Identification of possible cigarette smoke constituents responsible for muscle catabolism.

The age-related loss of muscle mass and strength also known as sarcopenia is significantly influenced by life style factors such as physical inactivity and impaired nutrition. Cigarette smoking is another life style habit that has been shown to be associated with sarcopenia and to affect skeletal muscle. Even today, smoking is still prevalent worldwide and is probably the most significant source of toxic chemicals exposure to humans. Cigarette smoke (CS) is a complex aerosol consisting of thousands of various constituents including reactive oxygen and nitrogen free radicals, toxic aldehydes and more. Previous epidemiological studies have identified tobacco smoking as a risk factor for sarcopenia. Clinical, in vivo and in vitro studies have revealed CS-induced skeletal muscle damage due to impaired muscle metabolism, increased inflammation and oxidative stress, over-expression of atrophy related genes and activation of various intracellular signaling pathways. This review aims to discuss and identify the components of CS that may promote catabolism of skeletal muscle.