title: Evaluation of acute effect of light-emitting diode (LED) phototherapy on muscle deoxygenation and pulmonary oxygen uptake kinetics in patients with diabetes mellitus: study protocol for a randomized controlled trial.
abstract: BACKGROUND
  Type 2 diabetes mellitus (DM) is responsible for a significant reduction in the quality of life due to its negative impact on functional capacity. Cardiopulmonary fitness impairment in DM patients has been associated with limited tissue oxygenation. Phototherapy is widely utilized to treat several disorders due to expected light-tissue interaction. This type of therapy may help to improve muscular oxygenation, thereby increasing aerobic fitness and functional capacity.
  
  
  METHODS
  This study is a randomized, double-blind, placebo-controlled crossover trial approved by the Ethics Committee of the Federal University of São Carlos and registered at ClinicalTrials.gov. Four separate tests will be performed to evaluate the acute effect of phototherapy. All participants will receive both interventions in random order: light-emitting diode therapy (LEDT) and placebo, with a minimum 14-day interval between sessions (washout period). Immediately after the intervention, participants will perform moderate constant workload cycling exercise corresponding to 80 % of the pulmonary oxygen uptake [Formula: see text] during the gas exchange threshold (GET). LEDT will be administered with a multidiode cluster probe (50 GaAIA LEDs, 850 ηm, 75 mW each diode, and 3 J per point) before each exercise session. Pulmonary oxygen uptake, muscle oxygenation, heart rate, and arterial pressure will be measured using a computerized metabolic cart, a near-infrared spectrometer, an electrocardiogram, and a photoplethysmography system, respectively.
  
  
  CONCLUSIONS
  The main objective of this study is to evaluate the acute effects of muscular pre-conditioning using LED phototherapy on pulmonary oxygen uptake, muscle oxygenation, heart rate, and arterial pressure dynamics during dynamic moderate exercise. We hypothesize that phototherapy may be beneficial to optimize aerobic fitness in the DM population. Data will be published after the study is completed.
  
  
  BACKGROUND
  Registered at ClinicalTrials.gov under trial number NCT01889784 (date of registration 5 June 2013).
authors.affiliation: Department of Physiotherapy, Federal University of São Carlos, Rod. Washington Luís, km 235, 13.565-905, São Carlos, São Paulo, Brazil. cristinaft05@gmail.com.
authors.forename: Cristina de Oliveira
authors.initials: Cde O
authors.lastname: Francisco
authors.affiliation: Faculty of Applied Health Sciences, University of Waterloo, 200 University Ave W, N2L 3G1, Waterloo, Ontario, Canada. beltramethomas@gmail.com.
authors.forename: Thomas
authors.initials: T
authors.lastname: Beltrame
authors.affiliation: Wellman Center for Photomedicine, Massachusetts General Hospital - Harvard Medical School, 55 Fruit Street, MA 02114, Boston, Massachusetts, USA. cleber.ferraresi@gmail.com.
authors.forename: Cleber
authors.initials: C
authors.lastname: Ferraresi
authors.affiliation: Department of Physiotherapy, Federal University of São Carlos, Rod. Washington Luís, km 235, 13.565-905, São Carlos, São Paulo, Brazil. nivaldoaparizotto@hotmail.com.
authors.forename: Nivaldo Antonio
authors.initials: NA
authors.lastname: Parizotto
authors.affiliation: São Carlos Institute of Physics, University od São Paulo, Av. Trabalhador São-carlense, 400, 13566-590, São Carlos, São Paulo, Brazil. vander@ifsc.usp.br.
authors.forename: Vanderlei Salvador
authors.initials: VS
authors.lastname: Bagnato
authors.affiliation: Department of Physiotherapy, Federal University of São Carlos, Rod. Washington Luís, km 235, 13.565-905, São Carlos, São Paulo, Brazil. audrey@ufscar.br.
authors.forename: Audrey
authors.initials: A
authors.lastname: Borghi Silva
authors.affiliation: Department of Statistics, Federal University of São Carlos, Rod. Washington Luís, km 235, 13.565-905, São Carlos, São Paulo, Brazil. benze@ufscar.br.
authors.forename: Benedito Galvão
authors.initials: BG
authors.lastname: Benze
authors.affiliation: Department of Biomedical Sciences for Health, University of Milan, Via Festa del Perdono 7, 20122, Milan, Italy. alberto.porta@unimi.it.|Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS, Policlinico San Donato, Milan, Italy. alberto.porta@unimi.it.
authors.forename: Alberto
authors.initials: A
authors.lastname: Porta
authors.affiliation: Department of Physiotherapy, Federal University of São Carlos, Rod. Washington Luís, km 235, 13.565-905, São Carlos, São Paulo, Brazil. mcatai@ufscar.br.
authors.forename: Aparecida Maria
authors.initials: AM
authors.lastname: Catai
mesh_terms: D000328:Adult; D062186:Arterial Pressure; D001938:Brazil; D002985:Clinical Protocols; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology / Q000532:radiotherapy*; D004311:Double-Blind Method; D004562:Electrocardiography; D005080:Exercise Test; D017079:Exercise Tolerance / Q000528:radiation effects*; D005260:Female; D006339:Heart Rate; D006801:Humans; D007700:Kinetics; D054023:Lasers, Semiconductor; D028022:Low-Level Light Therapy / Q000009:adverse effects / Q000295:instrumentation*; D008168:Lung / Q000378:metabolism / Q000503:physiopathology / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism / Q000503:physiopathology / Q000528:radiation effects*; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000528:radiation effects*; D017156:Photoplethysmography; D020127:Recovery of Function; D012107:Research Design; D019265:Spectroscopy, Near-Infrared; D016896:Treatment Outcome
chemical_list: D010100:Oxygen