Abstract / Summary
Introduction: Insulin resistance represents an early metabolic abnormality underlying the development of type 2 diabetes and related endocrine disorders. Simple anthropometric measures are widely used in clinical practice to assess obesity; however, their relative performance in relation to markers of insulin resistance (IR) remains uncertain. Despite the widespread use of BMI in clinical practice, it does not distinguish between visceral and subcutaneous fat distribution, which may limit its accuracy in reflecting metabolic risk. Although WHR and BFP have been proposed as alternative indicators of central adiposity, comparative evidence regarding their relative performance in predicting insulin resistance remains inconsistent across populations. This study aimed to evaluate the association of body mass index (BMI), waist-to-hip ratio (WHR), and body fat percentage (BFP) with fasting plasma glucose and HOMA-IR in adults attending an obesity outpatient clinic.Methods: In this cross-sectional study, adult patients presenting to an obesity clinic and not using oral antidiabetic medications were included. Of 1,135 eligible patients, 444 met the inclusion criteria and were included in the final analysis. No a priori sample size or power calculation was performed; all eligible patients within the study period were included. Anthropometric measurements (BMI, WHR, BFP) were obtained. Fasting plasma glucose and HOMA-IR were calculated from fasting insulin and glucose levels. Correlation analyses and multivariable regression models were performed to assess associations. Receiver operating characteristic (ROC) curve analysis was used to evaluate the discriminatory performance of anthropometric indices for IR.Results: A total of 444 participants were included. The study population was predominantly female (>90%), which should be considered when interpreting the findings. WHR demonstrated a stronger association with HOMA-IR compared to BMI and BFP. In multivariable analyses, WHR remained independently associated with IR after adjustment for potential confounders (OR=1.28, 95% CI: 1.08–1.52, p=0.004). ROC analysis showed moderate discriminatory ability of anthropometric indices, with WHR yielding the highest area under the curve (AUC=0.642, 95% CI: 0.589–0.695, p<0.001), followed by BFP (AUC=0.610) and BMI (AUC=0.585). The discriminatory performance was more pronounced among male participants (AUC=0.773), although subgroup findings should be interpreted cautiously due to the limited sample size.Conclusion: Among adults attending an obesity outpatient clinic, WHR showed relatively stronger associations with markers of IR compared to BMI and BFP. These findings suggest that central adiposity measures may provide additional clinical information beyond BMI in the assessment of metabolic risk. Further prospective studies are warranted to confirm these findings and clarify their implications in broader populations.