Interventions for preventing weight gain after smoking cessation

Targeting GLP-1 receptors to reduce nicotine use disorder: Preclinical and clinical evidence

Nicotine use disorder (NUD) remains a leading cause of preventable death in the U.S. Unfortunately, current FDA-approved pharmacotherapies for smoking cessation have limited efficacy and are associated with high rates of relapse. One major barrier to long-term smoking abstinence is body weight gain during withdrawal. Nicotine withdrawal-induced body weight gain can also lead to development of chronic disease states like obesity and type II diabetes mellitus. Therefore, it is critical to identify novel pharmacotherapies for NUD that decrease relapse and nicotine withdrawal symptoms including body weight gain. Recent studies demonstrate that glucagon-like peptide-1 receptor (GLP-1R) agonists attenuate voluntary nicotine taking and seeking and prevent withdrawal-induced hyperphagia and body weight gain. Emerging evidence also suggests that GLP-1R agonists improve cognitive deficits, as well as depressive- and anxiety-like behaviors, which contribute to smoking relapse during withdrawal. While further studies are necessary to fully characterize the effects of GLP-1R agonists on NUD and understand the mechanisms by which GLP-1R agonists decrease nicotine withdrawal-mediated behaviors, the current literature supports GLP-1R-based approaches to treating NUD.

Motivational support intervention to reduce smoking and increase physical activity in smokers not ready to quit: the TARS RCT

Background

Physical activity can support smoking cessation for smokers wanting to quit, but there have been no studies on supporting smokers wanting only to reduce. More broadly, the effect of motivational support for such smokers is unclear.

Objectives

The objectives were to determine if motivational support to increase physical activity and reduce smoking for smokers not wanting to immediately quit helps reduce smoking and increase abstinence and physical activity, and to determine if this intervention is cost-effective.

Design

This was a multicentred, two-arm, parallel-group, randomised (1 : 1) controlled superiority trial with accompanying trial-based and model-based economic evaluations, and a process evaluation.

Setting and participants

Participants from health and other community settings in four English cities received either the intervention (n = 457) or usual support (n = 458).

Intervention

The intervention consisted of up to eight face-to-face or telephone behavioural support sessions to reduce smoking and increase physical activity.

Main outcome measures

The main outcome measures were carbon monoxide-verified 6- and 12-month floating prolonged abstinence (primary outcome), self-reported number of cigarettes smoked per day, number of quit attempts and carbon monoxide-verified abstinence at 3 and 9 months. Furthermore, self-reported (3 and 9 months) and accelerometer-recorded (3 months) physical activity data were gathered. Process items, intervention costs and cost-effectiveness were also assessed.

Results

The average age of the sample was 49.8 years, and participants were predominantly from areas with socioeconomic deprivation and were moderately heavy smokers. The intervention was delivered with good fidelity. Few participants achieved carbon monoxide-verified 6-month prolonged abstinence [nine (2.0%) in the intervention group and four (0.9%) in the control group; adjusted odds ratio 2.30 (95% confidence interval 0.70 to 7.56)] or 12-month prolonged abstinence [six (1.3%) in the intervention group and one (0.2%) in the control group; adjusted odds ratio 6.33 (95% confidence interval 0.76 to 53.10)]. At 3 months, the intervention participants smoked fewer cigarettes than the control participants (21.1 vs. 26.8 per day). Intervention participants were more likely to reduce cigarettes by ≥ 50% by 3 months [18.9% vs. 10.5%; adjusted odds ratio 1.98 (95% confidence interval 1.35 to 2.90] and 9 months [14.4% vs. 10.0%; adjusted odds ratio 1.52 (95% confidence interval 1.01 to 2.29)], and reported more moderate-to-vigorous physical activity at 3 months [adjusted weekly mean difference of 81.61 minutes (95% confidence interval 28.75 to 134.47 minutes)], but not at 9 months. Increased physical activity did not mediate intervention effects on smoking. The intervention positively influenced most smoking and physical activity beliefs, with some intervention effects mediating changes in smoking and physical activity outcomes. The average intervention cost was estimated to be £239.18 per person, with an overall additional cost of £173.50 (95% confidence interval -£353.82 to £513.77) when considering intervention and health-care costs. The 1.1% absolute between-group difference in carbon monoxide-verified 6-month prolonged abstinence provided a small gain in lifetime quality-adjusted life-years (0.006), and a minimal saving in lifetime health-care costs (net saving £236).

Conclusions

There was no evidence that behavioural support for smoking reduction and increased physical activity led to meaningful increases in prolonged abstinence among smokers with no immediate plans to quit smoking. The intervention is not cost-effective.

Limitations

Prolonged abstinence rates were much lower than expected, meaning that the trial was underpowered to provide confidence that the intervention doubled prolonged abstinence.

Future work

Further research should explore the effects of the present intervention to support smokers who want to reduce prior to quitting, and/or extend the support available for prolonged reduction and abstinence.

Trial registration

This trial is registered as ISRCTN47776579.

Funding

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 4. See the NIHR Journals Library website for further project information.

Interventions for preventing weight gain after smoking cessation

BACKGROUND

Most people who stop smoking gain weight. This can discourage some people from making a quit attempt and risks offsetting some, but not all, of the health advantages of quitting. Interventions to prevent weight gain could improve health outcomes, but there is a concern that they may undermine quitting.

OBJECTIVES

To systematically review the effects of: (1) interventions targeting post-cessation weight gain on weight change and smoking cessation (referred to as 'Part 1') and (2) interventions designed to aid smoking cessation that plausibly affect post-cessation weight gain (referred to as 'Part 2').

SEARCH METHODS

Part 1 - We searched the Cochrane Tobacco Addiction Group's Specialized Register and CENTRAL; latest search 16 October 2020. Part 2 - We searched included studies in the following 'parent' Cochrane reviews: nicotine replacement therapy (NRT), antidepressants, nicotine receptor partial agonists, e-cigarettes, and exercise interventions for smoking cessation published in Issue 10, 2020 of the Cochrane Library. We updated register searches for the review of nicotine receptor partial agonists.

SELECTION CRITERIA

Part 1 - trials of interventions that targeted post-cessation weight gain and had measured weight at any follow-up point or smoking cessation, or both, six or more months after quit day. Part 2 - trials included in the selected parent Cochrane reviews reporting weight change at any time point.

DATA COLLECTION AND ANALYSIS

Screening and data extraction followed standard Cochrane methods. Change in weight was expressed as difference in weight change from baseline to follow-up between trial arms and was reported only in people abstinent from smoking. Abstinence from smoking was expressed as a risk ratio (RR). Where appropriate, we performed meta-analysis using the inverse variance method for weight, and Mantel-Haenszel method for smoking.

MAIN RESULTS

Part 1: We include 37 completed studies; 21 are new to this update. We judged five studies to be at low risk of bias, 17 to be at unclear risk and the remainder at high risk.  An intermittent very low calorie diet (VLCD) comprising full meal replacement provided free of charge and accompanied by intensive dietitian support significantly reduced weight gain at end of treatment compared with education on how to avoid weight gain (mean difference (MD) -3.70 kg, 95% confidence interval (CI) -4.82 to -2.58; 1 study, 121 participants), but there was no evidence of benefit at 12 months (MD -1.30 kg, 95% CI -3.49 to 0.89; 1 study, 62 participants). The VLCD increased the chances of abstinence at 12 months (RR 1.73, 95% CI 1.10 to 2.73; 1 study, 287 participants). However, a second study  found that no-one completed the VLCD intervention or achieved abstinence. Interventions aimed at increasing acceptance of weight gain reported mixed effects at end of treatment, 6 months and 12 months with confidence intervals including both increases and decreases in weight gain compared with no advice or health education. Due to high heterogeneity, we did not combine the data. These interventions increased quit rates at 6 months (RR 1.42, 95% CI 1.03 to 1.96; 4 studies, 619 participants; I² = 21%), but there was no evidence at 12 months (RR 1.25, 95% CI 0.76 to 2.06; 2 studies, 496 participants; I² = 26%). Some pharmacological interventions tested for limiting post-cessation weight gain (PCWG) reduced weight gain at the end of treatment (dexfenfluramine, phenylpropanolamine, naltrexone). The effects of ephedrine and caffeine combined, lorcaserin, and chromium were too imprecise to give useful estimates of treatment effects. There was very low-certainty evidence that personalized weight management support reduced weight gain at end of treatment (MD -1.11 kg, 95% CI -1.93 to -0.29; 3 studies, 121 participants; I² = 0%), but no evidence in the longer-term 12 months (MD -0.44 kg, 95% CI -2.34 to 1.46; 4 studies, 530 participants; I² = 41%). There was low to very low-certainty evidence that detailed weight management education without personalized assessment, planning and feedback did not reduce weight gain and may have reduced smoking cessation rates (12 months: MD -0.21 kg, 95% CI -2.28 to 1.86; 2 studies, 61 participants; I² = 0%; RR for smoking cessation 0.66, 95% CI 0.48 to 0.90; 2 studies, 522 participants; I² = 0%). Part 2: We include 83 completed studies, 27 of which are new to this update. There was low certainty that exercise interventions led to minimal or no weight reduction compared with standard care at end of treatment (MD -0.25 kg, 95% CI -0.78 to 0.29; 4 studies, 404 participants; I² = 0%). However, weight was reduced at 12 months (MD -2.07 kg, 95% CI -3.78 to -0.36; 3 studies, 182 participants; I² = 0%). Both bupropion and fluoxetine limited weight gain at end of treatment (bupropion MD -1.01 kg, 95% CI -1.35 to -0.67; 10 studies, 1098 participants; I² = 3%); (fluoxetine MD -1.01 kg, 95% CI -1.49 to -0.53; 2 studies, 144 participants; I² = 38%; low- and very low-certainty evidence, respectively). There was no evidence of benefit at 12 months for bupropion, but estimates were imprecise (bupropion MD -0.26 kg, 95% CI -1.31 to 0.78; 7 studies, 471 participants; I² = 0%). No studies of fluoxetine provided data at 12 months. There was moderate-certainty that NRT reduced weight at end of treatment (MD -0.52 kg, 95% CI -0.99 to -0.05; 21 studies, 2784 participants; I² = 81%) and moderate-certainty that the effect may be similar at 12 months (MD -0.37 kg, 95% CI -0.86 to 0.11; 17 studies, 1463 participants; I² = 0%), although the estimates are too imprecise to assess long-term benefit. There was mixed evidence of the effect of varenicline on weight, with high-certainty evidence that weight change was very modestly lower at the end of treatment (MD -0.23 kg, 95% CI -0.53 to 0.06; 14 studies, 2566 participants; I² = 32%); a low-certainty estimate gave an imprecise estimate of higher weight at 12 months (MD 1.05 kg, 95% CI -0.58 to 2.69; 3 studies, 237 participants; I² = 0%).

