Smoking is one of the most common risk factors for developing chronic obstructive pulmonary disease (COPD). One of my recent articles discussed the problem of muscle weakness in patients with COPD, but there is some specific data about smoking and muscle dysfunction which I would like to bring to your attention. The relationship of smoking and muscle dysfunction has been studied both in smokers with, and those without, COPD.
Cigarette smoking can cause muscle dysfunction even in patients who have not yet developed full blown COPD. The various chemicals in cigarette smoke induce the body to produce inflammatory molecules which affect protein metabolism. This effect of cigarette smoke leads to protein breakdown in muscles and the inability to repair this injury. All of this leads to weaker muscles and reduced activity.
The quadriceps muscle (the large muscle on the front part of the thigh) must be strong in order for us to climb stairs, get up from a chair, and straighten our legs. Carbon monoxide in cigarette smoke can interfere with the energy process within muscle cells leading to poor muscle function, including strength of the muscle’s contraction and its endurance.
This impairment of muscle function also includes the muscles we use to breathe, causing additional shortness of breath with activity. The damage cigarette smoking does to the lungs is not reversible but studies suggest that much of the muscle injury due to cigarette smoking may be reversible with smoking cessation and physical therapy.