男性脊髓損傷患者骨質疏鬆與血清瘦素及激素之關係(2/2)

Abstract

骨質疏鬆是最常見的骨頭代謝疾病，造成結構易脆性與骨折危險性，臨床上，脊髓 損傷後常快速發生嚴重的骨質疏鬆問題。而骨質密度檢查是預防、診斷與處理該問題重 要的工具，目前雙能量X 光骨密度儀是測量骨質密度最廣泛使用的方法。臥床不動、失 用、血流變化、激素變化都可能與脊髓損傷後骨流失有關。骨更新率在脊髓損傷後有增 加現象，可見骨再吸收增加而骨形成也有變化。瘦素係主要由脂肪細胞所分泌之小多胜 激素，它可透過與下視丘特異受器結合來控制體重及性腺功能。脊髓損傷患者之血清瘦 素濃度明顯升高，而血清瘦素濃度與身體質量指數呈現線性關係，且與血清皮醇濃度相 關，因此交感神經失能及中樞神經傳導物質變化都可能導致患者血清瘦素升高。 在這兩年之研究，我們探討脊髓損傷男性骨質疏鬆與血清瘦素及各種激素之相關 性。我們以雙能量X 光骨密度儀來測量受測者第六到第八胸椎、第二到第四腰椎及左髖 部之骨質密度，另以放射免疫法測定其血清，包括瘦素在內各種激素濃度。結果四肢癱 瘓患者的胸椎骨密度明顯低於下肢癱瘓患者，但各種血清激素或因子，包括骨性鹼磷酸 鹽、促白血球素6、C 反應蛋白質、第一型膠原碳端尾肽胜、瘦素、皮醇、類似胰島素 生長因子1、腎上腺皮促素、第四甲狀腺素、第三甲狀腺素、甲促素、睾固酮及生長激 素，在兩組病人之間並無有意義的差異。看來承重是影響骨質密度的重要因素，而各種 激素或因子的角色則需進一步分析及探討。

Osteoporosis is the most common metabolic disease of bone with increased structural fragility and fracture risk. SCI is associated with the development of a rapid and severe osteoporosis clinically. Bone mineral density (BMD) is an important tool in the prevention, diagnosis and management of osteoporosis. Dual energy X-ray absorptiometry has become the most widespread method of monitoring BMD. Immobilization, disuse, vascular changes and hormonal changes maybe responsible for the bone mineral loss after SCI. BMD of the lumbar spine was within the range of normal values and the BMD of femoral neck, shaft and proximal tibia was lower than normal values. Increased bone turnover is a sequel of SCI and a marked increase in bone resorption and modest changes in bone formation occur after SCI. II Leptin is a small polypeptide hormone secreted primarily by the adipocytes. It controls body weight and gonadal function following its binding to a specific receptor located in the hypothalamus. Serum leptin was significantly higher in the group of SCI. A linear correlation was found between serum leptin and bone mass index and serum cortisol correlated significantly with serum leptin level in SCI patients. Sympathetic denervation and possible central neurotransmission alternations after SCI may contribute to the elevation of serum leptin. In this two-year study, we investigated the relationship among osteoporosis, serum leptin, and various hormone levels in men with SCI. A dual energy X-ray absorptiometry is used to measure the BMD in the area of 6th to 8th thoracic vertebrae, 2nd to 4th lumbar vertebrae and left hip. Various baseline hormone levels, including serum leptin, will be measured by RIA. We found the BMD of thoracic vertebrae in tetraplegic patients is significant lower than that of paraplegic patients. There are no significant difference of various baseline hormone levels, including bone-ALP, IL-6, CRP, ICTP, leptin, cortisol, IGF-1, ACTH, T4, T3, TSH, prolactin, testosterone, GH between tetraplegic and paraplegic patients. It seems that weight-bearing is the important factor in affecting the BMD. The effect of various hormones or factors must be further analyzed and investigated.