Association of Preperitoneal Fat Thickness and Echogenicity on Ultrasound with Type 2 Diabetes Risk

Abstract

Background: Visceral adiposity is strongly associated with type 2 diabetes (T2DM), yet conventional anthropometric measures inadequately capture fat distribution and quality. This study evaluated the association of ultrasound-assessed preperitoneal fat thickness (PFT) and echogenicity with T2DM risk.

Methods: This cross-sectional study enrolled 450 adults aged 30-70 years. PFT was measured using standardized ultrasound protocols, and echogenicity was graded as hypoechoic, isoechoic, or hyperechoic. Participants were categorized by glycemic status: normal glucose tolerance (n=161), prediabetes (n=161), or T2DM (n=128). Multivariable logistic regression and ROC curve analyses assessed independent associations with T2DM.

Results: Mean PFT increased progressively across glycemic categories (13.2±3.9 mm normal, 17.3±4.6 mm prediabetes, 21.4±5.8 mm diabetes; p<0.001). Hyperechoic fat was present in 52.3% of diabetes patients versus 6.9% with normal glucose tolerance (p<0.001). Each 1-mm PFT increase conferred 12% higher diabetes odds (OR=1.12, 95%CI:1.08-1.17, p<0.001). Hyperechoic fat is independently associated with 3.4-fold increased odds (OR=3.42, 95%CI:1.86-6.28, p<0.001). Combined high PFT and hyperechoic fat yielded OR=7.23 (95%CI:3.98-13.14, p<0.001). The combined model achieved superior discriminatory performance (AUC=0.856) compared to PFT alone (AUC=0.782) or echogenicity alone (AUC=0.698).

Conclusion: PFT and echogenicity provide complementary assessment of visceral adiposity and independently predict T2DM risk. Ultrasound evaluation of both fat quantity and quality may enhance diabetes risk stratification beyond conventional anthropometric measures.