CT Emphysema and Deep Learning-derived Vertebral Bone Loss in Individuals without COPD: Findings from MESA.

Area of Science:

• Radiology
• Pulmonology
• Bone Metabolism

Background:

• The relationship between subclinical emphysema and bone mineral density (BMD) in individuals without chronic obstructive pulmonary disease (COPD) is not well understood.
• Early detection of lung and bone health markers is crucial for preventative strategies.

Purpose of the Study:

• To investigate the association between emphysema-like changes on chest CT and BMD loss in a large, multiethnic cohort without clinical COPD.
• To identify potential early imaging biomarkers for concurrent lung and bone health assessment.

Main Methods:

• Secondary analysis of chest CT scans from the SPIROMICS protocol within the MESA study.
• Deep learning models were used to quantify emphysema percentage and thoracic vertebral BMD.
• Linear mixed-effects models were employed, adjusting for covariates and analyzing interaction effects by sex and race/ethnicity.

Main Results:

• Increased emphysema percentage was associated with lower BMD cross-sectionally and greater annual BMD loss longitudinally.
• Significant associations were observed in men and Black/African American participants.
• A threshold of >2.7% emphysema predicted decreased BMD in men, affecting 39% of this subgroup.

Conclusions:

• Subclinical emphysema is an independent imaging marker associated with accelerated vertebral bone loss in individuals without COPD.
• These findings highlight a potential link between lung abnormalities and systemic skeletal decline, particularly in men.
• Emphysema-like changes on CT may serve as an early indicator of reduced bone health.