Middle-aged adults with lung disease may face increased dementia risk

A recent study revealed middle-aged adults living with lung disease could be at greater risk of developing dementia or cognitive impairment as they age.

The research was published in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.

"Preventing dementia is a public health priority, and previous studies have suggested that poor lung health, which is often preventable, may be linked to a greater risk of developing dementia," said lead study author Pamela L. Lutsey, MD, PhD, in an American Thoracic Society prepared statement. "In this study, we looked at the long-term association between poor lung function and the risk of developing dementia, using high-quality measures."

Lutsey and colleagues found restrictive and obstructive lung diseases were associated with dementia, Alzheimer’s disease and mild cognitive impairment. The link was stronger in those with restrictive lung diseases, such as idiopathic pulmonary fibrosis and sarcoidosis, than for chronic obstructive pulmonary disease (COPD).

As part of the study, the team analyzed data from more than 14,000 patients (average age of 54) from the Atherosclerosis Risk in Communities (ARIC) study who had undergone spirometry. Those patients were followed for an average of 23 years. Lutsey et al. found 1,407 instances of dementia during that time period.

Patients with restrictive lung disease had 58 percent higher odds of developing dementia or mild cognitive impairment compared to those without lung disease. Obstructive lung disease patients had 33 percent higher odds than those without the disease.

Low blood oxygen levels caused by lung disease may have led to inflammation, stress and damage to the brain’s blood vessels—a potential explanation for their findings, they wrote.

Though their study was neither randomized nor controlled, if the associations are causal, they wrote, it may provide an extra push lawmakers need to improve air quality and prevent people from smoking.

"Preventing lung disease is inherently important," Lutsey said in the release. "If other studies confirm our study's findings, both individuals and policymakers will have an added incentive to make changes that protect lung health, as doing so may also prevent dementia."