between serum trimethylamine N-oxide (TMAO), a gut-derived metabolite, and carotid intima–media thickness (CIMT) as an ultrasound marker of subclinical atherosclerosis in children with obesity.
Methods or Background: METHODS. We enrolled 70 children aged 4–18 years: 50 obese (BMI >95th percentile, waist circumference >90th percentile) and 20 normal-weight controls. Clinical evaluation included BMI, waist-to-height ratio, Tanner stage, and signs of insulin resistance. Serum TMAO was measured by liquid chromatography–mass spectrometry, alongside fasting glucose, insulin, lipid profile, transaminases, creatinine, uric acid, and vitamin D. CIMT was assessed bilaterally with high-resolution ultrasound. Arterial stiffness parameters (pulse wave velocity [PWV], augmentation index, and central and peripheral blood pressures) were recorded for comparison.
Results or Findings: RESULTS. Obese children had significantly higher TMAO levels (median 289.5 vs 218.7 µg/L, p=0.02) and CIMT (0.56 ± 0.07 vs 0.49 ± 0.05 mm, p<0.001) compared to controls. Serum TMAO correlated positively with CIMT (ρ=0.41, p<0.001), PWV (ρ=0.36, p=0.004), and systolic blood pressure (ρ=0.33, p=0.007). In multivariable regression, TMAO remained an independent predictor of CIMT (β=0.37, p<0.001), even after adjusting for BMI, waist measures, age, and puberty stage. Children with insulin resistance had higher CIMT and PWV than their non-insulin-resistant peers, but TMAO levels did not differ significantly between subgroups. Logistic regression showed that higher TMAO was associated with increased odds of acanthosis nigricans (p=0.03).
Conclusion: CONCLUSION. Serum TMAO is elevated in pediatric obesity and independently predicts carotid intima–media thickness, reinforcing the role of ultrasound as the key imaging modality to detect early vascular injury in this population.
Limitations: Limitations: cross-sectional design; limited control sample; absence of dietary/microbiome profiling
Funding for this study: No funding
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The Ethics Committee for Scientific Research of the “Pius Brinzeu” Emergency County Hospital has approved the study (No. 349/15.11.2022)