scholarly journals Smoking and subfertility: multivariable regression and Mendelian randomization analyses in the Norwegian Mother, Father and Child Cohort Study

2021 ◽  
Author(s):  
Alvaro Hernaez ◽  
Robyn E Wootton ◽  
Christian M Page ◽  
Karoline H Skara ◽  
Abigail Fraser ◽  
...  
Keyword(s):  
Smoking Cessation ◽  
Cohort Study ◽  
Tobacco Use ◽  
Mendelian Randomization ◽  
Smoking Initiation ◽  
Smoking Intensity ◽  
Genotype Information ◽  
Multivariable Regression ◽  
Multivariable Analyses ◽  
Study Intervention

Objective. To investigate the association between smoking-related traits and subfertility. Design. Prospective study. Setting. Nationwide cohort in Norway. Patients. 28,606 women (average age 30) and 27,096 men (average age 33) with questionnaire and genotype information from the Norwegian Mother, Father and Child Cohort Study. Intervention. Self-reported information on smoking (having ever smoked [both sexes], age at smoking initiation [women only], smoking cessation [women only], and cigarettes smoked per week in current smokers [both sexes]) was gathered. Genetically predetermined levels or likelihood of presenting the mentioned traits were estimated for Mendelian randomization (MR) analyses. Main outcome measure. Subfertility, defined as time-to-pregnancy >=12 months. Results. A total of 10% of couples were subfertile. In multivariable regression accounting for age, years of education, body mass index, and number of previous pregnancies, having ever smoked was not linked to subfertility in women or men. A higher intensity of tobacco use in women who were current smokers was related to greater odds of subfertility (+ 1 standard deviation [SD, 48 cigarettes/week]: odds ratio [OR] 1.12, 95% confidence interval [CI] 1.03 to 1.21), also after adjusting for the partner's tobacco use. Later smoking initiation (+ 1 SD [3.2 years]: OR 0.89, 95% CI 0.84 to 0.95) and smoking cessation (relative to not quitting: OR 0.83, 95% CI 0.75 to 0.93) were linked to decreased subfertility in women who had ever smoked. Nevertheless, MR results were not directionally consistent for smoking intensity and cessation and were imprecisely estimated in two-sample MR, with wide confidence intervals that overlapped with the multivariable regression results. In men, greater smoking intensity was marginally linked to greater odds of subfertility in multivariable analyses, but this association was attenuated when adjusting for the partner's smoking intensity (+ 1 SD [54 cigarettes/week]: OR 1.05, 95% CI 0.96 to 1.15). MR estimates were directionally consistent but again imprecisely estimated. Conclusions. We did not find robust evidence of an effect of smoking on subfertility. This may be due to a true lack of effect, weak genetic instruments, or other kinds of confounding. The relevant limitations across all methods highlights the need for larger studies with information on subfertility.

scholarly journals Association Between Initiation, Intensity, and Cessation of Smoking and Mortality Risk in Patients With Cardiovascular Disease: A Cohort Study

2021 ◽  
Vol 8 ◽  
Author(s):  
Jiang-lin Wang ◽  
Wen-jun Yin ◽  
Ling-yun Zhou ◽  
Ya-feng Wang ◽  
Xiao-cong Zuo
Keyword(s):  
Cardiovascular Disease ◽  
Smoking Cessation ◽  
Cohort Study ◽  
Cancer Mortality ◽  
Smoking Initiation ◽  
Smoking Intensity ◽  
All Cause Mortality ◽  
Specific Mortality ◽  
Former Smokers ◽  
Cvd Mortality