AUTHORS' CONCLUSIONS

Overall, there is no intervention for which there is moderate certainty of a clinically useful effect on long-term weight gain. There is also no moderate- or high-certainty evidence that interventions designed to limit weight gain reduce the chances of people achieving abstinence from smoking.

Pilot feasibility trial of dual contingency management for cigarette smoking cessation and weight maintenance among weight-concerned female smokers

Many women who smoke cigarettes report that concern about weight gain is a barrier to quitting. Indeed, most quitters gain weight and some attribute relapses to weight gain concern. Contingency management (CM), which refers to reinforcing a target behavior with financial incentives, has been demonstrated effective for promoting smoking abstinence and weight management independently. We conducted a pilot trial to establish the feasibility of dual CM, in which both smoking cessation and weight maintenance were incentivized, as a smoking cessation intervention for female weight-concerned smokers. Participants (N = 10) received a 12-week intervention during which they earned financial incentives for smoking abstinence, verified by breath carbon monoxide (CO) testing, and for maintaining their weight (larger incentives for gaining less than five pounds, smaller incentives for 5-10 pound gain) while abstaining from smoking. They attended an end of intervention visit at week 13 and a follow-up visit at week 26. Total compensation was up to $550 ($255 for participation independent of smoking and weight, $145 for smoking abstinence incentives, and $150 for weight maintenance incentives). Results indicated that five of the 10 participants (50%) were continuously abstinent for at least 4 weeks and received at least 2 weight maintenance incentives. Three participants (33%) were abstinent at every visit they attended from quit date through week 26; 2 of these 3 had gained more than 10 pounds by week 26. Additional formative research to test alternative incentive schedules and modalities should be conducted before CM-W is evaluated in a larger trial. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

A Pilot Randomized Controlled Trial of Distress Tolerance Treatment for Weight Concern in Smoking Cessation Among Women

INTRODUCTION

The majority of women who smoke cigarettes report that concern about weight gain is a barrier to quitting. We developed an intervention incorporating distress tolerance, appetite awareness, and mindful eating skills to target concerns about post-cessation weight gain and emotional eating (DT-W). In the current study, we conducted a pilot randomized controlled trial of DT-W versus a smoking health education (HE) intervention.

METHODS

Participants (N = 69 adult female, weight-concerned smokers) were recruited in cohorts of 4-11. Cohorts were randomized to DT-W or HE. DT-W and HE were matched on format (single individual session followed by eight group sessions), inclusion of cognitive behavioral therapy for smoking cessation (CBT) content, and pharmacotherapy (nicotine patches). Follow-up assessments occurred at 1-, 3-, and 6-months post-treatment.

RESULTS

The recruitment goal was met; 61 of the 69 participants attended at least one group session. There were no significant differences between DT-W and HE in the number of group sessions attended (DT-W adjusted M = 5.09, HE adjusted M = 5.03, p = .92), ratings of treatment effectiveness or usefulness of skills, or retention at 6-month follow-up (79% in DT-W vs. 78% in HE) (ps > .05), but comprehension ratings were lower in DT-W than in HE (p = .02).

CONCLUSIONS

Overall, these results suggest that the study procedures and interventions were feasible and acceptable, but changes to the DT-W intervention content to improve comprehension should be considered prior to conducting a fully powered trial.

IMPLICATIONS

A distress tolerance-based treatment targeting fear of weight gain after smoking cessation and post-cessation emotional eating was feasible and acceptable relative to a smoking HE comparison condition, but changes should be considered before conducting a larger trial. Continued innovation in treatment development for weight-concerned smokers is needed.

Nicotine Effects, Body Weight Concerns and Smoking: A Literature Review

How people become addicted to cigarette smoking and remain addicted despite repeated attempts to quit requires piecing together a rather complex puzzle. The present review contextualizes the role of nicotine and smoking sensory stimulation on maintaining smoking, describes nicotine's effects on feeding behavior and body weight, and explores the impact of smoking outcome expectancies, including the belief that nicotine suppresses appetite and body weight, on the decision to smoke or vape (use of e-cigarettes). The analysis concludes with a review of rat models of human nicotine intake that attempt to isolate the effects of nicotine on appetite and weight gain. Animal research replicates with relative closeness phenomena observed in smokers, but the rat model falls short of replicating the long-term weight gain observed post-smoking cessation.

Lifestyle Changes in Relation to Initiation of Antihypertensive and Lipid-Lowering Medication: A Cohort Study

Background Lifestyle modification is a key component of cardiovascular disease prevention before and concurrently with pharmacologic interventions. We evaluated whether lifestyle factors change in relation to the initiation of antihypertensive or lipid-lowering medication (statins). Methods and Results The study population comprised 41 225 participants of the FPS (Finnish Public Sector) study aged ≥40 years who were free of cardiovascular disease at baseline and responded to ≥2 consecutive surveys administered in 4-year intervals in 2000-2013. Medication use was ascertained through pharmacy-claims data. Using a series of pre-post data sets, we compared changes in body mass index, physical activity, alcohol consumption, and smoking between 8837 initiators and 46 021 noninitiators of antihypertensive medications or statins. In participants who initiated medication use, body mass index increased more (difference in change 0.19; 95% CI, 0.16-0.22) and physical activity declined (-0.09 metabolic equivalent of task hour/day; 95% CI, -0.16 to -0.02) compared with noninitiators. The likelihood of becoming obese (odds ratio: 1.82; 95% CI, 1.63-2.03) and physically inactive (odds ratio: 1.08; 95% CI, 1.01-1.17) was higher in initiators. However, medication initiation was associated with greater decline in average alcohol consumption (-1.85 g/week; 95% CI, -3.67 to -0.14) and higher odds of quitting smoking (odds ratio for current smoking in the second survey: 0.74; 95% CI, 0.64-0.85). Conclusions These findings suggest that initiation of antihypertensive and statin medication is associated with lifestyle changes, some favorable and others unfavorable. Weight management and physical activity should be encouraged in individuals prescribed these medications.

Physical activity and weight gain after smoking cessation in postmenopausal women

OBJECTIVE

Weight gain frequently occurs after smoking cessation. The objective of this study was to examine whether weight gain after smoking cessation was attenuated by physical activity (PA) in postmenopausal women.

METHODS

A total of 4,717 baseline smokers from the Women's Health Initiative were followed for 3 years. One thousand two hundred eighty-two women quit smoking, and 3,435 continued smoking. Weight was measured at baseline and at the year 3 visit. PA was assessed at both times by self-report, summarized as metabolic equivalent task-hours per week. Multiple linear regression models were used to assess the association between PA and postcessation weight gain, adjusting for potential confounding factors.

RESULTS

Compared with continuing smokers, quitters gained an average of 3.5 kg (SD = 5.6) between the baseline and year 3 visit. Quitters with decreased PA had the highest amount of weight gain (3.88 kg, 95% CI: 3.22-4.54); quitters with increased PA (≥15 metabolic equivalent task-hours /week) had the lowest weight gain (2.55 kg, 95% CI: 1.59-3.52). Increased PA had a stronger beneficial association for postcessation weight gain for women with obesity compared to normal weight women. Quitters who had low PA at baseline and high PA at year 3 and were also enrolled in a dietary modification intervention had nonsignificant weight gain (1.88 kg, 95% CI: -0.21-3.96) compared with continuing smokers.

CONCLUSIONS

Our data demonstrate that even a modest increase in PA (equivalent to current recommendations) can attenuate weight gain after quitting smoking among postmenopausal women, especially in combination with improved diet.

Worsening Dietary and Physical Activity Behaviors Do Not Readily Explain Why Smokers Gain Weight After Cessation: A Cohort Study in Young Adults

Introduction

The relationship between smoking cessation and weight gain is well established but the underlying mechanisms remain poorly understood. We aimed to determine whether postcessation weight gain was mediated by changing health behaviors.

Methods

A total of 281 smokers self-reported their demographic, smoking, and lifestyle characteristics in 2004-2006 (aged 26-36) and 2009-2011 (aged 31-41). Behaviors considered as potential mediators of weight gain were changes in consumption of breakfast, discretionary foods (servings/d), fruit and vegetables (servings/d), alcohol (g/d), takeaway food (times/wk), Diet Guideline Index score, leisure time physical activity (PA, min/wk), total PA (min/wk), time spent sitting (min/d), and TV viewing (h/d).

Results

In total, 124 smokers quit smoking during 5 years follow-up. After adjustment for age, sex, baseline body mass index, education, and follow-up length, smoking cessation was associated with average excess weight gain of 2.09kg (95% CI = 0.35-3.83). Compared with continuing smokers, quitters reported a higher Diet Guideline Index score and less consumption of alcohol at baseline and follow-up (all p < .05). In addition, there was a tendency towards healthier dietary and PA behaviors over 5 years among quitters than continuing smokers except for time spent sitting, although these differences did not reach statistical significance. Adjustment for changes in these behaviors made little difference to the magnitude of postcessation weight gain (β: 2.32kg, 95% CI = 0.54-4.10).

Conclusions

The weight gain associated with smoking cessation was not explained by worsening dietary and PA behaviors. Future research is needed to elucidate the complex mechanisms and particularly ways it may be prevented.

Implications

Fear of weight gain often discourages smokers from trying to quit but guidance on ways to most effectively avoid weight gain is lacking. It is important to identify what causes postcessation weight gain and the ways it may be prevented. The current study explored the effects of several changing dietary and PA behaviors on the relationship between smoking cessation and weight gain in 281 young Australian smokers. We found that quitters tended to adopt healthier dietary and PA behaviors than continuing smokers, so these behaviors did not readily explain the postcessation weight gain. Further investigations of other potential mechanisms are needed.

Distress Tolerance Treatment for Weight Concern in Smoking Cessation Among Women: The WE QUIT Pilot Study

Fear of gaining weight after quitting cigarette smoking is a major barrier to smoking cessation among women. Distress tolerance, which refers to one's ability and willingness to tolerate physical and emotional discomfort, predicts successful behavior change. Novel interventions rooted in Acceptance and Commitment Therapy (ACT) have emerged that aim to increase distress tolerance and engagement in values-oriented behavior. In this study, we developed a 9-week, group-based distress tolerance intervention for weight concern in smoking cessation among women (DT-W). Using an iterative process, we piloted DT-W with two small groups ( n = 4 and n = 7) of female weight-concerned smokers. Results indicated that we successfully established the feasibility and acceptability of DT-W, which was well-attended and well-received. Biochemically verified 7-day point-prevalence abstinence rates at post-intervention, 1, 3, and 6 months were 64%, 36%, 27%, and 27%, respectively. We are now evaluating DT-W in a randomized controlled trial.

