Peripheral Quantitative Computed Tomography (pQCT) can be used for muscle and fat area and density assessments. These may independently influence muscle and fat mass measurements from Dual Energy X-ray Absorptiometry (DXA).
Objective: To determine associations between pQCT-derived soft tissue density and area measures and DXA-derived soft tissue mass.
Methods: Linear regression models were developed based on BMI and calf fat and muscle cross-sectional area (FCSA and MCSA) and density measured by pQCT in healthy women (n=76) and men (n=82) aged 20-59 years. Independent variables for these models were leg and total bone-free lean mass (BFLM) and fat mass (FM) measured by DXA.
Results: Sex differences (p<0.01) were found in both muscle (Mean±SE: Women: 78.6±0.4; Men: 79.9±0.2 mg/cm3) and fat (Women: 0.8±0.4 Men: 9.1±0.6 mg/cm3) density. BMI, fat density, and age (R2=0.86, p<0.01) best accounted for the variability in total FM. FCSA, BMI, and fat density explained the variance in leg FM (R2=0.87, p<0.01). MCSA and muscle density explained the variance in total (R2=0.65, p<0.01) and leg BFLM (R2=0.70, p<0.01).
Conclusion: Calf muscle and fat area and density independently predict lean and fat tissue mass.
Sherk, V. D.; Thiebaud, R. S.; Karabulut, Murat; Kim, S. J.; and Bemben, D. A., "Associations between pQCT-based fat and muscle area and density and DXA-based total and leg soft tissue mass in healthy women and men" (2014). Health and Biomedical Sciences Faculty Publications and Presentations. 4.
Journal of Musculoskelet Neuronal Interactions