ANTECEDENTS OF THE TYPE A BEHAVIOR PATTERN

我们研究项目的持续目标是：(a)确定儿童和青少年心血管（CV）疾病行为风险因素的早期出现；(b)详细说明其前因后果。我们目前的项目测试了性别和种族的影响，发现行为和生物风险因素在儿童中聚集在一起，导致一些儿童的总体负担很大，而单独研究单个风险因素的发展并不明显。基于我们目前的研究结果，我们提出社会经济地位（SES）和种族的影响是相互交织的，部分原因是更大的环境压力，特别是社会冲突。反复暴露在社会冲突中会促使人们对可能的威胁保持警惕，将模棱两可的情况视为潜在的危害，不信任他人，并在潜在威胁期间表现出较高的CV反应。我们认为，随着青春期的发展，这些倾向变得更加自动和可重复，从而导致稳定的倾向。反过来，性格可能影响心血管风险的标志物，即总血压负担、主动脉僵硬度和左心室质量。这些选择是为了利用最近的技术改进和对心血管风险发展的理解。为了检验这些建议的关系，我们将招募100名青少年非裔美国人和100名白人，根据父母的教育和职业，每个种族群体中社会经济地位高低的人数大致相等。每位参与者将在一个上午完成一份心理生理学实验室协议、问卷调查、颈动脉扫描和超声心动图，并在两个上学日进行动态血压监测，并在每次测量时对压力情况进行日记评分。本设计允许我们测试SBS和社会压力对行为危险因素发展的影响，并测试行为危险因素在多大程度上介导青少年社会人口因素、压力和CV标记之间的关联。

The ongoing goals of our research program are: (a) to establish the early emergence of behavioral risk factors for cardiovascular (CV) disease in children and adolescents; and (b)to specify their antecedents and consequences. Our current project, which tested the influence of gender and ethnicity, found that behavioral and biological risk factors cluster together in children, resulting in a substantial overall burden among some children that is not apparent by studying the development of individual risk factors alone. Building on our current findings, we propose that the effects of socioeconomic status (SES) and ethnicity are intertwined, and are partly due to greater exposure to environmental stress, especially social conflict. Repeated exposure to social conflict encourages the development of a propensity to be vigilant for possible threat, to view ambiguous situations as potentially harmful, to mistrust others, and to exhibit elevated CV reactivity during potential threat. We suggest that these propensities become more automatic and repeatable with adolescent development, leading to stable dispositions. Dispositions, in turn, may influence markers of CV risk, namely total blood pressure burden, aortic stiffness, and left ventricular mass. These were chosen to taken advantage of recent technological improvements and advances in understanding the development of CV risk. To test these proposed relationships, we will recruit 100 adolescent African American and 100 Whites, with approximately equivalent numbers of upper and lower SES based on parental education and occupation within each ethnic group. Each participant will complete a psychophysiological laboratory protocol, questionnaires, carotid scan and echocardiogram in a single morning session, and two school days of ambulatory blood pressure monitoring accompanied by diary ratings of stressful circumstances at the time of each measure. This design allows us to test the influence of SBS and social stress on the development of behavioral risk factors and to test the extent to which behavioral risk factors mediate associations between sociodemographic factors, stress, and CV markers in adolescents.