心臟移植後骨密度之性別差異

Gender Differences in Bone Mineral Density after Heart Transplantation

研究背景與目的：心臟移植後病人常有骨量不足與骨折現象，本研究目的即在比較心臟移植後男、女性病患的骨密度，並探討影響之相關因素。方法：本研究之受試者是在台大醫院接受心臟移植的14位男性和7位女性病患，分別在移植後25.6±15.9月、39.9±20.7月接受雙能量X射線吸收測量計(dual energy X-ray absorptiometry, DEXA)檢測他們的腰椎(L2-L4)以及右側股骨頸及股骨髁之骨密度，並同時測量其最大攝氧量、股四頭肌之肌力、耐力、身體組成，並做鈣質攝取量及日常活動量的評估。結果：不論男性或女性之心臟移植患者，其腰椎、股骨頸平均骨密度之T-scores和Z-scores均為負值。男性與女性的Z-scores無明顯差異，女性腰椎骨密度的T-scores平均為-2.15 ±0.87，股骨頸為-1.31 ±1.01。女性之最大運動量、股四頭肌之肌力、日常活動量及非脂肪重量的絕對值均較男性明顯為低，肌力、日常活動量以體重校正後，則無明顯差異。腰椎、股骨頸及股骨髁之骨密度與心臟移植後時間均具負相關性(r = -0.50, -0.54, -0.47)，股骨頸與股骨髁之骨密度則與非脂肪組織重量呈正相關性(r = 0.51, 0.71)。結論：心臟移植後男性與女性病患的股骨頸以及女性腰椎之骨密度均有骨量不足現象，與同年齡相較，男性與女性病患無明顯差異。心臟移植病患除腰椎之骨密度和非脂肪組織重不具有意義之相關，其餘均與移植後時間和非脂肪組織重具有意義之相關性。

Background and Purpose. Fractures are common complications for patients after heart transplantation. The purpose of this study was to test bone mineral density(BMD) in patients who had undergone heart transplantation at National Taiwan University Hospital, and compare the difference in the decrease of BMD between male and female patients. Methods: Twenty-one heart transplant recipients (14 men and 7 women) participate in this study. The BMD of the spine (L2–L4), right femoral neck, and right femoral condyle of each subject was examined by dual X-ray absorptiometry (DEXA). Measurements of maximal exercise test, muscle strength, endurance, body composition and a questionnaire their calcium intake and daily energy expenditure were obtained from each subject. Results. The BMD at all three sites were negatively correlated with the duration after transplantation, while the BMD of the femoral neck and condyle were positively associated with fat free mass. The average T-score of L2-L4 was -2.15 ±0.87, and was -1.31 ±1.01 at the femoral neck for female patients. Female patients had lower absolute values of maximal work load, muscle strength, daily energy expenditure, and fat free mass than male patients. No gender differences in muscle strength and daily energy expenditure after being adjusted by body weight were found. Conclusion. The BMD of the lumbar spine (L2–L4) of female patients was below one SD of the mean of premenopausal women. Both genders were osteopenic at femoral neck. The BMD in heart transplant recipients was negatively associated with duration after transplantation. In addition, the BMD of right femoral neck and femoral condyle was positively correlated with fat free mass.