High blood pressure reduces breathing capacity due to hardening of the bronchi, research shows

High blood pressure (hypertension) causes thickening of the blood vessels and hardening of the arteries (arteriosclerosis). A study conducted by Brazilian researchers has shown for the first time that a similar phenomenon occurs in the lungs. High blood pressure hardens the bronchi and increases airway resistance, affecting breathing capacity.

The research group consisted of 731 men and women over the age of 60, both with and without high blood pressure. It is designed to investigate the effects of hypertension on lung mechanics, by detecting where and how high blood pressure impairs lung function. An article reporting the findings is published in the news Advances in respiratory medicine.

“Our analysis showed that subjects who practiced regular physical activities appeared to be partially protected against hardening of the bronchi,” Rodolfo de Paula Vieira, the last author of the paper, told Agência FAPESP. Vieira directs the Pulmonary Immunology and Exercise Laboratory at the Institute of Science and Technology of the Federal University of São Paulo (ICT-UNIFESP) in São José dos Campos, São Paulo State, Brazil.

The researchers performed spirometry tests to measure respiratory function, and assessed lung mechanics with impulse oscillometry, a technique that uses sound waves to measure resistance to the normal movement of air in and out of the lungs during breathing at rest.

General muscle strength was measured using a handgrip dynamometer, and respiratory muscle strength was evaluated using a manovacuometer to measure maximum inspiratory and expiratory pressures. The participants answered questionnaires about the intensity and frequency of physical activity, as well as items related to quality of life.

According to Vieira, the findings highlight the need to assess respiratory function in patients with hypertension, which affects approximately 1 billion people worldwide.

“It has long been known that hypertension impairs lung function, but until now the mechanism involved was not clearly understood. Our findings show that doctors should refer patients diagnosed with high blood pressure to a specialist for tests to assess lung function and mechanics, especially older people. Patients should also be counseled on the importance of an active lifestyle to prevent loss of lung function due to high blood pressure,” Vieira said.

Previous research has shown that lung function is closely linked to the ability of the lungs to expand and return to their previous state (distensibility and resistance), and that this was most altered in older patients with hypertension.

“Changes in lung mechanics are expected as a natural consequence of the aging process, but essentially the research shows that hypertension accelerates the hardening of the bronchi and that exercise partially keeps this process at bay,” Vieira explains.

“This is very important because the harder the bronchi become, the harder it becomes for air to enter and leave the lungs. In the long term, 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 in the entire organism.”

The consequences don’t stop there. “Accelerated aging increases the risk of cancer and non-communicable chronic diseases such as diabetes, heart attacks and thrombosis. This underlines the importance of including lung care in the treatment of hypertension,” he added.

Exercise for heart and lungs

In another unpublished study, the same researchers analyzed the relationship between exercise and protection against hardening of the arteries and bronchi due to hypertension in another group of 150 older volunteers, focusing on the extent to which the degree of stiffness can affect blood flow and lead to aneurysms or thrombosis (hemodynamics). The volunteers were subjected to a three-month training protocol, consisting of three exercise sessions per week.

“Exercise has virtually eliminated these cardiovascular changes. This proves once again that physical activity should be part of older people’s lives. There is no such thing as healthy aging with sedentarism,” Vieira said.