School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, New South Wales, Australia
Immune Health Research Program, Hunter Medical Research Institute, New Lambton Heights, New South Wales, Australia.
Thorax. 2023 Oct;78(10):957-965. doi: 10.1136/thorax-2022-219268. Epub 2023 Mar 22.
Obesity is associated with more severe asthma, however, the mechanisms responsible are poorly understood. Obesity is also associated with low-grade systemic inflammation; it is possible that this inflammation extends to the airways of adults with asthma, contributing to worse asthma outcomes. Accordingly, the aim of this review was to examine whether obesity is associated with increased airway and systemic inflammation and adipokines, in adults with asthma.
Medline, Embase, CINAHL, Scopus and Current Contents were searched till 11 August 2021. Studies reporting measures of airway inflammation, systemic inflammation and/or adipokines in obese versus non-obese adults with asthma were assessed. We conducted random effects meta-analyses. We assessed heterogeneity using the I statistic and publication bias using funnel plots.
We included 40 studies in the meta-analysis. Sputum neutrophils were 5% higher in obese versus non-obese asthmatics (mean difference (MD)=5.0%, 95% CI: 1.2 to 8.9, n=2297, p=0.01, I=42%). Blood neutrophil count was also higher in obesity. There was no difference in sputum %eosinophils; however, bronchial submucosal eosinophil count (standardised mean difference (SMD)=0.58, 95% CI=0.25 to 0.91, p<0.001, n=181, I=0%) and sputum interleukin 5 (IL-5) (SMD=0.46, 95% CI=0.17 to 0.75, p<0.002, n=198, I=0%) were higher in obesity. Conversely, fractional exhaled nitric oxide was 4.5 ppb lower in obesity (MD=-4.5 ppb, 95% CI=-7.1 ppb to -1.8 ppb, p<0.001, n=2601, I=40%). Blood C reactive protein, IL-6 and leptin were also higher in obesity.
Obese asthmatics have a different pattern of inflammation to non-obese asthmatics. Mechanistic studies examining the pattern of inflammation in obese asthmatics are warranted. Studies should also investigate the clinical relevance of this altered inflammatory response.
CRD42021254525.
肥胖与更严重的哮喘有关，但导致这种情况的机制尚不清楚。肥胖也与低度全身炎症有关；有可能这种炎症会扩展到患有哮喘的成年人的气道，导致更严重的哮喘结果。因此，本综述的目的是检查肥胖是否与成年人哮喘患者的气道和全身炎症以及脂肪因子增加有关。
直到 2021 年 8 月 11 日，检索了 Medline、Embase、CINAHL、Scopus 和 Current Contents，以评估报告肥胖与非肥胖成年人哮喘患者气道炎症、全身炎症和/或脂肪因子的研究。我们进行了随机效应荟萃分析。我们使用 I 统计量评估异质性，并使用漏斗图评估发表偏倚。
我们将 40 项研究纳入荟萃分析。与非肥胖哮喘患者相比，肥胖哮喘患者的痰液中性粒细胞高 5%（平均差异（MD）=5.0%，95%CI：1.2 至 8.9，n=2297，p=0.01，I=42%）。血液中性粒细胞计数也更高。痰液嗜酸性粒细胞百分比无差异；然而，支气管粘膜下嗜酸性粒细胞计数（标准化均数差（SMD）=0.58，95%CI：0.25 至 0.91，p<0.001，n=181，I=0%）和痰液白细胞介素 5（IL-5）（SMD=0.46，95%CI：0.17 至 0.75，p<0.002，n=198，I=0%）在肥胖患者中更高。相反，肥胖患者呼出的一氧化氮分数低 4.5 ppb（MD=-4.5 ppb，95%CI：-7.1 ppb 至 -1.8 ppb，p<0.001，n=2601，I=40%）。血液 C 反应蛋白、IL-6 和瘦素也更高。
肥胖哮喘患者的炎症模式与非肥胖哮喘患者不同。有必要进行检查肥胖哮喘患者炎症模式的机制研究。研究还应调查这种炎症反应改变的临床相关性。
PROSPERO 注册号：CRD42021254525。
