Study of the relationship between the Triglyceride-Glucose (TG/G) index and the species ratio of the microbiome

The triglyceride-glucose (TG/G) index is widely recognized as a surrogate marker of insulin resistance, providing valuable insights into the risk of cardiovascular diseases (CVD). Its elevation is associated with vascular calcification, coronary and carotid artery stenosis, and an increased likelihood of adverse CVD outcomes. The present study investigated the association between TG/G index levels and microbiome composition in patients with insulin resistance.

Materials and Methods:
Total DNA was extracted from 250 mg of fecal samples using the PureLink™ Microbiome DNA Purification Kit (Thermo Fisher Scientific, USA). Sequencing of the 16S rRNA gene was carried out on an Ion Gene Studio S5 Plus semiconductor sequencer in accordance with the Ion 16STM Metagenomics Kit protocol. The study enrolled 189 patients (mean age 49.3±7.2 years; 121 women and 68 men) diagnosed with insulin resistance.

Results:
The TG/G index revealed significant correlations with several clinical and laboratory parameters. Heart failure was present in 16% of patients, while effective antihypertensive treatment was observed in 92%. Elevated TG/G levels (>1.7 mmol/L) correlated with increased ESR, hemoglobin, leukocytes, neutrophils, lymphocytes, platelets, and LDL cholesterol (p<0.001). Echocardiographic analysis showed impaired diastolic function in 91 patients and a mean left ventricular mass index of 77.9±0.04. Carotid ultrasound revealed intima-media thickening in 24 individuals, strongly correlating with TG/G values and the presence of atherosclerotic plaques.

Importantly, microbiome sequencing indicated that elevated TG/G index values were associated with the presence of Bacteroidaceae, Prevotella copri, Enterobacter asburiae, and the phyla Firmicutes and Proteobacteria. The enrichment of pro-inflammatory Proteobacteria suggests that microbial imbalance may contribute to insulin resistance and cardiovascular complications, potentially through metabolite-mediated inflammation.

Conclusion:
The study demonstrates a strong link between the TG/G index and gut microbiome composition. Elevated TG/G values not only reflect metabolic and cardiovascular risk but are also associated with pro-inflammatory microbial shifts. These findings highlight the importance of integrating microbiome analysis with traditional clinical markers in assessing insulin resistance and CVD risk.

Abildinova Gulshara Zhusupovna was born in 1961 in the Republic of Kazakhstan. Geneticist of the highest category, doctor of medical sciences, professor, head of the laboratory of personalized genomic diagnostics in the hospital of the Presidential Administration of the Republic of Kazakhstan.

Experience of scientific and pedagogical work for 36 years. Published 200 scientific articles, including 65 after the defense of doctoral dissertation, in international editions and recommended by the Higher Attestation Commission of the Republic of Kazakhstan, 5 methodical recommendations, 7 patents and 4 monographs.

As a chief freelance geneticist of the Ministry of Health of the Republic of Kazakhstan . plays a major role in the improvement of medical and genetic care to the population of the Republic of Kazakhstan, effective implementation of the program of genetic screening of pregnant women and newborns, takes an active part in the system of protection of reproductive health of the population of the Republic of Kazakhstan; contributes to improving the level and quality of medical and genetic knowledge of doctors-geneticists and general practitioners, promotion of medical and genetic consultations.