Study Objectives: New and effective strategies are needed to manage the autonomic and cardiovascular sequelae of obstructive sleep apnea (OSA). We assessed the effect of daily inspiratory muscle strength training (IMT) on sleep and cardiovascular function in adults unable to use continuous positive airway pressure (CPAP) therapy. Methods: This is a placebo-controlled, single-blind study conducted in twenty four adults with mild, moderate, and severe OSA. Subjects were randomly assigned to placebo or inspiratory muscle strength training. Subjects in each group performed 5 min of training each day for 6 w. All subjects underwent overnight polysomnography at intake and again at study close. Results: We evaluated the effects of placebo training or IMT on sleep, blood pressure, and plasma catecholamines. Relative to placebo-trained subjects with OSA, subjects with OSA who performed IMT manifested reductions in systolic and diastolic blood pressures (−12.3 ± 1.6 SBP and −5.0 ± 1.3 DBP mmHg; P < 0.01); plasma norepinephrine levels (536.3 ± 56.6 versus 380.6 ± 41.2 pg/mL; P = 0.01); and registered fewer nighttime arousals and reported improved sleep (Pittsburgh Sleep Quality Index scores: 9.1 ± 0.9 versus 5.1 ± 0.7; P = 0.001). These favorable outcomes were achieved without affecting apneahypopnea index. Conclusions: The results are consistent with our previously published findings in normotensive adults but further indicate that IMT can modulate blood pressure and plasma catecholamines in subjects with ongoing nighttime apnea and hypoxemia. Accordingly, we suggest IMT offers a low cost, nonpharmacologic means of improving sleep and blood pressure in patients who are intolerant of CPAP. Keywords: hypertension, obstructive sleep apnea, respiratory training Citation: Vranish JR, Bailey EF. Inspiratory muscle training improves sleep and mitigates cardiovascular dysfunction in obstructive sleep apnea. SLEEP 2016;39(6):1179–1185.

INTRODUCTION: In Parkinson's disease (PD), respiratory insufficiency (including functional and muscle disorders) can impact dysarthria and swallowing. Most studies of this topic have been performed retrospectively in populations of patients with advanced PD. The objective of the present study was to characterize lung function (under off-drug conditions) in early-stage PD patients at baseline and then again two years later.
METHODS: Forty-one early-stage PD patients (mean ± SD age: 61.7 ± 7.7; mean ± SD disease duration: 1.9 ± 1.7 years) were prospectively enrolled and compared with 36 age-matched healthy controls. Neurological evaluations and pulmonary function testing were performed in the off-drug condition at the inclusion visit and then two years later.
RESULTS: Pulmonary function testing did not reveal any restrictive or obstructive disorders; at baseline, inspiratory muscle weakness was the only abnormality observed in the PD group (in 53.7% of the patients, vs. 25% in controls; p = 0.0105). The PD patients had a lower mean maximal inspiratory mouth pressure than controls and a lower sniff nasal inspiratory pressure. Two years after the initiation of chronic treatment with antiparkinsonian medications, the maximal inspiratory mouth pressure and the sniff nasal inspiratory pressure tended to be higher. Lastly, overall motor outcomes were not significantly worse in patients with inspiratory muscle weakness than in patients without inspiratory muscle weakness.
CONCLUSION: Inspiratory muscle weakness seems to be common in patients with early-stage PD, and was seen to be stable over a two-year period. Additional long-term follow-up studies are required to specify the impact of this new feature of PD.
PMID: 29329328 PMCID: PMC5766081 DOI: 10.1371/journal.pone.0190400

This study documented the effect of inspiratory muscle conditioning in children with cystic fibrosis. Subjects, ages 7 to 14 years, were divided into two groups. The experimental group (n = 10) trained at a high pressure load (> or = 29 cm H2O) and the control group (n = 10) trained at a minimal pressure load (< or = 15 cm H2O), using a threshold loading device. Subjects trained 30 min a day for 10 weeks. Pulmonary function, inspiratory muscle strength, and exercise tolerance were measured at the beginning and end of the training period. Pulmonary function was measured by body plethysmography. Inspiratory muscle strength was determined by standard measures of maximal inspiratory pressure against an occluded airway. Exercise tolerance was measured by the length of time subjects could walk on a treadmill. Findings indicated that the experimental group showed significant increases in inspiratory muscle strength, vital capacity, total lung capacity, and exercise tolerance in comparison to the control group.
PMID: 8222813 DOI: 10.1378/chest.104.5.1490

