High BP affects breathing capacity but physical activity can help: Study

High blood pressure impairs one's breathing capacity by hardening the airways in the respiratory system, thereby increasing resistance, a study has found.

However, being physically active can help by improving the functioning of respiratory muscles, resulting in better coordination between ventilation and blood flow in the lungs, researchers from the Federal University of Sao Paulo, Brazil, found.

Hypertension, in which one's blood pressure remains unusually high, is known to thicken the blood vessels and harden the arteries.

The researchers said that something similar happens with the bronchi -- branches of the main windpipe (trachea) -- in the respiratory system as well.

"This is very important as the more hardened the bronchi becomes, the more difficult it becomes for air to enter and leave the lungs. In the long run, this accelerated process of hardening of the bronchi makes breathing difficult for older people. Worse still, it's a cycle: lower oxygen saturation accelerates the aging process throughout the organism," last author Rodolfo de Paula Vieira, an invited professor at the Federal University of Sao Paulo, said.

However, performing physical activity was found to partly protect the airways from hardening due to increased blood pressure.

"We conclude that systemic arterial hypertension compromises lung function and mechanics in older adults and that a physically active lifestyle seems to partially accentuate these impairments. Thus, having a physically active lifestyle can mitigate these hypertension-induced pulmonary alterations in older adults," the authors wrote in the study published in the journal Advances in Respiratory Medicine.

While hypertension has been known to impair lung function, the mechanism involved was not clearly understood until now, Vieira said.

For the study, the researchers gauged the respiratory function of over 700 men and women aged 60 years or more, with or without high blood pressure, along with air resistance.

Muscle strength was assessed by looking at hand grip, while respiratory muscle strength was assessed by measuring air pressure as the participants inhaled and exhaled.

They also responded to questionnaires regarding their physical activity habits and quality of life.

The findings highlighted the need to look at lung function in patients having high blood pressure, Vieira said.

"Our findings show that physicians should refer patients diagnosed with high blood pressure to a specialist for tests to assess lung function and mechanics, especially older patients," Vieira said.

While changes to lung function are expected as one ages, the study showed that physical exercise can partly protect the lungs from the effects of hypertension, the researcher added.

Therefore, older patients "should also be given guidance on the importance of an active lifestyle to avoid loss of lung function due to high blood pressure," Vieira said.