title: Sarcopenia in COPD: prevalence, clinical correlates and response to pulmonary rehabilitation.
abstract: BACKGROUND
  Age-related loss of muscle, sarcopenia, is recognised as a clinical syndrome with multiple contributing factors. International European Working Group on Sarcopenia in Older People (EWGSOP) criteria require generalised loss of muscle mass and reduced function to diagnose sarcopenia. Both are common in COPD but are usually studied in isolation and in the lower limbs.
  
  
  OBJECTIVE
  To determine the prevalence of sarcopenia in COPD, its impact on function and health status, its relationship with quadriceps strength and its response to pulmonary rehabilitation (PR).
  
  
  METHODS
  EWGSOP criteria were applied to 622 outpatients with stable COPD. Body composition, exercise capacity, functional performance, physical activity and health status were assessed. Using a case-control design, response to PR was determined in 43 patients with sarcopenia and a propensity score-matched non-sarcopenic group.
  
  
  RESULTS
  Prevalence of sarcopenia was 14.5% (95% CI 11.8% to 17.4%), which increased with age and Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD) stage, but did not differ by gender or the presence of quadriceps weakness (14.9 vs 13.8%, p=0.40). Patients with sarcopenia had reduced exercise capacity, functional performance, physical activity and health status compared with patients without sarcopenia (p<0.001), but responded similarly following PR; 12/43 patients were no longer classified as sarcopenic following PR.
  
  
  CONCLUSIONS
  Sarcopenia affects 15% of patients with stable COPD and impairs function and health status. Sarcopenia does not impact on response to PR, which can lead to a reversal of the syndrome in select patients.
authors.affiliation: NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, London, UK.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Jones
authors.affiliation: King's College London, Cicely Saunders Institute, London, UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Maddocks
authors.affiliation: NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, London, UK.
authors.forename: Samantha S C
authors.initials: SS
authors.lastname: Kon
authors.affiliation: NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, London, UK.
authors.forename: Jane L
authors.initials: JL
authors.lastname: Canavan
authors.affiliation: NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, London, UK Harefield Pulmonary Rehabilitation Unit, Royal Brompton and Harefield NHS Foundation Trust, London, UK.
authors.forename: Claire M
authors.initials: CM
authors.lastname: Nolan
authors.affiliation: Harefield Pulmonary Rehabilitation Unit, Royal Brompton and Harefield NHS Foundation Trust, London, UK.
authors.forename: Amy L
authors.initials: AL
authors.lastname: Clark
authors.affiliation: NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, London, UK.
authors.forename: Michael I
authors.initials: MI
authors.lastname: Polkey
authors.affiliation: NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, London, UK Harefield Pulmonary Rehabilitation Unit, Royal Brompton and Harefield NHS Foundation Trust, London, UK.
authors.forename: William D-C
authors.initials: WD
authors.lastname: Man
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001823:Body Composition; D016022:Case-Control Studies; D017079:Exercise Tolerance; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D015995:Prevalence; D057216:Propensity Score; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology* / Q000503:physiopathology / Q000534:rehabilitation*; D052097:Quadriceps Muscle / Q000503:physiopathology*; D055948:Sarcopenia / Q000453:epidemiology* / Q000503:physiopathology / Q000534:rehabilitation*; D012720:Severity of Illness Index; D016138:Walking / Q000502:physiology
keywords: COPD epidemiology; Clinical Epidemiology; Pulmonary Rehabilitation