Middle-aged lung diseases increase the risk of dementia

How does the health of the lungs affect the risk of dementia??

To limit the risk of dementia, we should pay more attention to the health of our lungs. Researchers have now found that when middle-aged people suffer from lung disease, it increases the risk of dementia at later ages.

The researchers at the University of Minnesota's School of Public Health found in their current study that lung disease in middle age leads to an increased risk of dementia later in life. The physicians published the results of their study in the English language journal "Journal of Respiratory and Critical Care Medicine".

Lung diseases in middle age increase the risk of those affected to suffer from dementia in their later life. (Image: RFBSIP / fotolia.com)

What are restrictive and obstructive lung diseases?

Dementia refers to a number of neurodegenerative disorders in which a person's memory and other cognitive abilities decrease.

Physicians are now studying how lung disease affects the risk of dementia. The study shows that there are associations with dementia or a risk of cognitive impairment in both restrictive and obstructive pulmonary diseases. Doctors use the term restrictive lung disease when the lungs can not expand. These diseases include idiopathic pulmonary fibrosis, in which the lung has scars, and sarcoidosis, in which some lung tissue is abnormally swollen. In obstructive pulmonary disease, airflow into or out of the lungs is impaired. The most common form of obstructive pulmonary disease is chronic obstructive pulmonary disease (COPD).

Poor lung health is often preventable

The prevention of dementia is a public health priority. Previous studies have already shown that poor lung health, which is often preventable, is associated with a higher risk of dementia, explains study author Dr. Pamela Lutsey from the University of Minnesota's School of Public Health.

Data from more than 14,000 subjects were evaluated

The researchers worked with data from 14,184 individuals with a mean age of 54 years from their study Atherosclerosis Risk in Communities Study (ARIC). All participants were subjected to so-called spirometry, a standard test often used by physicians to diagnose lung disease. On average, the researchers monitored the development of the subjects' health over a period of 23 years. During this time, 1,407 people were diagnosed with dementia.

How much was the risk of dementia increased?

After analyzing all these data, the authors of the current study found that people who suffered from lung disease during middle age had an increased risk of dementia or mild cognitive impairment, although the risk was even higher in people with restrictive lung disease. For example, persons with restrictive lung disease in middle age had a 58 percent higher risk of dementia or cognitive impairment later in life compared to people without lung disease. Obstructive pulmonary disease was 33 percent more risky.

What was investigated?

The researchers also found an association between the risk of dementia and low ratings in two spirometry assessments: forced expiratory volume in one second (FEV1) and forced vital capacity (FVC). FEV1 measures how much air a person can exhale in one second, while FVC determines the size of a person's lungs, the researchers explain.

Low oxygen levels in the blood can promote inflammation

Why can cognitive problems be related to respiratory symptoms? The researchers believe that the explanation may lie in the fact that people with lung diseases have a low oxygen content in the blood. This fact can lead to abnormal inflammation in the body and contribute to damage to the blood vessels in the brain, the experts add.

Further research is needed

Researchers acknowledge that there were a number of limitations in their study, including the fact that participants' lung function was only tested at baseline and many of these individuals died before physicians had the opportunity to screen for dementia. Since this is an observational study, the results can not prove that there is a causal link between lung disease and cognitive impairment or dementia, say the experts. However, further evidence of causality could encourage public initiatives that seek to improve air quality and help people quit smoking. (As)