Relationship of Exercise Capacity With Respiratory Muscle Strength and Physical Activity in  Paediatric Patients With Pulmonary Arterial Hypertension

Abstract

Introduction: Pulmonary arterial hypertension (PAH) is a rare disease associated with significant morbidity and mortality in new-borns, infants, and children. Muscle weakness and poor quality of life exist in adult patients with PAH who had low functional exercise capacity. However, relationship of exercise capacity with respiratory muscle strength and physical activity in paediatric patients with PAH is still unknown which was therefore aimed to investigate in current study.

Methods: Eleven paediatric patients with PAH (11.46±4.44 years, 8F, 3M) were included in the study. Exercise capacity  (6-minute walk test (6-MWT)), respiratory muscle strength (maximal inspiratory and expiratory pressures (MIP, MEP)) (a mouth pressure device), and physical activity (a triaxial accelerometer) were evaluated.

Results: Out of 11 paediatric patients with PAH, 11 (100%), 2 (18.2%) and 3 (27.3%) were lower than 80% of predicted values of 6-MWT distance, MIP, and MEP values, respectively. Five (45.5%) patients (4101.4±1219.18 steps/day) were walking below 7500 steps per a day. The 6-MWT distance was significantly and positively correlated with sex (r=0.775, p=0.005), age (r=0.645, p=0.032), height (r=0.736, p=0.010), MIP (r=0.591, p=0.056), and total energy expenditure (r=0.767, p=0.016) (p<0.05).

Conclusions: All patients have suffering from decrease in exercise capacity. Moreover, some patients have experienced inspiratory (18.2%) and expiratory (27.3%) muscle weakness. Exercise capacity decreases as height, inspiratory muscle strength, and daily average total energy expenditure decline in paediatric patients with PAH. Counselling for providing regular physical activity and exercise in the patients should be initiated at the earliest period of paediatric PAH.

Keywords: Muscle Strength, Exercise, Exercise Test, Physical Activity, Pulmonary Arterial Hypertension