Insulin resistance in relation to inflammatory gene expression and metabolic features in apparently healthy obese individuals

The present study aimed to investigate the association of insulin resistance (IR) with inflammatory gene expression levels, metabolic health, lipid profile, and body composition in the apparently healthy obese. In this cross-sectional study, 88 apparently healthy obese subjects were recruited and divided into insulin-resistant and non-insulin-resistant (NIR) groups. Fasting blood samples were taken to determine serum metabolic features. mRNA expression of inflammatory genes were assessed in freshly isolated peripheral blood mononuclear cells (PBMCs), using quantitative real-time PCR (qPCR). Bioelectrical impedance analysis (BIA) was used to describe body composition. Among inflammatory genes, toll-like receptor 4 (TLR4) mRNA revealed significant upregulation in PBMCs of IR group compared with NIR individuals (p = 0.035). High-density lipoprotein cholesterol (HDL-C, p = 0.04), low-density lipoprotein cholesterol (LDL-C, p < 0.001), waist circumference (p = 0.025), and waist to hip ratio (p = 0.013) were significantly different between the two groups. A significant but weak correlation of HDL-C was observed with TLR4 (r = − 0.305; p = 0.011) and myeloid differentiation factor 88 (MyD88, r = − 0.27; p = 0.024) expression level. Also, LDL-C was found to be correlated with TLR4 (r = 0.302; p = 0.012) and MyD88 (r = 0.267; p = 0.027) expression levels. There was also a significant correlation between HOMA-IR and HDL-C (r = − 0.25; p = 0.019). The results of this study indicated the possible link between IR and TLR4. Also, there was a significant correlation between HDL-C and LDL-C as well as between TLR4 and MyD88. Some inflammatory genes and metabolic parameters were also significantly correlated.