Smoking Cessation and Changes in Body Mass Index: Findings From the First Randomized Cessation Trial in a Low-Income Country Setting

Different clinical characteristics of current smokers and former smokers with asthma: a cross-sectional study of adult asthma patients in China

Smoking is a trigger for asthma, which has led to an increase in asthma incidence in China. In smokers, asthma management starts with smoking cessation. Data on predictors of smoking cessation in Chinese patients with asthma are scarce. The objective of this study was to find the differences in clinical characteristics between current smokers and former smokers with asthma in order to identify factors associated with smoking cessation. Eligible adults with diagnosed asthma and smoking from the hospital outpatient clinics (n = 2312) were enrolled and underwent a clinical evaluation, asthma control test (ACT), and pulmonary function test. Information on demographic and sociological data, lung function, laboratory tests, ACT and asthma control questionnaire (ACQ) scores was recorded. Patients were divided into a current smokers group and a former smokers group based on whether they had quit smoking. Logistic regression analysis was used to analyze the factors associated with smoking cessation. Of all patients with asthma, 34.6% were smokers and 65.4% were former smokers, and the mean age was 54.5 ± 11.5 years. Compared with current smokers, the former smokers were older, had longer duration of asthma, had higher ICS dose, had more partially controlled and uncontrolled asthma, had more pack-years, had smoked for longer, and had worse asthma control. The logistic regression model showed that smoking cessation was positively correlated with age, female sex, pack-years, years of smoking, partially controlled asthma, uncontrolled asthma, and body mass index (BMI), but was negatively correlated with ACT, FEV₁, FEV₁%predicted, and widowed status. More than 30% of asthma patients in the study were still smoking. Among those who quit smoking, many quit late, often not realizing they need to quit until they have significant breathing difficulties. The related factors of smoking cessation identified in this study indicate that there are still differences between continuing smokers and former smokers, and these factors should be focused on in asthma smoking cessation interventions to improve the prognosis of patients with asthma.

Lack of utility of cigarettes per day cutoffs for clinical and laboratory smoking research

BACKGROUND

Most clinical and laboratory smoking research studies require that participants smoke at a certain level to be eligible for enrollment. However, there is limited evidence that use of these cutoffs differentiates groups of smokers along clinically meaningful criteria.

METHODS

Using receiver operating characteristic curves, we analyzed data from daily smokers in the National Epidemiologic Study of Alcohol Use and Related Conditions - III (NESARC-III) to examine the utility of smoking rates for determining whether participants met DSM-5 criteria for tobacco use disorder, experienced nicotine withdrawal or had a history of failed quit attempts. We also examined whether relationships between these variables differed as a function of key sample characteristics.

RESULTS

Smoking rate exhibited a weak relationship with the presence of tobacco use disorder (AUC = 0.664), whether individuals experience nicotine withdrawal (AUC = 0.672) and whether individuals had a history of failed quit attempts (AUC = 0.578). The relationship between smoking rate and a history of failed quit attempts was weaker for women than men (p < .05). Otherwise, utility did not differ as a function of sex, race/ethnicity, education, income, or use of multiple tobacco products. Optimal cutoffs varied somewhat across indices, but the largest number of correct classifications occurred at very low smoking rates.

CONCLUSIONS

Researchers should consider abandoning the use of smoking rate cutoffs to determine study eligibility. If smoking rate cutoffs are used, a rationale should be presented along with justification for the specific cutoff chosen.

An empirical investigation of the impact of smoking on body weight using an endogenous treatment effects model approach: the role of food consumption patterns

BACKGROUND

This study explored the influence of cigarette smoking and food consumption patterns on BMI after adjusting for various socio-demographic characteristics. Since weight-based stereotypes may have an impact on smoking behaviour and both obesity and smoking have been associated with detrimental health effects, an interdependency between them is quite possible.

METHODS

Cross-sectional data were collected via a formal standardized questionnaire administered in personal interviews and two additional self-completion questionnaires from a random sample of 3471 German adults. The empirical framework considered potential endogeneity between smoking and body weight by employing an endogenous treatment effects model with an ordered outcome. The estimations derived from the endogenous treatment effects approach were also compared to the univariate ordered probit model results.

RESULTS

Our findings showed that ignoring potential endogeneity may affect both the statistical significance of the smoking estimate and the direction of the influence of smoking on BMI. Smoking was positively associated with BMI in both male (β = 1.236, p < 0.01) and female (β = 0.634, p < 0.10) participants. Smokers presented a 23.1% higher risk of obesity and a 24.3% lower likelihood of being within a healthy weight range. Male smokers also appeared to have a considerably augmented probability of being obese compared to their female counterparts (23.6% vs 15.1%). The relationship between smoking and BMI may be attributed to dietary practices, since smoking was correlated with poor dietary habits characterized by the frequent intake of more energy-dense foods (meat products and white-toasted bread) and less frequent consumption of healthy food items, such as whole-grain bread, vegetables and fruits. Concerning the impact of eating habits on body weight, frequent consumption of meat products and confectionery was found to have a direct association with BMI in both genders. Furthermore, white-toasted bread consumption was negatively linked with body weight in males (β = - 0.337, p < 0.01).

