title: Catabolic/anabolic balance and muscle wasting in patients with COPD.
abstract: BACKGROUND
  The mechanisms leading to muscle wasting in patients with COPD are still uncertain. This study was undertaken to evaluate the relationships among circulating levels of catabolic factors (ie, interleukin [IL]-6 and cortisol), anabolic factors (ie, bioavailable testosterone [Tbio], dehydroepiandrosterone sulfate [DHEAS], and insulin-like growth factor [IGF]-I), and mid-thigh muscle cross-sectional area (MTCSA) in patients with COPD.
  
  
  METHODS
  Serum levels of the above factors were measured in 45 men with COPD (mean [+/- SEM] FEV(1), 43 +/- 3% predicted; mean age, 67 +/- 1 years) and 16 sedentary healthy men of similar age. MTCSA was quantified using CT scanning. Patients with COPD were subdivided into two groups according to the MTCSA (< 70 or >or= 70 cm(2)).
  
  
  RESULTS
  There was a greater prevalence of hypogonadism (ie, Tbio, < 2 nmol/L) in patients with COPD compared to control subjects (22% vs 0%, respectively). Patients with an MTCSA of < 70 cm(2) had significantly reduced levels of DHEAS compared to those in healthy subjects (p < 0.01). IL-6 levels were significantly higher in both subgroups of COPD patients compared to those in control subjects (p < 0.005). The cortisol/DHEAS, IL-6/DHEAS, IL-6/Tbio, and IL-6/IGF-I ratios were significantly greater in COPD patients with an MTCSA of < 70 cm(2) compared to those in control subjects (p < 0.05). The cortisol/DHEAS and IL-6/DHEAS ratios were also significantly greater in COPD patients with an MTCSA of < 70 cm(2) than in COPD patients with an MTCSA of >or= 70 cm(2) (p < 0.05). In a stepwise multiple regression analysis, the IL-6/DHEAS ratio explained 20% of the variance in MTCSA (p < 0.005).
  
  
  CONCLUSIONS
  Catabolic/anabolic disturbances were found in COPD patients leading to a shift toward catabolism and possibly to the development of peripheral muscle wasting.
authors.affiliation: Centre de Recherche, Hôpital Laval, Institut Universitaire de Cardiologie et de Pneumologie, Université Laval, Sainte-Foy, QC, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Debigaré
authors.forename: Karine
authors.initials: K
authors.lastname: Marquis
authors.forename: Claude H
authors.initials: CH
authors.lastname: Côté
authors.forename: Roland R
authors.initials: RR
authors.lastname: Tremblay
authors.forename: Annie
authors.initials: A
authors.lastname: Michaud
authors.forename: Pierre
authors.initials: P
authors.lastname: LeBlanc
authors.forename: François
authors.initials: F
authors.lastname: Maltais
mesh_terms: D000368:Aged; D019314:Dehydroepiandrosterone Sulfate / Q000378:metabolism; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000378:metabolism; D009135:Muscular Diseases / Q000150:complications / Q000378:metabolism*; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000378:metabolism*; D012044:Regression Analysis; D012129:Respiratory Function Tests; D013739:Testosterone / Q000378:metabolism; D013848:Thigh; D014057:Tomography, X-Ray Computed
chemical_list: D015850:Interleukin-6; D013739:Testosterone; D019314:Dehydroepiandrosterone Sulfate; D007334:Insulin-Like Growth Factor I; D006854:Hydrocortisone