Intramuscular Fat Assessed by AI-Assisted Muscle Ultrasound: Association With Cardiometabolic Risk Factors and Diabetic Nephropathy in Diabetes Mellitus.
Authors
Affiliations (1)
Affiliations (1)
- Hospital Clínico Universitario de Valladolid, Valladolid, Spain.
Abstract
Intramuscular fat (IMF) is increasingly recognized as a marker of ectopic adiposity and adverse cardiometabolic outcomes. Artificial intelligence (AI)-assisted ultrasound of the rectus femoris (RF) offers a non-invasive approach for quantifying IMF. This study evaluated the association of IMF with diabetes-related complications (particularly diabetic nephropathy) and metabolic risk factors in patients with diabetes mellitus (DM). In this cross-sectional study, outpatients from a tertiary Endocrinology and Nutrition Department underwent anthropometric assessment, bioimpedance analysis, and muscular ultrasound. Ultrasound images were analysed using the PIIXMED AI-system (DAWAKO MedTech; Valencia, Spain) to quantify muscle (Mi) and fat (FATi) percentages (the latter indicating the IMF). Associations between IMF, clinical characteristics, metabolic biomarkers, and vascular complications were examined. A total of 120 patients were included (57.5% men), with a mean age of 70.8 ± 10.3 years and diabetes duration of 13.8 ± 9.6 years. Most participants had type 2 DM (79.2%), with suboptimal glycaemic control (HbA1c 8.1% ± 1.5%). Individuals in the highest FATi quartile (> 43%) showed higher prevalence of microvascular complications, particularly diabetic nephropathy (44.0 vs. 14.7%, p = 0.001), and lower estimated glomerular filtration rate (63.6 ± 21.3 vs. 72.8 ± 20.1 mL/min/1.73m<sup>2</sup>, p = 0.045). Multivariate analysis showed that FATi remained independently associated with nephropathy (OR 6.01, 95% CI 1.99-18.14; p < 0.01). ROC analysis identified a FATi threshold of 43.5% with modest discriminative ability (AUC = 0.668). AI-assisted ultrasound-derived FATi is associated with adverse metabolic profiles and diabetic nephropathy. Assessment of IMF may provide an accessible biomarker related to microvascular complications. Longitudinal and multicentre studies are needed to determine the role of IMF in diabetes-related complications.