title: Effect of inspiratory muscle training with load compared with sham training on blood pressure in individuals with hypertension: study protocol of a double-blind randomized clinical trial.
abstract: Hypertension is a complex chronic condition characterized by elevated arterial blood pressure. Management of hypertension includes non-pharmacologic strategies, which may include techniques that effectively reduce autonomic sympathetic activity. Respiratory exercises improve autonomic control over cardiovascular system and attenuate muscle metaboreflex. Because of these effects, respiratory exercises may be useful to lower blood pressure in subjects with hypertension.
  
  
  
  This randomized, double-blind clinical trial will test the efficacy of inspiratory muscle training in reducing blood pressure in adults with essential hypertension. Subjects are randomly allocated to intervention or control groups. Intervention consists of inspiratory muscle training loaded with 40 % of maximum inspiratory pressure, readjusted weekly. Control sham intervention consists of unloaded exercises. Systolic and diastolic blood pressures are co-primary endpoint measures assessed with 24 h ambulatory blood pressure monitoring. Secondary outcome measures include cardiovascular autonomic control, inspiratory muscle metaboreflex, cardiopulmonary capacity, and inspiratory muscle strength and endurance.
  
  
  
  Previously published work suggests that inspiratory muscle training reduces blood pressure in persons with hypertension, but the effectiveness of this intervention is yet to be established. We propose an adequately sized randomized clinical trial to test this hypothesis rigorously. If an effect is found, this study will allow for the investigation of putative mechanisms to mediate this effect, including autonomic cardiovascular control and metaboreflex.
  
  
  
  ClinicalTrials.gov NCT02275377 . Registered on 30 September 2014.
authors.affiliation: Graduate Studies Program in Health Sciences: Cardiology and Cardiovascular Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Jerônimo de Ornelas, 721, Porto Alegre, RS, 90040-341, Brazil.
authors.forename: Simone Regina
authors.initials: SR
authors.lastname: Posser
authors.affiliation: Graduate Program in Integral Attention to Health (PPGAIS- UNICRUZ/UNIJUI). Universidade de Cruz Alta, Rodovia Municipal Jacob Della Méa, Km 5.6, Cruz Alta, RS, 98020-290, Brazil.
authors.forename: Carine Cristina
authors.initials: CC
authors.lastname: Callegaro
authors.affiliation: Graduate Studies Program in Health Sciences: Cardiology and Cardiovascular Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Jerônimo de Ornelas, 721, Porto Alegre, RS, 90040-341, Brazil.
authors.forename: Marina
authors.initials: M
authors.lastname: Beltrami-Moreira
authors.affiliation: Graduate Studies Program in Health Sciences: Cardiology and Cardiovascular Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Jerônimo de Ornelas, 721, Porto Alegre, RS, 90040-341, Brazil. lbmoreira@hcpa.edu.br.|Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos, 2350, room 943, 90035-903, Porto Alegre, RS, Brazil. lbmoreira@hcpa.edu.br.
authors.forename: Leila Beltrami
authors.initials: LB
authors.lastname: Moreira
mesh_terms: D000328:Adult; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory; D001945:Breathing Exercises / Q000009:adverse effects; D002985:Clinical Protocols; D004311:Double-Blind Method; D000075222:Essential Hypertension / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D006801:Humans; D001239:Inhalation; D008297:Male; D008875:Middle Aged; D011174:Portugal; D012107:Research Design; D012132:Respiratory Muscles / Q000503:physiopathology*; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D013997:Time Factors; D016896:Treatment Outcome
keywords: Blood pressure; Clinical trial; Fitness; Hypertension; Physical therapy; Respiratory exercises; Sympathetic nervous system