Novel insights into the consequences of obesity: a phenotype-wide Mendelian randomization study

Obesity is thought to significantly impact the quality of life. In this study, we sought to evaluate the health consequences of obesity on the risk of a broad spectrum of human diseases. The causal effects of exposing to obesity on health outcomes were inferred using Mendelian randomization (MR) analyses using a fixed effects inverse-variance weighted model. The instrumental variables were SNPs associated with obesity as measured by body mass index (BMI) reported by GIANT consortium. The spectrum of outcome consisted of the phenotypes from published GWAS and the UK Biobank. The MR-Egger intercept test was applied to estimate horizontal pleiotropic effects, along with Cochran’s Q test to assess heterogeneity among the causal effects of instrumental variables. Our MR results confirmed many putative disease risks due to obesity, such as diabetes, dyslipidemia, sleep disorder, gout, smoking behaviors, arthritis, myocardial infarction, and diabetes-related eye disease. The novel findings indicated that elevated red blood cell count was inferred as a mediator of BMI-induced type 2 diabetes in our bidirectional MR analysis. Intriguingly, the effects that higher BMI could decrease the risk of both skin and prostate cancers, reduce calorie intake, and increase the portion size warrant further studies. Our results shed light on a novel mechanism of the disease-causing roles of obesity.

Psychological Distress And Smoking Behaviors of Chinese College Students: Mediating Effects of The Dimensions of Learning Burnout

Objectives: Smokers or never smokers exposed to environmental tobacco use (ETS) are usually associated with various diseases and cancers. In order to better help college students prevent the tobacco use and thus preclude the incidences of avoidable diseases, this study explored the predictive power of different variables including demographic and psychological variables in relation to smoking behaviors. Methods: Maslach Burnout Inventory-Student Survey (MBI-SS) and Kessler Psychological Distress Scale (K10) were used in this study. Results: The multivariate logistic regression indicated that college students who were male (versus female, OR = 9.55), majoring in medicine and sports (versus nursing, ORmedicine = 2.19, ORsports=2.81), born in the non-singleton family (versus singleton family, OR= 0.63) with higher family income (versus lower family income, OR = 0.45), surrounded with smoking friends (versus without smoking friends, OR= 0.18), were more vulnerable to smoke. In addition, combined with the theory of planned behavior (TPB), the dimensions of learning burnout had full mediation effects between psychological distress and smoking behavior. Conclusions: Psychological distress can only indirectly affect smoking behavior via learning efficacy, cynicism and emotional exhaustion. Adjustment from different dimensions of learning burnout will help college students better prevent the tobacco use.

SMOKING BEHAVIORS AND ATTITUDES TOWARDS THE SMOKE-FREE CAMPUS POLICY: A SYSTEMATIC REVIEW

We conducted this systematic review to document the published literature related to smoking behaviors and attitudes towards the smoke-free campus policy. Studies on universities that had implemented the smoke-free campus policy were included in this review. The search for published articles from January 2010 to December 2020 involved three main electronic databases: Ovid MEDLINE, ScienceDirect, and Scopus. We searched the databases with the following Boolean string: [(smoke-free OR tobacco-free) AND (campus OR university OR college) AND (knowledge* OR attitude* OR practice*)]. Seventeen studies were included in this review. The majority (n = 8) were from the United States, followed by Saudi Arabia (n = 2) and one each from Israel, Lebanon, Australia, Canada, the United Kingdom, Spain, and China. Eight studies reported a positive impact of the policy on smoking behavior (plan to quit smoking, attempt to quit smoking, reduce smoking). However, 11 studies reported that respondents were still exposed to second-hand smoke and that cigarette butts were still scattered around the university area. Nine studies reported negative attitudes towards smoking, and seven of 12 studies reported positive attitudes towards the policy. Overall, the smoke-free campus policy had mixed impacts. Nevertheless, we found that attitude towards a smoke-free campus and smoking behavior has a good impact.

Prepared and Reactive Inhibition in Smokers and Non-smokers

Models of addiction have identified deficits in inhibitory control, or the ability to inhibit inappropriate or unwanted behaviors, as one factor in the development and maintenance of addictive behaviors. Current literature supports disruption of the prefrontal circuits that mediate reactive inhibitory control processes (i.e. inhibition in response to sudden, unplanned changes in environmental demands) in substance use disorders, however, the relationship between disorders of addiction, such as nicotine dependence, and planned inhibitory processes is unclear. The goal of the present study was to examine the extent to which reactive and planned inhibitory processes are differentially disrupted in nicotine dependent individuals. To this aim, we employed a novel stop signal task that explicitly separates planned and reactive inhibitory processes and assessed (1) group differences in task performance between smokers and non- smokers and (2) the relationship between task performance and smoking behaviors within the smoking group. We found significant differences in stop times for both trial between groups as well as within groups. Analyses of stopping behavior in the smoking group revealed an inverse correlation between stop times on planned stop trials and a measure of nicotine dependence derived from the Fagerstrom Test of Nicotine Dependence and, surprisingly, showed that greater daily average consumption of nicotine was inversely related to stop times for both trial types. Finally, we found that recency of the last cigarette smoked was unrelated to stopping behavior.

