Chronic Electronic Cigarette Use and Accelerated Skeletal Muscle Aging

As the use of electronic cigarettes becomes more and more prevalent, there is a need to rigorously test the long-term effects on metabolism, safety and overall health. We are asking the question of whether the continued use of electronic cigarettes will accelerate muscle aging. This could lead to weaker, smaller muscles that are not able to recover from injury due to strenuous use. Currently, how skeletal muscle response to chronic nicotine administration is controversial and incompletely understood. This is especially true when consumed as an e-cigarette “vapor” mixed with other reagents and artificial flavorings. Initial studies in our laboratory showed that mice that inhaled e-cigarette vapor daily for several months do not run well on a treadmill, have smaller muscles and a changed muscle metabolism. Smaller and weaker muscles are key signs of aging (referred to as sarcopenia) and reflect the inability to maintain proper connections between the nerves and muscle fibers. We plan to measure exercise performance, muscle strength and mass and characterize the nerve-muscle connections in mice that inhale daily periods of electronic cigarette vapor over many months. In addition the extent of muscle and nerve damage and the ability to recover will be measured following a form of muscle over-use damage in which muscle is stimulated to contract while it is full extended.