2179-P: Psoas Muscle Area Is a Useful Indicator of Muscle Mass in Older Men with Type 2 Diabetes: A Retrospective Study

Introduction and Objective: Sarcopenia is more prevalent in patients with diabetes than those without diabetes. Skeletal muscle mass is commonly assessed by the skeletal muscle mass index (SMI), for example, measured by bioelectrical impedance analysis (BIA); but BIA may overestimate muscle mass in patients with edema or implanted metal and is not applicable in some patients with implanted devices. We investigated whether the psoas muscle area (PMA) measured on CT could serve as an alternative marker of muscle mass. Methods: This retrospective study included 101 inpatients with type 2 diabetes aged ≥65 years (62 men, 39 women). Metabolic and physical parameters, including PMA and SMI, were assessed. PMA was measured by tracing bilateral psoas muscles on CT at the L4 level and summing both sides, and SMI was measured using InBody®. Analyses were performed separately by sex. Associations between PMA and clinical indices were evaluated by Pearson correlation. Using the Asian Working Group for Sarcopenia (AWGS) 2019 SMI cutoffs (men 7.00 kg/m², women 5.70 kg/m²), univariate ROC analysis with PMA as the predictor was conducted to identify the optimal PMA cutoff for reduced SMI based on the Youden index; AUC, sensitivity, and specificity were calculated. JMP Pro version 18 was used. Results: Men had higher PMA, handgrip strength, SMI, and visceral fat area than women (19.2 ± 4.42 vs 12.3 ± 2.58 cm²; 33.1 ± 8.77 vs 20.9 ± 5.33 kg; 7.11 ± 0.103 vs 5.84 ± 0.132 kg/m²; 121 ± 8.84 vs 89.4 ± 10.7 cm²; all p < 0.05), while subcutaneous fat area was higher in women(96.4 ± 7.68 cm2 vs 137 ± 9.54 cm2). No other differences were found. In men, PMA correlated with SMI (r = 0.397, p < 0.01) and handgrip strength (r = 0.389, p < 0.01) and was inversely correlated with age (r = −0.480, p < 0.01). In women, PMA showed no correlation with SMI or other indices. In men, ROC analysis showed that PMA was associated with reduced SMI, with an AUC of 0.78 (95% CI 0.71-0.85). Conclusion: PMA measured on CT may assess muscle mass in older men with type 2 diabetes, whereas PMA may be less suitable as a muscle-mass indicator in women. Disclosure S. Inagawa: None. S. Fujisaka: None. M. Tanabe: None. K. Kobayashi: None. S. Ohgaku: None. A. Takikawa: None. H. Honoki: None. K. Tobe: None. M. Kato: Speaker's Bureau; Ended; AbbVie Inc., Eli Lilly and Company.