CONCLUSIONS

Our findings raised questions about the general belief that smoking is an effective weight control tool. Health interventions should be oriented toward a simultaneous decrease in smoking and obesity, since both behaviours seem to be interdependent. Nutrition programmes should also be designed according to the characteristics of different target groups in order to promote a healthy lifestyle.

Nicotine replacement therapy versus control for smoking cessation

BACKGROUND

Nicotine replacement therapy (NRT) aims to temporarily replace much of the nicotine from cigarettes to reduce motivation to smoke and nicotine withdrawal symptoms, thus easing the transition from cigarette smoking to complete abstinence.

OBJECTIVES

To determine the effectiveness and safety of nicotine replacement therapy (NRT), including gum, transdermal patch, intranasal spray and inhaled and oral preparations, for achieving long-term smoking cessation, compared to placebo or 'no NRT' interventions.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group trials register for papers mentioning 'NRT' or any type of nicotine replacement therapy in the title, abstract or keywords. Date of most recent search is July 2017.

SELECTION CRITERIA

Randomized trials in people motivated to quit which compared NRT to placebo or to no treatment. We excluded trials that did not report cessation rates, and those with follow-up of less than six months, except for those in pregnancy (where less than six months, these were excluded from the main analysis). We recorded adverse events from included and excluded studies that compared NRT with placebo. Studies comparing different types, durations, and doses of NRT, and studies comparing NRT to other pharmacotherapies, are covered in separate reviews.

DATA COLLECTION AND ANALYSIS

Screening, data extraction and 'Risk of bias' assessment followed standard Cochrane methods. The main outcome measure was abstinence from smoking after at least six months of follow-up. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. We calculated the risk ratio (RR) for each study. Where appropriate, we performed meta-analysis using a Mantel-Haenszel fixed-effect model.

MAIN RESULTS

We identified 136 studies; 133 with 64,640 participants contributed to the primary comparison between any type of NRT and a placebo or non-NRT control group. The majority of studies were conducted in adults and had similar numbers of men and women. People enrolled in the studies typically smoked at least 15 cigarettes a day at the start of the studies. We judged the evidence to be of high quality; we judged most studies to be at high or unclear risk of bias but restricting the analysis to only those studies at low risk of bias did not significantly alter the result. The RR of abstinence for any form of NRT relative to control was 1.55 (95% confidence interval (CI) 1.49 to 1.61). The pooled RRs for each type were 1.49 (95% CI 1.40 to 1.60, 56 trials, 22,581 participants) for nicotine gum; 1.64 (95% CI 1.53 to 1.75, 51 trials, 25,754 participants) for nicotine patch; 1.52 (95% CI 1.32 to 1.74, 8 trials, 4439 participants) for oral tablets/lozenges; 1.90 (95% CI 1.36 to 2.67, 4 trials, 976 participants) for nicotine inhalator; and 2.02 (95% CI 1.49 to 2.73, 4 trials, 887 participants) for nicotine nasal spray. The effects were largely independent of the definition of abstinence, the intensity of additional support provided or the setting in which the NRT was offered. A subset of six trials conducted in pregnant women found a statistically significant benefit of NRT on abstinence close to the time of delivery (RR 1.32, 95% CI 1.04 to 1.69; 2129 participants); in the four trials that followed up participants post-partum the result was no longer statistically significant (RR 1.29, 95% CI 0.90 to 1.86; 1675 participants). Adverse events from using NRT were related to the type of product, and include skin irritation from patches and irritation to the inside of the mouth from gum and tablets. Attempts to quantitatively synthesize the incidence of various adverse effects were hindered by extensive variation in reporting the nature, timing and duration of symptoms. The odds ratio (OR) of chest pains or palpitations for any form of NRT relative to control was 1.88 (95% CI 1.37 to 2.57, 15 included and excluded trials, 11,074 participants). However, chest pains and palpitations were rare in both groups and serious adverse events were extremely rare.

