Abstract
Background
Adipose tissue (AT) is known as a passive reservoir for energy storage and an active endocrine organ responsible for the synthesis of bioactive molecules called adipokines. Omentin is known as an anti-inflammatory adipokine that can modulate insulin sensitivity. In the present study, we aimed to investigate the relationship between omentin mRNA expression and glucose homeostasis of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) in non-diabetic adults.
Methods
VAT and SAT adipose tissues were collected from 137 adults, aged ≥ 18 years, who were hospitalized for abdominal surgery. Preoperative venous blood samples were taken from the participants before surgery to measure fasting plasma glucose, insulin, and triglyceride. BMI, HOMA-IR, and HOMA-B were calculated. Insulin levels were measured with Mercodia kits using enzyme-linked immunosorbent assay (ELISA). In order to obtain omentin mRNA expression, real-time PCR was performed.
Results
Overall, 91 (51.7%) subjects were healthy (without insulin resistance (IR)), and 46 (26.1%) participants were with IR. Fold changes of VAT and SAT omentin expression in IR subjects were 2.32 and 1.30, respectively (P > 0.05). After controlling for age and BMI, linear regression analysis indicated a significant positive association of SAT omentin expression with insulin concentration (β = 0.048; 95% CI: 0.009, 0.088, P = 0.017) and HOMA-IR (β = 0.173; 95% CI: 0.023, 0.323, P = 0.014). Moreover, a negative association of SAT omentin expression with HOMA-B (β=-0.001; 95% CI: 0.002, -0.001, P < 0.001) was observed.
Conclusion
This study's finding confirms a direct association between IR with omentin mRNA levels in SAT. Besides, the indicator of insulin sensitivity had an inverse association with omentin gene expression in SAT. This aspect of research suggests that omentin secretion from SAT has a strong link with insulin regulation.