title: Relationship between respiratory muscle strength and physical performance in elderly hospitalized patients.
abstract: Background: Age-related changes in pulmonary function increase respiratory muscle work. In the face of this increased demand, poor muscle mass, frequently associated with age and multi-morbidity, can reduce endurance and strength of respiratory muscles. Furthermore, poor muscle mass may per se contribute to exercise intolerance and lower physical performance. The aim of the study was to evaluate if respiratory muscle strength has a significant impact on physical performance in an elderly population.
  
  
  METHODS
  We included 68 patients (28 men and 40 women) aged over 65 years (mean 79 years, standard deviation [SD] 6) in stable condition at discharge from our acute care geriatric ward. We assessed the function of respiratory muscle by measuring maximal inspiratory and expiratory pressures (MIP, MEP) and physical function using the 6-Minute Walk Test (6MWT).
  
  
  RESULTS
  The mean age of our sample was 78.2 years (SD 6.1). There was a statistically significant correlation between MIP or MEP and 6MWT distance (MIP, r=0.43, p<0.001; MEP, r=0.41, p=0.001). The association between respiratory pressures and 6MWT was maintained after adjustment for forced expiratory volume in 1 sec (FEV1), forced vital capacity (FVC), age, sex, fat-free mass index (FFMI), and leg strength. The multiple regression model showed a significant relation between 6-Minute Walk Test distance (6MWD) and both MIP and MEP after correction for sex, age, FEV1, and FVC. Furthermore, MEP can significant predict poorer performance at 6MWD in a multiple logistic regression model.
  
  
  CONCLUSIONS
  Reduced respiratory muscle strength is independently associated with worse physical performance in elderly patients.
authors.affiliation: 1 Area di Geriatria, Policlinico Universitario "Campus Bio-Medico" , Rome, Italy .
authors.forename: Renato
authors.initials: R
authors.lastname: Giua
authors.forename: Claudio
authors.initials: C
authors.lastname: Pedone
authors.forename: Simone
authors.initials: S
authors.lastname: Scarlata
authors.forename: Irma
authors.initials: I
authors.lastname: Carrozzo
authors.forename: Francesca Flavia
authors.initials: FF
authors.lastname: Rossi
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Valiani
authors.forename: Raffaele Antonelli
authors.initials: RA
authors.lastname: Incalzi
mesh_terms: D000367:Age Factors; D000368:Aged; D000375:Aging; D017097:Electric Impedance; D017079:Exercise Tolerance; D005260:Female; D005853:Geriatrics; D006760:Hospitalization; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D011312:Pressure; D011379:Prognosis; D012132:Respiratory Muscles / Q000503:physiopathology*; D013147:Spirometry / Q000379:methods*; D014797:Vital Capacity; D016138:Walking