title: The role of the inspiratory muscle weakness in functional capacity in hemodialysis patients.
abstract: BACKGROUND
  Inspiratory muscle function may be affected in patients with End-Stage Renal Disease (ESRD), further worsening the functional loss in these individuals. However, the impact of inspiratory muscle weakness (IMW) on the functional capacity (FC) of hemodialysis patients remains unknown. Thus, the present study aimed to evaluate the impact of IMW on FC in ESRD patients undergoing hemodialysis.
  
  
  METHODS
  ESRD patients on hemodialysis treatment for more than six months were evaluated for inspiratory muscle strength and FC. Inspiratory muscle strength was evaluated based on maximal inspiratory pressure (MIP). IMW was defined as MIP values less than 70% of the predicted value. FC was evaluated using the Incremental Shuttle Walk test (ISWT). Patients whose predicted peak oxygen uptake (VO2peak) over the distance walked during the ISWT was less than 16mL/kg/min were considered to have FC impairment. Associations between variables were assessed by linear and logistic regression, with adjustment for age, sex, body mass index (BMI), presence of diabetes and hemoglobin level. Receiver-operating characteristic (ROC) analysis was used to determine different cutoff values of the MIP for normal inspiratory muscle strength and FC.
  
  
  RESULTS
  Sixty-five ERSD patients (67.7% male), aged 48.2 (44.5-51.9) years were evaluated. MIP was an independent predictor of the distance walked during the ISWT (R2 = 0.44). IMW was an independent predictor of VO2peak < 16mL/kg/min. (OR = 5.7; p = 0.048) in adjusted logistic regression models. ROC curves showed that the MIP cutoff value of 82cmH2O had a sensitivity of 73.5% and specificity of 93.7% in predicting normal inspiratory strength and a sensitivity and specificity of 76.3% and 70.4%, respectively, in predicting VO2peak ≥ 16mL/kg/min.
  
  
  CONCLUSIONS
  IMW is associated with reduced FC in hemodialysis patients. Evaluation of the MIP may be important to functional monitoring in clinical practice and can help in the stratification of patients eligible to perform exercise testing.
authors.affiliation: Postgraduate Course in Physiological Sciences, Multicentric Program in Physiological Sciences, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, Minas Gerais, Brazil.|Cardiovascular Rehabilitation Laboratory (LABCAR), Physical Therapy School, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, Minas Gerais, Brazil.
authors.forename: Pedro Henrique Scheidt
authors.initials: PH
authors.lastname: Figueiredo
authors.affiliation: Cardiovascular Rehabilitation Laboratory (LABCAR), Physical Therapy School, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, Minas Gerais, Brazil.
authors.forename: Márcia Maria Oliveira
authors.initials: MM
authors.lastname: Lima
authors.affiliation: Postgraduate Program in Infectious Diseases and Tropical Medicine, School of Medicine, Universidade Federal Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Henrique Silveira
authors.initials: HS
authors.lastname: Costa
authors.affiliation: Cardiovascular Rehabilitation Laboratory (LABCAR), Physical Therapy School, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, Minas Gerais, Brazil.
authors.forename: Rosalina Tossige
authors.initials: RT
authors.lastname: Gomes
authors.affiliation: Cardiovascular Rehabilitation Laboratory (LABCAR), Physical Therapy School, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, Minas Gerais, Brazil.
authors.forename: Camila Danielle Cunha
authors.initials: CD
authors.lastname: Neves
authors.affiliation: Cardiovascular Rehabilitation Laboratory (LABCAR), Physical Therapy School, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, Minas Gerais, Brazil.
authors.forename: Evandro Silveira de
authors.initials: ES
authors.lastname: Oliveira
authors.affiliation: Hemodialysis Unit of the Santa Casa de Caridade de Diamantina Hospital, Diamantina, Minas Gerais, Brazil.
authors.forename: Frederico Lopes
authors.initials: FL
authors.lastname: Alves
authors.affiliation: Hemodialysis Unit of the Santa Casa de Caridade de Diamantina Hospital, Diamantina, Minas Gerais, Brazil.
authors.forename: Vanessa Gomes Brandão
authors.initials: VG
authors.lastname: Rodrigues
authors.affiliation: Hemodialysis Unit of the Santa Casa de Caridade de Diamantina Hospital, Diamantina, Minas Gerais, Brazil.
authors.forename: Emílio Henrique Barroso
authors.initials: EH
authors.lastname: Maciel
authors.affiliation: Cardiovascular Rehabilitation Laboratory (LABCAR), Physical Therapy School, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, Minas Gerais, Brazil.
authors.forename: Cláudio Heitor
authors.initials: CH
authors.lastname: Balthazar
mesh_terms: D003430:Cross-Sectional Studies; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D007320:Inspiratory Capacity; D007676:Kidney Failure, Chronic / Q000150:complications / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D018908:Muscle Weakness / Q000209:etiology / Q000503:physiopathology*; D010101:Oxygen Consumption; D006435:Renal Dialysis / Q000009:adverse effects*; D012132:Respiratory Muscles / Q000503:physiopathology*