Zheng Haoyi, Patel Milan, Cable Ritchard, Young Lawrence, Katz Stuart D
Section of Cardiovascular Medicine, Department of Internal Medicine, Yale School of Medicine, 135 College St., New Haven, CT 06510, USA.
Diabetes Care. 2007 Oct;30(10):2685-9. doi: 10.2337/dc07-0748. Epub 2007 Jul 13.
Reduced iron stores after blood donation are associated with improved vascular function and decreased cardiovascular risk. We sought to determine whether iron-dependent changes in glucose metabolism may contribute to improved vascular function in blood donors.
We conducted a prospective cross-sectional study in 21 high-frequency blood donors (more than eight donations in the last 2 years) and 21 low-frequency blood donors (one to two donations in the last 2 years) aged 50-75 years. Serum markers of iron stores, whole-body insulin sensitivity index (WBISI) during oral glucose tolerance testing, and flow-mediated dilation in the brachial artery were determined in all subjects.
Serum ferritin was decreased (median values 23 vs. 36 ng/ml, P < 0.05) and flow-mediated dilation in the brachial artery was increased (median values 5.9 vs. 5.3%, P < 0.05) in high-frequency donors compared with low-frequency donors, respectively, but WBISI (median values 4.8 vs. 4.7) and related measures of glucose tolerance did not differ between groups. Flow-mediated dilation significantly decreased at 1 h after oral glucose loading in both groups, but the decrease in flow-mediated dilation at 1 h did not differ between high- and low-frequency donors.
High-frequency blood donation reduced serum ferritin and increased flow-mediated dilation compared with low-frequency donation but did not improve insulin sensitivity or protect the vascular endothelium from the adverse effects of acute hyperglycemia after oral glucose loading. These findings suggest that the mechanisms linking blood donation to improved vascular function are not likely related to changes in glucose metabolism.
献血后铁储备减少与血管功能改善及心血管风险降低相关。我们试图确定葡萄糖代谢中铁依赖性变化是否有助于献血者血管功能的改善。
我们对21名高频献血者（过去2年中献血超过8次）和21名低频献血者（过去2年中献血1 - 2次）进行了一项前瞻性横断面研究，这些献血者年龄在50 - 75岁之间。测定了所有受试者的铁储备血清标志物、口服葡萄糖耐量试验期间的全身胰岛素敏感性指数（WBISI）以及肱动脉的血流介导的扩张。
与低频献血者相比，高频献血者的血清铁蛋白降低（中位数分别为23 vs. 36 ng/ml，P < 0.05），肱动脉血流介导的扩张增加（中位数分别为5.9 vs. 5.3%，P < 0.05），但WBISI（中位数分别为4.8 vs. 4.7）以及葡萄糖耐量的相关指标在两组间无差异。两组口服葡萄糖负荷后1小时血流介导的扩张均显著降低，但高频和低频献血者在1小时时血流介导的扩张降低幅度无差异。
与低频献血相比，高频献血降低了血清铁蛋白并增加了血流介导的扩张，但未改善胰岛素敏感性，也未保护血管内皮免受口服葡萄糖负荷后急性高血糖的不利影响。这些发现表明，将献血与血管功能改善联系起来的机制不太可能与葡萄糖代谢的变化有关。
