The Causal Association between Alcohol, Smoking, Coffee Consumption, and the Risk of Arthritis: A Meta-Analysis of Mendelian Randomization Studies.

Objective: To evaluate the genetic causality between alcohol intake, smoking, coffee consumption, and arthritis. Methods: Mendelian randomization (MR) studies with alcohol, smoking, and coffee consumption behaviors as exposures, and osteoarthritis (OA) and rheumatoid arthritis (RA) as outcomes were retrieved from up to July 2023. Two researchers with relevant professional backgrounds independently assessed the quality and extracted data from the included studies. Meanwhile, we applied MR analyses of four lifestyle exposures and five arthritis outcomes (two for OA and three for RA) with gene-wide association study (GWAS) data that were different from the included studies, and the results were also included in the meta-analysis. Statistical analyses were performed using Stata 16.0 and R software version 4.3.1. Results: A total of 84 studies were assessed. Of these, 11 were selected for meta-analysis. As a whole, the included studies were considered to be at a low risk of bias and were of high quality. Results of the meta-analysis showed no significant genetic causality between alcohol intake and arthritis (odds ratio (OR): 1.02 (0.94-1.11)). Smoking and arthritis had a positive genetic causal association (OR: 1.44 (1.27-1.64)) with both OA (1.44 (1.22-1.71)) and RA (1.37 (1.26-1.50)). Coffee consumption and arthritis also had a positive genetic causal association (OR: 1.02 (1.01-1.03)). Results from the subgroup analysis showed a positive genetic causality between coffee consumption and both OA (OR: 1.02 (1.00-1.03)) and RA (OR: 1.56 (1.19-2.05)). Conclusion: There is positive genetic causality between smoking and coffee consumption and arthritis (OA and RA), while there is insufficient evidence for genetic causality between alcohol intake and arthritis.

Joint Effects of Cigarette Smoking and Green Tea Consumption with miR-29b and DNMT3B mRNA Expression in the Development of Lung Cancer.

In tumor development, increased expression of DNA methyltransferase (DNMT) has been observed. In particular, cigarette smoke and tea polyphenols may influence DNMT3B mRNA expression by regulating microRNA (miR)-29b expression. Herein, we designed a case−control study to evaluate the joint effects of smoking and green tea consumption, with miR-29b and DNMT3B mRNA expression, in lung cancer development. A total of 132 lung cancer patients and 132 healthy controls were recruited to measure miR-29b and DNMT3B mRNA expression in whole blood. Results revealed that lung cancer patients had lower miR-29b expression (57.2 vs. 81.6; p = 0.02) and higher DNMT3B mRNA expression (37.2 vs. 25.8; p < 0.001) than healthy controls. Compared to non-smokers with both higher miR-29b and lower DNMT3B mRNA expression, smokers with both low miR-29b and higher DNMT3B mRNA expression had an elevated risk of lung cancer development (OR 5.12, 95% CI 2.64−9.91). Interactions of smoking with miR-29b or DNMT3B mRNA expression in lung cancer were significant. Interaction of green tea consumption with miR-29b expression and DNMT3B mRNA expression in lung cancer was also significant. Our study suggests that smokers and green tea nondrinkers with lower miR-29b expression and higher DNMT3B mRNA expression are more susceptible to lung cancer development.

Self-reported and genetically predicted coffee consumption and smoking in dementia: A Mendelian randomization study.

