Salivary Transcriptomic Biomarkers for Insulin Resistance

We have performed gene expression microarray analysis to profile transcriptomic signatures between insulin resistance high risk subjects and insulin resistance low risk subjects Participants enrolled in this study were recruited in the overnight fasted state, then the collection and processing of glucose (fasting, 30, 60 and 120 minutes) and insulin from blood samples, hemoglobin A1c (HbA1c) , assessment of medical history, socio-demographic characteristics, lifestyle factors, blood pressure and anthropometric and body composition measurements were conducted. During baseline visit, participants were asked to refrain from eating, drinking and oral hygiene procedures for at least 1-hour prior to saliva collection.5 ml of unstimulated whole saliva samples were consistently collected, stabilized and preserved, the sample supernatants were reserved at -80°C prior to assay. Based on the homeostasis model assessment of insulin resistance (HOMA-IR), using the formula [HOMA-IR= (fasting glucose*fasting insulin)/405], participants were divided into 2 groups: IR high risk group (HOMA-IR value ≥2.5) and IR low risk group (HOMA-IR value <2.5). Total RNA was extracted from saliva and subjected to gene expression microarray analysis using Affymetrix human genome 2.0 plus array