Effects of Respiratory Muscle Training on Respiratory Muscle Strength, Functional Capacity and Quality of Life in Pulmonary Hypertension

Pulmonary hypertension (HP) is a progressive pathological condition that HP presents with vascular changes in the lung that cause proliferative and obstructive remodeling promoting vasoconstriction with a consequent increase in pulmonary vascular resistance (PVR).

Cardiopulmonary changes in PH are considered the main limiting factor, however, it is known that the muscular alterations potentiate the symptomatology. Several HP factors and mechanisms have an impact on peripheral and respiratory muscle changes, such as: decreased cardiac output, hypoxemia, inflammation, increased insulin resistance, altered autonomic nervous system (ANS) response, and muscle disuse. These factors imply alteration of fiber type, atrophy, capillary vascular reduction, reduction of oxidative capacity, endothelial dysfunction and decreased muscle excitability by ANS.

Specifically, respiratory muscles are also altered in patients with PH. For the treatment of PH, in addition to optimized drug therapy, studies have demonstrated the effects of physical exercise for this population. Although there is no consensus about the best exercise modality, duration, frequency or intensity, physical training promotes benefits in exercise capacity, maximal oxygen capacity (VO2peak) and quality of life. The most recent European guideline [3] recommends supervised exercise in patients with PH who are clinically stable with optimized drug therapy (evidence grade IIa, Level B), but patients often do not have access to supervised physical rehabilitation programs, which Practice a challenge.

In the face of respiratory muscle weakness, inspiratory muscle training (IMT) has been shown to increase respiratory muscle strength and functional capacity in chronic conditions such as obstructive pulmonary disease (COPD) and heart failure (HF). At HP, the study by Saglam M et al., 2015 demonstrates improvement of respiratory muscle strength and functional capacity, resulting in decreased dyspnea and fatigue in PH patients who performed the IMT protocol during six weeks of outpatient training.

The objective of this study is to test whether a 12-week TMI protocol is capable of impacting functional capacity, respiratory muscle strength, spirometric values and quality of life in patients with PH.