Pulmonary function and cardiorespiratory fitness in idiopathic Parkinson's disease

Abstract

Idiopathic Parkinson’s disease (IPD) is a progressive neurodegenerative disorder, secondary to dopaminergic depletion, which primarily affects motor control via the basal ganglia. It is a multi system disease affecting dopaminergic neurones throughout the body. The Parkinsonian syndromes are associated with excess morbidity and mortality from respiratory causes. Pulmonary function studies have yielded conflicting results in IPD. There is a lack of high quality research examining the effect of exercise on pulmonary function and aerobic capacity in IPD. Understanding the pattern of any respiratory dysfunction and impairment in cardiorespiratory fitness in IPD, and interventions that could modify these, are of importance in dyspnoea, hypoxia, hypercapnia, pneumonia, speech, swallowing, sleep disordered breathing, daytime somnolence, acute respiratory failure, extubation difficulties, increased respiratory infections and reduced exercise tolerance and functional capacity. We recruited 103 individuals with IPD, at different disease stages, from the Northumbria Parkinson’s Disease Service to define the pattern of pulmonary dysfunction and respiratory muscle strength. 100 participants completed a cross-sectional study comprising demographics, questionnaires and comprehensive pulmonary function testing, including spirometry, flow volume loops, lung volume assessment and respiratory muscle strength testing. Of these 100, 32 volunteered for a randomised control trial (RCT) with additional measurements of aerobic capacity, assessed by cardiopulmonary exercise testing, and exercise capacity, assessed by six minute walk testing. The participants were randomised, 1:1, control:intervention. The intervention group participated in a 12 week, 3 times weekly, exercise intervention. The baseline assessments were repeated in both groups immediately after the intervention, with 27 completing the RCT. The cross-sectional pulmonary function study revealed an increased prevalence of obstructive spirometry, upper airway obstruction and inspiratory muscle weakness in this population. The randomised control trial demonstrated statistically significant improvements in the intervention group only in; aerobic capacity, exercise capacity, subjective parkinsonian symptoms, quality of life, depression, anxiety, sleep and sleepiness.