New research being conducted by Dr Hayley Scott*, from the University of Newcastle, points for the first time to a link between a form of airway inflammation called neutrophilia and the sex hormone oestrogen in obese young women.
Dr Scott says oestrogen stimulates the production of leptin, a hormone that regulates hunger but also promotes neutrophilia, which is linked with more severe asthma.
Obesity is known to be a major risk factor for asthma, although the relationship is not well understood.
“Neutrophilia doesn’t respond well to frontline asthma treatment with corticosteroid inhalers,” Dr Scott said. “There is potential to modulate sex hormone levels in obese young women with asthma for improved management of their respiratory condition.”
The findings were presented in Darwin this week at the annual scientific meeting of the Thoracic Society of Australia and New Zealand.
The study involved 130 obese and non-obese asthmatic women and a control group of men of all ages. The women were divided into two groups – one of reproductive age and the other of older subjects.
The participants were then tested for levels of neutrophils in sputum from the respiratory tract. It found the levels were significantly elevated in the obese group of fertile age women.
“The younger females tended to exhibit a more hormone related pattern of airway inflammation which was associated with higher oestrogen concentrations,” Dr Scott explained. “This association was not apparent in the older females or the men.”
* Dr Hayley Scott is a member of the Hunter Medical Research Institute’s VIVA (Virus, Infections/immunity, Vaccines and Asthma) program. HMRI is a partnership between the University of Newcastle, Hunter New England Health and the community.