Objectives: To examine the effect of smoking status, smoking intensity, duration of smoking cessation and age of smoking initiation on the risk of all-cause and cause-specific mortality among cardiovascular disease (CVD) patients.Design: A population-based prospective cohort study.Setting: The National Health Interview Survey (NHIS) in the U.S. that were linked to the National Death Index (NDI).Participants: 66,190 CVD participants ≥ 18 years of age who were interviewed between 1997 and 2013 in the NHIS linked to the NDI through December 31, 2015.Outcome Measures: The primary outcome was all-cause mortality and the secondary outcome was cause-specific mortality including CVD mortality and cancer mortality.Results: During the mean follow-up of 8.1 years, we documented 22,518 deaths (including 6,473 CVD deaths and 4,050 cancer deaths). In the overall CVD population, former and current smokers had higher risk of all-cause (Former smokers: hazard ratios (HRs), 1.26; 95% confidence interval (CI), 1.21–1.31, P < 0.001; Current smokers: HRs, 1.96; 95%CI, 1.86–2.07, P < 0.001), CVD (Former smokers: HRs, 1.12; 95%CI, 1.05–1.21, P = 0.001; Current smokers: HRs, 1.80; 95%CI, 1.64–1.97, P < 0.001) and cancer mortality (Former smokers: HRs, 1.49; 95%CI, 1.35–1.64, P < 0.001; Current smokers: HRs, 2.78; 95%CI, 2.49–3.09, P < 0.001) than never smokers. Furthermore, similar results were observed when the study subjects were stratified according to the type of CVD. Among current smokers, the risk for cancer mortality increased as the daily number of cigarettes increased, regardless of the specific type of CVD. However, the association of the risk for all-cause and CVD mortality with smoking intensity did not present a dose-response relationship. In participants with angina pectoris or stroke, smoking intensity was inversely associated with deaths from CVD. In addition, the risk for all-cause, CVD and cancer mortality declined as years of smoking cessation increased. Finally, the relative risk of all-cause mortality was not significantly different in individuals with a younger age of smoking initiation.Conclusions: CVD patients who are smokers have an increased risk of all-cause, CVD and cancer mortality, and the risk decreases significantly after quitting smoking. These data further provide strong evidence that supports the recommendation to quit smoking for the prevention of premature deaths among individuals with CVD.

scholarly journals Body mass index and subfertility: multivariable regression and Mendelian randomization analyses in the Norwegian Mother, Father and Child Cohort Study

2021 ◽  
Author(s):  
Alvaro Hernaez ◽  
Tormod Rogne ◽  
Karoline H. Skara ◽  
Siri E. Haberg ◽  
Christian M. Page ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Cohort Study ◽  
Body Mass ◽  
Mendelian Randomization ◽  
European Ancestry ◽  
Current Evidence ◽  
Obese Women ◽  
Time To Pregnancy ◽  
Current Evidence Base ◽  
Multivariable Regression

Background. Higher body mass index (BMI) is associated with subfertility in women and men. This relationship is further substantiated by a few small randomized-controlled trials of weight reduction and success of assisted reproduction. The aim of the current study was to expand the current evidence-base by investigating the association between BMI and subfertility in men and women using multivariable regression and Mendelian randomization. Methods and findings. We studied 34,157 women (average age 30, average BMI 23.1 kg/m2) and 31,496 men (average age 33, average BMI 25.4 kg/m2) who were genotyped and are participating in the Norwegian Mother, Father and Child Cohort Study. Self-reported information was available on time-to-pregnancy and BMI. A total of 10% of couples were subfertile (time-to-pregnancy ≥12 months). Our findings support a J-shaped association between BMI and subfertility in both sexes using multivariable logistic regression models. Non-linear Mendelian randomization validated this relationship. A 1 kg/m2 greater genetically predicted BMI was linked to 15% greater odds of subfertility (95% confidence interval 4% to 28%) in obese women (>=30.0 kg/m2) and 14% lower odds of subfertility (-25% to -3%) in women with BMI <20.0 kg/m2. A 1 kg/m2 higher genetically predicted BMI was linked to 23% greater odds of subfertility (6% to 43%) among obese men and 36% decreased odds (-62% to 7%) among men BMI <20.0 kg/m2. A genetically predicted BMI of 23 and 25 kg/m2 was linked to the lowest subfertility risk in women and men, respectively. The main limitations of our study were that we did not know whether the subfertility was driven by the woman, man, or both; the exclusive consideration of individuals of northern European ancestry; and the limited amount of participants with obesity or BMI values <20.0 kg/m2. Conclusions. We observed a J-shaped relationship between BMI and subfertility in both sexes, when using both a standard multivariable regression and Mendelian randomization analysis, further supporting a potential causal role of BMI on subfertility.

