Tobacco Smoke Can Damage Skeletal Muscle

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Tobacco Smoke Can Damage Skeletal Muscle

http://www.medicalnewstoday.com/articles/93581.php

A new study suggests that long term heavy tobacco smoking can lead

to potentially harmful structural and functional changes in skeletal

muscles outside the lungs, even in smokers who don't have chronic

obstructive pulmonary disease.

Smoking is the major cause of COPD, but relatively little is known

about the effect of smoking on skeletal muscles. Skeletal muscles

are striated and usually attached to the skeleton. By exerting force

on the bones and joints, the skeletal muscles contract to produce

movement.

Dr. Montes de Oca from Hospital Universitario de Caracas,

Venezuela, and colleagues compared the vastus lateralis muscle,

which originates in the thigh bone extends to the shin bone, in 14

heavy smokers without COPD and 20 healthy non-smokers. Subjects in

both groups led sedentary lifestyles.

According to their report, published in the medical journal, Chest,

the investigators observed significantly reduced cross sectional

area of two types of muscle fibers in smokers compared with non-

smokers.

The investigators note that smokers were also more apt to show

potentially harmful metabolic changes including an imbalance of

oxidant and antioxidant chemicals, suggesting preferential damage of

oxidative fibers among smokers.

The results also suggest that tobacco smoke alters the normal

process by which the body generates nitric oxide, a chemical that

helps open small blood vessels. This alteration could lead to

hypoxia (low oxygen levels), which in turn may explain the fiber

atrophy observed in the smokers.

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