Department of Epidemiology and Health Statistics, School of Public Health, Hangzhou Medical College, Hangzhou, China.
School of Public Health and the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
Br J Dermatol. 2022 Nov;187(5):684-691. doi: 10.1111/bjd.21718. Epub 2022 Aug 16.
Alcohol consumption and smoking have been reported to be associated with psoriasis risk. However, a conclusion with high-quality evidence of causality could not be easily drawn from regular observational studies.
This study aims to assess the causal associations of alcohol consumption and smoking with psoriasis.
Genome-wide association study (GWAS) summary-level data for alcohol consumption (N = 941 280), smoking initiation (N = 1 232 091), cigarettes per day (N = 337 334) and smoking cessation (N = 547 219) was obtained from the GSCAN consortium (Sequencing Consortium of Alcohol and Nicotine use). The GWAS results for lifetime smoking (N = 462 690) were obtained from the UK Biobank samples. Summary statistics for psoriasis were obtained from a recent GWAS meta-analysis of eight cohorts comprising 19 032 cases and 286 769 controls and the FinnGen consortium, comprising 4510 cases and 212 242 controls. Linkage disequilibrium score regression was applied to compute the genetic correlation. Bidirectional Mendelian randomization (MR) analyses were conducted to determine casual direction using independent genetic variants that reached genome-wide significance (P < 5 × 10 ).
There were genetic correlations between smoking and psoriasis. MR revealed a causal effect of smoking initiation [odds ratio (OR) 1·46, 95% confidence interval (CI) 1·32-1·60, P = 6·24E-14], cigarettes per day (OR 1·38, 95% CI 1·13-1·67, P = 0·001) and lifetime smoking (OR 1·96, 95% CI 1·41-2·73, P = 7·32E-05) on psoriasis. Additionally, a suggestive causal effect of smoking cessation on psoriasis was observed (OR 1·39, 95% CI 1·07-1·79, P = 0·012). We found no causal relationship between alcohol consumption and psoriasis (P = 0·379). The reverse associations were not statistically significant.
Our findings provide causal evidence for the effects of smoking on psoriasis risk. What is already known about this topic? Alcohol consumption and smoking have been reported to be associated with psoriasis risk. Whether alcohol consumption and smoking have a causal effect on psoriasis risk remains unclear. What does this study add? This Mendelian randomization study shows a causal association between smoking, but not alcohol consumption, and the risk of developing psoriasis. Restricting smoking could be helpful in reducing the burden of psoriasis.
饮酒和吸烟已被报道与银屑病风险相关。然而，从常规观察性研究中很难得出具有高质量证据的因果关系结论。
本研究旨在评估饮酒和吸烟与银屑病之间的因果关联。
从 GSCAN 联盟（酒精和尼古丁使用测序联盟）获得了饮酒（N=941280）、吸烟起始（N=1232091）、每天吸烟量（N=337334）和戒烟（N=547219）的全基因组关联研究（GWAS）汇总水平数据。从英国生物库样本中获得了终生吸烟（N=462690）的 GWAS 结果。从最近的八项队列的 GWAS 荟萃分析中获得了银屑病的汇总统计数据，这些队列包括 19032 例病例和 286769 例对照，以及 FinnGen 联盟，包括 4510 例病例和 212242 例对照。应用连锁不平衡评分回归计算遗传相关性。使用达到全基因组显著水平（P<5×10-8）的独立遗传变异进行双向孟德尔随机化（MR）分析，以确定因果关系方向。
吸烟与银屑病之间存在遗传相关性。MR 显示，吸烟起始（比值比[OR]1.46，95%置信区间[CI]1.32-1.60，P=6.24E-14）、每天吸烟量（OR1.38，95%CI1.13-1.67，P=0.001）和终生吸烟（OR1.96，95%CI1.41-2.73，P=7.32E-05）与银屑病存在因果关系。此外，还观察到戒烟对银屑病有提示性的因果作用（OR1.39，95%CI1.07-1.79，P=0.012）。我们没有发现饮酒与银屑病之间存在因果关系（P=0.379）。反向关联没有统计学意义。
我们的研究结果为吸烟对银屑病风险的影响提供了因果证据。
关于这个主题已知的内容是什么？饮酒和吸烟已被报道与银屑病风险相关。饮酒和吸烟是否对银屑病风险有因果关系仍不清楚。
这项研究增加了什么新内容？这项孟德尔随机化研究表明，吸烟与银屑病风险之间存在因果关系，但饮酒与银屑病风险之间不存在因果关系。限制吸烟可能有助于降低银屑病的负担。
