不同身體負載運動對女性運動員骨質密度與骨骼代謝之影響

The Effects of Different Weight-Bearing Exercise on Bone Mineral Density and Bone Metabolism in Female Athletes

目的：探討不同身體負載運動習慣對女性運動員骨質密度及骨骼代謝之影響。方法：三十三名女性受試者，依性別、運動型態分成三組（跑步組n=11、游泳組n=10，控制組n=12）。運動組之受試者，皆為維持每週至少三次，並持續三年以上的跑步或游泳訓練。控制組則是在一年內無規律運動習慣者。受試者接受雙能X光吸收儀（DEXA）的測量，以檢測全身及手臂、雙腳、肋骨、骨盆、脊椎、腰椎、股骨頸等身體各部位之骨質密度；並接受一次最大攝氧量的測試運動後，測量游離鈣、血鈣、副甲狀腺素、降鈣激素、骨鈣素、前膠原胺基端前胜月太（PINP）和梭基末端胜月太第一膠原（ICTP）等骨骼調節鈣離子激素及代謝指標在運動前後的變化。以單因子變異數分析（one-way ANOVA）及二因子共變數分析（two-way ANCOVA）比較各依變項的變化。結果：跑步組全身及各部位的骨質密度均顯著高於控制組（p<.05）；在脊椎、骨盆、雙腳、腰椎、股骨頸、沃氏三角及股骨粗隆等部位亦顯著高於游泳組（p<.05）。游泳組則僅是在手臂部位顯著高於控制組（p<.05）。在平時骨質代謝指標為代表骨質合成的骨鈣素跑步組與游泳組顯著高於控制組（p<.05），骨骼吸收指標各組間無顯著差異；運動後游泳組副甲狀腺素的改變量顯著高於控制組（p<.05），骨質代謝變化量則是跑步組的骨鈣素顯著高於游泳組、控制組（p<.05），游泳組則與控制組間無顯著差異。結論：游泳運動者在運動後副甲狀腺上昇，不利於骨質合成，造成運動後游泳組骨鈣素的下降，可能影響游泳運動者的骨質密度。跑步組為本研究中攝氧量最高、骨質密度最佳的一組，在平時與急性運動後代表骨質合成的骨鈣素上昇幅度最大，對於骨質的合成無論在身體負載之機械負荷或生化代謝方面均較各組有最佳的貢獻。

Purpose:To examine the effects of different weight-bearing exercise on bone mineral density and markers of bone turnover in female athletes. Method: Thirty-three female subjects were assigned into 3 groups with age-,weight-, and height-matched and according to their exercise type (runner n=11, swimmers n=10 and control group n=12). Subjects in experimented groups were asked to exercise at least three times a week and have at least three years of running and swimming training. As for control group, subjects must not have exercise regularly within a year. Duel-energy X-ray absorptiometry (DXA) was used to measure subjects' arms, legs, ribs, pelvis, lumbar spine, femoral neck, and total body bone mineral density (BMD). Subjects were asked to perform endurance exercises (V.O2 max). The blood pH, total serum calcium, ionized calcium, parathyroid hormone (PTH), calcitonin (CT), osteocalcin, intact N-terminal propeptide of type I collagen (PINP), and carboxyterminal telopeptide of type I collagen (ICTP) were measured before and after exercise. One-way ANOVA and two-way ANCOVA were used for data analysis. Results: (1) The BMD of runner was significantly higher than the control group in total body and site-specific BMD (p<.05). The runners' spine, pelvis, legs, lumbar spine, and total body BMD were significantly higher than the swimmers (p<.05).(2) The osteocalcin of bone formation marker in runner and swimmer were significantly higher than the control group (p<.05). The marker of bone resorption was not different between groups before and after exercise. (3) The osteocalcin of bone formation marker in the runners was significantly higher than the swimming group (p<.05). Conclusions: The PTH increased after exercise and force out the ionized calcium from the bone which has negative effect on bone formation for the swimmers. The running group has the highest V.O2 max and the best of bone density, and the osteocalcin also ascend significantly after regular or acute exercise which contribute to good bone formation ether use weight-bearing, mechanical loading or biochemical markers.