Abstract P008: Weight Gain and Cardiovascular Risk Reduction Associated With Tobacco Abstinence in Smokers With Serious Mental Illness

Abstract

Background: In patients with serious mental illness, high prevalence of smoking and obesity-related risk factors contribute to high rates of cardiovascular disease (CVD) and premature mortality. The impact of smoking cessation on weight gain, obesity-related risk factors, and overall cardiovascular risk among this population is unknown. Methods: We conducted secondary analyses to assess weight gain and change in CVD risk of 87 smokers with serious mental illness (schizophrenia, schizoaffective disorder, and bipolar disorder) who participated in a randomized controlled trial to test the long-term effectiveness of varenicline on smoking cessation. Initially, 203 smokers with serious mental illness were enrolled into an open-label 12-week course of varenicline. Subjects who attained abstinence at the end of the open-label phase were eligible to participate in the randomized phase, and 87 subjects were randomized to continue either varenicline or placebo for the following 40 weeks. Smoking cessation at week 52 (end of treatment) was defined as 21-day point prevalence abstinence. We compared subjects who were abstinent at week 52 (N=33) to subjects who had relapsed to smoking (N=54) on changes in weight and Framingham 10-year CVD risk score over the 52-week trial; outcomes were modeled with repeated measures analyses of variance. Results: At baseline, subjects who achieved week 52 abstinence were older (52 vs. 46 years, p=0.01) and had higher fasting serum glucose (98 vs. 89 mg/dL, p=0.008) than subjects who relapsed, but they did not differ on sex, race, smoking characteristics, blood pressure, lipids, treatment for diabetes, or treatment with antipsychotic medications. Baseline mean body mass index did not differ between abstinent and relapsed subjects (31.4 vs. 32.4, p=0.52), but the baseline mean Framingham risk score was higher for abstinent than relapsed subjects (14.2% vs. 10.8%, p=0.02). Over the 52 week study period, abstinent subjects gained more weight than relapsed subjects (4.8 kg vs. 1.2 kg, p=0.002 for time*abstinence interaction), but the mean Framingham risk score decreased substantially for abstinent subjects and not for relapsed subjects (-7.6% vs. 0.0%, p=0.003 for abstinence effect adjusting for sex, site, varenicline or placebo, and antipsychotic medications). Conclusion: Despite the high prevalence of obesity at baseline and substantial weight gain associated with long-term abstinence, smoking cessation resulted in a large reduction in the Framingham estimated 10-year CVD risk among patients with serious mental illness.