IMPLEMENTATION, RECRUITMENT AND BASELINE CHARACTERISTICS: A RANDOMIZED TRIAL OF COMBINED TREATMENTS FOR SMOKING CESSATION AND WEIGHT CONTROL

Background

Two-thirds of treatment-seeking smokers are obese or overweight. Most smokers are concerned about gaining weight after quitting. The average smoker experiences modest post-quit weight gain which discourages many smokers from quitting. Although evidence suggests that combined interventions to help smokers quit smoking and prevent weight gain can be helpful, studies have not been replicated in real world settings.

Methods

This paper describes recruitment and participant characteristics of the Best Quit Study, a 3-arm randomized controlled trial testing tobacco cessation treatment alone or combined with simultaneous or sequential weight management. Study participants were recruited via tobacco quitlines from August 5, 2013 to December 15, 2014.

Results

Statistical analysis on baseline data was conducted in 2015/2016. Among 5082 potentially eligible callers to a tobacco quitline, 2540 were randomized (50% of eligible). Compared with individuals eligible but not randomized, those randomized were significantly more likely to be female (65.7% vs 54.5%, p < 0.01), overweight or obese (76.3% vs 62.5%, p < 0.01), more confident in quitting (p < 0.01), more addicted (first cigarette within 5 min: 50.0% vs 44.4%, p < 0.01), and have a chronic disease (28.6% vs. 24.4%, p < 0.01). Randomized groups were not statistically significantly different on demographics, tobacco or weight variables. Two-thirds of participants were female and white with a mean age of 43.

Conclusions

Adding weight management interventions to tobacco cessation quitlines was feasible and acceptable to smokers. If successful for cessation and weight outcomes, a combined intervention may provide a treatment approach for addressing weight gain with smoking cessation through tobacco quitlines.

Trial registration

Clinicaltrials.gov NCT01867983.

The effect of tobacco cessation on weight gain, obesity, and diabetes risk

OBJECTIVE

Most smokers gain weight after quitting, and some develop new onset obesity and type 2 diabetes. The purpose of this paper is to synthesize the current science investigating the consequences of tobacco cessation on body weight and diabetes, as well as intervention strategies that minimize or prevent weight gain while still allowing for successful tobacco cessation.

METHODS

Systematic reviews and relevant studies that were published since prior reviews were selected.

RESULTS

Smoking cessation can cause excessive weight gain in some individuals and can be associated with clinically significant outcomes such as diabetes or obesity onset. Interventions that combine smoking cessation and weight control can be effective for improving cessation and minimizing weight gain but need to be tested in specific populations.

CONCLUSIONS

Despite the health benefits of quitting tobacco, post-cessation weight gain and new onset obesity and diabetes are a significant concern. Promising interventions may need to be more widely applied to reduce the consequences of both obesity and tobacco use.

Comparative effectiveness of adding weight control simultaneously or sequentially to smoking cessation quitlines: study protocol of a randomized controlled trial

Background

Prevalence of multiple health risk behaviors is growing, and obesity and smoking are costly. Weight gain associated with quitting smoking is common and can interfere with quit success. Efficacy of adding weight management to tobacco cessation treatment has been tested with women in group sessions over an extended period of time, but has never been tested in real-world settings with men and women seeking help to quit. This paper describes the Best Quit study which tests the effectiveness of delivering tobacco and weight control interventions via existing quitline infrastructures.

Methods

Eligible and consenting smokers (n = 2550) who call a telephone quitline will be randomized to one of three groups; the standard quitline or standard quitline plus a weight management program added either simultaneously or sequentially to the tobacco program. The study aims to test: 1) the effectiveness of the combined intervention on smoking cessation and weight, 2) the cost-effectiveness of the combined intervention on cessation and weight and 3) theoretically pre-specified mediators of treatment effects on cessation: reduced weight concerns, increased outcome expectancies about quitting and improved self-efficacy about quitting without weight gain.

Baseline, 6 month and 12 month data will be analyzed using multivariate statistical analyses and groups will be compared on treatment adherence, quit rates and change in weight among abstinent participants. To determine if the association between group assignment and primary outcomes (30-day abstinence and change in weight at 6 months) is moderated by pre-determined baseline and process measures, interaction terms will be included in the regression models and their significance assessed.

Discussion

This study will generate information to inform whether adding weight management to a tobacco cessation intervention delivered by phone, mail and web for smokers seeking help to quit will help or harm quit rates and whether a simultaneous or sequential approach is better at increasing abstinence and reducing weight gain post quit. If proven effective, the combined intervention could be disseminated across the U.S. through quitlines and could encourage additional smokers who have not sought cessation treatment for fear of gaining weight to make quit attempts.

Trial registration

Clinicaltrials.gov NCT01867983. Registered: May 30, 2013

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3231-6) contains supplementary material, which is available to authorized users.

Pharmacotherapy for Substance Use Disorders

This article reviews the current pharmacotherapy options available for the treatment of patients with substance use disorders. In the United States there are medications available to treat tobacco use disorders (nicotine replacement, bupropion, and varenicline), alcohol use disorders (naltrexone and acamprosate), and opioid use disorders (methadone and buprenorphine). These medications are likely underused and physicians should more readily prescribe for eligible patients.

Critical needs in drug discovery for cessation of alcohol and nicotine polysubstance abuse

Polysubstance abuse of alcohol and nicotine has been overlooked in our understanding of the neurobiology of addiction and especially in the development of novel therapeutics for its treatment. Estimates show that as many as 92% of people with alcohol use disorders also smoke tobacco. The health risks associated with both excessive alcohol consumption and tobacco smoking create an urgent biomedical need for the discovery of effective cessation treatments, as opposed to current approaches that attempt to independently treat each abused agent. The lack of treatment approaches for alcohol and nicotine abuse/dependence mirrors a similar lack of research in the neurobiology of polysubstance abuse. This review discusses three critical needs in medications development for alcohol and nicotine co-abuse: (1) the need for a better understanding of the clinical condition (i.e. alcohol and nicotine polysubstance abuse), (2) the need to better understand how these drugs interact in order to identify new targets for therapeutic development and (3) the need for animal models that better mimic this human condition. Current and emerging treatments available for the cessation of each drug and their mechanisms of action are discussed within this context followed by what is known about the pharmacological interactions of alcohol and nicotine. Much has been and will continue to be gained from studying comorbid alcohol and nicotine exposure.

The association between quitting smoking and weight gain: a systematic review and meta-analysis of prospective cohort studies

This systematic review and meta-analysis aimed to quantify weight gain after smoking cessation and the difference in weight gain between quitters and continuing smokers. Five electronic databases were searched before January 2015. Population-based prospective cohort studies were included if they recorded the weight change of adult smokers from baseline (before smoking cessation) to follow-up (at least 3 months after cessation). Thirty-five cohort studies were identified, including 63,403 quitters and 388,432 continuing smokers. The mean weight gain was 4.10 kg (95% confidence interval [CI]: 2.69, 5.51) and body mass index (BMI) gain was 1.14 kg m(-2) (95% CI: 0.50, 1.79) among quitters. Compared with continuing smoking, quitting smoking was significantly associated with absolute weight (adjusted mean difference [MD]: 2.61 kg; 95% CI: 1.61, 3.60) and BMI gain (adjusted MD: 0.63 kg m(-2) ; 95% CI: 0.46, 0.80). Subgroup analyses using geographic region found that the difference in weight gain was considerably greater in studies from North America than from Asia. Follow-up length was identified as a source of heterogeneity, such that studies with longer follow-up showed greater difference in weight gain. Effective strategies are needed to encourage smokers to quit irrespective of potential weight gain and to help quitters avoid excess weight gain.

Predictors of marked weight gain in a population of health care and industrial workers following smoking cessation

Background

Concerns about postcessational weight gain might hamper rather than encourage smokers to quit smoking.

Methods

We conducted a comprehensive multi-institutional smoking cessation program for health care and industrial workers (n = 654) employed at University Hospital Basel (Switzerland) and two local health industry companies (Novartis International AG, F. Hoffmann-La Roche AG). The program contained counselling with an option of pharmacological support. Changes in body weight were observed during 24 months of follow-up. Factors associated with longitudinal weight gain (>5 % of baseline weight) were identified by cox-regression analysis.

Results

In 51 % of permanent quitters no significant changes of mean body weight were observed after 12 (0.52 kg, SD ±2.87 kg) and 24 months (0.40 kg, SD ± 2.99 kg). Marked weight gain following smoking cessation was characterized by a wide margin of changes. In more than a half of former smokers (58 %) weight increases were moderate (<5 kg), whereas excessive increases (>10 kg) were seen in only 10 % of quitters. Lower baseline BMI (HR 0.60, 95 % CI 0.40- 0.80, p = 0.03), daily consumption of less than ten cigarettes (HR 0.53, 95 % CI 0.27- 0.63, p = 0.04) and ischemic cardiopathy (HR 0.21, 95 % CI 0.07-0.62; p < 0.01) were associated with a lower risk for weight gain. Employees with lower educational levels (HR 2.60, 95 % CI 1.60-5.50, p < 0.01), diabetes mellitus (HR 3.05, 95 % CI 2.20-8.06, p = 0.02) and those smoking to reduce boredom in life (HR 1.68, 95 % CI 1.21-2.33, p < 0.01) were at highest risk.

Conclusion

Marked postcessational weight gain occurs less often than expected, but remains difficult to be predicted. Our findings might be helpful to alleviate weight concerns in the average smoker willing to quit.

Misconceptions about smoking in patients with type 2 diabetes mellitus: a qualitative analysis

AIMS AND OBJECTIVES

To investigate the smoking behaviours, perceptions about quitting smoking and factors associated with intention to quit in patients with type 2 diabetes mellitus.

BACKGROUND

Smoking causes type 2 diabetes mellitus. There has been limited research on the needs and concerns of smokers with type 2 diabetes mellitus about quitting smoking.

DESIGN

The study used a qualitative design.

METHODS

Patients diagnosed with type 2 diabetes mellitus who had a history of smoking were recruited at the outpatient diabetic clinics of two major local hospitals in Hong Kong for a semi-structured interview (n = 42), guided by the theory of planned behaviour.

