To investigate the variability and determinants of menopause age in two European cohort studies, the European Respiratory Health Survey and the Swiss Air Pollution and Lung Disease in Adults Cohort.
Age at menopause was estimated in 5,288 women, aged 30 to 60 years, randomly selected in nine European countries between 1998 and 2002. Determinants of natural and surgically induced menopause were investigated by Cox regression and heterogeneity by meta-analysis. Follicle-stimulating hormone and luteinizing hormone levels were assessed in a subsample.
A quarter of the women were postmenopausal by age 50.8 years. Median age of natural menopause was 54 years. Hormone levels were within expected ranges for premenopausal and postmenopausal women. Surgically induced menopause was highly prevalent (22%-47%), associated with earlier timing of menopause. Determinants of earlier menopause were current smoking (hazard ratio [HR], 1.59; 95% CI, 1.27-1.98), body mass index greater than 30 kg/m2 (HR, 1.32; 95%, CI, 1.02-1.70), and low physical activity (HR, 1.37; 95%, CI, 1.12-1.67). The determinant for later menopause was multiparity (HR, 0.74; 95% CI, 0.62-0.89). Predictors were similar for naturally and surgically induced menopause. Oral contraceptive use yielded heterogeneous effects on timing of menopause. Later birth was associated with later menopause (HR, 0.934; 95% CI, 0.91-0.96). This evidence of a secular trend is heterogeneous across countries.
Age at menopause varies across Europe, shifting toward higher ages. This secular trend seems paradoxical because several adult determinants, that is, overweight, smoking, sedentarity, and nulliparity, associated with early menopause are on the rise in Europe. The heterogeneity of the secular trend suggests additional country-specific factors not included in the study, such as improved childhood nutrition and health, that have an influence on reproductive aging.
The article presents evidence of a secular trend and geographical variation of age at menopause in Europe. Determinants of timing of menopause remain consistent with prior research.
From the 1Institute of Social and Preventive Medicine, University of Basel, Basel, Switzerland; 2Department of Gynecology and Obstetrics, Haukeland University Hospital, Bergen, Norway; 3Division of Pulmonary Medicine, University Hospital of Geneva, Geneva, Switzerland; 4Molecular Epidemiology/Cancer Registry Zurich, Institutes of Social and Preventive Medicine/Surgical Pathology, University of Zurich, Zurich, Switzerland; 5Department of Thoracic Medicine, Haukeland University Hospital, Bergen, Norway; 6Epidémiologie des Maladies Respiratoires, INSERM U700, Faculté de Médecine Xavier Bichat, Paris, France; 7Institute of Inhalation Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; 8Institute of Genetic Medicine, EURAC Research, Bozen, Italy; 9Center for the Biology of Natural Systems, Queens College, City University of New York, Flushing, NY; and 10National Heart and Lung Institute, Imperial College, London, UK.
Received June 2, 2008; revised and accepted August 19, 2008.
Funding/support: Research support for Swiss Air Pollution and Lung Disease in Adults was received from the Swiss National Science Foundation (grants 4026-28099, 3347CO-108796, 3247BO-104283, 3247BO-104288, 3247BO-104284, 32-65896.01, 32-59302.99, 32-52720.97, and 32-4253.94); the Federal Office for Forest, Environment and Landscape; the Federal Office of Public Health; the Federal Office of Roads and Transport; the cantonal governments of Aargau, Basel-Stadt, Basel-Landschaft, Geneva, Lucerne, Ticino, and Zurich; the Swiss Lung League; the cantonal Lung Leagues of Basel Stadt/Basel Landschaft, Geneva, Ticino, and Zurich; and the National Institute of Environmental Health Sciences (US) (grant 2 P01 ES009825 to Diane R. Gold and grant R01 ES011636 to Joel Schwartz). European Respiratory Health Survey II was supported by the European Commission, as part of their Quality of Life program. The European Commission supported the transport of serum for hormone measurement to Paris. Hormone measures were funded by a local budget of the ECRHS Paris team, INSERM U700, Epidemiology, with further support from the Centre d'Investigation Clinique Bichat Hospital and the Comité National contre les Maladies Respiratoires (project R05037HH 2004/05).
Financial disclosure: None reported.
Address reprint requests to: Julia Dratva, MD, PhD, MPH, Steinengraben 49, 4053 Basel, Switzerland. E-mail: firstname.lastname@example.org