Female Hormones And Lung Health: Respiratory Symptoms Are More Frequent During Menopause, Oestrogens Play A Role In Protecting The Lungs

Main Category: Menopause
Also Included In: Respiratory / Asthma;  Endocrinology
Article Date: 17 Sep 2007 - 13:00 PDT

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The way menopause-related hormonal changes affect the lungs has been little studied in the past. Now, though, this important problem is the subject of a major international study of 1,300 women, which has just presented its first set of results to the annual Congress of the European Respiratory Society (ERS) in Stockholm.
It appears that, in both overweight and lean or thin women, the menopause brings a sharp increase in respiratory symptoms and a worsening of lung function.
These results are supported by the conclusions of two more studies presented in Stockholm, conducted on animal models, which find that oestrogens have a protective effect on the lungs.

Hot flushes, mood swings, problems with sleep: the menopause, with its drop in oestrogen levels, brings many troublesome symptoms. Less well-known, however, was the potential impact of these hormonal changes on lung function.
So Francisco Gómez Real (Bergen, Norway) and an international team undertook an original study on a group of 1,304 menopausal women.

The volunteers, aged 45 to 55, were all drawn from the enormous cohort of the European Community Respiratory Health Survey (ECRHS). They were recruited in 21 centres, in nine European countries and the USA. As well as completing a very detailed questionnaire with a focus on their respiratory health and menstrual cycle, the women received an objective assessment of their lung function. This included spirometric testing for forced expiratory volume in one second (FEV1) and forced vital capacity (FVC). Blood tests were conducted to measure sex hormones (FSH, LH and oestradiol) and IgE.

Asthma rates doubled

Gómez presented some striking results to the ERS Congress. Compared to women with regular menstruation, those who had not had a period for six months or longer suffered a significant drop in lung function, with a reduction in FEV1 and FVC.
The researchers also found an increase in respiratory symptoms, particularly of the allergic type. Asthma rates were almost doubled (a relative risk of 1.84).

These phenomena were particularly marked in lean or thin women (body mass index - BMI - of 22 or less) and overweight women (BMI over 27), Gómez and his team told the Congress in Stockholm. Normal weight, on the other hand, or a slightly round shape, did not seem to be associated with respiratory risks during menopause. The team also emphasised that the conclusions remain unchanged when the analysis is restricted to women who have never smoked. Finally, they add that objective measurements of sex hormone levels in blood show that the women were "remarkably accurate" in describing their menstrual status.

This groundbreaking work may soon bring practical benefits. "Doctors should now be aware that menopausal women may present respiratory problems", Gómez emphasised.
And women will now have an additional reason to watch their weight.

Oestrogens as protection…

Two more communications to the Stockholm Congress, based on animal experiments, provide support to this study. Two separate teams in the USA studied the effect of oestrogens on laboratory animals' lung function. Though the experiments were different, they both led to the same conclusion: oestrogen protects respiratory function.

The team led by Christiana Dimitropoulou (Medical College of Georgia, USA) experimented on mice whose ovaries had been removed, administering hormone replacement therapy to some and a placebo to others. Having provoked allergic asthma in all of the animals, the researchers compared the response to methacholin-induced artificial airway constriction in the animals that had received oestrogen to those that had not.

The result was clear-cut: hormone replacement therapy provided significant protection against the bronchial hyperreactivity that characterises asthma attacks.
Additionally, as Dimitropoulou and her colleagues told the Congress, the HRT was found to reduce the lung inflammation associated with asthma.
"This points to a new, potentially important role for oestrogens in asthma", the American team enthused.

… and as a repair mechanism

The other American team, led by Sami Said of the State University of New York's Health Sciences Center at Stony Brook, provides even more spectacular results.
It experimented on guinea pigs whose lungs had been damaged by a chemical toxin and on rats whose airways had suffered either hypoxia or herbicide damage.

"In all three groups, oestrogen therapy allowed significant reduction of pulmonary lesions, although these were severe if untreated", the researchers told the Congress.
Although oestrogens have recently been under attack because of an increased risk of breast cancer and stroke, "they cannot be all bad; they are probably good for the lungs, and most likely have therapeutic potential", Said concluded.

European Respiratory Society

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