RESULTS

At data saturation, 22 current smokers and 20 ex-smokers with type 2 diabetes mellitus were recruited. The current smokers reported they had not quit smoking because of satisfaction with present health status, and misconceptions about the association between diabetes and smoking, and the perceived hazards of quitting. In contrast, ex-smokers had a positive opinion about quitting smoking, accepted advice about quitting from health professionals and received more family support than current smokers. Psychological addiction and weight gain after cessation made quitting challenging.

CONCLUSIONS

Satisfaction with health status, inadequate knowledge about the relationship between type 2 diabetes mellitus and smoking, and misconceptions about quitting smoking resulted in negative attitudes toward quitting by type 2 diabetes mellitus smokers. Smoking peers, psychological addiction and post-cessation weight gain hindered the quitting process.

RELEVANCE TO CLINICAL PRACTICE

Education on the causal link between smoking, type 2 diabetes mellitus and its complications is important to raise health awareness and counter misconceptions about quitting smoking. Behavioural counselling with weight control strategies should be part of a comprehensive smoking cessation intervention for type 2 diabetes mellitus smokers.

Comparison of Diabetes Risk Following Smoking Cessation Treatment Using Varenicline Versus Bupropion Among Obese Smokers

BACKGROUND

Recent literature suggests an initial increased risk of diabetes following smoking cessation.

OBJECTIVES

To compare the risk of developing diabetes among obese smokers who tried to quit smoking using bupropion versus varenicline.

METHODS

A population-based retrospective cohort study was conducted using the General Electric (GE) electronic medical record database (2006-2011). The cohort consisted of obese adult smokers without a diabetes diagnosis at baseline and newly initiating use of either bupropion or varenicline. This cohort was then followed for 1 year to observe the risk of developing diabetes. The relative risk of bupropion versus varenicline on developing diabetes was assessed using Cox Proportional Hazards regression model after controlling for covariates.

RESULTS

The sample comprised of 78,002 obese smokers of which 1,937 (2.36%) developed diabetes during 1 year follow-up. Diabetes incidence rate was relatively comparable who used varenicline and bupropion (23.50 versus 25.80 per 1,000 person-years). Obese smokers who were prescribed bupropion had a statistically significant higher risk of developing diabetes during 1 year following cessation treatment than those who were prescribed varenicline. ([HR]: 1.58, 95% CI: 1.09-2.27) in the multivariate model.

CONCLUSIONS/IMPORTANCE

Obese smokers who were prescribed bupropion might have a higher risk of developing diabetes during 1 year follow up compared to those who were prescribed varenicline. The clinical significance of the finding that bupropion had a higher risk of developing diabetes may need further investigation.

Change in Body Weight Does Not Mediate the Relationship Between Exercise and Smoking Cessation Among Weight-Concerned Women Smokers

INTRODUCTION

Exercise has received attention as a method to prevent or reduce postcessation weight gain. However, little is known about how weight changes following quit attempts contribute to the relationship between exercise and smoking cessation. The present study assessed how exercise relates to cessation and whether initial changes in exercise after quitting smoking promote cessation through attenuated weight gain.

METHODS

Weight-concerned women smokers (N = 342) receiving cessation treatment provided biochemical validation of cessation, reported weekly exercise activities, and were weighed at 1, 3, and 6 months following treatment initiation. Survival analyses were used to determine time to and risk of relapse among women who reported engaging in varied levels of exercise at baseline. A mediation analysis was used to examine whether the effect of initial changes in exercise on longer-term cessation was driven by change in weight. All analyses were adjusted for relevant covariates.

RESULTS

Women smokers who reported high levels of exercise at baseline were less likely to relapse and returned to smoking more gradually than did women who reported low levels of exercise. Change in weight did not mediate the relationship between exercise and cessation.

CONCLUSIONS

Cessation interventions utilizing an exercise component may have to develop exercise regimens of either higher duration or greater intensity to produce beneficial cessation outcomes, particularly when targeting sedentary smokers. Given that change in weight did not mediate the relationship between exercise and cessation, it is likely that other mediational processes are involved.

Weight gain and smoking: perceptions and experiences of obese quitline participants

Background

Weight gain that commonly accompanies smoking cessation can undermine a person’s attempt to quit and increase the risk for metabolic disorders. Research indicates that obese smokers have more weight concerns and gain more weight after quitting than non-obese smokers, yet little is known about possible reasons for these outcomes. We sought to gain an understanding of obese smokers’ experiences of quitting and their attitudes and beliefs about the association between smoking and weight gain.

Methods

In-depth semi-structured interviews were conducted with obese smokers who called a state tobacco quitline. Interviewers elicited discussion of obese smokers’ thoughts about smoking, the effects of quitting on change in weight, challenges they faced with quitting, and how quitlines might better serve their needs.

Results

Participants (n = 29) discussed their fear of gaining weight after quitting, their beliefs about smoking and their weight and significant experiences related to quitting. Participants’ awareness of weight gain associated with quitting was based on prior experience or observation of others who quit. Most viewed cessation as their primary goal and discussed other challenges as being more important than their weight, such as managing stress or coping with a chronic health condition. Although weight gain was viewed as less important than quitting, many talked about changes they had made to mitigate the anticipated weight gain.

Conclusions

Weight gain is a concern for obese smokers interested in quitting. Understanding the relative importance of body weight and other challenges related to smoking cessation can help tailor interventions for the specific group of smokers who are obese and interested in smoking cessation.

Impact of baseline weight on smoking cessation and weight gain in quitlines

BACKGROUND

The use and effectiveness of tobacco quitlines by weight is still unknown.

PURPOSE

This study aims to determine if baseline weight is associated with treatment engagement, cessation, or weight gain following quitline treatment.

METHODS

Quitline participants (n = 595) were surveyed at baseline, 3 and 6 months.

RESULTS

Baseline weight was not associated with treatment engagement. In unadjusted analyses, overweight smokers reported higher quit rates and were more likely to gain weight after quitting than obese or normal weight smokers. At 3 months, 40 % of overweight vs. 25 % of normal weight or obese smokers quit smoking (p = 0.01); 42 % of overweight, 32 % of normal weight, and 33 % of obese quitters gained weight (p = 0.05). After adjusting for covariates, weight was not significantly related to cessation (approaching significance at 6 months, p = 0.06) or weight gain.

CONCLUSIONS

In the first quitline study of this kind, we found no consistent patterns of association between baseline weight and treatment engagement, cessation, or weight gain.

Strategies to prevent weight gain in adults: a systematic review

CONTEXT

A Healthy People 2020 objective is to increase the prevalence of healthy-weight adults in the U.S. A systematic review of the effectiveness and safety of strategies to prevent weight gain in adults was performed.

EVIDENCE ACQUISITION

MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, CINAHL, PsycINFO, and ClinicalTrials.gov were searched through June 2012. Two reviewers independently reviewed titles, abstracts, and articles. Trials and observational studies with at least 1 year of follow-up that reported on strategies to prevent weight gain or maintain weight were included. Data were abstracted on weight, adherence, safety, and quality-of-life outcomes. The quantity, quality, and consistency of the evidence were graded, with a focus on studies' risks of bias, consistency of results across studies, how directly the question of interest was addressed, and precision of results. A meaningful difference and a significant threshold (p<0.05) were used to identify effective strategies. Evidence was synthesized qualitatively.

EVIDENCE SYNTHESIS

Twenty-two studies (11 trials and 11 observational studies) involving 480,142 participants were included. The strength of evidence is low for all strategies, but effective approaches may include low-fat diets, eating fewer meals prepared away from home, eating more fruits and vegetables, monitoring heart rate during exercise, and participation in group lifestyle sessions with reminder text messages. Safety and quality of life were rarely reported.

CONCLUSIONS

Although the evidence is not strong, there may be effective strategies to prevent weight gain.

Effect of nicotine patch on energy intake and weight gain in postmenopausal women during smoking cessation

INTRODUCTION

Post-cessation weight gain is a commonly cited barrier to smoking cessation. Some evidence suggests that nicotine replacement therapy may limit post-cessation weight gain by reducing energy intake. This project aims to assess differential changes in energy intake and body weight during smoking cessation in a sample of postmenopausal women randomized to receive 21 mg nicotine or placebo patch for 12 weeks.

METHODS

Postmenopausal women who smoked ≥10 cigarettes/day were enrolled in this double-blind randomized placebo-controlled study. Total energy intake (via four-day food diaries), body mass index (BMI; kg/m(2)), cigarettes/day and smoking status (self-report verified by exhaled carbon monoxide) were assessed at three time points: 2 weeks prior to quit date, 12 weeks after quit date, and 12 months after smoking cessation treatment.

RESULTS

Participants (n = 119) were, on average, 55.8 ± 6.7 years old with a baseline BMI of 27.0 ± 5.2 and average cigarette/day was 21.1 ± 8.6. At Week 12, participants randomized to nicotine patch increased their mean caloric intake by 146.4 ± 547.7 kcal/day whereas those on placebo patch decreased their caloric intake by 175.3 ± 463.2 (f-value = 10.1, p-value = 0.002). Despite the differences in caloric intake, body weight remained similar between groups.

CONCLUSIONS

The results of this study indicate that nicotine patch may increase energy intake during treatment, and does not prevent post-cessation weight gain in postmenopausal smokers. Additional research is needed to replicate these findings and assess whether different forms of nicotine replacement therapy influence caloric intake and post-cessation weight gain in postmenopausal smokers.

Addressing weight gain in smoking cessation treatment: a randomized controlled trial

PURPOSE

To evaluate the effectiveness of a cognitive behavioral treatment (CBT) addressing cessation-related weight concerns delivered via a tobacco quitline that does not address weight concerns.

DESIGN

Randomized controlled trial, blinded 6-month follow-up.

SETTING

The Oklahoma Tobacco Helpline (OKHL).

SUBJECTS

All 7998 smokers who called the OKHL were screened; 4240 were eligible; 2000 were randomized to the standard quitline (STD) or the brief version of the CBT weight concerns program (WCP).

INTERVENTION

Telephone counseling to help people quit smoking and address concerns about cessation-related weight gain.

MEASURES

Demographics, weight, tobacco status, weight concerns, self-efficacy in quitting, and quitting without weight gain.

ANALYSIS

Descriptive statistics and logistic regression.

RESULTS

Of those randomized, 1002 participants completed the 6-month survey (response rates  =  53.2% for STD, 47% for WCP). Compared with STD, WCP led to reduced weight concerns (p < .01) and less weight gain among quitters (1.8 vs. -3.4 pounds; p  =  .01). Although not significant, participants in the WCP were more likely to report 30-day abstinence (33.3% vs. 36.8%, p  =  .24; intent to treat  =  17.7 vs. 17.3).

