Interstitial lung abnormalities linked to higher mortality

In four large, separate research cohorts in which middle-aged and older participants underwent lung CT, interstitial lung abnormalities were associated with a higher-than-average risk of death within 3-9 years, according to a report published online Feb. 16 in JAMA.

These imaging abnormalities were defined as specific patterns of increased lung density affecting more than 5% of any lung zone and included reticular or ground-glass abnormalities, diffuse centrilobular nodularity, nonemphysematous cysts, honeycombing, traction bronchiectasis, or pulmonary parenchymal architectural distortion diagnostic of fibrotic lung disease. They were identified in approximately 7% of the 11,691 study participants. The study findings, taken together with those of previous research, “demonstrate that despite often being undiagnosed and asymptomatic, interstitial lung abnormalities may be associated with lower survival rates among older persons,” said Dr. Rachel K. Putman of the pulmonary and critical care division at Brigham and Women’s Hospital and Harvard Medical School, Boston, and her associates.

Previously, interstitial lung abnormalities have been found in the same proportion, 7%, of the general population and have been associated with reduced lung capacity, exercise capacity, and gas exchange. They are more common in families affected by familial interstitial pneumonia and idiopathic pulmonary fibrosis. Given these correlations, “we hypothesized that the presence of interstitial lung abnormalities would be associated with an increased rate of mortality,” the investigators said.

To test this hypothesis, they analyzed data from four large study cohorts that included lung CT: 2,633 participants in the Framingham Heart Study (median follow-up of 4 years after CT), 5,320 in the Age Gene/Environment Susceptibility (AGES)-Reykjavik study (median follow-up, 8.9 years), 2,068 in the Genetic Epidemiology of COPD (COPDGene) study (median follow-up, 6.5 years), and 1,670 participants in the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) study (median follow-up, 2.9 years).

The absolute rates of all-cause mortality were significantly higher among participants who had interstitial lung abnormalities than among those who did not. Mortality rates were 7% vs. 1% in the FHS, 56% vs. 33% in AGES-Reykjavik, 16% vs. 11% in COPDGene, and 11% vs. 5% in ECLIPSE. After the data were adjusted to account for confounding factors such as age, sex, race, body-mass index, current smoking status, and pack-years of smoking, the lung abnormalities remained strongly associated with a higher risk of death in the FHS (hazard ratio, 2.7), AGES-Reykjavik (HR, 1.3), COPDGene (HR, 1.8), and ECLIPSE (HR, 1.4) studies.

The association remained robust in further analyses restricted only to nonsmoking participants, Dr. Putman and her associates said (JAMA. 2016 Feb 16;315[7]672-81. doi: 10.1001/jama.2016.0518).

The AGES-Reykjavik study was the only one to assess causes of death. In that cohort, participants who had interstitial lung abnormalities were more likely to die of a respiratory cause (13%) than were those who had no such abnormalities (4%) or those who had indeterminate findings on lung CT (6%). After the data were adjusted to account for confounding factors, participants with interstitial lung abnormalities were at much higher risk of dying from a respiratory cause (OR, 2.4) such as respiratory failure or pulmonary fibrosis. In contrast, there was no association between the lung abnormalities and deaths due to cardiovascular disease, cancer, or other causes.

The clinical implications of the association between interstitial lung abnormalities and mortality, particularly respiratory-related mortality, require further investigation, the investigators added.

This study was supported by the National Institutes of Health; the Icelandic Research Fund; the Lanspitali Scientific Fund; the National Cancer Institute; the National Heart, Lung, and Blood Institute; GlaxoSmithKline; the National Institute on Aging; the Icelandic Heart Association; and the Icelandic Parliament. Dr. Putman reported having no relevant financial disclosures; her associates reported numerous ties to industry sources.

[email protected]

In four large, separate research cohorts in which middle-aged and older participants underwent lung CT, interstitial lung abnormalities were associated with a higher-than-average risk of death within 3-9 years, according to a report published online Feb. 16 in JAMA.

These imaging abnormalities were defined as specific patterns of increased lung density affecting more than 5% of any lung zone and included reticular or ground-glass abnormalities, diffuse centrilobular nodularity, nonemphysematous cysts, honeycombing, traction bronchiectasis, or pulmonary parenchymal architectural distortion diagnostic of fibrotic lung disease. They were identified in approximately 7% of the 11,691 study participants. The study findings, taken together with those of previous research, “demonstrate that despite often being undiagnosed and asymptomatic, interstitial lung abnormalities may be associated with lower survival rates among older persons,” said Dr. Rachel K. Putman of the pulmonary and critical care division at Brigham and Women’s Hospital and Harvard Medical School, Boston, and her associates.

Previously, interstitial lung abnormalities have been found in the same proportion, 7%, of the general population and have been associated with reduced lung capacity, exercise capacity, and gas exchange. They are more common in families affected by familial interstitial pneumonia and idiopathic pulmonary fibrosis. Given these correlations, “we hypothesized that the presence of interstitial lung abnormalities would be associated with an increased rate of mortality,” the investigators said.

To test this hypothesis, they analyzed data from four large study cohorts that included lung CT: 2,633 participants in the Framingham Heart Study (median follow-up of 4 years after CT), 5,320 in the Age Gene/Environment Susceptibility (AGES)-Reykjavik study (median follow-up, 8.9 years), 2,068 in the Genetic Epidemiology of COPD (COPDGene) study (median follow-up, 6.5 years), and 1,670 participants in the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) study (median follow-up, 2.9 years).

