Abstract
Both cardiovascular reactivity (CVR) and ambulatory blood pressure (ABP) have been used for prediction and identification purposes in healthy and at-risk youth. The relationship between CVR and ABP, however, provide evidence for the reactivity hypothesis. When studying the ability of CVR to predict ABP, research tends to show modest effects in youth. The use of multi-level modeling and the inclusion of recovery from stressors as a predictor of ABP, techniques successfully used in adults in previous research, will allow for a fuller examination of these relationships. This study intends to use latent growth curve modeling of reactivity as well as the inclusion of recovery to explore the reactivity hypothesis in youth. 122 adolescents( 91 boys, 31 girls; mean age 16.1), identified as having or not having elevated blood pressure, wore ambulatory blood pressure monitors for 24 hours and completed a cold pressor task as part of a larger study examining characteristics of youth. Within the structural part of the model, BMI and positive family history of hypertension were expected to be entered as predictors of baseline blood pressure, cardiovascular reactivity, cardiovascular recovery and ABP. Regarding our exogenous variables, significant relationships were noted between baseline blood pressure and BMI, baseline blood pressure and family history and diastolic recovery and family history. While reactivity and recovery were successful modeled, neither were found to predict ABP. Baseline blood pressure was the only significant predictor of ABP observed. Possible reasons for the inability to predict ABP using reactivity during and recovery from the cold pressor task are discussed. Methodological (i.e. the use of different stressors, additional readings, techniques for increasing reliability) as well as theoretical considerations (i.e., inclusion of other physiological stress response mechanisms) could help direct future studies. This study continued to highlight the complex nature of understanding and generalizing cardiovascular responses in youth.