Department of Pulmonology, JSS Medical College, JSS Academy of Higher Education and Research, Mysore, India.
Allergy Asthma and Chest Center, Mysore, India.
J Asthma. 2021 Jan;58(1):26-37. doi: 10.1080/02770903.2019.1658205. Epub 2019 Sep 3.
Asthma is a heterogeneous disease with varying clinical presentations, severity and ability to achieve asthma control. The present study aimed to characterize clinical phenotypes of asthma in an Indian cohort of subjects using a cluster analysis approach.
Patients with confirmed asthma ( = 100) and at least 6-months of follow-up data, identified by retrospective chart review, were included in this study. Demographics, age at disease onset, disease duration, body mass index, serial spirometry and allergen sensitization were assessed. Asthma control was assessed prospectively using Global Initiative for Asthma and Asthma Control Test. R version 3.4.3 was used for statistical analysis. Ward's minimum-variance hierarchical clustering method was performed using an agglomerative (bottom-up) approach. To compare differences between clusters, analysis of variance using Kruskal-Wallis test (continuous variables) and chi-square test (categorical variables) was used.
Cluster analysis of 100 treatment-naive patients with asthma identified four clusters. Cluster 1, ( = 40), childhood onset of disease, normal body weight, equal gender distribution and achieved normal lung function. Cluster 2 ( = 16) included adolescent disease-onset, obese, majority males and had poor attainment of maximum lung functions. Cluster 3 ( = 20) were older, late-onset of disease, obese, majority male and had poor attainment of maximum lung function. Cluster 4 ( = 24) had adult-onset of disease, obese, predominantly female and achieved normal lung function.
In an Indian cohort of well-characterized patients with asthma, cluster analysis identified four distinct clinical phenotypes of asthma, two of which had poor attainment of maximum lung functions.
哮喘是一种具有不同临床表现、严重程度和控制能力的异质性疾病。本研究旨在采用聚类分析方法描述印度队列中哮喘的临床表型特征。
通过回顾性病历审查，纳入了 100 名确诊哮喘且至少有 6 个月随访数据的患者。评估了人口统计学特征、发病年龄、疾病持续时间、体重指数、系列肺活量测定和过敏原致敏情况。采用全球哮喘倡议和哮喘控制测试对哮喘控制进行前瞻性评估。使用 R 版本 3.4.3 进行统计分析。采用自下而上的聚集（Ward 最小方差层次聚类方法）进行聚类分析。为了比较聚类之间的差异，使用方差分析 Kruskal-Wallis 检验（连续变量）和卡方检验（分类变量）。
对 100 名未经治疗的哮喘患者进行聚类分析，确定了 4 个聚类。聚类 1（n=40）为疾病在儿童时期发作、体重正常、性别分布均衡且实现了正常肺功能。聚类 2（n=16）包括青少年发病、肥胖、多数为男性且最大肺功能的实现较差。聚类 3（n=20）为年龄较大、发病较晚、肥胖、多数为男性且最大肺功能的实现较差。聚类 4（n=24）为成年发病、肥胖、女性为主且实现了正常肺功能。
在印度队列中，对特征明确的哮喘患者进行聚类分析，确定了 4 种不同的哮喘临床表型，其中两种患者最大肺功能的实现较差。
