title: Reference Range of Respiratory Muscle Strength and Its Clinical Application in Amyotrophic Lateral Sclerosis: A Single-Center Study.
abstract: OBJECTIVE
  Evaluating respiratory function is important in neuromuscular diseases. This study explored the reference ranges of the maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and sniff nasal inspiratory pressure (SNIP) in healthy adults, and applied them to amyotrophic lateral sclerosis (ALS) patients.
  
  
  METHODS
  MIP, MEP, and SNIP were measured in 67 healthy volunteers aged from 21 to 82 years. Reference ranges were evaluated by multivariate regression analysis using the generalized additive modeling of location, scale, and shape method. Thirty-six ALS patients were reviewed retrospectively, and abnormal values of MIP, MEP, and SNIP were determined according to the reference ranges.
  
  
  RESULTS
  MIP, MEP, and SNIP were abnormal in 57.1%, 51.4%, and 25.7% of the ALS patients, respectively. MIP and SNIP were significantly correlated with the degree of restrictive pattern and respiratory symptoms. The ALS Functional Rating Scale-Revised score was correlated with SNIP.
  
  
  CONCLUSIONS
  This study has provided the reference range of respiratory muscle strength in healthy adults. This range is suitable for evaluating respiratory function in ALS patients.
authors.affiliation: Department of Neurology, Gyeongsang National University Hospital, Jinju, Korea.
authors.forename: Kee Hong
authors.initials: KH
authors.lastname: Park
authors.affiliation: Regional Cardiocerebrovascular Center, Gyeongsang National University Hospital, Jinju, Korea.
authors.forename: Rock Bum
authors.initials: RB
authors.lastname: Kim
authors.affiliation: Department of Neurology, Gil Medical Center, Gachon University, Incheon, Korea.
authors.forename: Jiwon
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Neurology, Jeju National University School of Medicine, Jeju, Korea.
authors.forename: Jung Hwan
authors.initials: JH
authors.lastname: Oh
authors.affiliation: Department of Neurology, Korea Cancer Center Hospital, Seoul, Korea.
authors.forename: Su Yeon
authors.initials: SY
authors.lastname: Park
authors.affiliation: Department of Neurology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Dong Gun
authors.initials: DG
authors.lastname: Kim
authors.affiliation: Department of Neurology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Je Young
authors.initials: JY
authors.lastname: Shin
authors.affiliation: Department of Neurology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea. jjsaint@snu.ac.kr.
authors.forename: Jung Joon
authors.initials: JJ
authors.lastname: Sung
keywords: amyotrophic lateral sclerosis; maximal expiratory pressure; maximal inspiratory pressure; sniff nasal inspiratory pressure