Symptom prevalence during menopause and factors associated with symptoms and menopausal age. Results from the Norwegian Hordaland Women's Cohort study.

Objectives: To describe symptoms during the menopausal transition and age at menopause in a representative Norwegian female cohort over a ten year period, to analyze factors associated with frequency and burden of symptoms and influence on self-rated health.

Study Design: 2229 women aged 40-44 years at inclusion, randomly selected from a national health survey in Hordaland County, Norway, and followed with seven postal questionnaires from 1997 throughout 2009. Data for 2002 women (90%) were eligible for analyses.

Results: In a longitudinal analysis, 36% of the women reported daily hot flushes in one or more questionnaires, whereas 29% did not experience hot flushes at all. The prevalence of daily hot flushes increased from 2% at age 41-42 to 22% at age 53-54, decreasing to 20% at age 55-57. The odds ratio for reporting daily hot flushes vs. never/seldom for daily smokers was 1.6 (1.24-2.10). Women in the lowest education group had an OR=1.8 (1.21-2.56) for reporting daily hot flushes compared to women with a university degree. There was no relation between the symptom burden and degree of physical exercise, overall feeling of health, BMI, family income, parity or menarche age as recorded at baseline. The mean age for final menstruation period (FMP) in the cohort was 51.1 (50.9-51.3) years. Smokers had a mean age of FMP 0.9 years earlier compared to the non-smokers.

Conclusions: Daily smoking and educational level were independent risk factors for experiencing daily menopausal symptoms. Degree of physical exercise, BMI, parity or menarche age did not have significant influence.