BACKGROUND AND AIMS: Studies of self-reported coffee consumption and smoking on risk of dementia have shown results conflicting with two-sample Mendelian randomization studies. We tested the hypotheses that coffee consumption and smoking influence risk of dementia using observational and one-sample Mendelian randomization designs with individual level data. METHODS: We included 114,551 individuals from two Danish general population cohorts (median age 58 years). First, we tested whether high self-reported coffee consumption/smoking were associated with risk of dementia. Second, whether genetically predicted high coffee consumption/smoking due to variation near CYP1A1/AHR/CHRNA3 genes were associated with risk of dementia. RESULTS: We observed 3,784 dementia events. Moderate self-reported coffee consumption was associated with low risk of all dementia and non-Alzheimer's dementia, with a similar trend for Alzheimer's disease. Genetically predicted high coffee consumption was associated with high risk of all dementia (hazard ratio [95% confidence interval] per +1 cup/day: 1.20 [1.01-1.42]), with a similar trend for non-Alzheimer's dementia (1.23 [0.95-1.53]). High self-reported smoking was associated with high risk of non-Alzheimer's dementia. High genetically predicted smoking was associated with a trend towards high risk of all dementia and Alzheimer's disease (hazard ratios per +1 pack-year: 1.04 [0.96-1.11]) and 1.06 [0.97-1.16]). CONCLUSIONS: Moderate self-reported coffee consumption was associated with low risk of all and non-Alzheimer's dementia, while high genetically predicted coffee consumption was associated with a trend towards the opposite. High self-reported smoking was associated with high risk of non-Alzheimer's dementia, with a similar trend for genetically predicted smoking on all dementia and Alzheimer's disease.

Heritability of tea drinking and its relationship with cigarette smoking in the Chinese male adult twins.

The aims of this study are to estimate the contributions of genetic factors to the variation of tea drinking and cigarette smoking, to examine the roles of genetic factors in their correlation and further to investigate underlying causation between them. We included 11 625 male twin pairs from the Chinese National Twin Registry (CNTR). Bivariate genetic modelling was fitted to explore the genetic influences on tea drinking, cigarette smoking and their correlation. Inference about Causation through Examination of FAmiliaL CONfounding (ICE FALCON) was further used to explore the causal relationship between them. We found that genetic factors explained 17% and 23% of the variation in tea drinking and cigarette smoking, respectively. A low phenotypic association between them was reported (rph = 0.21, 95% confidence interval [CI]: [0.19, 0.24]), which was partly attributed to common genetic factors (rA = 0.45, 95% CI [0.19, 1.00]). In the ICE FALCON analysis with current smoking as the exposure, tea drinking was associated with his own (ßself = 0.39, 95% CI [0.23, 0.55]) and his co-twin's smoking status (ßco-twin = 0.25, 95% CI [0.10, 0.41]). Their association attenuated with borderline significance conditioning on his own smoking status (p = 0.045), indicating a suggestive causal effect of smoking status on tea drinking. On the contrary, when we used tea drinking as the predictor, we found familial confounding between them only. In conclusion, both tea drinking and cigarette smoking were influenced by genetic factors, and their correlation was partly explained by common genetic factors. In addition, our finding suggests that familial confounders account for the relationship between tea drinking and cigarette smoking. And current smoking might have a causal effect on weekly tea drinking, but not vice versa.

Metabolic and lifestyle factors in relation to senile cataract: a Mendelian randomization study.

We conducted a Mendelian randomization study to determine the associations of body mass index (BMI), type 2 diabetes (T2D), systolic blood pressure (SBP), coffee and alcohol consumption and smoking initiation with senile cataract. Independent single nucleotide polymorphisms associated with the metabolic and lifestyle factors at the p < 5 × 10-8 were selected as instrument variables. Summary-level data for senile cataract were obtained from the FinnGen consortium (20,157 cases and 154,905 non-cases) and UK Biobank study (6332 cases and 354,862 non-cases). Higher genetically predicted BMI and SBP and genetic predisposition to T2D and smoking initiation were associated with an increased risk of senile cataract. The combined odds ratios were 1.19 (95% confidence interval (CI) 1.09-1.29; p < 0.001) per one standard deviation increase in BMI (~ 4.8 kg/m2), 1.13 (95% CI 1.04-1.23; p = 0.004) per 10 mmHg increase in SBP, 1.06 (95% CI 1.03-1.09; p < 0.001) per one unit increase in log-transformed odds ratio of T2D, and 1.19 (95% CI 1.10-1.29; p < 0.001) per one standard deviation increase in prevalence of smoking initiation. Genetically predicted coffee consumption showed a suggestive association with senile cataract (odds ratio per 50% increase, 1.18, 95% CI 1.00-1.40; p = 0.050). This study suggests causal roles of obesity, T2D, SBP and smoking in senile cataract.

