目前尚无全面的Mendelian随机化研究集中在肥胖如何影响呼吸系统疾病。通过对来自英国生物库的BMI和腰围数据以及来自FinnGen生物库的35种呼吸系统疾病进行Mendelian随机化分析。本研究主要采用逆方差加权法作为主要分析方法，并辅以MR-Egger和加权中位数方法。利用MR-PRESSO方法检测水平的多效性和潜在的异常值。 本研究结果显示肥胖增加了急性上呼吸道感染的可能性（BMI：OR=1.131，p<0.0001；WC：OR=1.097，p=0.00406），急性鼻窦炎（BMI：OR=1.161，p=0.000262；WC：OR=1.209，p=0.000263），急性咽炎（WC：OR=1.238，p=0.0258），急性喉咽炎和气管炎（BMI：OR=1.202，p=0.0288；WC：OR=1.381，p=0.00192），各类流感（BMI：OR=1.243，p=0.000235；WC：OR=1.206，p=0.0119），病毒性肺炎（WC：OR=1.446，p=0.000870），所有肺炎（BMI：OR=1.174，p<0.0001；WC：OR=1.272，p<0.0001），细菌性肺炎（BMI：OR=1.183，p=0.000290；WC：OR=1.274，p<0.0001），急性支气管炎（BMI：OR=1.252，p<0.0001；WC：OR=1.237，p=0.000268），急性不明确的下呼吸道感染（BMI：OR=1.303，p=0.000403），慢性扁桃体和腺样体疾病（BMI：OR=1.236，p<0.0001；WC：OR=1.178，p=0.000157），慢性喉气管炎和喉炎（WC：OR=1.300，p=0.00785），慢性阻塞性肺病（BMI：OR=1.429，p<0.0001；WC：OR=1.591，p<0.0001），哮喘（BMI：OR=1.358，p<0.0001；WC：OR=1.515，p<0.0001），下呼吸道的坏死性和化脓性疾病（WC：OR=1.405，p=0.0427），胸腔积液（BMI：OR=1.277，p=0.00225；WC：OR=1.561，p<0.0001），胸膜斑（BMI：OR=1.245，p=0.0312），呼吸系统其他疾病（BMI：OR=1.448，p<0.0001；WC：OR=1.590，p<0.0001）和非小细胞肺癌（BMI：OR=1.262，p=0.00576；WC：OR=1.398，p=0.00181）。同时，本研究还发现肥胖降低了支气管扩张的风险（BMI：OR=0.705；p=0.00200）。 本研究揭示了肥胖增加了大多数呼吸系统疾病的风险（包括35种呼吸系统疾病中的20种），并降低了支气管扩张的风险。 版权所有 © 2023 杨, 杨, 郭, 郭, 马和韩。

No existing comprehensive Mendelian randomization studies have focused on how obesity affects respiratory diseases.BMI and waist circumference, mainly from the UK Biobank, and 35 respiratory diseases from the FinnGen Biobank were subjected to Mendelian randomization analyses. In this study, the inverse variance weighting method was used as the predominant analysis method and was complemented by MR-Egger and weighted median methods. Horizontal pleiotropy and potential outliers were detected by employing the MR-PRESSO method.This study indicated that obesity rises the possibility of acute upper respiratory infections (BMI: OR=1.131, p<0.0001; WC: OR=1.097, p=0.00406), acute sinusitis (BMI: OR=1.161, p=0.000262; WC: OR=1.209, p=0.000263), acute pharyngitis (WC: OR=1.238, p=0.0258), acute laryngitis and tracheitis (BMI: OR=1.202, p=0.0288; WC: OR=1.381, p=0.00192), all influenza (BMI: OR=1.243, p=0.000235; WC: OR=1.206, p=0.0119), viral pneumonia (WC: OR=1.446, p=0.000870), all pneumoniae (BMI: OR=1.174, p <0.0001; WC: OR=1.272, p <0.0001), bacterial pneumoniae (BMI: OR=1.183, p=0.000290; WC: OR=1.274, p<0.0001), acute bronchitis (BMI: OR=1.252, p <0.0001; WC: OR=1.237, p=0.000268), acute unspecified lower respiratory infection (BMI: OR=1.303, p=0.000403), chronic tonsils and adenoids diseases (BMI: OR=1.236, p <0.0001; WC: OR=1.178, p=0.000157), chronic laryngotracheitis and laryngitis (WC: OR=1.300, p=0.00785), COPD (BMI: OR=1.429, p <0.0001; WC: OR=1.591, p <0.0001), asthma (BMI: OR=1.358, p <0.0001; WC: OR=1.515, p <0.0001), necrotic and suppurative conditions of lower respiratory tract (WC: OR=1.405, p=0.0427), pleural effusion (BMI: OR=1.277, p=0.00225; WC: OR=1.561, p<0.0001), pleural plaque (BMI: OR=1.245, p=0.0312), other diseases of the respiratory system (BMI: OR=1.448, p <0.0001; WC: OR=1.590, p <0.0001), and non-small cell lung cancer (BMI: OR=1.262, p=0.00576; WC: OR=1.398, p=0.00181). This study also indicated that obesity decreases the possibility of bronchiectasis (BMI: OR=0.705; p=0.00200).This study revealed that obesity increases the risk of the majority of respiratory diseases (including 20 of all 35 respiratory diseases) and that obesity decreases the risk of bronchiectasis.Copyright © 2023 Yang, Yang, Guo, Guo, Ma and Han.