Intramuscular and Intermuscular Abdominal Fat Infiltration in COPD: A Propensity Score Matched Study

Area of Science:

• Radiology
• Pulmonary Medicine
• Body Composition Analysis

Background:

• Skeletal muscle composition changes, including lipid infiltration, are increasingly recognized in chronic obstructive pulmonary disease (COPD).
• Low-attenuation muscle area (LAMA) signifies lipid-rich muscle, normal-attenuation muscle area (NAMA) signifies lipid-poor muscle, and intermuscular adipose tissue (IMAT) represents fat deposits between muscle groups.

Purpose of the Study:

• To quantitatively assess intramuscular and intermuscular fat infiltration in individuals with COPD.
• To evaluate low-attenuation muscle area (LAMA), normal-attenuation muscle area (NAMA), and intermuscular adipose tissue (IMAT) using abdominopelvic computed tomography (APCT).

Main Methods:

• A cross-sectional study involving 250 pairs of control and COPD subjects selected via propensity score matching from a larger cohort.
• APCT images were analyzed to quantify LAMA, NAMA, and IMAT.
• Comparison of intra-abdominal fat components between control and COPD groups, including mild and moderate COPD subgroups.

Main Results:

• COPD patients exhibited significantly lower NAMA attenuation and greater IMAT and LAMA indexes compared to controls.
• Mild and moderate COPD subgroups showed increased IMAT and LAMA indexes versus controls.
• Moderate COPD subjects, but not mild, displayed significantly lower NAMA attenuation and NAMA index.

Conclusions:

• Intramuscular and intermuscular abdominal fat infiltration is detectable in individuals with mild COPD.
• Fat infiltration in COPD appears to be exacerbated with increasing disease severity, particularly in moderate stages.