- 10:00: Trial lecture
- 12:00: Public defence
The ordinary opponents are:
- First opponent: Professor Ulrik Schiøler Kesmodel, Aalborg University Hospital, Denmark
- Second opponent: Senior Researcher Maria Christine Magnus, Norwegian Institute of Public Health
- Leader of the committee: Professor Trine B Haugen, OsloMet
The leader of the public defense is Associate Professor Hege Bentzen, OsloMet.
The main supervisor is Professor Elisabeth Krefting Bjelland, OsloMet.
The co-supervisors are Professor Anne Eskild, Akershus University Hospital and University of Oslo, and Professor Solveig Sand-Hanssen Hofvind, Norwegian Institute of Public Health and UiT The Arctic University of Norway.
Thesis abstract
Menopause is the permanent cessation of menstrual periods and natural menopause occurs in most women between the ages of 40 and 60 years. A woman’s age at menopause has implications for her health in postmenopausal years.
Early menopause increases the risk of cardiovascular disease, osteoporosis, and early death, while late menopause increases the risk of breast and endometrial cancers. To date, valid knowledge about the influence of lifestyle factors on the large variation in age at menopause between women is limited.
We know that smokers and women with low BMI have an increased risk of early menopause, but the influence of alcohol consumption, exercise habits, and weight change patterns remain unclear.
In her doctoral project, Julie Røgler Langås has studied how alcohol consumption, exercise, and weight change patterns across the life course are related to age at natural menopause. The articles are based on self-reported data from almost 300,000 participants, aged 50-69 years, in the Norwegian breast cancer screening programme (Breast Screen Norway) during the years 2006-2015.
Findings
The findings in the first article suggest that abstainers of alcohol reach menopause earlier than alcohol consumers. Among the alcohol consumers, however, the level of alcohol consumption was not associated with age at menopause in a dose-dependent manner, suggesting minimal influence of alcohol on women’s age at menopause. Thus, the earlier menopause among non-consumers of alcohol may rely on factors not adjusted for in the statistical analyses.
The findings in the second article suggest that women with low exercise levels across the life course reach menopause earlier than women with high exercise levels. However, the association was weak, suggesting that differences in exercise behaviours between women only to a small extent can explain the large variation in age at menopause.
Finally, the findings in the third article suggest that women who lose weight from adolescence to midlife reach menopause earlier compared to women who maintain a stable average weight. Women with a stable high weight had the latest menopause, which is consistent with previous research reporting that high BMI is associated with later timing of menopause. Women with the highest weight loss had the earliest menopause. Disease and illness may induce weight loss, and the early menopause among women with high weight loss may be a result of underlying disease, not accounted for in the analyses.
The findings in this doctoral thesis add to the existing knowledge about three important lifestyle factors with uncertain relation to age at menopause. Weight change patterns and exercise levels across the life course were associated with the timing of menopause, whereas the influence of alcohol consumption of age at menopause was minimal.