Alcohol, coffee consumption, and smoking in relation to migraine: a bidirectional Mendelian randomization study.

ABSTRACT: We conducted a Mendelian randomization study to assess whether alcohol and coffee consumption and smoking are causally associated with risk of developing migraine. Independent single-nucleotide polymorphisms associated with the potential risk factors at P < 5 × 10-8 in large-scale genome-wide association studies were selected as instrumental variables. Summary-level data for the associations of the selected single-nucleotide polymorphisms with migraine were obtained from the FinnGen consortium comprising 6687 cases and 144,780 noncases and the UK Biobank study comprising 1072 cases and 360,122 noncases. Estimates derived from the FinnGen and UK Biobank cohorts were combined using fixed-effects meta-analysis. We found evidence for associations of genetically predicted alcohol consumption (odds ratio [OR] 0.54 per SD increase in log-transformed alcoholic drinks per week, 95% confidence interval [CI], 0.35-0.82; P = 0.004), coffee consumption (OR 0.56 per 50% increase in coffee consumption, 95% CI, 0.45-0.70; P < 0.001), and smoking initiation (OR 1.15 for one SD increase in the prevalence of smoking initiation, 95% CI, 1.01-1.31; P = 0.038). These associations persisted in sensitivity analyses, including mutual adjustment in multivariable Mendelian randomization analyses. In reverse Mendelian randomization analyses, genetic liability to migraine was inversely associated with alcohol consumption but was not associated with coffee consumption or smoking initiation. This study provides genetic evidence in support of a protective role of moderate coffee consumption and a detrimental role of cigarette smoking in the etiology of migraine. The inverse association between alcohol consumption and migraine risk may be attributable to reverse causality.

Combined effects of cigarette smoking, DNA methyltransferase 3B genetic polymorphism, and DNA damage on lung cancer.

BACKGROUND: Smoking increases DNA methylation and DNA damage, and DNA damage acts as a vital cause of tumor development. The DNA methyltransferase 3B (DNMT3B) enhances promoter activity and methylation of tumor suppressor genes. Tea polyphenols may inhibit DNMT activity. We designed a case-control study to evaluate the combined effects of smoking, green tea consumption, DNMT3B - 149 polymorphism, and DNA damage on lung cancer occurrence. METHODS: Questionnaires were administered to obtain demographic characteristics, life styles, and family histories of lung cancer from 190 primary lung cancer cases and 380 healthy controls. Genotypes and cellular DNA damage were determined by polymerase chain reaction and comet assay, respectively. RESULTS: The mean DNA tail moment for lung cancer cases was significantly higher than that for healthy controls. Compared to nonsmokers carrying the DNMT3B - 149 CT genotype, smokers carrying the TT genotype had a greater lung cancer risk (odds ratio [OR]: 2.83, 95% confidence interval [CI]: 1.62-4.93). DNA damage levels were divided by the tertile of the healthy controls' values. Compared to nonsmokers with low DNA damage, smokers with moderate DNA damage (OR: 2.37, 95% CI: 1.54-3.63) and smokers with high DNA damage (OR: 3.97, 95% CI: 2.63-5.98) had elevated lung cancer risks. Interaction between smoking and DNA damage significantly affected lung cancer risk. CONCLUSIONS: Our study suggested that the DNMT3B - 149 TT genotype, which has higher promoter activity, can increase the lung cancer risk elicited by smoking, and DNA damage may further promote smoking related lung cancer development.

Smoking, alcohol and coffee consumption and pregnancy loss: a Mendelian randomization investigation.

