中文摘要
捐血，短時間內的血液大量流失，雖然是社會及醫學上認可的無害義舉，卻是對身體生理機能的一項挑戰。長期規則性的失血對身體的影響，國外的研究，從臨床的血鐵狀態檢驗到先進的基因體學，深入且層面寬廣。反觀台灣的捐血研究，多局限在傳染性疾病的預防或行為模式的分析，鮮見針對捐血者身體機能的整合性評估。本篇研究的目的在經由比對經常性捐血者和對照組的實驗數據，探討經常性捐血對人體生理機能的影響，也研究體鐵狀態和病理變化的相關性。
本研究乃橫斷面研究。民國九十九年十至十二月間，經由兩個採血點，蓃集中台灣62位經常性捐血者，及57位對照組的基本資料及血液、尿液，進行檢驗後納入統計分析。問卷填寫的項目包括性別、年齡、體重、身高、居住地、教育程度、經濟情形、飲食、生活習慣、營養素補充、月經史、避孕方式、生產史、過去現在病史、職業史、藥物使用、最近一年捐血次數及最近捐血日期；檢驗的項目則為血鐵狀態、肝腎功能、甲狀腺、營養狀態、電解質、金屬離子、骨替換標記等。
統計分析採SPSS(12.0版)套裝軟體。連續性變項採用學生 t 檢定評估或多元線性迴歸。類別變項採用卡方檢定或多元邏輯式迴歸。當雙尾檢定其機率值低於0.05時，視為有顯著的差異。
結果發現：實驗組八成的個案最近一年捐血超過兩次，樣本收集到最近的捐血日期九成逾兩星期。經常捐血者和國外的文獻報告最大的不同：血鐵狀態的數據顯現幾乎沒有貧血或鐵缺乏的個案。相反的，血鐵值在實驗組反而有意義的偏高。統計的結果另外發現，經常性捐血者其膽固醇、鉀離子、鋅離子，較對照組為有意義的偏高；造骨標記則反而降低。其他諸如年齡、身高、體重、身體質量指數、血色素、血比容、血糖、三甘酸油脂、肝腎及甲狀腺功能、尿酸、鈉、氯、鈣、總鐵結合能、含鐵蛋白、運鐵蛋白、蝕骨標記等則無明顯差別。另外，就對照組中比對血鐵狀態，男女間有明顯差異，男大於女。此差異在經常捐血組則變的較不明顯。
依結果推論，中台灣的經常捐血者，血鐵不降反升，而且血中膽固醇值偏高。此現象長期的影響，有待緊密觀察。再者，經常捐血誘發的骨髓造血反應可能導致造骨標記的偏低但蝕骨標記正常，會不會繼而發生骨鈣質的代謝異常，則有待進一步的研究。同理，鉀及鋅離子的偏高濃度、可能的機轉及後續影響也有待探討。
Abstract
Background:
Blood donation with large amount of blood loss within a short while, although regarded as harmless by the medical profession and accepted by the society, still poses a challenge to the health of the donor. The blood donation researches at Taiwan lacked comprehensive probing into the physical health of individual blood donor.
Aim:
This article was aimed to compare several laboratory parameters between central Taiwan regular blood donors and controls to weigh the impact of regular blood donation upon physiological function and to study the iron status related pathological changes.
Methods and Materials:
This is a cross-sectional study which recruited 62 regular blood donors who donated blood more than twice within the recent year and 57 controls via two sampling points in Taichung City, Taiwan from Oct till Dec 2010. Questionnaire including various items were answered. The urine and blood were collected and analyzed for iron status, hepatic and renal function, thyroid function, electrolytes, nutritional status, metal ions and bone turnover markers.
Statistics:
Statistical analysis was performed using SPSS 12.0 software (SPSS Inc, Chicago, IL). Student’s t-test and multiple linear regression were used for continuous variables. Chi-square test and multiple logistic regression were used for categorical situations. Fisher’s exact test was applied when small numbers were encountered. A two-tailed test of P<0.05 was considered significant.
Results:
More than 80% recruited donors donated more than two times within last year. The interval from sample collection to the most recent blood donation was at least 2 weeks among 90% donors.
The most remarkable difference with the literatures reviewed abroad was that there were nearly no cases of anemia nor iron deficiency detected among our regular blood donors. On the contrary, there were statistically significant signs of excess iron evidenced by serum iron and several other iron status parameters. The level of cholesterol, potassium and zinc were also higher for regular blood donors than controls with p value less than 0.05. On the contrary, the bone formation marker(BAP) was lower among the regular donors.
Moreover, there were marked differences between male and female controls in iron status values. This gender difference seemed blunted after regular blood donations.
Conclusion:
Serum iron excess and elevated cholesterol were found among central Taiwan blood donors. The long term effects of this phenomenon urge tight follow-ups. The impact of increased bone formation markers presumably the results of blood loss-induced erythropoiesis needs to be explored further.
