Dataset Information

Meta-analysis reveals significant association of 3'-UTR VNTR in SLC6A3 with smoking cessation in Caucasian populations.

ABSTRACT: Many studies have examined the association between SLC6A3 3'-untranslated region (UTR) variable number tandem repeat (VNTR) polymorphism and smoking cessation; however, the results are inconclusive, primarily because of the small-to-moderate size samples. The primary goal of this study was to determine whether this polymorphism has any effect on smoking cessation by a meta-analysis of all reported studies. We adopted a 9-repeat dominant model that considers 9-repeat and non-9-repeat as two genotypes and compared their frequencies in former vs current smokers. Eleven studies with 5480 participants were included. Considering the presence of study heterogeneity and differences in the availability of information from each study, three separate meta-analyses were performed with the Comprehensive Meta-Analysis statistical software (version 2.0). The first meta-analysis provided evidence of association between the 9-repeat genotype and smoking cessation under the fixed-effects model (pooled odds ratio (OR)=1.13; 95% confidence interval (CI)=1.01, 1.27; P=0.037) but not in the random-effects model (pooled OR=1.11; 95% CI=0.96, 1.29; P=0.159). Given the marginal evidence of heterogeneity among studies (P=0.10; I2=35.9%), which likely was caused by inclusion of an Asian population treatment study with an opposite effect of the polymorphism on smoking cessation, we excluded the data of this study, revealing a significant association between the 9-repeat genotype and smoking cessation under both the fixed- and random-effects models (pooled OR=1.15; 95% CI=1.02, 1.29; P=0.02 for both models). By analyzing adjusted and unadjusted results, we performed the third meta-analysis, which showed consistently that the 9-repeat genotype was significantly associated with smoking cessation under both the fixed- and random-effects models (pooled OR=1.17; 95% CI=1.04, 1.31; P=0.009 for both models). We conclude that the 3'-UTR VNTR polymorphism is significantly associated with smoking cessation, and smokers with one or more 9-repeat alleles have a 17% higher probability of smoking cessation than smokers carrying no such allele.

SUBMITTER: Ma Y

PROVIDER: S-EPMC4705003 | biostudies-other | 2016 Feb

REPOSITORIES: biostudies-other

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Meta-analysis reveals significant association of 3'-UTR VNTR in SLC6A3 with smoking cessation in Caucasian populations.

Ma Y Y Yuan W W Cui W W Li M D MD

The pharmacogenomics journal 20150707 1

Many studies have examined the association between SLC6A3 3'-untranslated region (UTR) variable number tandem repeat (VNTR) polymorphism and smoking cessation; however, the results are inconclusive, primarily because of the small-to-moderate size samples. The primary goal of this study was to determine whether this polymorphism has any effect on smoking cessation by a meta-analysis of all reported studies. We adopted a 9-repeat dominant model that considers 9-repeat and non-9-repeat as two genot ...[more]

PMID: 26149737

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Project description:ImportanceCigarette smoking during pregnancy increases the risk of preterm birth, low birth weight, and infant mortality.ObjectiveTo assess the probability of preterm birth among expectant mothers who smoked cigarettes before pregnancy and quit smoking at the start or during pregnancy.Design, setting, and participantsThis cross-sectional study analyzed information provided on live birth certificates from 2011 through 2017 that were obtained from US states that implemented the 2003 revision of the US live birth certificate. In total, 25?233?503 expectant mothers who delivered live neonates and had known prepregnancy and trimester-specific cigarette smoking frequency were included in the analyses.ExposuresCigarette smoking frequency (1-9, 10-19, and ?20 cigarettes per day) 3 months prior to pregnancy and for each trimester during pregnancy.Main outcomes and measuresCigarette smoking cessation throughout pregnancy, after the first trimester, after the second trimester, and during the third trimester irrespective of first and second trimester smoking. Probability of preterm birth (<37 weeks' gestation).ResultsOf 25?233?503 expectant mothers who delivered live neonates between 2011 and 2017, the modal age at delivery was 25 to 29 years; 52.9% were non-Hispanic white, 23.6% were Hispanic, and 14.2% were non-Hispanic black women; 22?600?196 mothers did not smoke during the 3 months prior to pregnancy, and 2?633?307 smoked during the 3 months prior to pregnancy. The proportion of prepregnancy smokers who quit throughout pregnancy was 24.3% in 2011 and 24.6% in 2017. The proportion of prepregnancy smokers who quit during the third trimester was 39.5% in 2011 and 39.7% in 2017. High-frequency cigarette smoking often occurred among expectant mothers who smoked during pregnancy (eg, 46.9% of third-trimester smokers smoked ?10 cigarettes per day in 2017). The probability of preterm birth decreased more the earlier smoking cessation occurred in pregnancy. For example, the probability of preterm birth was 9.8% (95% CI, 9.7%-10.0%) among 25- to 29-year-old, non-Hispanic white, primigravida and primiparous expectant mothers (ie, pregnant for the first time and not yet delivered) who smoked 1 to 9 cigarettes per day prior to pregnancy and maintained this frequency throughout their pregnancy. The probability of preterm birth was 9.0% (95% CI, 8.8%-9.1%) if smoking cessation occurred at the start of the second trimester (an 8.9% relative decrease), and 7.8% (95% CI, 7.7%-8.0%) if cessation occurred at the start of pregnancy (a 20.3% relative decrease).Conclusions and relevanceQuitting smoking-and quitting early in pregnancy-was associated with reduced risk of preterm birth even for high-frequency cigarette smokers.

