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, impairing respiratory capacity.

The study sample comprised 731 men and women over 60, both with and without high blood pressure. It was designed to investigate the effects of hypertension on lung mechanics, detecting where and how high blood pressure impaired lung function. An article reporting the findings is published in the journal Advances in Respiratory Medicine .

The study was supported by FAPESP. "Our analysis showed that subjects who practiced regular physical activities appeared to be partially protected against hardening of the bronchi," Rodolfo de Paula Vieira, last author of the article, told Agência FAPESP. Vieira heads the Pulmonary Immunology and Exercise Laboratory at the Federal University of São Paulo's Institute of Science and Technology (ICT-UNIFESP) in São José dos Campos, São Paulo state, Brazil.

The researchers conducted spirometry tests to gauge respiratory function, and assessed lung mechanics by impulse oscillometry, a technique that uses sound waves to measure resistance to the normal movement of air in and out of the lungs when breathing at rest. General muscle strength was measured using a hand grip dynamometer, and respiratory.