scholarly journals Investigating causality in associations between education and smoking: A two-sample Mendelian randomization study

2017 ◽  
Author(s):  
Suzanne H. Gage ◽  
Jack Bowden ◽  
George Davey Smith ◽  
Marcus R. Munafo
Keyword(s):  
Smoking Cessation ◽  
Educational Attainment ◽  
Mendelian Randomization ◽  
Association Studies ◽  
Smoking Initiation ◽  
Self Report ◽  
Genome Wide Association Studies ◽  
Summary Statistics ◽  
Increased Risk ◽  
Higher Educational Attainment

AbstractBackgroundLower educational attainment is associated with increased rates of smoking, but ascertaining causality is challenging. We used two-sample Mendelian randomization (MR) analyses of summary statistics to examine whether educational attainment is causally related to smoking.Methods and FindingsWe used summary statistics from genome-wide association studies of educational attainment and a range of smoking phenotypes (smoking initiation, cigarettes per day, cotinine levels and smoking cessation). Various complementary MR techniques (inverse-variance weighted regression, MR Egger, weighted-median regression) were used to test the robustness of our results. We found broadly consistent evidence across these techniques that higher educational attainment leads to reduced likelihood of smoking initiation, reduced heaviness of smoking among smokers (as measured via self-report and cotinine levels), and greater likelihood of smoking cessation among smokers.ConclusionsOur findings indicate a causal association between low educational attainment and increased risk of smoking, and may explain the observational associations between educational attainment and adverse health outcomes such as risk of coronary heart disease.

scholarly journals 454Relationships between sleep traits and metabolic profiles: evidence from multivariable regression and Mendelian randomization analyses

2021 ◽  
Vol 50 (Supplement_1) ◽  
Author(s):  
Neil Goulding ◽  
Maxime Bos ◽  
Diana van Heemst ◽  
Raymond Noordam ◽  
Deborah Lawlor
Keyword(s):  
Sleep Duration ◽  
Mendelian Randomization ◽  
Causal Effect ◽  
Association Studies ◽  
Inflammatory Marker ◽  
Genome Wide Association Studies ◽  
Inverse Variance ◽  
Multivariable Regression ◽  
Multivariable Analyses ◽  
Insomnia Symptoms

Abstract Background Sleep traits are associated with cardiometabolic disease. The aim of this study was to explore the causal effect of sleep traits (duration and insomnia) on multiple metabolic traits. Methods We used age, sex and BMI adjusted multivariable regression (N = 17,370) and two-sample summary statistic Mendelian randomization (MR) to examine effects of sleep duration and insomnia symptoms on ∼150 NMR metabolites. Multivariable analyses were conducted on data from nine European cohorts and meta-analysed. MR analyses utilised summary statistics from published genome-wide association studies (GWAS) of self-reported sleep traits (sample 1; N = 446,118 to 1,331,010) and from GWAS on NMR serum metabolites (sample 2; N = 38,618). We used inverse-variance weighted (IVW) for the main MR analyses and weighed median (WM) and MR-Egger to explore bias due to pleiotropy. Results MR IVW and multivariable analyses both suggest a positive effect of insomnia symptoms on glycoprotein acetyls (MR: 0.06 s.d. increase in mean concentration comparing any symptoms to none; p = 5.9e-4) and between total sleep duration and creatinine (MR: 0.16 s.d. increase per additional hour; p = 0.03). WM and MR-Egger analyses show consistent results. There was evidence for thirteen and eight effects of insomnia and duration in multivariable only and three and one, respectively, in MR only. Conclusions Insomnia symptoms lead to higher levels of an inflammatory marker (glycoprotein acetyls) and longer sleep duration leads to higher creatinine levels. Key messages We found no evidence of widespread metabolic disruption by sleep traits.

