Gender differences in non-cystic fibrosis bronchiectasis severity and bacterial load: the potential role of hormones.

Anna Brooke-Hollidge,Adam Lewis,Joy Conway

doi:10.1177/17534666211035311

Abstract

Non cystic-fibrosis bronchiectasis (NCFB) is a complex chronic respiratory disease, characterised by excessive sputum production and abnormal permanent dilation of bronchi. Mucus accumulation leads to recurrent bacterial infections and increased bacterial load, causing vicious cycles of structural damage and decreased lung function. Respiratory physiotherapy management of NCFB includes airway clearance techniques and use of nebulised, hypertonic saline. Despite advances in treatment, a consistent relationship has been observed between gender and disease occurrence, with a higher prevalence amongst females. Furthermore, NCFB presents most aggressively amongst post-menopausal females, a group likely exposed to higher levels of progesterone (P4) over a longer period of time. The effects of gender-specific hormones on bacterial load and physiotherapy management of people living with NCFB remain unknown. The aim of this narrative review was to discuss the potential influence of gender specific hormones on NCFB disease progression and influence on physiotherapy, medical management and future research. SCOPUS and PUBMED electronic databases were used to conduct searches for relevant studies using specific inclusion and exclusion criteria. Secondary inclusion of relevant literature was obtained from primary paper references. Previous literature suggests that P4 may impair Cilia Beat Frequency (CBF) in airway epithelium. Reduction in CBF may further reduce ability to expectorate amongst individuals with NCFB, increasing bacterial load and likelihood of exacerbations, negatively impacting on disease progression. Furthermore, coadministration of Estrogen has been suggested to offer opposing effects to that of P4 only. These findings question whether hormonal levels may be monitored, controlled and optimised within management and treatment of females with NCFB to improve airway clearance, reduce exacerbations and improve quality of life. Larger scale, long-term trials are required to further explore the effects of gender specific hormones on NCFB and the viability of treatment with hormone replacement therapy.The reviews of this paper are available via the supplemental material section.

Highlights

Received: 16 February 2021; revised manuscript accepted: 16 June 2021. This narrative review explores the role of gender in the pathogenesis and management of noncystic fibrosis bronchiectasis (NCFB)
NCFB is a chronic respiratory disease (CRD) associated with increased mucus accumulation and expectoration difficulty – a mechanism which is linked directly with cilia beat frequency (CBF)
NCFB is more common amongst females, presenting most aggressively post-menopause

Summary

Introduction

This narrative review explores the role of gender in the pathogenesis and management of noncystic fibrosis bronchiectasis (NCFB). The same has been found in pregnant females, where P4 levels increase.[28] In such circumstances, where there is a rise in P4, literature has found CBF to demonstrate improvements when exposed to additional oestrogen.[26] Pregnancy zone protein (PZP) is a high-molecular-weight glycoprotein that is elevated in the serum of pregnant women and the synthesis of PZP is oestrogen dependent.[28] Finch et al performed a validation study of 124 patients with NCFB to characterise PZP in airways and explored its relationship with disease severity.[28] Sputum protein profiling was achieved using label-free liquid chromatography and mass spectrometry. Further research is required to examine the combined effects of oestrogen and P4 on inflammation and susceptibility to exacerbation, taking into account their naturally fluctuating levels and those optimum for CBF

Management of NCFB

Findings

Conclusion