Gender-specific asthma phenotypes, inflammatory patterns and asthma control in a cluster analysis

Publication date: Available online 28 August 2018

Source: The Journal of Allergy and Clinical Immunology: In Practice

Author(s): Han-Pin Hsiao, Meng-Chih Lin, Chao-Chien Wu, Chin-Chou Wang, Tsu-Nai Wang

Abstract

Background

Asthma is a heterogeneous disease with complex mechanisms and involves many risk factors and in vivo cellular molecules. It is notable that gender differences may have a potential effect on asthma phenotype.

Objective

Our study aims to identify gender-specific phenotypes and health outcomes of asthma.

Methods

We conducted the Taiwanese adult asthma cohorts (TAAC) study to enroll female (n=421) and male (n=299) adult stable asthma patients. Eight variables were selected by a factor analysis. We further performed a two-step and sensitivity cluster analysis to classify asthma clusters. The risks of asthma-related outcomes among the clusters were assessed using simple logistic regressions.

Results

Three different clusters were identified in males and females. In the female clusters, atopy/eosinophil-predominant (cluster 2), and obesity/neutrophil-predominant pattern (cluster 3) had more than a two-fold risk of asthma exacerbations (OR=2.51, 95% CI=1.12 to 5.59 and OR=2.22, 95% CI=1.01 to 4.93). In the male clusters, current smoker/neutrophilic atopic cluster (cluster 5), and ex-smoker/eosinophil-predominant or mixed inflammatory pattern (cluster 6) also had a higher risk of asthma exacerbations.

Conclusions

This study identified heterogeneous characteristics between genders. In females, the analysis showed atopy with eosinophil-predominant and obese with neutrophil-predominant inflammation. Two distinct asthma phenotypes were found in current and ex-smokers in males. Understanding asthma phenotypes and explaining the potentially biological pathways have become important.