Kunitomo Yukiko, Woo Han, Balasubramanian Aparna, Fawzy Ashraf, Lin Cheng Ting, Raju Sarath, Belz Daniel C, McCormack Meredith C, Koehler Kirsten, Hansel Nadia N, Putcha Nirupama
Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, 5501 Hopkins Bayview Circle, Baltimore, MD, 21224, USA.
Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Respir Res. 2024 Dec 19;25(1):437. doi: 10.1186/s12931-024-03071-y.
Anemia is a prevalent comorbidity in COPD associated with increased morbidity. However, the significance of longitudinal anemia status and variation in anemia status trends over time in COPD are not known. Furthermore, individuals with COPD and smoking history often have multiple comorbidities, in particular cardiovascular disease. The objective of this study was to evaluate the association between longitudinal anemia status and COPD outcomes, accounting for comorbid cardiovascular disease.
Serial hemoglobin measures and clinical outcomes were obtained in former smokers with moderate to severe COPD from two clinical studies over a 6-to-9-month period. In the first analysis, the association between repeated measures of time-varying anemia status and outcomes was assessed by generalized estimating equations adjusted for covariates including cardiovascular disease. In the second analysis, each participant's anemia risk profile during the study period was characterized as high versus low anemia risk-growth rate. Mean differences in the progression of COPD outcomes over time between the two groups were assessed using a generalized linear mixed model. Effect modification by baseline coronary artery calcium (CAC) burden was explored.
There were 159 individuals with mean age of 66.5 years (± 8.3) and mean FEV% predicted of 51.4% (± 17.0), of which 41% were ever-anemic during the study period. Repeated measures of anemia status were associated with higher St. George's Respiratory Questionnaire (SGRQ) scores (β 2.5, 95% CI: 0.1,4.8, p = 0.04), lower 6-minute walk distance (6MWD) (β -38.6, 95% CI: -67.7,-7.4, p = 0.02), and higher rate of moderate-to-severe exacerbations over the prospective follow-up period (IRR 1.8, 95% CI: 1.1,2.8, p = 0.02). There was effect modification by CAC burden such that with higher burden the mean difference in COPD outcome by anemia status was greater for a subset of symptom scores. Participants with profiles of increasing anemia risk had higher estimated rates of decline in the FEV% predicted and 6MWD and increase in SGRQ scores compared to those with stable or decreasing anemia risk.
Longitudinal anemia status trends may be predictive of COPD disease trajectory. Anemia status by repeated measures analysis is associated with COPD morbidity with potentially stronger associations in the setting of high CAC burden.
贫血是慢性阻塞性肺疾病（COPD）中一种常见的合并症，与发病率增加相关。然而，COPD患者纵向贫血状态及其随时间变化趋势的意义尚不清楚。此外，有COPD和吸烟史的个体通常有多种合并症，尤其是心血管疾病。本研究的目的是评估纵向贫血状态与COPD预后之间的关联，并考虑合并的心血管疾病。
从两项临床研究中获取了6至9个月期间中度至重度COPD既往吸烟者的系列血红蛋白测量值和临床预后。在第一次分析中，通过对包括心血管疾病在内的协变量进行调整的广义估计方程，评估随时间变化的贫血状态重复测量值与预后之间的关联。在第二次分析中，将每位参与者在研究期间的贫血风险概况分为高贫血风险增长率和低贫血风险增长率。使用广义线性混合模型评估两组之间COPD预后随时间进展的平均差异。探讨了基线冠状动脉钙化（CAC）负担的效应修正作用。
共有159名个体，平均年龄66.5岁（±8.3），预计平均第一秒用力呼气容积（FEV%）为51.4%（±17.0），其中41%在研究期间曾患贫血。贫血状态的重复测量与较高的圣乔治呼吸问卷（SGRQ）评分（β2.5，95%可信区间：0.1，4.8，p = 0.04）、较短的6分钟步行距离（6MWD）（β -38.6，95%可信区间：-67.7，-7.4，p = 0.02）以及前瞻性随访期间中至重度急性加重发生率较高（发病率比1.8，95%可信区间：1.1，2.8，p = 0.02）相关。存在CAC负担的效应修正作用，即对于一部分症状评分，随着负担增加，贫血状态导致的COPD预后平均差异更大。与贫血风险稳定或降低的参与者相比，贫血风险增加的参与者预计FEV%和6MWD下降率更高，SGRQ评分增加。
纵向贫血状态趋势可能预测COPD疾病轨迹。通过重复测量分析的贫血状态与COPD发病率相关，在高CAC负担情况下可能存在更强的关联。
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