Peripheral muscle composition and health status in patients with COPD.
OBJECTIVE
The present study evaluated the relationship between health status (HS) and peripheral muscle histochemical characteristics in chronic obstructive pulmonary disease (COPD), and identified selected independent respiratory and extrapulmonary variables that predicted the HS of these patients.


METHODS
Cross-sectional study.


METHODS
Outpatient respiratory clinic of a university hospital.


METHODS
We studied 29 patients (63+/-10 yrs) with a forced expiratory volume in 1s (FEV1) of 39+/-12%. All patients underwent vastus lateralis muscle biopsies for histochemical analysis. They also had spirometry, arterial blood gas analysis, body mass index (BMI), dyspnea determined with the MMRC scale and responded to the St. George's Respiratory Questionnaire (SGRQ) for HS assessment.


RESULTS
SGRQ total score correlated with fiber type distribution. A stepwise multiple regression identified three independent predictors of SGRQ total score: type I fiber proportion, BMI, and FEV1; r = 0.78 and r2 = 0.61.


CONCLUSIONS
These results indicate that impaired HS in COPD is related to the peripheral muscle changes characterized by less type I fibers proportion. The findings argue in favor of an important contribution of the systemic consequences on the HS in COPD independently from the airflow limitation severity, and help to explain the observation of the poor correlation between the degree of airflow limitation and SGRQ total score.
Pulmonary Division, Hospital Universitario de Caracas, Universidad Central de Venezuela, Caracas, Venezuela. mmdeoca@cantv.net
María
M
Montes de Oca
Sonia H
SH
Torres
Yudith
Y
Gonzalez
Elizabeth
E
Romero
Noelina
N
Hernández
Abdón
A
Mata
Carlos
C
Tálamo
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D001784:Blood Gas Analysis; D015992:Body Mass Index; D004417:Dyspnea / Q000473:pathology; D005541:Forced Expiratory Volume / Q000502:physiology; D006304:Health Status; D006801:Humans; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000473:pathology*; D052097:Quadriceps Muscle / Q000473:pathology*; D014797:Vital Capacity / Q000502:physiology