Asthma and sex hormones.

Abstract

A chronic in ammatory state of the airways is considered the hallmark of asthma (1). However, the incidence, severity, and prognosis of asthma can be affected by a number of factors, including the patient's sex and age. The sex of the fetus seems to in uence the development of the respiratory apparatus. In fact, between weeks 28 and 40 of gestation, the lungs are in a more advanced state in females than in males (2), a fact which could explain, at least in part, the higher incidence of respiratory distress in male infants (3). Clinical observations and epidemiologic studies agree that childhood asthma is more frequent in boys than in girls (4). Moreover, in some children, usually boys, asthmatic symptoms that started in infancy disappear around puberty (5), while many girls have the disease only during adolescence (6). Age has been implicated in the severity of asthma. Asthma beginning during adulthood is generally more severe than childhood-onset asthma (7). Asthma that starts around the menopause or in old age is generally quite severe (5). According to two recent epidemiologic investigations, the patient's sex and age affect the hospitalization rate for asthma (8, 9), which is a marker of severity. In the ®rst study (a retrospective study of 33 269 patients), the admission rate of boys in the 0±10-year age group was almost twice that of girls. In the next decade, sex differences in the hospitalization rate were irrelevant, although there was a small, but signi®cant prevalence of females. At all ages above 20 years, hospital admission rates were higher in women than men, with a female/ male ratio ranging from 3:1 in subjects aged 20±50 years to 2.5:1 in those over 50 years of age (8). Similar data were reported by Elliasson (9). Both studies found a relationship between the age and sex of the patient and the severity of the asthma attack as indicated by duration of hospitalization. In fact, the duration of hospitalization increased with age in both sexes; moreover, hospital stays were longer in women over 30 years of age than in men of the same age (8, 9). Abbreviations. FSH: follicle-stimulating hormone; LH: luteinizing hormone; NK cell: natural killer cell; IL-1, -4, -5, -6: interleukin-1, -4, -5, -6; TGF-b: tumor growth factor-beta; PEFR: peak expiratory ow rate. Allergy 2001: 56: 13±20 Printed in UK. All rights reserved Copyright # Munksgaard 2001