Smoking-induced metabolic disorders: a review.

Smoking is the leading avoidable cause of cardiovascular mortality worldwide. The aim of this report is to briefly review the existing evidence regarding smoking and cardiovascular risk, and to analyze in greater detail the links between tobacco use and metabolic disorders. The evidence so far shows that smoking dose-dependently increases the risk of impaired glucose tolerance, the incidence of type 2 diabetes mellitus and abdominal-type obesity. Although smokers have a lower body mass index than do nonsmokers, recent data show that they have higher waist-to-hip ratios and waist circumferences, established risk factors for cardiovascular disorders-in particular, for coronary heart disease. We propose that smoking may lead not only directly, but also indirectly via these metabolic risk factors, to cardiovascular disorders. As both weight and waist circumference may increase on stopping smoking, further studies are needed to assess whether the post-smoking weight increase and potential changes in waist-to-hip ratio (or waist circumference) have consequences that may reduce the benefits of smoking cessation.