Gender and skeletal muscle characteristics in subjects with chronic obstructive pulmonary disease.
BACKGROUND
The influence of gender in the clinical expression of COPD has received important attention. Limited information exists regarding gender differences in the skeletal muscle characteristics in COPD subjects. The present study was aimed to determine the differences in the skeletal muscle characteristics in men and women with and without COPD.


METHODS
For comparison we studied 24 female (61 ± 9 years) and 30 male (65 ± 8 years) COPD patients with similar disease severity. In addition healthy subjects, 17 women (58 ± 8 years), and 9 men (57 ± 8 years) were studied. Pulmonary function, health status, six minute walk distance test (6MWD) and vastus lateralis muscle biopsy were assessed. Fiber type proportion, fiber type cross sectional area (CSA), capillary counts, and activity of citrate synthase (CS), 3-hydroxyacyl-CoA-dehydrogenase (HAD) and lactate-dehydrogenase (LDH) were determined.


RESULTS
Pulmonary function, health status and 6MWD were similar in male and female COPD patients. Fiber type distribution was similar between women (I = 42 ± 9%, IIA = 39 ± 13%, IIX = 19 ± 7%) and men (I = 39 ± 13%, IIA = 38 ± 9%, IIX = 29 ± 10%) with COPD, as well as CSA, capillarity and enzymes (CS 8.59 ± 1.6 vs.9.74 ± 2.6, HAD 9.03 ± 1.9 vs. 9.84 ± 2.5, LDH 124 ± 48 vs. 151 ± 68 μmol min(-1) g(-1)). In normal subjects a decrease in type IIX fibers CSA was found in women compared with men (3703 ± 1478 vs. 5426 ± 1386 μm(2), respectively).


CONCLUSIONS
Female and male with COPD have similar skeletal muscle characteristics; it is possible that the disease blurs the gender differences. On the other hand, there seems to be fewer differences in muscle characteristics between older men and women, perhaps due to lower male testosterone levels and physical inactivity.
Torres
Sonia H
SH
Muscle Adaptation Section, Institute of Experimental Medicine, Faculty of Medicine, Central University of Venezuela, Venezuela. sonia.hecker@gmail.com
Montes de Oca
María
M
Loeb
Eduardo
E
Mata
Abdón
A
Hernández
Noelina
N
D000368:Aged; D004198:Disease Susceptibility / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000473:pathology* / Q000503:physiopathology; D012129:Respiratory Function Tests; D012307:Risk Factors; D012727:Sex Characteristics; D012737:Sex Factors