scholarly journals Does Smoking Cause Lower Educational Attainment and General Cognitive Ability? Triangulation of causal evidence using multiple study designs

2019 ◽  
Author(s):  
Suzanne H. Gage ◽  
Hannah Sallis ◽  
Glenda Lassi ◽  
Robyn Wootton ◽  
Claire Mokrysz ◽  
...  
Keyword(s):  
Cohort Study ◽  
Educational Attainment ◽  
Cognitive Ability ◽  
Mendelian Randomization ◽  
Causal Effect ◽  
Smoking Initiation ◽  
Sensitivity Analyses ◽  
Genome Wide Association Studies ◽  
Summary Statistics ◽  
Lower Educational Attainment

AbstractObjectivesObservational epidemiological studies have found associations between smoking and both poorer cognitive ability and lower educational attainment; however, evaluating causality is more challenging. We used two complementary methods to attempt to ascertain whether smoking causes poorer cognitive ability and lower educational attainment.DesignA cohort study (Study One) and a two-sample Mendelian randomization study using publicly-available summary statistics (Study Two).SettingThe Avon Longitudinal Study of Parents and Children (ALSPAC), a birth-cohort study based in Bristol, United Kingdom, and general population samples from published genome-wide association studies (GWAS).ParticipantsUp to 12,004 young people in ALSPAC (complete case analysis N = 2,107) (Study One and Study Two), and summary statistics from three previously published GWAS (not individual-level data) (Study Two).Main outcome measuresCognitive ability at age 15 (assessed via the Wechsler Abbreviated Scale of Intelligence) and educational attainment at age 16 (assessed via school records) (Study One), and educational attainment (measured as years in education) and fluid intelligence from previously published GWAS (Study Two).ResultsIn Study One, heaviness of smoking at age 15 was associated with lower cognitive ability at age 15 and lower educational attainment at age 16. Adjustment for potential confounders and earlier cognitive ability or educational attainment attenuated findings although evidence of an association remained (e.g., fully adjusted cognitive ability beta - 0.736, 95% CI −1.238 to −0.233, P = 0.004; fully adjusted educational attainment beta −1.254, 95% CI −1.597 to −0.911, P < 0.001). Comparable results were found in sensitivity analyses of multiply imputed data. In Study Two, two-sample Mendelian randomization indicated that both smoking initiation and lifetime smoking lower educational attainment and cognitive ability (e.g., smoking initiation to educational attainment inverse-variance weighted MR beta −0.197, 95% CI −0.223, −0.171, P = 1.78 × 10−49). Educational attainment results were robust to various sensitivity analyses, while cognition analyses were less so.ConclusionsOur results provide evidence consistent with a causal effect of smoking on lower educational attainment, although were less consistent for cognitive ability. The triangulation of evidence from observational and Mendelian randomisation methods is an important strength for causal inference.Summary boxesWhat is already known on this topicAssociations are seen between smoking and both educational attainment and cognition. These is some evidence that educational attainment might causally influence smoking, but causality in the opposite direction has not been assessed.What this study addsUsing multiple methodologies, we found evidence consistent with a causal effect of smoking on lower educational attainment. An exploration of potential mechanisms could inform the development of interventions to mitigate this risk.

scholarly journals Pattern of cigarette smoking: intensity, cessation, and age of beginning: evidence from a cohort study in West of Iran