INTRODUCTION AND OBJECTIVES: Despite the prevalence of heart failure with preserved ejection fraction (HFpEF), there is currently no evidence-based effective therapy for this disease. This study sought to evaluate whether inspiratory muscle training (IMT), functional electrical stimulation (FES), or a combination of both (IMT + FES) improves 12- and 24-week exercise capacity as well as left ventricular diastolic function, biomarker profile, and quality of life in HFpEF.
METHODS: A total of 61 stable symptomatic patients (New York Heart Association II-III) with HFpEF were randomized (1:1:1:1) to receive a 12-week program of IMT, FES, or IMT + FES vs usual care. The primary endpoint of the study was to evaluate change in peak exercise oxygen uptake at 12 and 24 weeks. Secondary endpoints were changes in quality of life, echocardiogram parameters, and prognostic biomarkers. We used a mixed-effects model for repeated-measures to compare endpoints changes.
RESULTS: Mean age and peak exercise oxygen uptake were 74 ± 9 years and 9.9 ± 2.5mL/min/kg, respectively. The proportion of women was 58%. At 12 weeks, the mean increase in peak exercise oxygen uptake (mL/kg/min) compared with usual care was 2.98, 2.93, and 2.47 for IMT, FES, and IMT + FES, respectively (P < .001) and this beneficial effect persisted after 6 months (1.95, 2.08, and 1.56; P < .001). Significant increases in quality of life scores were found at 12 weeks (P < .001). No other changes were found.
CONCLUSIONS: In HFpEF patients with low aerobic capacity, IMT and FES were associated with a significant improvement in exercise capacity and quality of life. This trial was registered at ClinicalTrials.gov (Identifier: NCT02638961)..
Copyright © 2018 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.
KEYWORDS: Calidad de vida; Capacidad funcional; Exercise capacity; Heart failure with preserved ejection fraction; Insuficiencia cardiaca con función sistólica conservada; Physical therapy; Quality of life; Terapia física
PMID: 29551699 DOI: 10.1016/j.rec.2018.01.010

The crural diaphragm (CD) is an essential component of the esophagogastric junction (EGJ), and inspiratory exercises may modify its function. This study's goal is to verify if inspiratory muscle training (IMT) improves EGJ motility and gastroesophageal reflux (GER). Twelve GER disease [GERD; 7 males, 20-47 yr, 9 esophagitis, and 3 nonerosive reflex disease (NERD)] and 7 healthy volunteers (3 males, 20-41 yr) performed esophageal pH monitoring, manometry, and heart rate variability (HRV) studies. A 6-cm sleeve catheter measured average EGJ pressure during resting, peak inspiratory EGJ pressures during sinus arrhythmia maneuver (SAM) and inhalations under 17-, 35-, and 70-cmH2O loads (TH maneuvers), and along 1 h after a meal. GERD patients entered a 5-days-a-week IMT program. One author scored heartburn and regurgitation before and after IMT. IMT increased average EGJ pressure (19.7 ± 2.4 vs. 29.5 ± 2.1 mmHg; P < 0.001) and inspiratory EGJ pressure during SAM (89.6 ± 7.6 vs. 125.6 ± 13.3 mmHg; P = 0.001) and during TH maneuvers. The EGJ-pressure gain across 35- and 70-cmH2O loads was lower for GERD volunteers. The number and cumulative duration of the transient lower esophageal sphincter relaxations decreased after IMT. Proximal progression of GER decreased after IMT but not the distal acid exposure. Low-frequency power increased after IMT and the higher its increment the lower the increment of supine acid exposure. IMT decreased heartburn and regurgitation scores. In conclusion, IMT improved EGJ pressure, reduced GER proximal progression, and reduced GERD symptoms. Some GERD patients have a CD failure, and IMT may prove beneficial as a GERD add-on treatment.
KEYWORDS: GERD; crural diaphragm; lower esophageal sphincter; muscle training
PMID: 24113771 DOI: 10.1152/ajpgi.00054.2013