<p>Multiple linear regression of FVC% of predicted.</p>

Introduction Type 2 diabetes is associated with mild airways restriction, yet obstructive lung conditions are prevalent in people with diabetes. Obesity is a confounding factor and has been reported to be both protective and to enhance risk of lung disease independent of hyperglycaemia. The aim of this systematic review was to evaluate how Type 2 diabetes and obesity affect lung function measurements in people with and without chronic obstructive pulmonary disease (COPD) and asthma. Methods Ovid MEDLINE and Embase databases were methodically searched for studies published between 2011–2024. Ninety-three studies were included, with 35,891 participants. Included studies had data on Type 2 diabetes and/or obesity and forced expiratory volume in one second (FEV1) and/or forced vital capacity (FVC). All studies were assessed for quality (Newcastle-Ottawa scale) or risk of bias (Cochrane methodology). Data was extracted as combined means and standard deviation, and significance tested by Kruskal-Wallis. Multiple linear regression was conducted to account for the impact of age, BMI, Type 2 diabetes and geographical region. Results Those with Type 2 diabetes without a lung disease had mild airway restriction. However, outcomes for those with asthma and COPD in the presence of Type 2 diabetes were largely comparable to those who had either condition in the absence of Type 2 diabetes. A Type 2 diabetes diagnosis and being in the geographical region of Asia were significantly associated with decreased FEV1 and FVC, but obesity was not. The study is limited by the large number of cross-sectional studies using single time points from which conclusions on causality cannot be drawn. Conclusion Type 2 diabetes is independently associated with airways restriction suggesting that monitoring of lung function following a diabetes diagnosis may be warranted.引言： 2型糖尿病（Type 2 diabetes）与轻度气道受限相关，而糖尿病患者群体中阻塞性肺部疾病患病率较高。肥胖属于混杂因素，有研究报道其既可对肺部疾病起到保护作用，也可在独立于高血糖（hyperglycaemia）的情况下增加肺部疾病风险。本系统综述旨在评估2型糖尿病与肥胖对合并/未合并慢性阻塞性肺疾病（chronic obstructive pulmonary disease, COPD）及哮喘（asthma）人群的肺功能检测指标的影响。 方法： 系统检索Ovid MEDLINE与Embase数据库中2011年至2024年发表的相关研究，最终纳入93项研究，共涉及35891名受试者。纳入研究均包含2型糖尿病和/或肥胖相关数据，以及一秒用力呼气容积（forced expiratory volume in one second, FEV1）和/或用力肺活量（forced vital capacity, FVC）相关数据。所有研究均采用纽卡斯尔-渥太华量表（Newcastle-Ottawa scale）进行质量评价，或采用Cochrane方法评估偏倚风险。研究数据以合并均数与标准差形式提取，采用Kruskal-Wallis检验进行显著性分析；并开展多元线性回归，以校正年龄、体质量指数（BMI）、2型糖尿病及地理区域的影响。 结果： 无肺部疾病的2型糖尿病患者存在轻度气道受限。然而，合并2型糖尿病的哮喘或慢性阻塞性肺疾病患者的肺功能检测结局，与仅患哮喘或慢性阻塞性肺疾病而无2型糖尿病者大体相当。2型糖尿病诊断以及地处亚洲地理区域，与FEV1和FVC水平降低显著相关，但肥胖未发现此关联。本研究存在局限性：纳入研究多为单时间点横断面研究，故无法得出因果性结论。 结论： 2型糖尿病与气道受限独立相关，提示糖尿病确诊后或许有必要开展肺功能监测。