CONCLUSION

The WCP was successfully delivered via a quitline and resulted in improved attitudes about weight and decreased cessation-related weight gain without harming quit rates. Promotion of a quitline focused on addressing weight in conjunction with quitline treatment for smoking cessation may improve cessation and weight outcomes. Study limitations include use of self-report and survey response.

Overcoming limitations in previous research on exercise as a smoking cessation treatment: rationale and design of the "Quit for Health" trial

Aerobic exercise has been proposed as a stand-alone or adjunct smoking cessation treatment, but findings have been mixed. Laboratory studies have shown that individual exercise sessions lead to decreases in withdrawal symptoms and cigarette cravings, but findings are limited by lack of follow-up and artificial settings. On the other hand, smoking cessation treatment RCTs have generally failed to show positive effects of exercise on smoking cessation, but have been plagued by poor and/or unverified compliance with exercise programs. This paper describes the rationale and design for Quit for Health (QFH)--an RCT designed to determine the efficacy of aerobic exercise as an adjunct smoking cessation treatment among women. To overcome limitations of previous research, compliance with the exercise (and wellness contact control) program is incentivized and directly observed, and ecological momentary assessment is used to examine change over time in withdrawal symptoms and cigarette cravings in participants' natural environments.

Psychosocial interventions for supporting women to stop smoking in pregnancy

BACKGROUND

Tobacco smoking in pregnancy remains one of the few preventable factors associated with complications in pregnancy, stillbirth, low birthweight and preterm birth and has serious long-term implications for women and babies. Smoking in pregnancy is decreasing in high-income countries, but is strongly associated with poverty and increasing in low- to middle-income countries.

OBJECTIVES

To assess the effects of smoking cessation interventions during pregnancy on smoking behaviour and perinatal health outcomes.

SEARCH METHODS

In this fifth update, we searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 March 2013), checked reference lists of retrieved studies and contacted trial authors to locate additional unpublished data.

SELECTION CRITERIA

Randomised controlled trials, cluster-randomised trials, randomised cross-over trials, and quasi-randomised controlled trials (with allocation by maternal birth date or hospital record number) of psychosocial smoking cessation interventions during pregnancy.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and trial quality, and extracted data. Direct comparisons were conducted in RevMan, and subgroup analyses and sensitivity analysis were conducted in SPSS.

MAIN RESULTS

Eighty-six trials were included in this updated review, with 77 trials (involving over 29,000 women) providing data on smoking abstinence in late pregnancy.In separate comparisons, counselling interventions demonstrated a significant effect compared with usual care (27 studies; average risk ratio (RR) 1.44, 95% confidence interval (CI) 1.19 to 1.75), and a borderline effect compared with less intensive interventions (16 studies; average RR 1.35, 95% CI 1.00 to 1.82). However, a significant effect was only seen in subsets where counselling was provided in conjunction with other strategies. It was unclear whether any type of counselling strategy is more effective than others (one study; RR 1.15, 95% CI 0.86 to 1.53). In studies comparing counselling and usual care (the largest comparison), it was unclear whether interventions prevented smoking relapse among women who had stopped smoking spontaneously in early pregnancy (eight studies; average RR 1.06, 95% CI 0.93 to 1.21). However, a clear effect was seen in smoking abstinence at zero to five months postpartum (10 studies; average RR 1.76, 95% CI 1.05 to 2.95), a borderline effect at six to 11 months (six studies; average RR 1.33, 95% CI 1.00 to 1.77), and a significant effect at 12 to 17 months (two studies, average RR 2.20, 95% CI 1.23 to 3.96), but not in the longer term. In other comparisons, the effect was not significantly different from the null effect for most secondary outcomes, but sample sizes were small.Incentive-based interventions had the largest effect size compared with a less intensive intervention (one study; RR 3.64, 95% CI 1.84 to 7.23) and an alternative intervention (one study; RR 4.05, 95% CI 1.48 to 11.11).Feedback interventions demonstrated a significant effect only when compared with usual care and provided in conjunction with other strategies, such as counselling (two studies; average RR 4.39, 95% CI 1.89 to 10.21), but the effect was unclear when compared with a less intensive intervention (two studies; average RR 1.19, 95% CI 0.45 to 3.12).The effect of health education was unclear when compared with usual care (three studies; average RR 1.51, 95% CI 0.64 to 3.59) or less intensive interventions (two studies; average RR 1.50, 95% CI 0.97 to 2.31).Social support interventions appeared effective when provided by peers (five studies; average RR 1.49, 95% CI 1.01 to 2.19), but the effect was unclear in a single trial of support provided by partners.The effects were mixed where the smoking interventions were provided as part of broader interventions to improve maternal health, rather than targeted smoking cessation interventions.Subgroup analyses on primary outcome for all studies showed the intensity of interventions and comparisons has increased over time, with higher intensity interventions more likely to have higher intensity comparisons. While there was no significant difference, trials where the comparison group received usual care had the largest pooled effect size (37 studies; average RR 1.34, 95% CI 1.25 to 1.44), with lower effect sizes when the comparison group received less intensive interventions (30 studies; average RR 1.20, 95% CI 1.08 to 1.31), or alternative interventions (two studies; average RR 1.26, 95% CI 0.98 to 1.53). More recent studies included in this update had a lower effect size (20 studies; average RR 1.26, 95% CI 1.00 to 1.59), I(2)= 3%, compared to those in the previous version of the review (50 studies; average RR 1.50, 95% CI 1.30 to 1.73). There were similar effect sizes in trials with biochemically validated smoking abstinence (49 studies; average RR 1.43, 95% CI 1.22 to 1.67) and those with self-reported abstinence (20 studies; average RR 1.48, 95% CI 1.17 to 1.87). There was no significant difference between trials implemented by researchers (efficacy studies), and those implemented by routine pregnancy staff (effectiveness studies), however the effect was unclear in three dissemination trials of counselling interventions where the focus on the intervention was at an organisational level (average RR 0.96, 95% CI 0.37 to 2.50). The pooled effects were similar in interventions provided for women with predominantly low socio-economic status (44 studies; average RR 1.41, 95% CI 1.19 to 1.66), compared to other women (26 studies; average RR 1.47, 95% CI 1.21 to 1.79); though the effect was unclear in interventions among women from ethnic minority groups (five studies; average RR 1.08, 95% CI 0.83 to 1.40) and aboriginal women (two studies; average RR 0.40, 95% CI 0.06 to 2.67). Importantly, pooled results demonstrated that women who received psychosocial interventions had an 18% reduction in preterm births (14 studies; average RR 0.82, 95% CI 0.70 to 0.96), and infants born with low birthweight (14 studies; average RR 0.82, 95% CI 0.71 to 0.94). There did not appear to be any adverse effects from the psychosocial interventions, and three studies measured an improvement in women's psychological wellbeing.

AUTHORS' CONCLUSIONS

Psychosocial interventions to support women to stop smoking in pregnancy can increase the proportion of women who stop smoking in late pregnancy, and reduce low birthweight and preterm births.

Topiramate for smoking cessation: a randomized, placebo-controlled pilot study

INTRODUCTION

Topiramate (TOP) blocks glutamate receptors and facilitates GABA (γ-aminobutyric acid) neurotransmission, effects that may facilitate smoking cessation. We compared the effects of behavioral counseling combined with (a) TOP, (b) TOP/nicotine patch (TOP/NIC), or (c) placebo (PLC) for smoking cessation.

METHODS

We conducted a 10-week randomized trial in which subjects and research personnel were blinded to TOP versus PLC but not to the TOP/NIC patch condition. In groups receiving TOP, the medication dosage was titrated gradually up to 200 mg/day. The smoking quit date (QD) was scheduled after 2 weeks of medication treatment. NIC (21 mg) was started on the QD in subjects randomized to the TOP/NIC condition. The main outcome measure was the end-of-treatment, 4-week continuous abstinence rate (CAR; biochemically confirmed).

RESULTS

Fifty-seven subjects were randomized to treatment. The 4-week CAR was 1 of 19 (5%) in the PLC group, 5 of 19 (26%) in the TOP group, and 7 of 19 (37%) in the TOP/NIC group (p = .056). Pairwise comparisons showed a difference between TOP/NIC and PLC (p = .042) and a nonsignificant difference between TOP and PLC (p = .18). The PLC group gained 0.37 lb/week, the TOP group lost 0.41 lb/week, and the TOP/NIC group lost 0.07 lb/week (p = .004). Pairwise comparisons showed a difference between TOP and PLC (p < .001) and between TOP/NIC and PLC groups (p = .035). Paresthesia was more frequent in subjects on TOP than PLC (p = .011).

CONCLUSIONS

TOP, alone or in combination with the NIC, resulted in a numerically higher quit rate than PLC and decreased weight. A larger, PLC-controlled trial is needed to confirm these findings.

Mechanisms linking socioeconomic disadvantage and BMI in smokers

OBJECTIVES

To evaluate a conceptual model of the psychosocial pathways linking socioeconomic status and body mass index (BMI) among smokers.

METHODS

A latent variable modeling approach was used to evaluate the interrelationships among socioeconomic status, perceived neighborhood disadvantage, social support, negative affect, and BMI among smokers recruited from the Houston metropolitan area (N = 424).

RESULTS

A total of 42.4% of participants were obese, with the highest prevalence of obesity among Latinos followed by African Americans. Across all racial/ethnic groups, perceived neighborhood disadvantage, social support, and negative affect functioned as pathways linking socioeconomic status and BMI.

CONCLUSIONS

Findings indicate the need for interventions that target obesity among socioeconomically disadvantaged smokers and provide potential intervention targets for the prevention and treatment of obesity.

Sugar restriction: the evidence for a drug-free intervention to reduce cardiovascular disease risk

BACKGROUND/AIM

Uncertainty exists about what dietary component is most likely to cause coronary heart disease. Over the last thirty years, attention has focused on saturated fat and salt as guilty parties. More recently, evidence suggests that excess sugar intake is more likely than either traditional factor to lead to atherosclerotic disease. Some researchers have also speculated that sugar is addictive, in a similar manner to caffeine and established drugs of abuse.

METHODS

Here we review the epidemiological, biochemical and psychological evidence that implicates excess sugar intake as an important cause of ill-health.

RESULTS

We found relatively consistent evidence of association between markers of sugar intake and risk factors for cardiovascular disease, or the disease itself. This evidence contrasted with rather weaker evidence which linked either saturated fat or salt with cardiovascular disease endpoints. We also found some evidence of a sugar addiction syndrome.