Project description:BACKGROUND: Smoking remains the leading preventable cause of premature deaths. Several pharmacological interventions now exist to aid smokers in cessation. These include Nicotine Replacement Therapy [NRT], bupropion, and varenicline. We aimed to assess their relative efficacy in smoking cessation by conducting a systematic review and meta-analysis. METHODS: We searched 10 electronic medical databases (inception to Sept. 2006) and bibliographies of published reviews. We selected randomized controlled trials [RCTs] evaluating interventions for smoking cessation at 1 year, through chemical confirmation. Our primary endpoint was smoking cessation at 1 year. Secondary endpoints included short-term smoking cessation (approximately 3 months) and adverse events. We conducted random-effects meta-analysis and meta-regression. We compared treatment effects across interventions using head-to-head trials and when these did not exist, we calculated indirect comparisons. RESULTS: We identified 70 trials of NRT versus control at 1 year, Odds Ratio [OR] 1.71, 95% Confidence Interval [CI], 1.55-1.88, P =< 0.0001). This was consistent when examining all placebo-controlled trials (49 RCTs, OR 1.78, 95% CI, 1.60-1.99), NRT gum (OR 1.60, 95% CI, 1.37-1.86) or patch (OR 1.63, 95% CI, 1.41-1.89). NRT also reduced smoking at 3 months (OR 1.98, 95% CI, 1.77-2.21). Bupropion trials were superior to controls at 1 year (12 RCTs, OR1.56, 95% CI, 1.10-2.21, P = 0.01) and at 3 months (OR 2.13, 95% CI, 1.72-2.64). Two RCTs evaluated the superiority of bupropion versus NRT at 1 year (OR 1.14, 95% CI, 0.20-6.42). Varenicline was superior to placebo at 1 year (4 RCTs, OR 2.96, 95% CI, 2.12-4.12, P =< 0.0001) and also at approximately 3 months (OR 3.75, 95% CI, 2.65-5.30). Three RCTs evaluated the effectiveness of varenicline versus bupropion at 1 year (OR 1.58, 95% CI, 1.22-2.05) and at approximately 3 months (OR 1.61, 95% CI, 1.16-2.21). Using indirect comparisons, varenicline was superior to NRT when compared to placebo controls (OR 1.66, 95% CI 1.17-2.36, P = 0.004) or to all controls at 1 year (OR 1.73, 95% CI 1.22-2.45, P = 0.001). This was also the case for 3-month data. Adverse events were not systematically different across studies. CONCLUSION: NRT, bupropion and varenicline all provide therapeutic effects in assisting with smoking cessation. Direct and indirect comparisons identify a hierarchy of effectiveness.

