African Americans (AAs) experience a high prevalence and early onset of essential hypertension (EH), which has been partly attributed to exposure to chronic environmental stress. AA youth exhibit higher resting BP than Whites. Since BP ranking tracks from late childhood onward, AA adolescents with high normal BP are at increased risk for development of EH. Need for development of effective primary prevention programs for EH is highlighted by the fact that EH is now a pediatric problem due to recent increased prevalence among youth. To date, there have been no controlled studies evaluating stress reduction approaches on BP control in AA youth, particularly within the framework of an underlying psychological and physiological based model of stress-induced EH. This proposal will examine the effects of 2 behavioral stress reduction programs, mindfulness meditation (MM) and the Lifeskills Program (LP), and a health education control program (CTL) on cardiovascular function at rest, during laboratory stress and in the natural environment. Subjects will be 320 ninth graders (50% male) with high normal systolic BP (i.e., SBP from greater than or equal to 85th percentile to less than or equal to 95th percentile on 3 occasions). Following BP screenings and baseline evaluation, subjects will be assigned to a CTL, MM, LP or MM and LP group. Subjects will be reevaluated after a 12-week intervention and again at a 12 week follow-up.
Specific aims are to determine whether MM and/or LP results in:(1) decreases in the primary outcome variables of resting SBP and 24-hour ambulatory SBP; (2) decreases in sympathetic nervous system (SNS) tone (i.e., decreased overnight urine norepinephrine [NE] excretion) and decreases in sodium intake (i.e., decreased overnight sodium excretion); (3) decreases in SBP reactivity to behavioral stressors; (4) decreases in SNS arousal (i.e., decreased urinary NE excretion) and greater increases in renal function (i.e., increased urinary sodium excretion) to the behavioral stressors; (5) decreases in self-reported hostility and anger; (6) improvement in vascular function (i.e., increases in % endothelium dependent arterial vasodilation to reactive hyperemia); (7) improvement in ventricular structure and function (i.e., decreases in left ventricular mass index and resting heart rate). It is anticipated that the combination of MM and LP will result in even greater positive impacts than either treatment alone. The study will be conducted during health classes at school by teachers. If shown to be successful, incorporation of these programs into the regular school curriculum is quite feasible.
