Blood pressure and pulse responses to three stressors: associations with sociodemographic characteristics and cardiovascular risk factors

Pre-pregnancy stress reactivity and pregnancy outcome

Stress has been proposed as a cause of preterm birth (PTB) and small-for-gestational age (SGA), but stress does not have the same effects on all women. It may be that a woman's reaction to stress relates to her pregnancy health, and previous studies indicate that higher reactivity is associated with reduced birthweight and gestational age. The objective of this study was to examine the relationship between pre-pregnancy cardiovascular reactivity to stress and pregnancy outcome. The sample included 917 women in the Coronary Artery Risk Development in Young Adults Study who had cardiovascular reactivity measured in 1987-88 and at least one subsequent singleton livebirth within an 18-year period. Cardiovascular reactivity was measured using a video game, star tracing and cold pressor test. Gestational age and birthweight were based on the women's self-report, with PTB defined as birth <37 weeks' gestation and SGA as weight <10th percentile for gestational age. Linear and Poisson regression and generalised estimating equations were used to model the relationship between reactivity to stress and birth outcomes with control for confounders. Few associations were seen between reactivity and pregnancy outcomes. Higher pre-pregnancy diastolic blood pressure (adjusted relative risk 1.14; 95% confidence interval [CI] 0.98, 1.34) and mean arterial pressure reactivity (1.15; 0.98, 1.36) were associated with risk of PTB at first pregnancy, while SGA was associated with lower systolic blood pressure reactivity (0.76; 0.60, 0.95). No associations were seen with other measures of reactivity. Contrary to hypothesis, the association between heart rate reactivity and PTB in first pregnancy was stronger in whites (adjusted relative risk 1.39; 1.03, 1.88) than in blacks (1.00; 0.83, 1.20; P for interaction = 0.08). Similar results were found for mean arterial pressure. No strong associations were found between higher pre-pregnancy stress reactivity and SGA or PTB, and stress reactivity did not have a stronger association with birth outcomes in blacks than whites.

Dehydration does not influence cardiovascular reactivity to behavioural stress in young healthy humans

Enhanced hydration increases the human cardiovascular reactivity to mental stress. If reduced water intake has the opposite effect, this would suggest controlling for water deprivation when studying such responses. Blood pressure, heart rate and parasympathetically dominated beat-to-beat heart rate fluctuations were assessed during resting baseline and mental stress. Two challenging cognitive-motor tasks, a 5-Choice Reaction Time Task (CRTT) and a Paced Auditory Serial Addition Task (PASAT), served as mental stress tests. Eight female and eight male volunteers were examined twice, after 24 h of water deprivation and after normal water intake (counterbalanced order, 7-day interval). Water deprivation resulted in moderate dehydration with a mean 2.6% decrease of total body weight. Dehydration did neither affect baseline blood pressure, heart rate, nor blood pressure reactivity to mental stress. However, dehydration slightly (-1.2 bpm) diminished heart rate reactivity to the PASAT (P = 0.03) and increased beat-to-beat heart rate fluctuations in response to the CRTT (P = 0.05). Dehydration intensified CRTT- and PASAT-induced reductions of beat-to-beat heart rate fluctuations in females (gender x dehydration interactions: P = 0.04-0.05). Moderate dehydration induced by water restriction has no effect on blood pressure reactivity to mental stress. The effects on heart rate reactivity are small. However, stress-induced parasympathetic withdrawal may be fortified during dehydration in females, which suggests controlling for water intake when studying such responses.

Interactive effects of perceived racism and coping responses predict a school-based assessment of blood pressure in black youth

BACKGROUND

Research indicates that perceived racism and coping responses are associated with basal blood pressure (BP) levels and BP reactivity in Black adults. No study could be found, however, that has explored the independent and interactive effects of perceived racism and coping responses in a cohort who probably has the greatest risk of developing primary hypertension--Black youth.

PURPOSE

This study examined the relationship of perceived racism and coping responses to a continuous measure of BP and to a categorical measure of BP status (normal vs. high-normal or high).

METHODS

The convenience sample consisted of 217 Black youth (M age = 11.4 years, SD = 1.3). Participants reported on perceived racism and coping responses (Accepting It, Self-Blame, Taking Action, and Talking to Someone). BP was assessed with an automated monitor in school.

RESULTS

Approximately 32% of the sample had average BP levels that were high-normal or high. Hierarchical linear and logistic regression analyses were used to assess the predictive utility of perceived racism and the four coping responses to the continuous and categorical BP assessments. Although perceived racism and the coping response variables did not emerge as significant independent predictors in the linear or logistic regression analyses, perceived racism interacted with Accepting It (p = .009) in the linear regression analysis predicting systolic BP. Follow-up linear regression analyses indicated that perceived racism was not significantly associated with systolic BP among participants low in Accepting It but was inversely related to systolic BP among participants high in Accepting It. Perceived racism also interacted with Accepting It (p = .016) and Talking to Someone (p = .0009) in the logistic regression analysis predicting BP status. Follow-up logistic regression analyses revealed that (a) perceived racism was not significantly associated with BP status among participants low in Accepting It but was inversely related to BP status among participants high in Accepting It, and (b) perceived racism was inversely associated with BP status among participants low in Talking to Someone but was not significantly related to BP status among participants high in Talking to Someone.

