Anthropometric and biochemical markers of insulin resistance according to adipose tissue in overweight and obese patients: a cross-sectional study

Background: The need to diagnose insulin resistance (IR) is increasingly relevant since an early diagnosis may lead to timely interventions that may slow down onset of associated diseases. Currently, the gold standard for assessing insulin sensitivity is the euglycemic clamp, however, its reproducibility at the clinical level is challenging. Hence, the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), and the oral glucose tolerance test (OGTT) are being used in the clinical setting to identify insulin resistance, prediabetes, and diabetes. Thus, the purpose of this study was to compare HOMA-IR with insulin curves and their association with early insulin resistance in overweight patients in relation to biochemical markers and anthropometric measurements. Methods: This was descriptive cross-sectional study in 199 patients between 18 and 80 years of age for which demographic data, anthropometric measurements including body composition by bioelectrical impedance, and paraclinical tests (blood glucose, insulin, lipid profile) were performed. Measures of central tendency (mean or median) and dispersion (standard deviation or percentiles) were analyzed for quantitative variables according to data distribution. Shapiro-Wilk and Shapiro-Francia tests were performed to determine normality, which showed that none of the variables are normally distributed, and were therefore corrected with the Spearman correlation coefficient (non parametrical test). Results: Correlation analyses between anthropometric and biochemical measurements (body mass index, hip perimeter, waist-to-hip ratio, waist-to-height ratio, glucose curves 0-120 min, and insulin curve 0-30 min) and body composition (body fat percentage, visceral adipose tissue, and HOMA-IR) were performed. This analysis showed a statistically significant association between insulin curve at 0-30 minutes and body fat percentage (rho= 0.3256; p < 0.001); (rho= 0.2383; p= 0.0007); visceral adipose tissue (rho= 0.2900; p < 0.001) and HOMA-IR (rho= 0.9835; p < 0.001); (rho= 0.5301; p < 0.001). No statistically significant association was identified between plasma glucose at 0 and 120 minutes and body fat percentage (p< 0.1226) or visceral fat (p < 0.2471). Conclusion: By approaching the correlation between basal insulin at 0 and 30 minutes post-loading with VAT, BFP, and other anthropometric indices, we obtained results that strongly suggest that HOMA-IR and glucose curves are altered late and without correlation to the amount of adipose tissue.