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Behrooz Hamzeh ◽  
Vahid Farnia ◽  
Mehdi Moradinazar ◽  
Yahya Pasdar ◽  
Ebrahim Shakiba ◽  
...  
Keyword(s):  
Cohort Study ◽  
Cigarette Smoking ◽  
Rural Areas ◽  
Communicable Disease ◽  
Smoking Behavior ◽  
Smoking Initiation ◽  
Smoking History ◽  
Chi Square ◽  
Smoking Intensity ◽  
Premature Deaths

Abstract Background Smoking is a social epidemic and one of the main risk factors for premature deaths and disabilities worldwide. In the present study, we investigated the Pattern of Cigarette Smoking: intensity, cessation, and age of the beginning. Methods Data collected from the recruitment phase of Ravansar (a Kurd region in western Iran) Non-Communicable Disease (RaNCD) cohort study was analyzed by using Chi-square test, univariate and multivariate logistic regressions, Poisson regression, and linear regression. Results Totally 10,035 individuals (47.42% males) participated in the study. Mean age was lower for males (47.45 yr) than for females (48.36 yr). Prevalence of smoking was 20% (36.4% of males and 5.23% of females). Compared to female participants, males showed a 7-fold higher prevalence of smoking and started smoking about 4 years earlier. Being married, having a lower BMI, living in rural areas, and being exposed to secondhand smoke (SHS) were predictors of higher smoking prevalence rates. Furthermore, current exposure to SHS, higher smoking intensity, later smoking initiation, male gender, younger age, lower education, and lower BMI were related to lower likelihood of stopping smoking. Heavy smokers began to smoke about 4 years earlier than casual smokers did. Finally, being divorced/ widow/ widower/ single and childhood exposure to SHS were found to increase the likelihood of becoming a smoker. Conclusions Based on present research results, health programs specific to smoking cessation should take socio-demographic factors, smoking history, and current smoking behavior into account.

scholarly journals Mendelian randomization analysis provides causality of smoking on the expression of ACE2, a putative SARS-CoV-2 receptor

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Hui Liu ◽  
Junyi Xin ◽  
Sheng Cai ◽  
Xia Jiang
Keyword(s):  
Alcohol Consumption ◽  
Research Council ◽  
Mendelian Randomization ◽  
Smoking Initiation ◽  
Smoking Intensity ◽  
Swedish Research Council ◽  
Inverse Variance ◽  
Nominal Significance ◽  
Weighted Median

Background: To understand a causal role of modifiable lifestyle factors in ACE2 expression (a putative SARS-CoV-2 receptor) across 44 human tissues/organs, and in COVID-19 susceptibility and severity, we conducted a phenome-wide two-sample Mendelian randomization (MR) study. Methods: More than 500 genetic variants were used as instrumental variables to predict smoking and alcohol consumption. Inverse-variance weighted approach was adopted as the primary method to estimate a causal association, while MR-Egger regression, weighted median and MR-PRESSO were performed to identify potential horizontal pleiotropy. Results: We found that genetically predicted smoking intensity significantly increased ACE2 expression in thyroid (β=1.468, p=1.8 10-8); and increased ACE2 expression in adipose, brain, colon and liver with nominal significance. Additionally, genetically predicted smoking initiation significantly increased the risk of COVID-19 onset (odds ratio=1.14, p=8.7 10-5). No statistically significant result was observed for alcohol consumption. Conclusions: Our work demonstrates an important role of smoking, measured by both status and intensity, in the susceptibility to COVID-19. Funding: Dr. Jiang is supported by research grants from the Swedish Research Council (VR-2018-02247) and Swedish Research Council for Health, Working Life and Welfare (FORTE-2020-00884).