CONCLUSION

We suggest that advice to restrict sugar intake should be a routine part of clinical care, particularly when patients are being counselled about cardiovascular risk.

Exercise-based smoking cessation interventions among women

Although smoking rates are lower among women than men, women are less likely to quit smoking in cessation trials. This is in part due to their tendency to smoke to help prevent or mitigate negative mood/affect, depression and/or postcessation weight gain. Exercise helps to alleviate women's fear of postcessation weight gain and reduces their cessation-related mood symptoms, making it a theoretically ideal smoking cessation intervention for women. In addition, short bouts of exercise decrease cigarette cravings and withdrawal symptoms among temporarily abstinent smokers. However, results from exercise-based smoking cessation interventions to date have been mostly nonsignificant. This paper describes the theoretical mechanisms (psychological, behavioral, physiological and neurobiological) and practical reasons underlying our belief that exercise-based smoking cessation interventions should not yet be abandoned despite their current paucity of supporting evidence. It also presents ideas for modifying future exercise-based smoking cessation interventions to increase adherence and, as a result, more accurately evaluate the effect of exercise on smoking cessation.

Pharmacological interventions for smoking cessation: an overview and network meta-analysis

BACKGROUND

Smoking is the leading preventable cause of illness and premature death worldwide. Some medications have been proven to help people to quit, with three licensed for this purpose in Europe and the USA: nicotine replacement therapy (NRT), bupropion, and varenicline. Cytisine (a treatment pharmacologically similar to varenicline) is also licensed for use in Russia and some of the former socialist economy countries. Other therapies, including nortriptyline, have also been tested for effectiveness.

OBJECTIVES

How do NRT, bupropion and varenicline compare with placebo and with each other in achieving long-term abstinence (six months or longer)? How do the remaining treatments compare with placebo in achieving long-term abstinence? How do the risks of adverse and serious adverse events (SAEs) compare between the treatments, and are there instances where the harms may outweigh the benefits?

METHODS

The overview is restricted to Cochrane reviews, all of which include randomised trials. Participants are usually adult smokers, but we exclude reviews of smoking cessation for pregnant women and in particular disease groups or specific settings. We cover nicotine replacement therapy (NRT), antidepressants (bupropion and nortriptyline), nicotine receptor partial agonists (varenicline and cytisine), anxiolytics, selective type 1 cannabinoid receptor antagonists (rimonabant), clonidine, lobeline, dianicline, mecamylamine, Nicobrevin, opioid antagonists, nicotine vaccines, and silver acetate. Our outcome for benefit is continuous or prolonged abstinence at least six months from the start of treatment. Our outcome for harms is the incidence of serious adverse events associated with each of the treatments. We searched the Cochrane Database of Systematic Reviews (CDSR) in The Cochrane Library, for any reviews with 'smoking' in the title, abstract or keyword fields. The last search was conducted in November 2012. We assessed methodological quality using a revised version of the AMSTAR scale. For NRT, bupropion and varenicline we conducted network meta-analyses, comparing each with the others and with placebo for benefit, and varenicline and bupropion for risks of serious adverse events.

MAIN RESULTS

We identified 12 treatment-specific reviews. The analyses covered 267 studies, involving 101,804 participants. Both NRT and bupropion were superior to placebo (odds ratios (OR) 1.84; 95% credible interval (CredI) 1.71 to 1.99, and 1.82; 95% CredI 1.60 to 2.06 respectively). Varenicline increased the odds of quitting compared with placebo (OR 2.88; 95% CredI 2.40 to 3.47). Head-to-head comparisons between bupropion and NRT showed equal efficacy (OR 0.99; 95% CredI 0.86 to 1.13). Varenicline was superior to single forms of NRT (OR 1.57; 95% CredI 1.29 to 1.91), and to bupropion (OR 1.59; 95% CredI 1.29 to 1.96). Varenicline was more effective than nicotine patch (OR 1.51; 95% CredI 1.22 to 1.87), than nicotine gum (OR 1.72; 95% CredI 1.38 to 2.13), and than 'other' NRT (inhaler, spray, tablets, lozenges; OR 1.42; 95% CredI 1.12 to 1.79), but was not more effective than combination NRT (OR 1.06; 95% CredI 0.75 to 1.48). Combination NRT also outperformed single formulations. The four categories of NRT performed similarly against each other, apart from 'other' NRT, which was marginally more effective than NRT gum (OR 1.21; 95% CredI 1.01 to 1.46). Cytisine (a nicotine receptor partial agonist) returned positive findings (risk ratio (RR) 3.98; 95% CI 2.01 to 7.87), without significant adverse events or SAEs. Across the 82 included and excluded bupropion trials, our estimate of six seizures in the bupropion arms versus none in the placebo arms was lower than the expected rate (1:1000), at about 1:1500. SAE meta-analysis of the bupropion studies demonstrated no excess of neuropsychiatric (RR 0.88; 95% CI 0.31 to 2.50) or cardiovascular events (RR 0.77; 95% CI 0.37 to 1.59). SAE meta-analysis of 14 varenicline trials found no difference between the varenicline and placebo arms (RR 1.06; 95% CI 0.72 to 1.55), and subgroup analyses detected no significant excess of neuropsychiatric events (RR 0.53; 95% CI 0.17 to 1.67), or of cardiac events (RR 1.26; 95% CI 0.62 to 2.56). Nortriptyline increased the chances of quitting (RR 2.03; 95% CI 1.48 to 2.78). Neither nortriptyline nor bupropion were shown to enhance the effect of NRT compared with NRT alone. Clonidine increased the chances of quitting (RR 1.63; 95% CI 1.22 to 2.18), but this was offset by a dose-dependent rise in adverse events. Mecamylamine in combination with NRT may increase the chances of quitting, but the current evidence is inconclusive. Other treatments failed to demonstrate a benefit compared with placebo. Nicotine vaccines are not yet licensed for use as an aid to smoking cessation or relapse prevention. Nicobrevin's UK license is now revoked, and the manufacturers of rimonabant, taranabant and dianicline are no longer supporting the development or testing of these treatments.

AUTHORS' CONCLUSIONS

NRT, bupropion, varenicline and cytisine have been shown to improve the chances of quitting. Combination NRT and varenicline are equally effective as quitting aids. Nortriptyline also improves the chances of quitting. On current evidence, none of the treatments appear to have an incidence of adverse events that would mitigate their use. Further research is warranted into the safety of varenicline and into cytisine's potential as an effective and affordable treatment, but not into the efficacy and safety of NRT.

Weight concerns among Finnish ever-smokers: a population-based study

INTRODUCTION

Concern over weight gain after smoking cessation has been hypothesized to discourage quit attempts and consequently reduce smoking cessation rates. The aim of this study was to examine the association between smoking status and weight concerns among a population-based sample of Finnish ever-smokers.

METHODS

Data were collected in conjunction with the National FINRISK 2007 Study from a population-based sample of 25- to 74-yearold Finns. These analyses were based on a subsample of 1,614 ever-smokers. Participants were divided into 4 groups (daily smokers, occasional smokers, recent quitters, and former smokers) based on the self-reported smoking status. Weight concerns were analyzed as a sum score including 6 items (range 0-24). Regression analyses were used to examine the association between smoking status and weight concerns, while adjusting for multiple confounders.

RESULTS

Smoking status was significantly associated with weight concerns, current daily smokers reporting the highest levels of weight concerns. After adjusting for potential confounders (age, gender, body mass index, socioeconomic status, and health behavior), the weight concerns of daily smokers remained significantly higher in comparison with all other groups. Although women were more concerned about their weight than men, no gender-specific associations were found between weight concerns and smoking status.

CONCLUSIONS

Current daily smokers are more concerned about their weight than recent quitters, as well as former and occasional smokers. Weight concerns should be taken into account in tobacco dependence treatment.

“Hike up yer skirt, and quit.” what motivates and supports smoking cessation in builders and renovators

Construction-related occupations have very high smoking prevalence rates and are an identified priority population for efforts to promote cessation. This study sought to identify the smoking cessation supports and services which best suited this workforce group, and to identify gaps in reach of preventive health services. We performed qualitative text analysis on pre-existing conversations about smoking cessation among workers in this sector. The material appeared on a discussion forum about residential construction from 1998 and 2011. Roughly 250 unique user names appeared in these discussions. The qualitative analysis addressed knowledge, motivation, environmental influences, and positive and negative experiences with supports for cessation. Self-identified smokers tended to want to quit and described little social value in smoking. Actual quit attempts were attributed to aging and tangible changes in health and fitness. Peer-to-peer social support for cessation was evident. Advice given was to avoid cigarettes and smokers, to focus on personal skills, personal commitment, and the benefits of cessation (beyond the harms from smoking). Many discussants had received medical support for cessation, but behavioural counselling services appeared underutilized. Our findings support efforts toward more complete bans on workplace smoking and increased promotion of available behavioural support services among dispersed blue-collar workers.

Thyroid function and obesity

Important interaction exists between thyroid function, weight control, and obesity. Several mechanisms seem to be involved, and in studies of groups of people the pattern of thyroid function tests depends on the balance of obesity and underlying thyroid disease in the cohort studied. Obese people with a normal thyroid gland tend to have activation of the hypothalamic-pituitary-thyroid axis with higher serum TSH and thyroid hormones in serum. On the other hand, small differences in thyroid function are associated with up to 5 kg difference in body weight. The weight loss after therapy of overt hypothyroidism is caused by excretion of water bound in tissues (myxoedema). Many patients treated for hyperthyroidism experience a gain of more weight than they lost during the active phase of the disease. The mechanism for this excessive weight gain has not been fully elucidated. New studies on the relation between L-T3 therapy and weight control are discussed. The interaction between weight control and therapy of thyroid disease is important to many patients and it should be studied in more detail.

Pharmacological interventions for promoting smoking cessation during pregnancy

BACKGROUND

Smoking in pregnancy is a substantial public health problem. When used by non-pregnant smokers, pharmacotherapies [nicotine replacement therapy (NRT), bupropion and varenicline] are effective treatments for smoking cessation, however, their efficacy and safety in pregnancy remains unknown.

OBJECTIVES

To determine the efficacy and safety of smoking cessation pharmacotherapies, including NRT, varenicline and bupropion (or any other medications) when used to support smoking cessation in pregnancy.

SEARCH METHODS

We searched the Pregnancy and Childbirth Group's Trials Register (5 March 2012), checked references of retrieved studies and contacted authors in the field.

