NEW YORK (Reuters Health) - Women who have irregular menstrual periods with unpredictable flow are more likely than other women to have abnormal lung function and asthma, according to a new report.
“Physicians should be aware that women with menstrual irregularity seem to be at greater risk of asthma and impaired lung function,” Dr. Francisco Gomez Real from Haukeland University Hospital, Bergen, Norway told Reuters Health.
Previous research has found links between airway abnormalities and sex hormone irregularities. For example, findings have implied relationships between asthma and abnormal levels of sex hormones; obesity, asthma and lung function; and between lung function and insulin resistance.
In the current study, Real and colleagues investigated whether menstrual irregularity is associated with lung function and asthma, and examined whether potential associations are modified by body mass index (BMI) and physical activity. BMI is the ratio between height and weight frequently used to classify individuals as underweight, overweight or normal weight.
Women with menstrual irregularity (irregular cycles and/or cycles longer than 32 days) were significantly more likely to have asthma and asthma symptoms than were women with normal menstrual cycles, the authors report.
Forced vital capacity, a measure of lung function, was significantly lower in women with menstrual irregularity, but there was only an insignificant association between menstrual irregularities and forced expiratory volume in one second (FEV1).
The effects of menstrual irregularity on asthma symptoms were additive to those of BMI, the researchers note in the September issue of the Journal of Allergy and Clinical Immunology.
Asthma symptoms were most prevalent among women with menstrual irregularity who exercised daily, the report indicates.
The association between menstrual irregularity and asthma and lung function persisted after excluding women currently using asthma medication, excluding those reporting daily strenuous physical exercise, and adjusting the data for BMI.
“Obesity, low physical activity, and menstrual irregularity are risk factors in airway pathology,” Real concluded.
“I would say that especially women with menstrual irregularity who do not exercise daily should undergo lung function testing, as those women represent, by far, a greater health concern,” Real added. “In addition, women exercising daily do not seem to be at risk of (irregular) lower lung function.”
SOURCE: Journal of Allergy and Clinical Immunology, September 2007.