OBJECTIVE: To determine the associations of smoking and alcohol and coffee consumption with pregnancy loss. DESIGN: Mendelian randomization study. SETTING: The UK Biobank study and FinnGen consortium. PATIENTS: A total of 60,565 cases with pregnancy loss and 130,687 noncases from UK Biobank and 3,312 cases with pregnancy loss and 64,578 noncases from FinnGen. INTERVENTION(S): None. MAINS OUTCOME MEASURE: Pregnancy loss. RESULT(S): Genetic predisposition to smoking initiation was associated with an increased risk of pregnancy loss in both UK Biobank and FinnGen. The combined odds ratio (OR) was 1.31 (95% confidence interval [CI], 1.25-1.37) for one standard deviation increase in the prevalence of smoking initiation. There were no significant associations of genetically predicted consumption of alcohol (OR, 1.09; 95% CI, 0.93-1.27) or coffee (OR, 0.96; 95% CI, 0.87-1.06) with pregnancy loss. CONCLUSION(S): This study on the basis of genetic data suggests the causal potential of the association of smoking but not moderate alcohol and coffee consumption with pregnancy loss.

APOE genotype influences P3b amplitude and response to smoking abstinence in young adults.

RATIONALE: There is strong evidence that nicotine can enhance cognitive functions and growing evidence that this effect may be larger in young healthy APOE ε4 carriers. However, the moderating effects of the APOE ε4 allele on cognitive impairments caused by nicotine deprivation in chronic smokers have not yet been studied with brain indices. OBJECTIVE: We sought to determine whether young female carriers of the APOE ε4 allele, relative to noncarriers, would exhibit larger abstinence-induced decreases in P3b amplitude during a two-stimulus auditory oddball task. METHODS: We compared parietal P3bs in female chronic smokers with either APOE ε3/ε3 (n = 54) or ε3/ε4 (n = 20) genotype under nicotine-sated conditions and after 12-17-h nicotine deprivation. RESULTS: Nicotine deprivation significantly reduced P3b amplitudes in APOE ε4 carriers, but not in APOE-ε3/ε3 individuals, such that the difference seen prior to nicotine deprivation was eliminated. CONCLUSIONS: The results suggest that subjects with the APOE ε4 allele are more sensitive to nicotine, which could influence smoking patterns, the risk for nicotine dependence, and the cognitive effects of nicotine use in these individuals.

Race and smoking status associated with paclitaxel drug response in patient-derived lymphoblastoid cell lines.

The use of ex-vivo model systems to provide a level of forecasting for in-vivo characteristics remains an important need for cancer therapeutics. The use of lymphoblastoid cell lines (LCLs) is an attractive approach for pharmacogenomics and toxicogenomics, due to their scalability, efficiency, and cost-effectiveness. There is little data on the impact of demographic or clinical covariates on LCL response to chemotherapy. Paclitaxel sensitivity was determined in LCLs from 93 breast cancer patients from the University of North Carolina Lineberger Comprehensive Cancer Center Breast Cancer Database to test for potential associations and/or confounders in paclitaxel dose-response assays. Measures of paclitaxel cell viability were associated with patient data included treatment regimens, cancer status, demographic and environmental variables, and clinical outcomes. We used multivariate analysis of variance to identify the in-vivo variables associated with ex-vivo dose-response. In this unique dataset that includes both in-vivo and ex-vivo data from breast cancer patients, race (P = 0.0049) and smoking status (P = 0.0050) were found to be significantly associated with ex-vivo dose-response in LCLs. Racial differences in clinical dose-response have been previously described, but the smoking association has not been reported. Our results indicate that in-vivo smoking status can influence ex-vivo dose-response in LCLs, and more precise measures of covariates may allow for more precise forecasting of clinical effect. In addition, understanding the mechanism by which exposure to smoking in-vivo effects ex-vivo dose-response in LCLs may open up new avenues in the quest for better therapeutic prediction.