SELECTION CRITERIA

Randomised controlled trials (RCTs) with designs that permit the independent effects of any type of NRT (e.g. patch, gum etc.) or any other pharmacotherapy on smoking cessation to be ascertained were eligible for inclusion. Trials must provide very similar (ideally identical) levels of behavioural support or cognitive behaviour therapy (CBT) to participants in active drug and comparator trial arms.The following RCT designs are considered acceptable.Placebo RCTs: any form of NRT or other pharmacotherapy, with or without behavioural support/CBT, or brief advice compared with placebo NRT and additional support of similar intensity.RCTs providing a comparison between i) behavioural support/CBT or brief advice and ii) any form of NRT or other pharmacotherapy added to behavioural support of similar (ideally identical) intensity.Parallel- or cluster-randomised design trials are eligible for inclusion. However, quasi-randomised, cross-over and within-participant designs are not eligible for inclusion due to the potential biases associated with these designs.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias and extracted data. Two assessors independently extracted data and cross checked individual outcomes of this process to ensure accuracy. The primary efficacy outcome was smoking cessation in later pregnancy (in all but one trial, at or around delivery); safety was assessed by seven birth outcomes that indicated neonatal well being and we also collated data on adherence.

MAIN RESULTS

Six trials of NRT enrolling 1745 pregnant smokers were included; we found no trials of varenicline or bupropion. No statistically significant difference was seen for smoking cessation in later pregnancy after using NRT as compared to control (risk ratio (RR) 1.33, 95% confidence interval (CI) 0.93 to 1.91, six studies, 1745 women). Subgroup analysis comparing placebo-RCTs with those which did not use placebos found that efficacy estimates for cessation varied with trial design (placebo RCTs, RR 1.20, 95% CI 0.93 to 1.56, four studies, 1524 women; non-placebo RCTs, RR 7.81, 95% CI 1.51 to 40.35, two studies, 221 women; P value for random-effects subgroup interaction test = 0.03). There were no statistically significant differences in rates of miscarriage, stillbirth, premature birth, birthweight, low birthweight, admissions to neonatal intensive care or neonatal death between NRT or control groups.

AUTHORS' CONCLUSIONS

Nicotine replacement therapy is the only pharmacotherapy for smoking cessation that has been tested in RCTs conducted in pregnancy. There is insufficient evidence to determine whether or not NRT is effective or safe when used to promote smoking cessation in pregnancy or to determine whether or not using NRT has positive or negative impacts on birth outcomes. Further research evidence of efficacy and safety is needed, ideally from placebo-controlled RCTs that investigate higher doses of NRT than were tested in the included studies.

Smoking cessation and body weight: evidence from the Behavioral Risk Factor Surveillance Survey

OBJECTIVE

To investigate the role of smoking cessation in body weight.

DATA SOURCES

2004-2005 and 2009-2010 Behavioral Risk Factor Surveillance Surveys (BRFSS) (N = 349,000), Centers for Disease Control and Prevention; Tax Burden on Tobacco (Orzechowski and Walker 2010).

STUDY DESIGN

The Gaussian treatment effect model is estimated for three age categories by gender. Treatment effects of quitting smoking on body mass index (BMI) by quit length are calculated.

PRINCIPAL FINDINGS

Quitting is found to be endogenous. Differentiated effects of quitting smoking on BMI are found among quitters by gender, between age groups, and by length of time since quitting smoking, and positive association between smoking cessation and body weight confirmed. Declining smoking rates have only a modest effect in the overweight population. The effects of quitting on BMI are considerably lower among younger men and women.

CONCLUSION

The price that must be paid, in terms of weight gain, to enjoy the health benefits of smoking cessation is trivial even for the obese population.

Dietary intake after smoking cessation among weight-concerned women smokers

Weight gain typically accompanies smoking cessation, and women smokers concerned about postcessation weight gain are prone to substantial gain. Little is known about the ways in which cessation affects dietary composition. Understanding postcessation changes in dietary composition may inform the design of smoking cessation interventions to address postcessation weight gain. Participants were women smokers concerned about postcessation weight gain enrolled in a randomized trial and assigned to either bupropion or placebo and to either standard cessation intervention or standard intervention plus components to address weight concerns. Women completed three, 24-hr food recall interviews at baseline, and at 1 and 6 months following a targeted quit date. At 6 months, 22% of women were abstinent and had gained 3.6 (±2.7) kg, compared to 0.91 (±2.0) kg for women who continued to smoke, p = .42. Abstinent women reported significantly higher energy intake and consumed a smaller percentage of fat across assessment points than did those who continued to smoke. Intervention was not associated with differential weight gain or change in percent of calories from protein, fat, or carbohydrates. This study is the first documentation of energy and macronutrient intake during smoking cessation treatment using a validated 24-hr dietary recall methodology. Although cessation was associated with overall increases in energy intake among women, neither bupropion nor weight concerns treatment affected energy or macronutrient intake. Future research to understand the relation between cessation and dietary intake needs to replicate and extend these findings to elucidate how, if at all, smoking cessation affects dietary intake.

The endocrine effects of nicotine and cigarette smoke

With a current prevalence of approximately 20%, smoking continues to impact negatively upon health. Tobacco or nicotine use influences the endocrine system, with important clinical implications. In this review we critically evaluate the literature concerning the impact of nicotine as well as tobacco use on several parameters of the endocrine system and on glucose and lipid homeostasis. Emphasis is on the effect of smoking on diabetes mellitus and obesity and the consequences of smoking cessation on these disorders. Understanding the effects of nicotine and cigarettes on the endocrine system and how these changes contribute to the pathogenesis of various endocrine diseases will allow for targeted therapies and more effective approaches for smoking cessation.

Changes in body weight and food choice in those attempting smoking cessation: a cluster randomised controlled trial

BACKGROUND

Fear of weight gain is a barrier to smoking cessation and significant cause of relapse for many people. The provision of nutritional advice as part of a smoking cessation programme may assist some in smoking cessation and perhaps limit weight gain. The aim of this study was to determine the effect of a structured programme of dietary advice on weight change and food choice, in adults attempting smoking cessation.

METHODS

Cluster randomised controlled design. Classes randomised to intervention commenced a 24-week intervention, focussed on improving food choice and minimising weight gain. Classes randomised to control received "usual care".

RESULTS

Twenty-seven classes in Greater Glasgow were randomised between January and August 2008. Analysis, including those who continued to smoke, showed that actual weight gain and percentage weight gain was similar in both groups. Examination of data for those successful at giving up smoking showed greater mean weight gain in intervention subjects (3.9 (SD 3.1) vs. 2.7 (SD 3.7) kg). Between group differences were not significant (p = 0.23, 95% CI -0.9 to 3.5). In comparison to baseline improved consumption of fruit and vegetables and breakfast cereal were reported in the intervention group. A higher percentage of control participants continued smoking (74% vs. 66%).

CONCLUSIONS

The intervention was not successful at minimising weight gain in comparison to control but was successful in facilitating some sustained improvements in the dietary habits of intervention participants. Improved quit rates in the intervention group suggest that continued contact with advisors may have reduced anxieties regarding weight gain and encouraged cessation despite weight gain. Research should continue in this area as evidence suggests that the negative effects of obesity could outweigh the health benefits achieved through reductions in smoking prevalence.

Extended duration therapy with transdermal nicotine may attenuate weight gain following smoking cessation

AIM

People who quit smoking often gain 11-12 lb, on average, which can frequently lead to a relapse to smoking. This study evaluated whether extended vs. standard duration treatment with nicotine patch helps those able to quit smoking to reduce cessation-induced weight gain and explored nicotine patch adherence as a mediator of treatment effects.

DESIGN AND SETTING

We examined data from a completed randomized placebo-controlled clinical trial of extended (24 weeks) vs. standard (8 weeks plus 16 weeks of placebo) transdermal nicotine patch therapy. Changes in measured weight over 24 weeks were compared across the two treatment arms, controlling for gender, baseline smoking rate, and previous weight. Adherence to patch use was assessed using self-report of daily use over 24 weeks.

PARTICIPANTS

139 clinical trial participants who were confirmed to be abstinent at weeks 8 and 24.

FINDINGS

Compared to participants who received 8 weeks of nicotine patch therapy, participants who received 24 weeks of treatment showed significantly less weight gain from pre-treatment to week 24 (β=-4.76, 95% CI: -7.68 to -1.84, p=.002) and significantly less weight gain from week 8 to week 24 (β=-2.31, 95% CI: -4.39 to -0.23, p=.03). Extended treatment increased patch adherence which, in turn, reduced weight gain; patch adherence accounted for 20% of the effect of treatment arm on weight gain.

CONCLUSION

Compared to 8 weeks of transdermal nicotine therapy, 24 weeks of patch treatment may help to reduce the weight gain that is typical among smokers who are able to achieve abstinence from tobacco use. Extended treatment increased nicotine patch adherence which, in turn, reduced weight gain.

Factors affecting commencement and cessation of smoking behaviour in Malaysian adults

Background

Tobacco consumption peak in developed countries has passed, however, it is on the increase in many developing countries. Apart from cigarettes, consumption of local hand-rolled cigarettes such as bidi and rokok daun are prevalent in specific communities. Although factors associated with smoking initiation and cessation has been investigated elsewhere, the only available data for Malaysia is on prevalence. This study aims to investigate factors associated with smoking initiation and cessation which is imperative in designing intervention programs.

Methods

Data were collected from 11,697 adults by trained recording clerks on sociodemographic characteristics, practice of other risk habit and details of smoking such as type, duration and frequency. Smoking commencement and cessation were analyzed using the Kaplan-Meier estimates and log-rank tests. Univariate and multivariate Cox proportional hazard regression models were used to calculate the hazard rate ratios.

Results

Males had a much higher prevalence of the habit (61.7%) as compared to females (5.8%). Cessation was found to be most common among the Chinese and those regularly consuming alcoholic beverages. Kaplan-Meier plot shows that although males are more likely to start smoking, females are found to be less likely to stop. History of betel quid chewing and alcohol consumption significantly increase the likelihood of commencement (p < 0.0001), while cessation was least likely among Indians, current quid chewers and kretek users (p < 0.01).

Conclusions

Gender, ethnicity, history of quid chewing and alcohol consumption have been found to be important factors in smoking commencement; while ethnicity, betel quid chewing and type of tobacco smoked influences cessation.

A systematic review of nicotine by inhalation: is there a role for the inhaled route?