The absolute rates of all-cause mortality were significantly higher among participants who had interstitial lung abnormalities than among those who did not. Mortality rates were 7% vs. 1% in the FHS, 56% vs. 33% in AGES-Reykjavik, 16% vs. 11% in COPDGene, and 11% vs. 5% in ECLIPSE. After the data were adjusted to account for confounding factors such as age, sex, race, body-mass index, current smoking status, and pack-years of smoking, the lung abnormalities remained strongly associated with a higher risk of death in the FHS (hazard ratio, 2.7), AGES-Reykjavik (HR, 1.3), COPDGene (HR, 1.8), and ECLIPSE (HR, 1.4) studies.

The association remained robust in further analyses restricted only to nonsmoking participants, Dr. Putman and her associates said (JAMA. 2016 Feb 16;315[7]672-81. doi: 10.1001/jama.2016.0518).

The AGES-Reykjavik study was the only one to assess causes of death. In that cohort, participants who had interstitial lung abnormalities were more likely to die of a respiratory cause (13%) than were those who had no such abnormalities (4%) or those who had indeterminate findings on lung CT (6%). After the data were adjusted to account for confounding factors, participants with interstitial lung abnormalities were at much higher risk of dying from a respiratory cause (OR, 2.4) such as respiratory failure or pulmonary fibrosis. In contrast, there was no association between the lung abnormalities and deaths due to cardiovascular disease, cancer, or other causes.

The clinical implications of the association between interstitial lung abnormalities and mortality, particularly respiratory-related mortality, require further investigation, the investigators added.

This study was supported by the National Institutes of Health; the Icelandic Research Fund; the Lanspitali Scientific Fund; the National Cancer Institute; the National Heart, Lung, and Blood Institute; GlaxoSmithKline; the National Institute on Aging; the Icelandic Heart Association; and the Icelandic Parliament. Dr. Putman reported having no relevant financial disclosures; her associates reported numerous ties to industry sources.

[email protected]

In four large, separate research cohorts in which middle-aged and older participants underwent lung CT, interstitial lung abnormalities were associated with a higher-than-average risk of death within 3-9 years, according to a report published online Feb. 16 in JAMA.

These imaging abnormalities were defined as specific patterns of increased lung density affecting more than 5% of any lung zone and included reticular or ground-glass abnormalities, diffuse centrilobular nodularity, nonemphysematous cysts, honeycombing, traction bronchiectasis, or pulmonary parenchymal architectural distortion diagnostic of fibrotic lung disease. They were identified in approximately 7% of the 11,691 study participants. The study findings, taken together with those of previous research, “demonstrate that despite often being undiagnosed and asymptomatic, interstitial lung abnormalities may be associated with lower survival rates among older persons,” said Dr. Rachel K. Putman of the pulmonary and critical care division at Brigham and Women’s Hospital and Harvard Medical School, Boston, and her associates.

Previously, interstitial lung abnormalities have been found in the same proportion, 7%, of the general population and have been associated with reduced lung capacity, exercise capacity, and gas exchange. They are more common in families affected by familial interstitial pneumonia and idiopathic pulmonary fibrosis. Given these correlations, “we hypothesized that the presence of interstitial lung abnormalities would be associated with an increased rate of mortality,” the investigators said.

To test this hypothesis, they analyzed data from four large study cohorts that included lung CT: 2,633 participants in the Framingham Heart Study (median follow-up of 4 years after CT), 5,320 in the Age Gene/Environment Susceptibility (AGES)-Reykjavik study (median follow-up, 8.9 years), 2,068 in the Genetic Epidemiology of COPD (COPDGene) study (median follow-up, 6.5 years), and 1,670 participants in the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) study (median follow-up, 2.9 years).

The absolute rates of all-cause mortality were significantly higher among participants who had interstitial lung abnormalities than among those who did not. Mortality rates were 7% vs. 1% in the FHS, 56% vs. 33% in AGES-Reykjavik, 16% vs. 11% in COPDGene, and 11% vs. 5% in ECLIPSE. After the data were adjusted to account for confounding factors such as age, sex, race, body-mass index, current smoking status, and pack-years of smoking, the lung abnormalities remained strongly associated with a higher risk of death in the FHS (hazard ratio, 2.7), AGES-Reykjavik (HR, 1.3), COPDGene (HR, 1.8), and ECLIPSE (HR, 1.4) studies.

The association remained robust in further analyses restricted only to nonsmoking participants, Dr. Putman and her associates said (JAMA. 2016 Feb 16;315[7]672-81. doi: 10.1001/jama.2016.0518).

The AGES-Reykjavik study was the only one to assess causes of death. In that cohort, participants who had interstitial lung abnormalities were more likely to die of a respiratory cause (13%) than were those who had no such abnormalities (4%) or those who had indeterminate findings on lung CT (6%). After the data were adjusted to account for confounding factors, participants with interstitial lung abnormalities were at much higher risk of dying from a respiratory cause (OR, 2.4) such as respiratory failure or pulmonary fibrosis. In contrast, there was no association between the lung abnormalities and deaths due to cardiovascular disease, cancer, or other causes.

The clinical implications of the association between interstitial lung abnormalities and mortality, particularly respiratory-related mortality, require further investigation, the investigators added.

This study was supported by the National Institutes of Health; the Icelandic Research Fund; the Lanspitali Scientific Fund; the National Cancer Institute; the National Heart, Lung, and Blood Institute; GlaxoSmithKline; the National Institute on Aging; the Icelandic Heart Association; and the Icelandic Parliament. Dr. Putman reported having no relevant financial disclosures; her associates reported numerous ties to industry sources.

[email protected]