Pulmonary arterial hypertension (PAH) is a complex disease characterized by elevated pulmonary arterial pressure, pulmonary vascular remodelling and occlusive pulmonary vascular lesions, leading to right heart failure. Evidence from recent epidemiological studies suggests the influence of gender on the development of PAH with an approximate female to male ratio of 4:1, depending on the underlying disease pathology. Overall, the therapeutic strategy for PAH remains suboptimal with poor survival rates observed in both genders. Endogenous sex hormones, in particular 17β oestradiol and its metabolites, have been implicated in the development of the disease; however, the influence of sex hormones on the underlying pathobiology remains controversial. Further understanding of the influence of sex hormones on the normal and diseased pulmonary circulation will be critical to our understanding the pathology of PAH and future therapeutic strategies. In this review, we will discuss the influence of sex hormones on the development of PAH and address recent controversies.
LINKED ARTICLESThis article is part of a themed section on Biological Sex and Cardiovascular Pharmacology. To view the other articles in this section visit http://dx.doi.org/10. 1111/bph.2014.171.issue-3 Abbreviations AR, androgen receptor; BMPR2, bone morphogenetic protein receptor 2; CYP19A1, aromatase; CYP1B1, cytochrome P450 1B1; DHEA, dehydroepiandosterone; DHT, dihydrotestosterone; ER, oestrogen receptor; ERα, oestrogen receptor alpha; ERβ, oestrogen receptor beta; ET-1, endothelin-1; GPER, G protein-coupled oestrogen receptor; PAH, pulmonary arterial hypertension; PASMC, pulmonary artery smooth muscle cell; SERT, serotonin transporter; Su-Hx, SUGEN hypoxic; Tph1, tryptophan hydroxylase 1 Pulmonary arterial hypertension (PAH) is a progressive disease leading to right heart failure. Recent epidemiological data reports an increased incidence of PAH among females compared to males. For example, in the UK/Ireland and the USA, the percentage of female patients is 70 and 80% respectively (Badesch et al., 2010;Ling et al., 2012). There is mounting evidence to suggest that oestrogen and its metabolites may influence the pathogenesis of PAH. Here, we will examine the pathology, current therapies and the basis for gender differences in PAH, considering evidence gathered from both patient data and animal studies.
Pulmonary arterial hypertensionPAH is defined by vascular remodelling and complex vascular lesion formation arising from the accelerated proliferation of pulmonary endothelial, smooth muscle and fibroblast cells (Rabinovitch, 2008). Clinically, the disease is defined as a mean pulmonary artery pressure of >25 mmHg at rest or >30 mmHg during exercise. Symptoms are often non-specific, including fatigue, exertional dyspnoea, oedema and syncope and as a result diagnosis is frequently delayed until the disease is well established.The main genetic defect associated with PAH is a mutation in the gene encoding bone morphogenetic protein receptor 2 (BMPR2). Ge...