| Objective To compare the differences of bone mineral density (BMD) among postmenopausal women in different levels of exercise participation, and their BMD changes during 12 months. Methods 82 eligible community-dwelling postmenopausal women were recruited as the participants in this follow-up study. The participates were divided into two groups: exercise-standard Group (ESG, n=42) and non-standard exercise Group (NSG, n=40). The NSG group was then furtherly divided into non-exercise group (NOG) and occasional exercise group (OEG). Changes in BMD parameters include T-score, Z-score, Speed of Sound (SOS), and Broadband Ultrasound Attenuation (BUA) were monitored using a heel quantitative ultrasound (QUS) device. Meanwhile, the percentage at different risk levels of having osteoporosis in each group was calculated. Variables were measured at baseline, at 6-month and at 12-month follow-up. Results BMD parameters in the ESG group remained stable during 12 months (P>0.05). The percentage of having high risk of osteoporosis in ESG group was 16.7%, and remained unchanged. In the NSG group, the value of T-score (F=11.877, P=0.000), Z-score (F=7.459, P=0.002) and BUA (F=4.207, P=0.026) decreased significantly during 12 months. The percentage of having high risk of osteoporosis in NSG group increased from 20.0% to 30.0%. Changes of T-score revealed a significant main effect of group (F=4.268, P=0.042) and time (F=6.378, P=0.004). The values of BMD parameters in NEG group declined faster during 12 months than the OEG group. Conclusion Different levels of exercise participation can maintain the bone mineral density level of postmenopausal women or delay their aging loss.Constant and regular physical exercise can improve the condition of BMD among postmenopausal women. |