Abstract P462: Myosteatosis: Differences in Association With Type 2 Diabetes by Anatomical Location

Abstract

Background: CT-derived muscle density (MD) reflects the degree of adiposity in muscle (i.e., myosteatosis) with lower MD indicating greater adiposity. Previous research indicates lower MD is associated with increased risk of type 2 diabetes (T2D). However, few studies have compared the association of simultaneously measured MD by anatomic location. The relationship between myosteatosis and cardiometabolic health may differ by body site and influence which location(s) is most useful for risk assessment. We investigated potential differential relationships between T2D and MD of the locomotor muscles of the abdomen (psoas), thigh, and calf among 539 African Caribbean men from Tobago. Methods: Men were aged 50-91 years (mean 64.4 years, mean BMI 27.5 kg/m 2 ). Calf MD was measured at 66% of calf length using peripheral quantitative CT; calf MD was defined as the ratio of muscle mass to cross-sectional muscle area. Psoas MD was measured in the abdomen (between L3/L4) and thigh MD was measured in the mid-thigh using CT; for these, MD was defined as the average muscle attenuation across each site. MDs were converted to per-SD units for comparability. T2D was defined as a fasting serum glucose level of ≥126 mg/dL or currently taking antidiabetic medication. Results: Psoas and thigh MDs were more highly correlated (r = 0.70) than psoas and calf (r = 0.33) or thigh and calf (r = 0.53) MDs, and calf MD was moderately correlated with BMI (r = -0.38) compared to lower BMI correlations for thigh (r = -0.18) or psoas (r = -0.16) MDs (all significant p < 0.05). After age and lifestyle factor adjustment (Table), a 1-SD lower MD of the thigh or calf was significantly associated with higher odds of T2D. Additional adjustment for BMI completely attenuated the association with T2D for thigh MD, but not calf MD. Conclusion: In our study of African Ancestry men, only calf MD was associated with higher odds of T2D independent of BMI and other muscle groups. Longitudinal studies are needed to better characterize specific muscle myosteatosis and metabolic abnormalities.