Interstitial Lung Abnormalities Increase the Risk of Death

The presence of interstitial lung abnormalities is linked to an increased risk of death, according to a new research published in JAMA.

Lead author Rachel K. Putman, MD, and colleagues studied the link between interstitial lung abnormalities and the risk of mortality through 4 prospective cohort studies. The researchers found that the presence of these lung abnormalities leads to a higher risk of death across all groups. Even after the adjustment for smoking, cancer, chronic obstructive pulmonary disease (COPD), or coronary artery disease, the association between the abnormality and mortality is not lessened.

“These findings, in conjunction with those previously published, demonstrate that despite often being undiagnosed and asymptomatic, interstitial lung abnormalities may be associated with lower survival rates among older persons,” the authors wrote.

The Study Process

The study included participants from 4 cohort studies: 2633 patients from the Framingham Heart Study (FHS); 5320 from the Age Gene/Environment Susceptibility (AGES)-Reykjavik Study; 2068 from the COPD Gene Study; and 1670 from Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE).

The number of participants with interstitial lung abnormalities in each group was as follows:

• 177 (7%) from the FHS
• 378 (7%) from AGES-Reykjavik
• 156 (8%) from COPD Gene
• 157 (9%) from ECLIPSE

The follow-up period for the study was approximately 3 to 9 years. Except for the COPD Gene Study, there was a greater absolute rate of mortality among participants with interstitial lung abnormalities as compared to those with no interstitial lung abnormalities.

• 7% vs 1% in FHS
• 56% vs 33% in AGES-Reykjavik
• 11% vs 5% in ECLIPSE

Conclusion

Interstitial lung abnormalities are specific patterns of increased lung density noted on chest computed tomography scans. It is termed as an abnormality when it is identified in patients who don’t even have a prior history of interstitial lung disease in the first place. Interstitial lung disease is a progressive scarring of the lung tissue between the air sacs.

Patients suffering from interstitial lung abnormalities experience reductions in lung capacity, exercise capacity, gas exchange, and genetic abnormalities. The effects are very similar to patients who suffer from familial interstitial pneumonia and idiopathic pulmonary fibrosis. Usually, interstitial lung abnormalities may represent an early and mild form of pulmonary fibrosis.

The study provides evidence to show that interstitial lung abnormalities are associated with reduced survival rates in all groups. What’s worse is that the associations between interstitial lung abnormalities and mortality are not lessened after adjustment for smoking, cancer, COPD, or coronary artery disease.

“Follow-up studies should determine the risk factors for and the events that lead to death among people with interstitial lung abnormalities,” the authors concluded. “Given the ability to treat more advanced stages of pulmonary fibrosis, future clinical trials attempting to reduce the overall mortality associated with pulmonary fibrosis should consider including early stages of the disease.”