AUTHORS' CONCLUSIONS

There is high-quality evidence that all of the licensed forms of NRT (gum, transdermal patch, nasal spray, inhalator and sublingual tablets/lozenges) can help people who make a quit attempt to increase their chances of successfully stopping smoking. NRTs increase the rate of quitting by 50% to 60%, regardless of setting, and further research is very unlikely to change our confidence in the estimate of the effect. The relative effectiveness of NRT appears to be largely independent of the intensity of additional support provided to the individual. Provision of more intense levels of support, although beneficial in facilitating the likelihood of quitting, is not essential to the success of NRT. NRT often causes minor irritation of the site through which it is administered, and in rare cases can cause non-ischaemic chest pain and palpitations.

Gender differences in sociodemographic and behavioural factors associated with BMI in an adult population in rural Burkina Faso - an AWI-Gen sub-study

BACKGROUND

The global health transition is linked with an increased burden of non-communicable diseases with cardiovascular diseases leading the epidemic. In sub-Saharan Africa (SSA), the prevalence of obesity has increased during the past decades and there is a need to investigate the associated driving factors. In Burkina Faso obesity remains low, especially in rural areas. In this study we recruited middle-aged adults, as part of a larger study on genetic and environmental contributions to cardiometabolic disease among Africans.

OBJECTIVES

To investigate the distribution of BMI and prevalence of obesity in a cross-sectional population-based study and to determine the sociodemographic and behavioural correlates with BMI.

METHODS

Participants (N = 2,076) were recruited from the Nanoro Health and Demographic Surveillance System area and were aged 40-60 years. We applied hierarchical modelling to identify factors associated with BMI and structural equation modelling to identify mediated effects of sociodemographic and behavioural variables on BMI.

RESULTS

Data are presented on 2,076 participants (49.9% female). Men had significantly higher BMI than women with medians of 21.1 (19.2 - 23.4) vs 19.8 (18.1 - 21.6) (p < 0.001), and there were significantly more underweight women compared to men (31.0% vs 17.4%) (p < 0.001). More men were overweight and obese than women (11.9% vs 5.2% and 2.2% vs 1.4%). Socioeconomic status was the major contributor to increased BMI for men, and education was the main contributor in women. Tobacco smoking and chewing, and problematic alcohol consumption were associated with a decrease in BMI in men and women.

CONCLUSION

Overweight and obesity are relatively low among adults in rural Burkina Faso, and men had a higher median BMI than women. Behavioural factors, including tobacco use and alcohol consumption, contributed to a decrease in BMI, whereas socioeconomic status and education (which were both generally low in this community) contributed to an increase in BMI.

Factors associated with stage of change in smoker in relation to smoking cessation based on the Korean National Health and Nutrition Examination Survey II-V

Despite a decrease in incidence, smoking remains the most serious public health problem worldwide. Identification of the factors contributing to changes in willingness to quit smoking may aid the development of strategies that encourage smoking cessation. Pooled cross-sectional data from 11,924 smokers from the Korean National Health and Nutrition Examination Survey II–V were analyzed. The stages of change in smoking cessation were categorized as pre-contemplation, contemplation, and preparation. Baseline characteristics, socioeconomic factors, quality of life, psychological status, and smoking-related factors were compared between groups. The smokers were grouped as follows: 32.4% pre-contemplation, 54.4% contemplation, and 13.1% preparation. The proportion of smokers in the pre-contemplation group decreased (from 37.4% to 28.4%) from 2001 to 2012, while the proportion in the preparation group increased (from 6.4% to 18.1%). Compared with the preparation group, after adjusting for confounding factors, the pre-contemplation group was older [≥65 years-old; odds ratio (OR) = 1.40], more often single (OR = 1.38), less educated (elementary school or lower; OR = 1.93), less physically active in terms of walking (OR = 1.38) or performing strengthening exercises (OR = 1.61), smoked more heavily (≥20 cigarettes per day; OR = 4.75), and had a lower prevalence of chronic disease (OR = 0.76). Moreover, smokers who had never received education on smoking cessation were less willing to quit than those who had (OR = 0.44). In Korean smokers, the stages of change for smoking cessation were associated with age, education, marital status, chronic diseases, physical activity, and participation in smoking cessation programs.

Reflections on 15 Years in the Global Tobacco Trenches

This paper is based on my 2017 Research Laureate Presentation at the Annual Scientific Meeting of the American Academy of Health Behavior in Tucson, Arizona. It provides a brief overview of the history of the smoking epidemic, and describes my work in global tobacco control, focusing on my experiences over the last 15 years as a co-founder and intervention director of the Syrian Center for Tobacco Studies (SCTS) in Aleppo, Syria. The SCTS is an NIH-funded research center that draws on a broad range of complementary expertise and resources from developed and developing nations to address the tobacco epidemic in the Arab World. The SCTS strives to serve as a model of scientific excellence and commitment to the health of people in the Middle East and beyond. Major research streams using qualitative, epidemiological, clinical lab, and intervention methodologies are reviewed, along with some of the successes and challenges encountered since the SCTS's founding.