Epigenome Wide Associations of Smoking Behavior in the Health and Retirement Study

DNA methylation (DNAm) is an increasingly popular biomarker of health and aging outcomes. Smoking behaviors have a significant and well documented correlation with methylation signatures within the epigenome and are important confounding variables to account for in epigenome-wide association studies (EWAS). However, the common classification of individuals as ‘current’, ‘former’, and ‘never’ smokers may miss crucial DNAm patterns associated with other smoking behaviors such as duration, intensity, and frequency of cigarette smoking, resulting in an underestimation of the contribution of smoking behaviors to DNAm and potentially biasing EWAS results. We investigated associations between multiple smoking behavioral phenotypes (smoking pack years, smoking duration, smoking start age, and smoking end age) and single site DNAm using linear regressions adjusting for age, sex, race/ethnicity, education, and cell-type proportions in a subsample of individuals who participated in the HRS 2016 Venous Blood Study (N=1,775). DNAm was measured using the Infinium Methylation EPIC BeadChip. All 4 phenotypes had significant associations (FDR < 0.05) with many methylation sites (packyears=6859, smoking duration=6572, start age=11374, quit age=773). There was not much overlap in DNAm sites between the full set of models with only 6 overlapping between all 4. However, the phenotypes packyears and smoking duration showed large overlap (N=3782). Results suggest additional smoking phenotypes beyond current/former/never smoker classification should be included in EWAS analyses to appropriately account for the influence of smoking behaviors on DNAm.

Reporting and methodological quality of systematic literature reviews evaluating the associations between e-cigarette use and cigarette smoking behaviors: a systematic quality review

Introduction Several published systematic reviews have examined the potential associations between e-cigarette use and cigarette smoking, but their methodological and/or reporting quality have not yet been assessed. This systematic quality review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and AMSTAR (A MeaSurement Tool to Assess systematic Reviews) 2 to evaluate the quality of systematic reviews investigating potential associations between e-cigarette use and cigarette smoking. Materials and methods PubMed/MEDLINE, Embase, and PsycINFO were searched from 01 January 2007 to 24 June 2020. Methodological quality was assessed using AMSTAR 2, and reporting quality was assessed using PRISMA guidelines. Results Of 331 potentially relevant systematic reviews, 20 met predefined inclusion criteria. Most reviews (n = 15; 75%) reported on e-cigarette use and cigarette smoking cessation, while three reported on e-cigarette use and cigarette smoking initiation (15%); and two reported on cigarette smoking initiation and cessation (10%). According to AMSTAR 2 guidelines, 18 of the 20 reviews (90%) were “critically low” in overall confidence of the results, while two were ranked “low.” Additionally, reporting quality varied across the reviews, with only 60% reporting at least half of the PRISMA items. Discussion Methodological limitations were identified across reviews examining potential associations between e-cigarette use and cigarette smoking behaviors, indicating that findings from these reviews should be interpreted with caution. Conclusions Future systematic reviews in this field should strive to adhere to AMSTAR 2 and PRISMA guidelines, to provide high quality syntheses of the available data with transparent and complete reporting.

SPATIAL ASSOCIATION PATTERNS OF SMOKING, TOBACCO OUTLET DENSITY, AND SECONDHAND SMOKE IN THAILAND

Thailand has a higher prevalence of smoking behaviors which puts people at risk of morbidity and mortality. This study aimed to determine the spatial association of smoking behaviors and their associated factors among the population of Thailand. This study was conducted using a data set from the National Statistical Office of Thailand, 2017. A Moran’s I, local indicators of spatial association (LISA), and spatial regression were used to identify the spatial autocorrelation between tobacco outlet density, the prevalence of secondhand smoke, and smoking behaviors among Thai people. According to the results, among 88,689 participants, the prevalence of smoking behaviors was 18.00 per 1,000 population. There was global spatial autocorrelation between tobacco outlet density, the prevalence of secondhand smoke, and smoking behaviors with the Moran’s I values of 0.120 and 0.375, respectively. The LISA analysis identified significant positive spatial local autocorrelation of smoking behaviors in the form of nine high-high clusters of tobacco outlets density and ten high-high prevalence clusters of secondhand smoke. The prevalence of secondhand smoke predicted smoking behaviors by 62.8 percent. There were spatial associations between tobacco outlet density and secondhand smoke problems that led the youngsters to start smoking. It is a general recommendation to strictly enforce policies and laws to control smoking, and cover all regions in Thailand.