Djalali Mahmoud, Neyestani Tirang R, Bateni Jamil, Siassi Fereydoun
Tehran University of Medical Sciences, Department of Nutrition and Biochemistry, School of Public Health and Institute of Public Health Research Tehran, Iran.
Int J Vitam Nutr Res. 2006 May;76(3):132-7. doi: 10.1024/0300-9831.76.3.132.
Blood donation leads to substantial iron loss, as about 0.5 mg iron is lost per each milliliter of blood donated. If not compensated for efficiently, the iron loss may eventually lead to anemia, though non-anemic iron deficiency per se may be problematic. The aim of this study was to evaluate the effects of blood donation, and its frequency over a year's time, on iron status of Iranian male blood donors attended blood transfusion stations of the Iranian Blood Transfusion Organization (IBTO).
A cross-sectional, descriptive, and analytic study was conducted. 91 male volunteer blood donors aged from 20 to 50 years attending three IBTO stations located in central areas of Tehran, and 63 apparently healthy controls that were matched for age, gender, monthly income, height, and weight, were included in the study. Blood donors were divided into 4 groups according to the frequency of blood donation per year; i.e. 1, 2, 3, and 4 with 20, 30, 26, and 15 persons in each group, respectively. Just before blood donation, 10 mL venous blood sample was taken and divided into heparinized and non-heparinized tubes for determination of hemoglobin (Hb), hematocrit (Hct), serum iron (SI), total iron binding capacity (TIBC), ferritin, transferrin saturation (TS), and mean corpuscular hemoglobin concentration (MCHC). Dietary assessment was also done using 3 different questionnaires; i.e. general health, food frequency, and 24hr recall.
The levels of Hb, Hct, and iron status indices were all significantly lower in the subjects than in controls and a gradual but significant decrease in iron status indices in each time of blood donation was found. Serum ferritin showed significant correlations with age (r = 0.33, p < 0.001) and body-mass index (BMI) (r = 0.26, p = 0.03) only in the control group. Frequency of blood donation per year was also inversely correlated with Hb (r = -0.67, p < 0.001), Hct (r = -0.65, p < 0.001), MCHC (r = -0.56, p < 0.001), serum ferritin (r = -0.38, p < 0.001), SI (r = -0.62, p < 0.001), and TS (r = -0.61, p < 0.001), but was directly correlated with TIBC (r = 0.56, p < 0.001). Interestingly in blood donors, but not in healthy controls, serum ferritin levels showed weak but statistically significant correlations with daily intake of iron (r = 0.17, p < 0.05) and energy (r = 0.20, p = 0.03).
Though repeated blood donations might diminish iron status, it could be safe to donate 2-3 U/year without an appreciable incidence of iron deficiency, provided that the pre-donation Hb and ferritin values are >/= 14.7 g/dL and 58.9 mug/L, respectively. The male volunteers with Hb >/= 14.2 g/dL and serum ferritin >/= 57.2 mug/L could donate 1-2 U/year and those with Hb >/= 13.1 g/dL and serum ferritin >/= 35.3 mug/L could donate just once a year. Volunteers who undergo (repeated) blood donation should receive special nutritional care, especially in terms of iron and energy.
献血会导致大量铁流失，因为每捐献1毫升血液大约会流失0.5毫克铁。如果不能得到有效补充，铁流失最终可能导致贫血，尽管非贫血性缺铁本身也可能存在问题。本研究的目的是评估献血及其在一年时间内的频率对前往伊朗输血组织（IBTO）输血站的伊朗男性献血者铁状态的影响。
进行了一项横断面、描述性和分析性研究。研究纳入了91名年龄在20至50岁之间的男性志愿献血者，他们前往位于德黑兰市中心的三个IBTO站点，以及63名年龄、性别、月收入、身高和体重相匹配的明显健康的对照者。献血者根据每年献血频率分为4组；即每年献血1次、2次、3次和4次的组，每组分别有20人、30人、26人和15人。在献血前，采集10毫升静脉血样本，分别放入肝素化和非肝素化试管中，用于测定血红蛋白（Hb）、血细胞比容（Hct）、血清铁（SI）、总铁结合力（TIBC）、铁蛋白、转铁蛋白饱和度（TS）和平均红细胞血红蛋白浓度（MCHC）。还使用3种不同的问卷进行饮食评估；即一般健康问卷、食物频率问卷和24小时回顾问卷。
受试者的Hb、Hct和铁状态指标水平均显著低于对照组，并且发现每次献血时铁状态指标都有逐渐但显著的下降。仅在对照组中，血清铁蛋白与年龄（r = 0.33，p < 0.001）和体重指数（BMI）（r = 0.26，p = 0.03）呈显著相关。每年献血频率也与Hb（r = -0.67，p < 0.001）、Hct（r = -0.65，p < 0.001）、MCHC（r = -0.56，p < 0.001）、血清铁蛋白（r = -0.38，p < 0.001）、SI（r = -0.62，p < 0.001）和TS（r = -0.61，p < 0.001）呈负相关，但与TIBC呈正相关（r = 0.56，p < 0.001）。有趣的是，在献血者中，而不是在健康对照组中，血清铁蛋白水平与铁的每日摄入量（r = 0.17，p < 0.05）和能量摄入量（r = 0.20，p = 0.03）呈弱但统计学上显著的相关。
尽管反复献血可能会降低铁状态，但如果献血前Hb和铁蛋白值分别≥14.7 g/dL和58.9 μg/L，那么每年捐献2 - 3单位血液可能是安全的，缺铁发生率不会明显增加。Hb≥14.2 g/dL且血清铁蛋白≥57.2 μg/L的男性志愿者每年可以捐献1 - 2单位血液，而Hb≥13.1 g/dL且血清铁蛋白≥35.3 μg/L的男性志愿者每年只能捐献一次。接受（反复）献血的志愿者应接受特殊的营养护理，特别是在铁和能量方面。