Project description:CHRNA5-A3-B4 variants, rs16969968, rs588765 and rs578776, are consistently associated with tobacco consumption among smokers, but the association with smoking cessation is less consistent. Among the studies that reported significant associations with cessation, the effects were observed in smokers treated with placebo treatment in some studies and conversely in those receiving active pharmacological therapy (bupropion and nicotine replacement therapies) in others. Thus, it remains unclear whether CHRNA5-A3-B4 is a useful marker for optimizing smoking cessation. Using data from 654 Caucasian smokers treated with placebo, nicotine patch or varenicline, we investigated whether CHRNA5-A3-B4 variants were associated with smoking cessation outcomes, and whether there were significant genotype-by-treatment or haplotype-by-treatment interactions. We observed no significant associations between CHRNA5-A3-B4 variants and smoking cessation, despite replicating previous associations with baseline tobacco consumption. At end of treatment the effect size on smoking cessation in the placebo, patch and varenicline groups for rs16969968 [GG vs. GA+AA] was OR = 0.66 (P = 0.23), OR = 1.01 (P = 0.99), and OR = 1.30 (P = 0.36) respectively, of rs588765 [CC vs. CT+TT] was OR = 0.96 (P = 0.90), OR = 0.84 (P = 0.58), and OR = 0.74 (P = 0.29) respectively, and for rs578776 [GG vs. GA+AA] on smoking cessation was OR = 1.02 (P = 0.95), OR = 0.75 (P = 0.35), and OR = 1.20 (P = 0.51) respectively. Furthermore, we observed no associations with cessation using the CHRNA5-A3-B4 haplotype (constructed using rs16969968 and rs588765), nor did we observe any significant genotype-by-treatment interactions, with or without adjusting for the rate of nicotine metabolism (all P>0.05). We also observed no significant genetic associations with 6 month or 12 month smoking abstinence. In conclusion, we found no association between CHRNA5-A3-B4 variants and smoking cessation rates in this clinical trial; however, as expected, significant associations with baseline tobacco consumption were replicated. Our data suggest that CHRNA5-A3-B4 gene variants do not exhibit a robust association with smoking cessation and are unlikely to be useful for clinically optimizing smoking cessation pharmacotherapy for Caucasian smokers.

Project description:ImportancePatients with cancer who smoke after diagnosis risk experiencing reductions in treatment effectiveness, survival rates, and quality of life, and increases in complications, cancer recurrence, and second primary cancers. Smoking cessation can significantly affect these outcomes, but to date comprehensive treatment is not widely implemented in the oncologic setting.ObjectivesTo describe a potential model tobacco treatment program (TTP) implemented in a cancer setting, report on its long-term outcomes, and highlight its importance to quality patient care.Design, setting, and participantsA prospective cohort of smokers was treated in the TTP at a comprehensive cancer center from January 1, 2006, to August 31, 2015. Data analysis was performed from November 2017 to December 2018. Participants included 3245 patients (2343 with current cancer; 309 with previous cancer; 593 with no cancer history) drawn from a population of 5061 smokers referred for treatment in the TTP. Reasons for exclusion included follow-up for a noncancerous disease, no medical consultation, smoked less than 1 cigarette per day; or died before the 9-month follow-up.ExposuresTreatment consisted of an in-person medical consultation, 6 to 8 in-person and telephone follow-up counseling sessions, and 10 to 12 weeks of pharmacotherapy.Main outcomes and measuresPrimary outcome was 9-month 7-day point-prevalence abstinence evaluated using time-specific (3-, 6-, and 9-month follow-ups) and longitudinal covariate-adjusted and unadjusted regression models with multiple imputation, intention-to-treat, and respondent-only approaches to missing data. The Fagerström Test for Cigarette Dependence was used as a measure of dependence (possible range, 0-10; higher numbers indicate greater dependence).ResultsOf the 3245 smokers, 1588 (48.9%) were men, 322 (9.9%) were of black race/ethnicity, 172 (5.3%) were of Hispanic race/ethnicity, and 2498 (76.0%) were of white race/ethnicity. Mean (SD) age was 54 (11.4) years; Fagerström Test for Cigarette Dependence score, 4.41 (2.2), number of cigarettes smoked per day, 17.1 (10.7); years smoked, 33 (13.2); and 1393 patients (42.9%) had at least 1 psychiatric comorbidity. Overall self-reported abstinence was 45.1% at 3 months, 45.8% at 6 months, and 43.7% at 9 months in the multiply imputed sample. Results across all models were consistent, suggesting that, in comparison with smokers with no cancer history, abstinence rates within this TTP program did not differ appreciably whether smokers had current cancer, were a cancer survivor, or had smoking-related cancers, with the exception of patients with head and neck cancer; the rates were higher at 9 months (relative risk, 1.31; 95% CI, 1.11-1.56; P = .001) and in longitudinal models (relative risk, 1.24; 95% CI, 1.08-1.42; P = .002).Conclusions and relevanceIn this study, mean smoking abstinence rates did not differ significantly between patients with cancer and those without cancer. These findings suggest that providing comprehensive tobacco treatment in the oncologic setting can result in sustained high abstinence rates for all patients with cancer and survivors and should be included as standard of care to ensure the best possible cancer treatment outcomes.

Dataset Information

Meta-analysis reveals significant association of 3'-UTR VNTR in SLC6A3 with smoking cessation in Caucasian populations.

Publications

Meta-analysis reveals significant association of 3'-UTR VNTR in SLC6A3 with smoking cessation in Caucasian populations.

Similar Datasets

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