S1 Data -

Background
The impact of marijuana on the general population is largely unknown. The present study aimed to assess the association between marijuana use and liver steatosis and fibrosis in the general United States population utilizing data from the National Health and Nutrition Examination Survey (NHANES).
Methods
This cross-sectional study was performed with data from the 2017–2018 cycle of NHANES. The target population comprised adults in the NHANES database with reliable vibration controlled transient elastography (VCTE) results. The median values of the controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) were used to evaluate liver steatosis and fibrosis, respectively. After adjusting for relevant confounders, a logistic regression analysis was used to assess the association between marijuana use and liver steatosis and fibrosis.
Results
A total of 2622 participants were included in this study. The proportions of never marijuana users, past users, and current users were 45.9%, 35.0%, and 19.1%, respectively. Compared to never marijuana users, past and current users had a lower prevalence of liver steatosis (P = 0.184 and P = 0.048, respectively). In the alcohol intake-adjusted model, current marijuana use was an independent predictor of a low prevalence of liver steatosis in people with non-heavy alcohol intake. The association between marijuana use and liver fibrosis was not significant in univariate and multivariate regression.
Conclusion
In this nationally representative sample, current marijuana use is inversely associated with steatosis. The pathophysiology is unclear and needs further study. No significant association was established between marijuana use and liver fibrosis, irrespective of past or current use.

研究背景
大麻对普通人群的影响在很大程度上尚未明确。本研究旨在利用美国国家健康与营养检查调查（National Health and Nutrition Examination Survey, NHANES）的数据，评估美国普通人群中大麻使用与肝脏脂肪变性及肝纤维化的关联。

研究方法
本横断面研究采用美国国家健康与营养检查调查2017-2018周期的数据开展。研究目标人群为该调查数据库中拥有可靠振动控制瞬时弹性成像（vibration controlled transient elastography, VCTE）结果的成年受试者。本研究分别采用受控衰减参数（controlled attenuation parameter, CAP）与肝脏硬度测量（liver stiffness measurement, LSM）的中位值来评估肝脏脂肪变性与肝纤维化程度。在校正相关混杂因素后，采用logistic回归分析评估大麻使用与肝脏脂肪变性及肝纤维化的关联。

研究结果
本研究共纳入2622名受试者。从未使用过大麻者、既往使用过大麻者与当前使用者的占比分别为45.9%、35.0%与19.1%。与从未使用大麻者相比，既往使用者与当前使用者的肝脏脂肪变性患病率更低（分别对应P=0.184与P=0.048）。在校正饮酒量的模型中，在非大量饮酒人群中，当前大麻使用是肝脏脂肪变性低患病率的独立预测因素。单因素与多因素回归分析均显示，大麻使用与肝纤维化之间的关联无统计学意义。

研究结论
在这项具有全国代表性的样本中，当前大麻使用与肝脏脂肪变性呈负相关。其病理生理机制尚不明确，有待进一步研究。无论既往还是当前使用大麻，均未发现其与肝纤维化存在显著关联。