Chenglong Zhang, Jing Lei, Xia Ke, Yang Tianlun
Central South University, Xiangya Hospital, Department of Cardiology, Changsha, Hunan/China.
Clinics (Sao Paulo). 2016 Jul;71(7):375-80. doi: 10.6061/clinics/2016(07)04.
Previous studies have demonstrated that both low and high hemoglobin concentrations are predictive of adverse cardiovascular outcomes in various populations. However, an association of hemoglobin with the ankle-brachial index, which is widely used as a screening test for peripheral arterial disease, has not yet been identified.
We examined 786 subjects (236 women and 550 men) who received routine physical check-ups. The ankle-brachial index and several hematological parameters, including the hemoglobin level, hematocrit and red blood cell count and other demographic and biochemical characteristics were collected. Univariate and multivariate linear regression analyses were performed to assess the relationships between the ankle-brachial index and the independent determinants. Receiver operating characteristic curve analysis was conducted to calculate the cut-off level of hemoglobin for detecting a relatively low ankle-brachial index (less than 20% of all subjects, which was 1.02).
The hemoglobin level, hematocrit and red blood cell count were correlated with the ankle-brachial index in the males (r=-0.274, r=-0.224 and r=-0.273, respectively, p<0.001 for all), but these associations were not significant in the females. Multivariate linear regression analysis revealed that the independent determinants of the ankle-brachial index included age, total cholesterol, high-density lipoprotein cholesterol and the white blood cell count for the females and age, hypertension, total cholesterol and hemoglobin (β=-0.001, p<0.001) for the males after adjusting for confounding factors. Receiver operating characteristic curve analysis revealed that the cut-off level of hemoglobin for predicting a low ankle-brachial index was 156.5 g/L in the males.
A high hemoglobin concentration was independently correlated with a low ankle-brachial index in the healthy males, indicating that an elevation in this level may be associated with an increased atherosclerosis risk.
既往研究表明，血红蛋白浓度过低和过高均预示着不同人群心血管不良结局。然而，尚未发现血红蛋白与踝臂指数之间的关联，而踝臂指数被广泛用作外周动脉疾病的筛查指标。
我们对786名接受常规体检的受试者（236名女性和550名男性）进行了检查。收集了踝臂指数和多项血液学参数，包括血红蛋白水平、血细胞比容、红细胞计数以及其他人口统计学和生化特征。进行单因素和多因素线性回归分析，以评估踝臂指数与各独立决定因素之间的关系。绘制受试者工作特征曲线进行分析，以计算用于检测相对较低踝臂指数（低于所有受试者的20%，即1.02）的血红蛋白临界值。
男性的血红蛋白水平、血细胞比容和红细胞计数与踝臂指数相关（分别为r = -0.274、r = -0.224和r = -0.273，p均<0.001），但这些关联在女性中不显著。多因素线性回归分析显示，校正混杂因素后，女性踝臂指数的独立决定因素包括年龄、总胆固醇、高密度脂蛋白胆固醇和白细胞计数；男性的独立决定因素包括年龄、高血压、总胆固醇和血红蛋白（β = -0.001，p<0.001）。受试者工作特征曲线分析显示，男性预测低踝臂指数的血红蛋白临界值为156.5 g/L。
在健康男性中，高血红蛋白浓度与低踝臂指数独立相关，这表明该水平升高可能与动脉粥样硬化风险增加有关。
