Challenges in the diagnosis of insulin resistance: Focusing on the role of HOMA-IR and Tryglyceride/glucose index

Metabolic Syndrome (MS) prevalence is increasing worldwide in line with the growing prevalence of obesity. The underlying mechanism of MS is insulin resistance which can be diagnosed by measuring Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and Triglyceride/Glucose (TyG) Index. This review will focus on comparing studies assessing the HOMA-IR and TyG index cut-off points. We carried out a comprehensive review of the literature using suitable keywords on the search engines of PubMed, Scopus, Research Gate, and Google Scholar in the month of October 2020. There is a high degree of variability in determining threshold levels of HOMA-IR for defining insulin resistance. The distribution of the HOMA-IR varies according to the demographic characteristics of the subjects, such as age, sex, and race, making it difficult to estimate the optimal cut-off point. Another simpler method without requiring the use of insulin assays is TyG Index. Similar to HOMA-IR, the TyG Index cut-off point from existing data shows varying results. The HOMA-IR and the TyG index are simple and widely used methods for determining insulin resistance. However, an issue that arises is determining the insulin resistance cut-off point for both methods. Further studies are needed to assess the cut-off point of insulin resistance for various ethnicities associated with the risk of developing MS later in life.