DESIGN NARRATIVE:
Beginning in 1980, the longitudinal study examined the Type A behavior pattern, hostility, physiological responses and family interactive behaviors in primarily white, upper-middle class children and parents. The study was renewed several times. In the fiscal year 1992 renewal, the research was extended to include the study of Black children and those from lower-middle to middle class families. The inclusion of these groups is important not only because these they have been understudied, but also because an examination is needed of developmental factors that may be important in accounting for the much higher incidence of hypertension and related disorders in Blacks and in lower and lower-middle class groups. The current study examines the patterns of cardiovascular responses exhibited by Black and white children in order to better assess hemodynamic and autonomic nervous system mechanisms that underlie these responses. It also examines how these hemodynamic patterns relate to cardiovascular risk factors such as body fat distribution, left ventricular geometry (via echocardiography), as well as insulin, glucose, and lipid levels and it explores a new conceptualization of hostility indices and cardiovascular risk factors.
A total of 184 Black and white children and adolescents of both genders are recruited for participation, half being pre-pubescent (9-10 years old) and half being post-pubescent (15-16 years old). The first laboratory session consists of a fasting venous blood draw, collection of anthropomorphic data, a psychophysiological stress protocol involving four tasks selected to elicit different autonomic nervous system responses, and completion of standardized questionnaires to assess hostility and social support. A second session involves an echocardiographic assessment of left ventricular geometry and cardiac performance variables, the Type A Structured Interview, and an interview examining how subjects process information about hostile intentions and actions of others.
The study has been extended through August 2007 to re-assess adolescents enrolled in Project Pressure three years after their initial assessment to address key hypotheses regarding the early emergence of behavioral risk factors for cardiovascular disease (CVD) in adolescence and their antecedents and consequences. In the initial phase of Project Pressure, the investigators collected data from 217 black and white, male and female high school students to test cross-sectionally a model of the development of CVD risk factors. Their model suggests that adolescents' socioeconomic status and ethnicity affect their exposure to psychological stress, including discrimination, which, in turn, is thought to lead to the development of the propensity to be vigilant for possible threat, to view ambiguous situations as potentially harmful, and to mistrust others. These cognitive propensities may become more automatic with development and lead to stable traits of hostility, anxiety, and heightened cardiovascular responsivity to stress. These traits may then affect the early development of vascular stiffness and left ventricular mass. They now propose to test the model longitudinally using the same measures as in the initial assessment, plus adding some new measures that take advantage of recent technological and conceptual advances: (a) endothelial dysfunction and carotid intima medial thickness; (b) coping with discrimination and ethnic identity; and (c) depression. They anticipate that 165 of the previous adolescents will be reassessed, which is adequate in terms of power to test our key hypotheses. The longitudinal design will be a stronger test of the model than the previous cross-sectional study.