EFFECTS OF SMOKING ON THE DISEASE PROGNOSIS IN CANCER PATIENTS

2019 ◽  
Vol 65 (3) ◽  
pp. 321-329
Author(s):  
David Zaridze ◽  
Anush Mukeriya
Keyword(s):  
Smoking Cessation ◽  
Cancer Patients ◽  
Malignant Tumors ◽  
Scientific Data ◽  
Second Primary ◽  
Primary Tumors ◽  
Smoking Intensity ◽  
Risk Of Death ◽  
Disease Prognosis ◽  
Increased Risk

Smoking not only increases the risk of the development of malignant tumors (MT), but affects the disease prognosis, mortality and survivability of cancer patients. The link between the smoking of cancer patients and increased risk of death by all diseases and oncological causes has been established. Mortality increases with the growth of the smoking intensity, i.e. the number of cigarettes, smoked per day. Smoking is associated with the worst general and oncological survivability. The statistically trend-line between the smoking intensity and survivability was observed: each additional unit of cigarette consumption (pack/year) leads to the Overall Survival Reduction by 1% (p = 0.002). The link between smoking and the risk of developing second primary tumors has been confirmed. Smoking increases the likelihood of side effects of the antitumor therapy both drug therapy and radiation therapy and reduces the treatment efficacy. The smoking cessation leads to a significant improvement in the prognosis of a cancer patient. Scientific data on the negative effect of smoking on the prognosis of cancer patients have a major clinical importance. The treatment program for cancer patients should include science-based methods for the smoking cessation. The latter is fundamentally important, taking into account that the smoking frequency among cancer patients is much higher than in the population.

Post creation strategies in a smoking cessation intervention based on motivational interviewing using Facebook: a mixed-methods content analysis (Preprint)

2019 ◽  
Author(s):  
David Pócs ◽  
Tímea Óvári ◽  
Csaba Hamvai ◽  
Oguz Kelemen
Keyword(s):  
Smoking Cessation ◽  
Motivational Interviewing ◽  
Tobacco Use ◽  
Negative Feedback ◽  
Smoking Cessation Intervention ◽  
Control Group ◽  
Tobacco Use Cessation ◽  
Web Based ◽  
Cessation Intervention ◽  
Significant Difference

BACKGROUND Smoking cessation support on Facebook (FB) is a cost-effective and extensible way to reduce tobacco use among young people. Motivational interviewing (MI) is a practical counselling style in face-to-face smoking cessation support and can be useful in web-based interventions as well. OBJECTIVE This study aimed at identifying which post creation strategies based on MI could achieve positive changes in FB post characteristics and FB users’ comments. METHODS We included MI-adherent posts (N=701) which were not boosted and were targeted at tobacco users. These FB posts have been categorized into five different groups according to specific MI strategies. The control group comprised entertaining and informative posts. Primary outcomes seem to highlight how the content has stimulated interactions (engagement rate), inhibited interactions (negative feedback) or appealed to the audience of the FB page (fan-total reach ratio). The first comments received on the FB posts were evaluated and used as secondary outcomes. We applied the classification of MI approach: change talk (CT), sustain talk (ST), desire, ability, reason, need (DARN), and commitment, activation, taking steps (CAT). RESULTS FB posts which used MI strategies were associated with significantly higher engagement rate (p=.010), higher fan-total reach ratio (p<.001), and more CT (p<.001), DARN (p=.005), or CAT comments (p=.003) compared to the control group. ‘Elaborating CT’ strategies elicited considerably more CT (p<.001) and DARN comments (p=.020). ‘Affirming CT’ strategies obtained higher fan-total reach ratio (p=.011) and generated significantly more CT (p=.006) and CAT comments (p<.001). ‘Reflecting CT’ strategies received significantly higher fan-total reach ratio (p<.001). Finally, ‘relational MI’ strategies achieved significantly higher engagement rate (p<.001) compared to the control group. It should be noted that we did not find significant difference in negative feedback and the number of ST comments. CONCLUSIONS Post creation strategies based on MI stimulated interactions with FB users and generated conversation about tobacco use cessation without relevant negative feedback. Our findings suggest that MI strategies may play a remarkable role in post creation within a web-based smoking cessation intervention. In the future, these strategies could be applicable to other online platforms, such as public health websites, health blogs, mobile applications or social networking groups.

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