Effect of daity physical activity, bone mineral density, muscle thickness and urinary free-deoxypyridinoline on the prevention of fractures in middle-aged and elderly women.

本研究旨在探讨每日体力活动、肌肉厚度及尿中游离脱氧吡啶(Free-DPYR)排泄量对中老年妇女骨密度(BMD)及骨折预防的影响。在这些横断面和纵向研究中，我们采用双X射线骨密度仪测量腰椎和股骨的骨密度，用Osteon‘s骨分析仪单次X射线骨密度仪测量跟骨骨密度，用超声测量股骨肌肉厚度和尿中游离DPYR排泄量(ELISA法)。此外，我们还评估了健康中老年女性骨密度与日常体力活动的关系。得到了以下结果。1997年腰椎、跟骨、股骨骨密度与年龄呈负相关。尤其是跟骨、股骨颈和Ward‘s三角的骨密度呈显著正相关。此外，股骨肌厚度与年龄呈显著负相关。1998年，骨密度和肌肉厚度在一年内的变化显著减少。然而，自由-DPYR的值略高于初始值。此外，经常锻炼的受试者的BMD明显高于不经常锻炼的受试者。结果表明，结合BMD测量和骨吸收标记物(Free-DPYR)，除了建立日常体育活动和促进肌肉质量之外，还有助于改善对女性骨骼健康和骨折风险的评估。此外，体育活动和锻炼可能是防止肌肉质量和力量丧失的重要因素。

The purpose of this study was to examine the effect of daily physical activity, muscle thickness and urinary excretion of free-deoxypyridinoline (free-Dpyr) on bone mineral density (BMD) and the prevention of fracture in middle-aged and elderly women. In these cross-sectional and longitudinal studies, we measured the BMD in the lumbar spine and the femur using dual X-ray absorptiometry with Hologic's QDR-1500 and that in the calcaneus using single X-ray absorptiometry with Osteon's Osteoanalyzer and the femoral muscle thickness using ultrasonography and urinary excretion of free-Dpyr (ELISAmethod). In addition, we evaluated the relationship between BMD and daily physical activity in healthy middle-aged and elderly women. The following results wereobtained. In 1997, the BMD in the lumbar spine, the calcaneus and the femur showed a negative correlation with age. In particular, those in the calcaneus, the femoral neck and ward's triangle showed significant correlations. Moreover, the femoral muscle thickness showed a significant negative correlation with age. In 1998, the change in the BMD and muscle thickness over a 1-year period was significantly decreased. However, values of free-Dpyr were slightly higher than those of the initial value. In addition, subjects who exercised regularly had significantly higher BMD than those who did not.The results suggested that combining the measurement of BMD and bone resorptionmarker (free-Dpyr), in addition to establishing daily physical activity routinesand promoting muscle mass, are useful to improve the assessment of bone health and the risk of fracture in women. Moreover, physical activity and exercise may beimportant factors in preventing loss of muscle mass and strength.