title: An impaired health related muscular fitness contributes to a reduced walking capacity in patients with schizophrenia: a cross-sectional study.
abstract: BACKGROUND
  Patients with schizophrenia report muscle weakness. The relation of this muscle weakness with performing daily life activities such as walking is however not yet studied. The aim of this study was to quantify walking capacity and health related muscular fitness in patients with schizophrenia compared with age-, gender and body mass index (BMI)-matched healthy controls. Secondly, we identified variables that could explain the variability in walking capacity and in health related muscular fitness in patients with schizophrenia.
  
  
  METHODS
  A total of 100 patients with schizophrenia and 40 healthy volunteers were initially screened. Eighty patients with schizophrenia (36.8±10.0 years) and the 40 age-, gender- and body mass index (BMI)-matched healthy volunteers (37.1±10.3 years) were finally included. All participants performed a standing broad jump test (SBJ) and a six-minute walk test (6MWT) and filled out the International Physical Activity Questionnaire. Patients additionally had a fasting metabolic laboratory screening and were assessed for psychiatric symptoms.
  
  
  RESULTS
  Patients with schizophrenia did have lower 6MWT (17.9%, p<0.001) [effect size (ES)=-1.01] and SBJ (14.1%, p<0.001) (ES=-0.57) scores. Patients were also less physically active (1291.0±1201.8 metabolic equivalent-minutes/week versus 2463.1±1365.3, p<0.001) (ES=-0.91) than controls. Schizophrenia patients with metabolic syndrome (MetS) (35%) had a 23.9% lower (p<0.001) SBJ-score and 22.4% (p<0.001) lower 6MWT-score than those without MetS. In multiple regression analysis, 71.8% of the variance in 6MWT was explained by muscular fitness, BMI, presence of MetS and physical activity participation, while 53.9% of the variance in SBJ-score was explained by age, illness duration, BMI and physical activity participation.
  
  
  CONCLUSIONS
  The walking capacity and health-related muscular fitness are impaired in patients with schizophrenia and both should be a major focus in daily clinical practice and future research.
authors.affiliation: University Psychiatric Centre Catholic University Leuven, Campus Kortenberg, Kortenberg, Belgium. Davy.Vancampfort@uc-kortenberg.be
authors.forename: Davy
authors.initials: D
authors.lastname: Vancampfort
authors.forename: Michel
authors.initials: M
authors.lastname: Probst
authors.forename: Amber
authors.initials: A
authors.lastname: De Herdt
authors.forename: Rui Manuel Nunes
authors.initials: RM
authors.lastname: Corredeira
authors.forename: Attilio
authors.initials: A
authors.lastname: Carraro
authors.forename: Dirk
authors.initials: D
authors.lastname: De Wachter
authors.forename: Marc
authors.initials: M
authors.lastname: De Hert
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology; D000328:Adult; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity; D018908:Muscle Weakness / Q000150:complications / Q000503:physiopathology; D010809:Physical Fitness / Q000502:physiology / Q000523:psychology; D012559:Schizophrenia / Q000150:complications* / Q000503:physiopathology; D016138:Walking / Q000502:physiology / Q000523:psychology