Department of Health Management and Social Development Research Center, Golestan University of Medical Sciences, Gorgan, Iran.
Department of Epidemiology, School of Public Health, Iran University of Medical Sciences, Shahid Hemmat Highway, Tehran, Iran.
Behav Genet. 2021 Jul;51(4):385-393. doi: 10.1007/s10519-021-10052-0. Epub 2021 Mar 12.
Gateway hypothesis presumes that using a psychotropic drug can increase the probability of using another drug. The study was to assess whether cigarette smoking is a gateway drug for subsequent opium use. Mendelian randomization (MR) analysis was applied to test and estimate the size of causal effect of cigarette smoking on opium use. The CHRNA3 rs1051730 polymorphism was used as an instrumental variable. A population-based case control study in the setting of Fasa Cohort Study was carried out using 477 cases and 531 controls based on their opium use status at the baseline of cohort study. The logistic two stage estimator method was applied. The Number of cigarettes smoked per day was associated with opium use (OR 1.17, 95% CI 1.15-1.19). In the MR analysis, rs1051730 T alleles were associated with increased risk of opium use among ever smokers (OR 5.73, 95% CI 1.72-19.07) however there found no evidence of association among never smokers. In instrumental variable analysis, showed that on average smoking every 1 more cigarette per day increases the odds of opium use by 1.17 (OR 1.17, 95%CI:1.14-1.19). The MR analysis found a positive finding on the relationship between cigarette smoking and opium use which supports the gateway hypothesis. It adds new information to the gateway theory regarding the relation of cigarette smoking and drug use, and increases our understanding of the importance of tobacco control for prevention of opium addiction.
瘾品使用的“门户”假说认为，使用一种精神活性物质会增加使用另一种物质的概率。本研究旨在评估吸烟是否是导致随后使用鸦片的“门户”。本研究采用孟德尔随机化（MR）分析来检验和估计吸烟对鸦片使用的因果效应大小。采用 CHRNA3 rs1051730 多态性作为工具变量。本研究采用基于人群的病例对照研究，基于队列研究基线时的鸦片使用状况，纳入 477 例病例和 531 例对照。采用二阶段逻辑回归估计法。每天吸烟的支数与鸦片使用有关（OR 1.17，95%CI 1.15-1.19）。在 MR 分析中，rs1051730 的 T 等位基因与吸烟者（OR 5.73，95%CI 1.72-19.07）中鸦片使用风险增加有关，但在从不吸烟者中未发现关联。在工具变量分析中，显示每天多吸 1 支烟，会使鸦片使用的几率平均增加 1.17 倍（OR 1.17，95%CI：1.14-1.19）。MR 分析发现吸烟与鸦片使用之间存在正相关关系，支持“门户”假说。该研究为吸烟与药物使用之间的关系提供了“门户”理论的新信息，增加了我们对烟草控制在预防鸦片成瘾方面重要性的理解。
