1-Year stability and prediction of cardiovascular functioning at rest and during laboratory stressors in youth with family histories of essential hypertension

Abstract

Blood pressure (BP). heart rate, cardiac index, and total peripheral resistance index were measured at rest and in response to postural change, forehead cold stimulation, and a video game challenge in a sample of 128 White and 155 African-American normotensive youth with family histories of essential hypertension (EH). These measurements were readministered 1 year later (12.5 +/- 3.2 months). Moderate temporal stability was observed for all resting and absolute stress responses. Reliability estimates for reactivity change scores were lower, although some were within acceptable ranges. African-American youth exhibited greater BP and peripheral resistance index reactivity to forehead cold on both evaluations. After controlling for various anthropometric and demographic parameters and the pertinent previous year's resting cardiovascular (CV) parameter, mean video game systolic blood pressure (SBP) responses were predictive of resting SBP whereas absolute forehead cold and video game diastolic responses predicted resting diastolic blood pressure (DBP) 1 year later. Mean video game DBP responses were also predictive of resting peripheral resistance index after controlling for significant demographic and anthropometric measures. CV reactivity is discussed with regard to possible value in prediction of changes in resting BP and cardiac structure prior lo establishment of EH.

Hypertension in Black Patients

“…For example, Murphy et al 15 reported that black children and adolescents exhibit significantly higher blood pressure increase during a video game challenge. Similarly, Dysart et al 16 and Treiber et al 17 demonstrated that black children with a family history of essential hypertension manifest greater increases in total peripheral resistance, leading to greater increases in blood pressure in response to cold pressor test and the mental stress of playing a video game. Another group found that black children tended to have augmented pressor responses compared with white children during isometric hand-grip exercise and orthostatic testing.…”

Racial Differences in Endothelin-1 at Rest and in Response to Acute Stress in Adolescent Males

“…11,27 A total of 41 adolescent males (23 whites, 18 blacks; mean age 18.6 years) participated in the study. All subjects had a positive family history of EH, defined as having at least 1 parent and 1 grandparent with EH, as verified by the individuals' physicians.…”

“…Next, a 10-minute video game (Breakout; Atari, Inc) was presented under a monetary incentive challenge as described previously. 11 After a 20-minute recovery period, forehead cold stimulation was conducted by placing a plastic bag containing 1.5 cups of water and 6 cups of crushed ice on the subject's forehead for 1 minute. Then, 5-mL blood samples were drawn, and hemodynamics were concomitantly measured immediately on completion of each stressor and at minutes 15 and 20 during the recovery period that followed each stressor.…”

“…4 Although not entirely consistent, exaggerated blood pressure (BP) reactivity to brief laboratory stressors has been shown to be an independent predictor of future BP levels in youths and of EH in adults (see reviews [5][6][7]. Studies that involve normotensive adults 8,9 and youths 10,11 have found that blacks exhibit greater BP increases in response to acute stress than do whites and that these differences are frequently mediated by greater increases in total peripheral resistance (TPR).…”

“…26 Among youths with a positive family history of EH, blacks have been shown to exhibit greater vasoconstrictionmediated BP levels at rest or during acute stress than whites. 10,11 Thus, an examination of ET-1 levels in multiethnic samples of youths with family histories of EH may be particularly informative regarding possible racial differences in the underlying pathophysiology of EH. Based on previous findings indicating that ET-1 mediates vasoconstrictive tone and that blacks exhibit greater vasoconstriction-mediated BP at rest and during acute stress, it was hypothesized that blacks would experience greater vascular tone concomitant with increased plasma ET-1 levels at baseline and in response to 2 acute stressors known to elicit vasoconstriction-mediated BP increases.…”