Smoking cessation in HIV patients: rate of success and associated factors.

BACKGROUND: Smoking is the modifiable cardiovascular (CV) risk factor that contributes most to causing premature CV disease. Prevalence of smoking in patients with HIV infection is double that of the general population. OBJECTIVES: To determine the rate of patients succeeding in quitting smoking after 12 months, factors associated with this success, and the characteristics of tobacco consumption and nicotine dependence. METHODS: Longitudinal descriptive study. Three hundred and sixty-eight HIV-infected patients were interviewed. Smokers in Prochaska's stage of action began a programme to quit smoking. We registered the variables related to tobacco consumption and the level of success of cessation. RESULTS: 63.9% of the patients were active smokers and 14% of them began the cessation programme. Average motivation for cessation was 7.8 +/- 1.4 (Richmond) and nicotine dependence rate 5.5 +/- 3.0 (Fagerström). After 1 year, 25% had quit smoking. Those patients who stopped smoking presented a higher motivation level (8.8 +/- 1.3 vs. 7.5 +/- 1.5, P=0.048). Cessation significantly reduced their CV risk at 12 months [2.5 [interquartile range (IQR) 2.0-5.2] vs. 1.7 [IQR 1.0-3.5], P=0.026]. CONCLUSIONS: The prevalence of smokers in our population of HIV-infected patients was 63.9%. Only 14% began a smoking cessation programme. Twelve months after a programme to quit smoking, cessation rate was 25%; this was influenced mostly by the level of motivation of the patient.

Smoking cessation and weight gain.

Cigarette smoking is the single most important preventable cause of death and illness. Smoking cessation is associated with substantial health benefits. Weight gain is cited as a primary reason for not trying to quit smoking. There is a great variability in the amount of weight gain but younger ages, lower socio-economic status and heavier smoking are predictors of higher weight gain. Weight change after smoking cessation appears to be influenced by underlying genetic factors. Besides, weight gain after smoking cessation is largely because of increased body fat and some studies suggest that it mostly occurs in the subcutaneous region of the body. The mechanism of weight gain includes increased energy intake, decreased resting metabolic rate, decreased physical activity and increased lipoprotein lipase activity. Although there is convincing evidence for the association between smoking cessation and weight gain, the molecular mechanisms underlying this relationship are not well understood. This review summarizes current information of the effects of nicotine on peptides involved in feeding behaviour. Smoking was shown to impair glucose tolerance and insulin sensitivity and cross-sectional studies have demonstrated that smokers are insulin-resistant and hyperinsulinaemic, as compared with non-smokers. Smoking cessation seems to improve insulin sensitivity in spite of the weight gain. Nicotine replacement - in particular nicotine gum - appears to be effective in delaying post-cessation weight gain. In a group of women who failed to quit smoking because of weight gain, a dietary intervention (intermittent very-low-calorie diet) plus nicotine gum showed to both increase success rate in terms of smoking cessation and prevent weight gain. On the other hand, body weight gain at the end of treatment was significantly lower in the patients receiving bupropion or bupropion plus nicotine patch, compared with placebo. Studies with new drugs available for the treatment of obesity - sibutramine and orlistat - are warranted.