Smoking, Alcohol, and Neuromuscular Function in Older Women-Reply

Dr Slade suggests that nicotine may impair neuromuscular performance and increase the risk of subsequent injury. A relaxing effect of nicotine on the neuromuscular system has been described.1 It may be one of several mechanisms acting together in a cumulative fashion to impair function. Dr Spilich suggests that one more such mechanism may be a direct effect of nicotine on the central nervous system. Nicotine and brain neurotransmitter systems have been studied, although their relationships to performance have been limited to animal investigations.2 Others have documented lower cerebral blood perfusion levels in elderly chronic smokers compared with nonsmokers with improvement in perfusion within 1 year after smoking cessation.3 Both of these central nervous system mechanisms could contribute to impaired performance. We hope our observations stimulate physiologic studies of the mechanism for this important adverse effect of smoking on the quality of smokers' lives.