Hormone replacement therapy, body mass index, and asthma in peri-menopausal women: a cross-sectional survey

• Published in: Thorax
• Main Authors: Real, Francisco Gómez, Svanes, Cecilie, Björnsson, Eythor H, Franklin, Karl A, Gislason, David, Gislason, Thorarinn, Gulsvik, Amund, Janson, Christer, Jogi, Rain, Kiserud, Torvid, Norbäck, Dan, Nyström, Lennarth, Toren, Kjell, Wentzel-Larsen, Tore, Omenaas, Ernst R
• Format: Text
• Language: English
• Published: BMJ Publishing Group Ltd 2005
• Subjects: Papers; Norway; Iceland
• Online Access: http://thorax.bmj.com/cgi/content/short/thx.2005.040881v1; https://doi.org/10.1136/thx.2005.040881

Background : Hormone replacement therapy (HRT) and obesity both appear to increase asthma risk. We wanted to investigate the association of HRT with asthma and hay fever in a population of peri-menopausal women, focusing on possible interaction with body mass index (BMI). Methods : A postal questionnaire was sent to population-based samples in Denmark, Estonia, Iceland, Norway and Sweden in 1999-2001, and 8588 women aged 25-54 years responded (77%). Pregnant women, women using oral contraceptives, and women <46 years were excluded. Analyses included 2206 women aged 46-54 of which 884 were menopausal and 540 used HRT. Stratified analyses by BMI in tertiles were performed. Results : HRT was associated with increased risk for asthma (OR=1.57[95% CI=1.07-2.30]), wheeze (OR=1.60[1.22-2.10]) and hay fever (OR=1.48[1.15-1.90]). The associations with asthma and wheeze were significantly stronger among women with BMI in the lower tertile (asthma OR=2.41[1.21-4.77]; wheeze OR=2.04[1.23-3.36]) as compared with heavier women (asthma: pinteraction= 0.030; wheeze: pinteraction=0.042). Increasing BMI was associated with more asthma (OR=1.08 [1.05-1.12] per kg/m2). This effect was only found in women not taking HRT (OR=1.10 [1.05-1.14] per kg/m2), while no such association could be detected in women taking HRT (OR=1.00 [0.92-1.08] per kg/m2) (pinteraction=0.046). Menopause was not significantly associated with asthma, wheeze or hay fever. Conclusions : In peri-menopausal women there was an interaction between HRT and BMI in effects on asthma. HRT-users among lean women had as high a risk for asthma as overweight women not taking HRT. The authors suggest that HRT and overweight increase asthma risk through partly common pathways.