Introduction: There is an association between skeletal muscle mass and static lunge volume in patients with COPD. However, how the changes in static lunge volumes affects the thoracic muscle mass (TMM) is unknown.

Aim: To investigate whether there is an association between changes in static lung volumes and changes of TMM.

Methods: A prospective 1-year follow-up of patients with stable COPD. Patients underwent body plethysmography and high-resolution CT.

One axial HRCT image at the first slice above the aortic arch was segmented using in-house semiautomated software. Hounsfield units (HU) between -29 to 150 was regarded as muscle.

Muscle was reported as cumulated height adjusted skeletal muscle index (SMI, cm2/m2). Baseline was reported as mean (95% confidence interval). Linear regression was applied for changes in SMI against the changes in total lung capacity (TLC), residual volume (RV), inspiratory capacity/TLC ratio (IC/TLC) adjusting for sex.

Results: Thirty-three patients (16 men, 17 women) were included with mean age 65.1 y.o.(61.9;68.2) . Table 1 shows demographics.

Table 1 

The demographics had no significant changes at follow-up.

There was a significant reduction in SMI within one year -2.1 cm2/m2 (p<0.0001).

There were no significant associations between the changes in SMI and TLC (R² 0.094), RV (R² 0.095), or IC/TLC (R² 0.049).

Conclusion: This pilot study suggests that the there is no association between the changes in static lung volumes and changes in thoracic muscle mass. However, further studies are needed.