Consistent with the adverse effects of nicotine on insulin sensitivity, there is a clear, dose-dependent relation between diabetes or glucose intolerance and both active and passive cigarette exposure [79]. However, in keeping with the paradox of smoking-associated weight loss and greater insulin-resistance, some studies found that the amount of smoking interacts with BMI to produce either adverse or favorable effects on diabetes [80]. The incidence of diabetes may be lower with smoking if the weight loss leads to a net improvement in central adiposity [77]. With smoking cessation, the risk of diabetes decreases over time [81], but it may also paradoxically increase in association with the weight gain that occurs during the first 3–5 years following smoking cessation