title: Respiratory muscle function in patients with cystic fibrosis.
abstract: Respiratory muscle function in patients with cystic fibrosis (CF) can be assessed by measurement of maximal inspiratory pressure (Pimax ), maximal expiratory pressure (Pemax ), and pressure-time index of the respiratory muscles (PTImus ). We investigated the differences in maximal respiratory pressures and PTImus between CF patients with no gross hyperinflation and healthy controls and described the effects of pulmonary function and nutrition impairment on respiratory muscle function in this group of CF patients. Forced expiratory volume in 1 sec (FEV1 ), forced vital capacity (FVC) and maximal expiratory flow between 25% and 75% of VC (MEF25-75 ), body mass index (BMI), upper arm muscle area (UAMA), Pimax , Pemax , and PTImus were assessed in 140 CF patients and in a control group of 140 healthy subjects matched for age and gender. Median Pimax and Pemax were significantly lower in CF patients compared to the controls [Pimax  = 74 (57-94) in CF vs. 84 (66-102) in controls, P = 0.009], [Pemax  = 71 (50-95) in CF vs. 84 (66-102) in controls, P < 0.001]. Median PTImus in CF patients compared to controls was significantly increased [PTImus  = 0.110 (0.076-0.160) in CF vs. 0.094 (0.070-0.137) in controls, P = 0.049] and it was significantly higher in CF patients with impaired pulmonary function. In CF patients, PTImus was significantly negatively related to upper arm muscle area (r = 0.184, P = 0.031). These findings suggest that CF patients with no severe lung disease compared to healthy subjects exhibit impaired respiratory muscle function, while CF patients with impaired pulmonary function and nutrition indices exhibit higher PTImus values.
authors.affiliation: Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Hills Road, Cambridge CB2 0SW, United Kingdom.
authors.forename: Theodore
authors.initials: T
authors.lastname: Dassios
authors.forename: Anna
authors.initials: A
authors.lastname: Katelari
authors.forename: Stavros
authors.initials: S
authors.lastname: Doudounakis
authors.forename: Stefanos
authors.initials: S
authors.lastname: Mantagos
authors.forename: Gabriel
authors.initials: G
authors.lastname: Dimitriou
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003550:Cystic Fibrosis / Q000503:physiopathology*; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008297:Male; D012132:Respiratory Muscles / Q000503:physiopathology*; D014797:Vital Capacity / Q000502:physiology; D055815:Young Adult
keywords: cystic fibrosis; pressure-time index of the respiratory muscles; respiratory muscles strength