Abstract

Background: Prediabetes, defined as blood glucose levels above normal but below the diagnostic threshold for type 2 diabetes (T2D), represents a high-risk state with a substantial likelihood of progression to T2D. This condition is characterized by a gradual decline in insulin sensitivity and pancreatic beta-cell function. Indices such as HOMA-IR and HOMA-%B, together with emerging surrogate markers like TyG, are widely used to assess insulin resistance and beta-cell function. In Asian populations, including Vietnam, T2D often develops even among individuals with normal BMI, highlighting the critical role of beta-cell dysfunction. However, data on insulin resistance and beta-cell function in prediabetes in Vietnam remain limited.

Methods: A cross-sectional study was conducted on 280 newly diagnosed prediabetic individuals in Quang Binh from July 2022 to September 2023. Insulin resistance was assessed using HOMA-IR and TyG, while pancreatic beta-cell function was evaluated with HOMA-%B.

Results: Impaired pancreatic beta-cell function was observed in 78.7% of participants and was significantly associated with overweight–obesity (OR=16.15; p<0.01) and abdominal obesity (OR=4.31; p<0.05). The prevalence of insulin resistance detected by TyG was higher than that detected by HOMA-IR (32.5% vs. 29.8%). TyG was positively correlated with HOMA-IR (r=0.395; p<0.001) and was strongly associated with triglycerides and non-HDL-C.

Conclusion: Pancreatic beta-cell dysfunction and insulin resistance appear early in Vietnamese individuals with prediabetes, even at relatively low mean BMI, reflecting the “weak beta-cell” phenotype of Asian populations. The TyG index was more sensitive than HOMA-IR in detecting insulin resistance and was closely linked to dyslipidemia, while HOMA-%B highlighted the influence of overweight and central obesity. The application of simple, low-cost indices such as HOMA-%B and TyG is valuable for early screening, detection, and risk stratification, and supports the need to establish population-specific diagnostic thresholds for the Vietnamese population.