Early menopause: increased fracture risk at older age.

The aim of this study was primarily to determine the relationship between early menopause and the presence of fractures later in life, and secondly, to check for the significance of confounding factors (such as smoking habits, body mass index (BMI), weight and use of hormones). In this cross-sectional population based study, the subjects were 4725 postmenopausal women, 50-80 years of age, registered with 23 general practitioners (GPs). For the purpose of the present study, the total population was analyzed as well as the subgroup of 2757 women (the study population) with a natural menopause. Medical history questionnaire, weight, height and bone mineral density measurements were taken. Bivariate and multivariate analyses were carried out with documented fractures in three categories: during lifetime; after menopause and after age 50 years) as dependent variable and age, BMI, bone mineral density, weight, smoking habits, use of hormones and early menopause as independent variables. The total study population as well as the subgroups "early" and "normal menopause", stratified in three 10-year and in six 5-year categories, were analyzed. Results are expressed as odds ratio and 95% confidence intervals (CI). Multivariate logistic regression analysis revealed that over 70 years of age, BMD< or =0.800 ( t-score<2.5) and early menopause were the only systemic independent predictors of all three fracture categories. Comparing the subgroups normal menopause and early menopause, the early menopause group showed a statistically significant higher overall fracture rate (OR=1.5; CI 1.2-1.8). Over age 70, the difference in the prevalence of fractures reached statistical significance in each age category (OR: 1.8 and 2.1, respectively). Smoking was found to be associated with early menopause (OR=1.5; CI 1.2-1.8) but not with the presence of fractures. Height above 165 cm was found to be associated with a higher prevalence of fractures during lifetime. The present study shows that early menopause is statistically significant associated with the presence of fractures during lifetime, after age 50 years and after menopause. Especially at older age, early menopause is an important predictor of fractures.