Abstract and Introduction
Objectives: To describe the prevalence of risk factors for osteoporosis in a population-based cohort of Australian-born midlife women; determine the effect of these risk factors on premenopausal and early perimenopausal bone mineral density (BMD); and describe changes in risk factors and any effect of these on bone loss.
Design: 4-year longitudinal community-based study. BMD of the lumbar spine (LS) and femoral neck (FN) was measured using dual x-ray absorptiometry (DXA).
Setting: Melbourne, Australia
Participants: 224 Australian-born women aged 46-56 years
Main Outcome Measures: Risk factors for osteoporosis, LS-BMD, FN-BMD, and change in risk factors and BMD.
Results: At baseline, 52% reported a calcium intake of less than 800 mg/day and 46% reported a caffeine intake of more than 360 mg/day; 29% exercised less than 1.5 hours/week; 5% had a body mass index (BMI) of less than 20; 14% were current smokers; 23% were past smokers; 10% reported abnormal menstrual histories; and 25% reported a family history of osteoporosis. BMD was positively associated with weight; BMI; and waist, hip, and trunk skin-fold measure (P < .0005). At 4-year follow-up, there were increases in weight (P < .0005), waist/hip ratio (P < .05), trunk skin-fold measurements (P < .005), and calcium intake (P < .05). In women who became late perimenopausal or postmenopausal, bone loss was associated with time in relation to the final menstrual period but not with other variables.
Conclusions: There are multiple risk factors for osteoporosis in this Australian-born population of midlife women, but only anthropometric variables were associated with BMD at baseline. Significant changes during the menopausal transition in anthropometric variables and calcium intake were in the direction that could decrease the risk of osteoporosis but were not found to affect menopausal bone loss.
As women age and experience the menopausal transition, the risk of developing osteoporosis increases. There are a number of other factors that have been reported to increase the risk of osteoporosis and may contribute to the marked heterogeneity in the rates of bone loss experienced by midlife women. Anthropometric measures of body size and composition, lifestyle, and gynecologic factors have all been shown to be associated with bone mineral density (BMD) and may contribute to the risk of developing osteoporosis. There is also some evidence that genetic factors may influence rates of bone loss. The prevalence of risk factors in an Australian-born population sample of midlife women and the changes, beneficial or otherwise, that occur in these risk factors as women pass through the menopausal transition have yet to be documented.
The aims of this study were the following: (1) to describe the prevalence of risk factors for osteoporosis in a population-based sample of Australian-born midlife women; (2) to determine the effect of these risk factors on premenopausal and early perimenopausal BMD and on bone loss associated with the menopausal transition; and (3) to describe changes in risk factors that occur during the menopausal transition and any effect of these changes on bone loss.
© 2000 Medscape
Cite this: Risk Factors for Osteoporosis: Prevalence, Change, and Association With Bone Density - Medscape - Oct 19, 2000.