Medical assessments and measurements in ELSA-Brasil

The article describes assessments and measurements performed in the Brazilian Longitudinal Study for Adult Health (ELSA-Brasil). Some assessments including anthropometric assessment, casual blood pressure measurement, and ankle-brachial index have an established clinical application while others including pulse wave velocity, heart rate variability, and carotid intima-media thickness have no established application and do not have reference values for healthy Brazilian population but may be important predictors of cardiovascular outcomes. Blood pressure measurement following postural change maneuver was included in the ELSA-Brasil because it has not been much tested in epidemiological studies. Innovative approaches were developed for assessing the ankle-brachial index using an automatic device instead of the mercury column to measure blood pressure and for assessing the anterior-posterior diameter of the right lobe of the liver by ultrasound for quantitative assessment of nonalcoholic fatty liver disease. All ELSA-Brasil subjects were younger (35 years or more) than those included in other cohorts studying subclinical atherosclerosis. The inclusion of younger individuals and a variety of assessments make the ELSA-Brasil a relevant epidemiology study nationwide and worldwide.本文阐述了巴西成人健康纵向研究（ELSA-Brasil）中开展的各类评估与测量工作。部分评估项目已具备成熟的临床应用场景，包括人体测量评估、偶测血压测量以及踝臂指数（ankle-brachial index）检测；而另一部分评估项目，如脉搏波速度、心率变异性以及颈动脉内膜中层厚度（carotid intima-media thickness），则尚未确立标准化临床应用规范，且缺乏针对巴西健康人群的参考值，但它们或可作为心血管不良结局的重要预测因子。研究纳入了体位改变后的血压测量项目，原因在于此类测量在流行病学研究中尚未得到充分验证。本次研究开发了两项创新评估方法：一是采用自动化设备替代汞柱式血压计进行踝臂指数检测；二是通过超声扫描测量肝脏右叶前后径，以实现非酒精性脂肪性肝病（nonalcoholic fatty liver disease）的定量评估。ELSA-Brasil的所有研究对象年龄均为35岁及以上，相较于其他针对亚临床动脉粥样硬化的队列研究，其纳入的研究对象更为年轻。纳入年轻研究对象并设置多样化评估项目，使得ELSA-Brasil成为一项兼具全国与全球影响力的重要流行病学研究。