INTRODUCTION

A considerable minority of adults remain addicted to smoking cigarettes despite substantial education and public health efforts. Nicotine replacement therapies have only modest long-term quit rates. The pulmonary route of nicotine delivery has advantages over other routes. However, there are regulatory and technical barriers to the development of pulmonary nicotine delivery devices, and hence, none are commercially available. Current knowledge about pulmonary nicotine delivery is scattered throughout the literature and other sources such as patent applications. This review draws together what is currently known about pulmonary nicotine delivery and identifies potential ways that deep lung delivery can be achieved with a simple portable device.

AIMS

To systematically review clinical trials of nicotine inhalers, determine whether they delivered nicotine via the lung, and identify ways that pulmonary delivery of medicinal nicotine might be achieved and the technical issues involved.

METHODS

Systematic search of Medline and Embase.

RESULTS

Thirty-eight trials met the inclusion criteria. Cough, reflex interruption of smooth inspiration, and throat scratch limited the usefulness of nicotine inhalers. The pharmacokinetic profiles of portable nicotine inhalers were inferior to smoking, but among commercially available products, electronic cigarettes are currently the most promising.

CONCLUSIONS

Pulmonary nicotine delivery might be maximized by use of nicotine salts, which have a more physiological pH than pure nicotine, by ensuring the mass of the particles is optimal for alveolar absorption, and by adding flavoring agents. Metered-dose inhalers potentially can deliver nicotine more efficiently than other nicotine products, facilitating smoking cessation and improving smokers' lives.

Interventions for preventing weight gain after smoking cessation

BACKGROUND

Most people who stop smoking gain weight. There are some interventions that have been designed to reduce weight gain when stopping smoking. Some smoking cessation interventions may also limit weight gain although their effect on weight has not been reviewed.

OBJECTIVES

To systematically review the effect of: (1) Interventions targeting post-cessation weight gain on weight change and smoking cessation.(2) Interventions designed to aid smoking cessation that may also plausibly affect weight on post-cessation weight change.

SEARCH METHODS

Part 1 - We searched the Cochrane Tobacco Addiction Group's Specialized Register and CENTRAL in September 2011.Part 2 - In addition we searched the included studies in the following "parent" Cochrane reviews: nicotine replacement therapy (NRT), antidepressants, nicotine receptor partial agonists, cannabinoid type 1 receptor antagonists and exercise interventions for smoking cessation published in Issue 9, 2011 of the Cochrane Library.

SELECTION CRITERIA

Part 1 - We included trials of interventions that were targeted at post-cessation weight gain and had measured weight at any follow up point and/or smoking cessation six or more months after quit day.Part 2 - We included trials that had been included in the selected parent Cochrane reviews if they had reported weight gain at any time point.

DATA COLLECTION AND ANALYSIS

We extracted data on baseline characteristics of the study population, intervention, outcome and study quality. Change in weight was expressed as difference in weight change from baseline to follow up between trial arms and was reported in abstinent smokers only. Abstinence from smoking was expressed as a risk ratio (RR). We used the most rigorous definition of abstinence available in each trial. Where appropriate, we performed meta-analysis using the inverse variance method for weight and Mantel-Haenszel method for smoking using a fixed-effect model.

MAIN RESULTS

Part 1: Some pharmacological interventions tested for limiting post cessation weight gain (PCWG) resulted in a significant reduction in WG at the end of treatment (dexfenfluramine (Mean difference (MD) -2.50 kg, 95% confidence interval (CI) -2.98 to -2.02, 1 study), phenylpropanolamine (MD -0.50 kg, 95% CI -0.80 to -0.20, N=3), naltrexone (MD -0.78 kg, 95% CI -1.52 to -0.05, N=2). There was no evidence that treatment reduced weight at 6 or 12 months (m). No pharmacological intervention significantly affected smoking cessation rates.Weight management education only was associated with no reduction in PCWG at end of treatment (6 or 12m). However these interventions significantly reduced abstinence at 12m (Risk ratio (RR) 0.66, 95% CI 0.48 to 0.90, N=2). Personalised weight management support reduced PCWG at 12m (MD -2.58 kg, 95% CI -5.11 to -0.05, N=2) and was not associated with a significant reduction of abstinence at 12m (RR 0.74, 95% CI 0.39 to 1.43, N=2). A very low calorie diet (VLCD) significantly reduced PCWG at end of treatment (MD -3.70 kg, 95% CI -4.82 to -2.58, N=1), but not significantly so at 12m (MD -1.30 kg, 95% CI -3.49 to 0.89, N=1). The VLCD increased chances of abstinence at 12m (RR 1.73, 95% CI 1.10 to 2.73, N=1). There was no evidence that cognitive behavioural therapy to allay concern about weight gain (CBT) reduced PCWG, but there was some evidence of increased PCWG at 6m (MD 0.74, 95% CI 0.24 to 1.24). It was associated with improved abstinence at 6m (RR 1.83, 95% CI 1.07 to 3.13, N=2) but not at 12m (RR 1.25, 95% CI 0.83 to 1.86, N=2). However, there was significant statistical heterogeneity.Part 2: We found no evidence that exercise interventions significantly reduced PCWG at end of treatment (MD -0.25 kg, 95% CI -0.78 to 0.29, N=4) however a significant reduction was found at 12m (MD -2.07 kg, 95% CI -3.78 to -0.36, N=3).Both bupropion and fluoxetine limited PCWG at the end of treatment (bupropion MD -1.12 kg, 95% CI -1.47 to -0.77, N=7) (fluoxetine MD -0.99 kg, 95% CI -1.36 to -0.61, N=2). There was no evidence that the effect persisted at 6m (bupropion MD -0.58 kg, 95% CI -2.16 to 1.00, N=4), (fluoxetine MD -0.01 kg, 95% CI -1.11 to 1.10, N=2) or 12m (bupropion MD -0.38 kg, 95% CI -2.00 to 1.24, N=4). There were no data on WG at 12m for fluoxetine.Overall, treatment with NRT attenuated PCWG at the end of treatment (MD -0.69 kg, 95% CI -0.88 to -0.51, N=19), with no strong evidence that the effect differed for the different forms of NRT. There was evidence of significant statistical heterogeneity caused by one study which reported a 4.3 kg reduction in PCWG due to NRT. With this study removed, the difference in weight change at end of treatment was -0.45 kg (95% CI -0.66 to -0.27, N=18). There was no evidence of an effect on PCWG at 12m (MD -0.42 kg, 95% CI -0.92 to 0.08, N=15).We found evidence that varenicline significantly reduced PCWG at end of treatment (MD -0.41 kg, 95% CI -0.63 to -0.19, N=11), but this effect was not maintained at 6 or 12m. Three studies compared the effect of bupropion to varenicline. Participants taking bupropion gained significantly less weight at the end of treatment (-0.51 kg (95% CI -0.93 to -0.09 kg), N=3). Direct comparison showed no significant difference in PCWG between varenicline and NRT.

AUTHORS' CONCLUSIONS

Although some pharmacotherapies tested to limit PCWG show evidence of short-term success, other problems with them and the lack of data on long-term efficacy limits their use. Weight management education only, is not effective and may reduce abstinence. Personalised weight management support may be effective and not reduce abstinence, but there are too few data to be sure. One study showed a VLCD increased abstinence but did not prevent WG in the longer term. CBT to accept WG did not limit PCWG and may not promote abstinence in the long term. Exercise interventions significantly reduced weight in the long term, but not the short term. More studies are needed to clarify whether this is an effect of treatment or a chance finding. Bupropion, fluoxetine, NRT and varenicline reduce PCWG while using the medication. Although this effect was not maintained one year after stopping smoking, the evidence is insufficient to exclude a modest long-term effect. The data are not sufficient to make strong clinical recommendations for effective programmes to prevent weight gain after cessation.

Exercise interventions for smoking cessation

BACKGROUND

Taking regular exercise may help people give up smoking by moderating nicotine withdrawal and cravings, and by helping to manage weight gain.

OBJECTIVES

To determine whether exercise-based interventions alone, or combined with a smoking cessation programme, are more effective than a smoking cessation intervention alone.

SEARCH METHODS

In July 2011, we searched the Cochrane Tobacco Addiction Group Specialized Register for studies including the terms 'exercise' or 'physical activity'. We also searched MEDLINE, EMBASE, PsycINFO, Dissertation Abstracts and CINAHL using the terms 'exercise' or 'physical activity' and 'smoking cessation'.

SELECTION CRITERIA

We included randomized trials which compared an exercise programme alone, or an exercise programme as an adjunct to a cessation programme, with a cessation programme, recruiting smokers or recent quitters, and with a follow up of six months or more.

DATA COLLECTION AND ANALYSIS

We extracted data on study characteristics and smoking outcomes. Because of differences in studies we summarized the results narratively, making no attempt at meta-analysis.

MAIN RESULTS

We identified 15 trials, seven of which had fewer than 25 people in each treatment arm. They varied in the timing and intensity of the smoking cessation and exercise programmes. Three studies showed significantly higher abstinence rates in a physically active group versus a control group at end of treatment. One of these studies also showed a significant benefit for exercise versus control on abstinence at the three-month follow up and a benefit for exercise of borderline significance (p = 0.05) at the 12-month follow up. One study showed significantly higher abstinence rates for the exercise group versus a control group at the three-month follow up but not at the end of treatment or 12-month follow up. The other studies showed no significant effect for exercise on abstinence.

AUTHORS' CONCLUSIONS

Only one of the 15 trials offered evidence for exercise aiding smoking cessation at a 12-month follow up. All the other trials were too small to reliably exclude an effect of intervention, or included an exercise intervention which was insufficiently intense to achieve the desired level of exercise. Trials are needed with larger sample sizes, sufficiently intense interventions, equal contact control conditions, and measures of exercise adherence and change in physical activity in both exercise and comparison groups.

Reuptake inhibitors of dopamine, noradrenaline, and serotonin

Pharmacological inhibition of monoamine reuptake transporters has been known for many years as an effective therapy to reduce food intake and body weight in obese subjects. However, most of the marketed drugs failed after a distinct period in clinical use and had to be withdrawn because of serious adverse effects resulting in a negative benefit-risk profile. The most common side effects for this drug class included increases in systemic or pulmonary blood pressure and/or heart rate, cardiac valvulopathies, higher cardiovascular event rates, psychiatric disorders, or high abuse potential. The recent withdrawal of sibutramine as result of its adverse actions on the cardiovascular system highlighted again the problems with this drug class in antiobesity therapy. Recent developments to combine reuptake inhibitors with other drug classes, for example, opioid antagonists seem to be a promising approach to improve the benefit-risk profile of these compounds.This chapter will discuss the history of this drug class in appetite control, its mechanism of action, and the clinical effects of selected drugs from this class.