Role of estimated glucose disposal rate in predicting myosteatosis: Insights from abdominal CT analysis.

BACKGROUND AND AIMS: Myosteatosis, or fat infiltration in skeletal muscle, impairs muscle quality and contributes to insulin resistance. The estimated glucose disposal rate (eGDR) has emerged as a noninvasive marker of insulin resistance in diabetes mellitus. This study aimed to investigate the association between eGDR and myosteatosis in the general population.

METHODS AND

RESULTS

This cross-sectional study included 18,251 adults who underwent abdominal computed tomography (CT) scans as part of health screening examinations. eGDR was calculated using the formula: eGDR = 21.16 - (0.09 × waist circumference [cm]) - (3.41 × hypertension) - (0.55 × glycated hemoglobin [%]). Patients were categorized into three groups according to eGDR tertiles. To evaluate myosteatosis, the total abdominal muscle area (TAMA) at the L3 vertebral level of the axial CT image was segmented into normal-attenuation muscle area (NAMA), low-attenuation muscle area (LAMA), and inter/intra-muscular adipose tissue (IMAT). Myosteatosis was defined by the T-score of the NAMA/TAMA index, which was calculated as: NAMA/TAMA × 100. As a result, lower eGDR levels were significantly associated with an increased risk of myosteatosis. Adjusted ORs for class I myosteatosis were 3.71 (3.27-4.21) in men and 4.68 (3.97-5.52) in women. The NAMA/BMI and NAMA/TAMA indices, which reflect good muscle quality, decreased with lower eGDR, while LAMA/BMI and IMAT, indicators of poor muscle quality, increased. In the ROC analysis, eGDR outperformed HOMA-IR in predicting myosteatosis risk.

CONCLUSION

This study demonstrated a significant association between decreased eGDR levels and increased myosteatosis, as defined by sex-specific cutoffs of CT-based myosteatosis indices.