Department of Thoracic Surgery, Shanxi Provincial People's Hospital, Taiyuan, Shanxi Province, China.
Fifth Clinical Medical College, Shanxi Medical University, Taiyuan, Shanxi Province, People's Republic of China.
PLoS One. 2024 Jun 14;19(6):e0303286. doi: 10.1371/journal.pone.0303286. eCollection 2024.
The relationship between the levels of Systemic Immune-inflammation Index (SII) and chronic obstructive pulmonary disease (COPD), lung function, and COPD severity were not fully understood. We conducted this cross-sectional, population-based study to investigate the complex association between SII and COPD, lung function, and COPD severity among the US adults.
Overall, 18,349 participants were included in the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2018. The exposure variable was SII, calculated from platelet counts, neutrophil counts, and lymphocyte counts. Weighted univariable and multivariable logistic regression, subgroup analysis, and restricted cubic spline (RCS) regression were performed to assess the relationship between COPD, lung function, COPD severity and SII. Last, we used a propensity score matching (PSM) analysis to reduce selective bias and validate these relationships.
Approximately 1,094 (5.96%) of the participants were diagnosed as COPD. The multivariable-adjusted odds ratio (OR) (95% confidence interval, CI) for the Q2 group (Log-SII > 2.740) was 1.39 (1.16 to 1.68). Before and after matching, multivariable logistic regression models revealed that increased Log-SII levels (SII Logarithmic transformation) associated positively with the risk of COPD. The subgroup analysis showed no interaction between Log-SII and a variety of variables (P for interaction > 0.05). RCS showed a reversed L-shaped relationship between Log-SII with COPD (P for nonlinear = 0.001) in individuals. In addition, we observed negative significant correlations between forced expiratory volume in one second (FEV1) / forced vital capacity (FVC) %, FEV1/FVC% predicted and SII, and reversed U-shaped curve relationships between FEV1, FEV1% predicted and SII. High SII level is associated with severity of COPD, especially at Global Initiative on Obstructive Lung Disease (GOLD) 1 and GOLD 3.
In summary, the Log-SII level is associated with COPD risk, lung function, and COPD severity.
系统免疫炎症指数（SII）水平与慢性阻塞性肺疾病（COPD）、肺功能和 COPD 严重程度之间的关系尚未完全阐明。我们进行了这项横断面、基于人群的研究，旨在调查美国成年人中 SII 与 COPD、肺功能和 COPD 严重程度之间复杂的关联。
共有 18349 名参与者纳入了 2005 年至 2018 年期间的国家健康和营养调查（NHANES）。暴露变量是 SII，由血小板计数、中性粒细胞计数和淋巴细胞计数计算得出。采用加权单变量和多变量逻辑回归、亚组分析和限制性立方样条（RCS）回归来评估 COPD、肺功能、COPD 严重程度与 SII 之间的关系。最后，我们使用倾向评分匹配（PSM）分析来减少选择性偏差并验证这些关系。
大约 1094 名（5.96%）参与者被诊断为 COPD。Q2 组（Log-SII > 2.740）的多变量调整比值比（OR）（95%置信区间，CI）为 1.39（1.16 至 1.68）。在匹配前后，多变量逻辑回归模型显示，Log-SII 水平升高（SII 对数转换）与 COPD 风险呈正相关。亚组分析显示，Log-SII 与多种变量之间无交互作用（P 交互>0.05）。RCS 显示 Log-SII 与 COPD 之间呈反向 L 形关系（P 非线性=0.001）。此外，我们观察到用力呼气量一秒（FEV1）/用力肺活量（FVC）%、FEV1/FVC%预计值与 SII 之间呈负相关，FEV1、FEV1%预计值与 SII 之间呈反向 U 形曲线关系。高 SII 水平与 COPD 严重程度相关，尤其是在全球倡议慢性阻塞性肺疾病（GOLD）1 级和 GOLD 3 级。
综上所述，Log-SII 水平与 COPD 风险、肺功能和 COPD 严重程度相关。
