The relationship between body mass index and physical activity levels in relation to bone mineral density in premenopausal and postmenopausal women

Abstract

We prospectively analyzed 283 women to evaluate the effects of body mass index (BMI) and physical activity levels on bone mineral density (BMD) progression in pre- and postmenopausal women over 2 years. In postmenopausal women, lower BMI was linked with worsening BMD, and moderate activity levels were associated with a lower likelihood of worsening BMD at 2 years. The aim of our study is to evaluate the effects of BMI and physical activity levels on BMD progression in pre- and postmenopausal Asian women over 2 years. We prospectively analyzed 283 women from 2006 to 2009. They were divided into two groups (159 pre- and 124 postmenopausal) and analyzed separately to avoid confounding by age and menopausal hormonal status. The mean follow-up period was 771 days. Demographic data was obtained, including medical history, calcium supplementation, BMI, and physical activity levels (IPAQ scale). Bilateral femoral neck BMD was determined at the time of recruitment, 1 year, and after 2 years. Generalized linear modeling was used to evaluate the effects of BMI and physical activity levels on BMD progression over a 2-year period. Amongst premenopausal women, lower initial femoral neck BMD scores were linked to worsening BMD (p = 0.048). In postmenopausal women, lower BMI was linked with worsening BMD (p = 0.012). Postmenopausal patients with moderate activity levels had a lower likelihood of worsening BMD at 2 years (p = 0.038). High physical activity levels were linked to a lower risk of BMD worsening (p = 0.066). Higher BMI scores are protective for osteoporosis in postmenopausal women. Moderate levels of physical activity are beneficial for bone health in postmenopausal women, while low physical activity levels are not helpful. We recommend that, in the secondary prevention of osteoporosis, postmenopausal women should be encouraged to participate regularly in moderate physical activities. A practical approach would be walking 30 min a day for at least 5 days per week.