Abstract
PURPOSE: This study investigates the clinical significance of ectopic fat and iron deposition in the liver and pancreas for glucose metabolism in elderly obese patients, with a focus on their potential for early diabetes screening and intervention. METHODS: We conducted a cross-sectional study of 140 elderly obese patients (aged 65-80 years, BMI ≥28 kg/m²) who underwent MRI quantification of hepatic and pancreatic fat (MRI-PDFF) and iron content (R2* values), along with measurements of visceral and subcutaneous fat via T2-weighted imaging. Glucose metabolism was assessed through oral glucose tolerance testing and related biomarkers. RESULTS: Compared to normal glucose tolerance (NGT) and impaired glucose regulation (IGR) groups, elderly obese patients with type 2 diabetes mellitus (T2DM) showed significantly higher ectopic fat in the liver (16.6% vs 6.9-13.4%) and pancreas (13.5% vs 8.5-9.0%), as well as increased visceral fat area (198.0cm² vs 137.8-163.9cm²). Liver fat percentage >11.8% was identified as an independent risk factor for abnormal glucose metabolism (OR=2.05, 95% CI 1.22-3.14), with a 2.05-fold increased risk compared to lower levels. The optimal diagnostic thresholds were determined as 11.8% for liver fat (sensitivity 83.2%, specificity 56.1%; AUC = 0.823) and 6.9% for pancreatic fat (sensitivity 72.2%, specificity 50.2%; AUC = 0.688), highlighting their clinical utility for early risk stratification. CONCLUSION: Ectopic fat deposition in the liver, particularly when exceeding 11.8%, is a significant independent risk factor for glucose metabolism abnormalities in elderly obese patients. Our findings demonstrate that MRI-based quantification of hepatic fat provides a valuable tool for early identification of diabetes risk, enabling targeted interventions to prevent disease progression. This study highlights the clinical importance of monitoring ectopic fat deposition in clinical practice for elderly obese populations.