Peripheral Muscle Alterations in Non-COPD Smokers

Klotho and smoking – An interplay influencing the skeletal muscle function deficits that occur in COPD

“…Oxidative stress is increased in the quadriceps of smokers and COPD patients, in whom it relates to skeletal muscle dysfunction (36). Although we only demonstrated increased oxidative stress in weak patients, smokers with normal spirometry exhibit evidence of nitrosative stress (28).…”

“…Secondly, it has been clearly demonstrated that rectus femoris cross sectional area and quadriceps maximal voluntary contraction force are reduced in patients with mild disease, in whom there is only minimal pulmonary impairment to exercise (26). Thirdly, muscle biopsy studies have shown changes which we would now recognise as typical of COPD, such as type II fibre shift or loss of oxidative enzymes, in smokers compared with non-smokers (27) and of oxidative stress in smokers with normal spirometry (28). Similarly, Gagnon et al (29) found evidence of impaired angiogenic signalling in the quadriceps of patients with minimal airflow obstruction, however, as controls had a very similar tobacco history to the patients it was impossible to evaluate the effect of smoking.…”

Quadriceps wasting and physical inactivity in patients with COPD

“…Disuse may also increase susceptibility to systemic factors, particularly the effects of smoking, which is in itself known to be associated with skeletal muscle oxidative stress [36] and quadriceps weakness [37]. It should be noted, however, that inactivity may act as a significant confounder when observing quadriceps dysfunction as an effect of smoking.…”

Changes in Sympathetic Nervous System Activity in Male Smokers After Moderate-Intensity Exercise

“…27 Smokers also experience muscle wasting 28 and loss of type-1 muscle fibers. 29 Furthermore, weight loss, including cachexia, is associated with increased morbidity and mortality. 5,30,31 Thus, normal-weight smokers may benefit from anti-smoking measures to prevent weight loss.…”