CONCLUSIONS

The contribution of environmental and psychosocial factors to hypertension risk should be considered when exploring correlates of continuous and categorical assessments of BP in Black youth.

Quantitative genetic analysis of blood pressure reactivity to orthostatic tilt using principal components analysis

Blood pressure (BP) reactivity to orthostatic tilt may be predictive of cardiovascular disease. However, the genetic and environmental influences on BP reactivity to tilt have not been well examined. Identifying different influences on BP at rest and BP during tilt is complicated by the intercorrelation among multiple measurements. In this study, we use principal components analysis (PCA) to reduce multivariate BP data into components that are orthogonal. The objective of this study is to characterize and examine the genetic architecture of BP at rest and during head-up tilt (HUT). Specifically, we estimate the heritability of individual BP measures and three principal components (PC) derived from multiple BP measurements during HUT. Additionally, we estimate covariate effects on these traits. The study sample consisted of 444 individuals, distributed across four large families. HUT consisted of 70 degrees head-up table tilting while strapped to a tilt table. BP reactivity (deltaBP) was defined as BP during HUT minus BP while supine. Three PC extracted from the PCA were interpreted as 'general BP' (PC1), 'pulse pressure' (PC2) and 'BP reactivity' (PC3). Variance components methods were used to estimate the heritabilities of resting BP, HUT BP, deltaBP, as well as the three BP PC. Significant (P<0.05) heritabilities were found for all BP measurements, except for systolic deltaBP at 1 and 3 min, and diastolic deltaBP at 2 min. Significant genetic effects were also found for the three PC. Each of these orthogonal components is significantly influenced by somewhat different sets of covariates.

Decreased pituitary response to insulin-induced hypoglycaemia in young lean male patients with essential hypertension

Essential hypertension is associated with changes in central catecholaminergic pathways which might also be reflected in the pituitary response to stress stimuli. The aim of this study was to determine whether the response of pituitary hormones, cortisol, plasma renin activity, aldosterone and catecholamines to insulin-induced hypoglycaemia is changed in hypertension. We studied 22 young lean male patients with newly diagnosed untreated essential hypertension and 19 healthy normotensive, age- and body mass index (BMI)-matched controls. All subjects underwent an insulin tolerance test (0.1 IU insulin/kg body weight intravenously) with blood sampling before and 15, 30, 45, 60 and 90 min after insulin administration. Increased baseline levels of norepinephrine (P<0.05), increased response of norepinephrine (P<0.001) and decreased response of growth hormone (P<0.001), prolactin (P<0.001), adrenocorticotropic hormone (P<0.05) and cortisol (P<0.001) were found in hypertensive patients when compared to normotensive controls. Increased norepinephrine levels and a decreased pituitary response to metabolic stress stimuli may represent another manifestation of chronically increased sympathetic tone in early hypertension.

Blood pressure reactivity to stress is better for people who recently had penile–vaginal intercourse than for people who had other or no sexual activity

Penile-vaginal intercourse (PVI) but not other sexual behavior is associated with better psychological and physiological function. I examined the relationship of sexual behavior patterns to blood pressure (BP) and its reactivity to stress (public speaking and verbal arithmetic). For a fortnight, 24 women and 22 men used daily diaries to record PVI, masturbation, and partnered sexual behavior in the absence of PVI. Persons who reported PVI (but no other sexual activities) had better stress response (less reactivity and/or lower baseline levels) than persons reporting other or no sexual behaviors. Persons who only masturbated or had partnered sex without PVI had 14 mmHg more systolic BP reactivity than those who had PVI but not the other behaviors. Many variables were examined but failed to confound the observed relationships. The magnitude of the sexual behavior effect on BP reactivity is greater than of other factors in the literature. These findings add to the research corpus on the benefits of PVI (differentiated from other sexual activities).

Blood pressure changes highlight gender differences in emotional reactivity to arousing pictures

The current study was aimed at investigating the effects of gender on the magnitude and patterning of blood pressure responses to specific pleasant and unpleasant, arousing visual stimuli. Systolic and diastolic blood pressure (SBP and DBP), as well as heart rate (HR) and skin conductance (SCR) responses were investigated during picture viewing in 21 female and 25 male students. The pattern of SCR and HR reactivity across emotional categories was found to be similar for men and women. Gender was found to be an effective moderator of BP responses specifically to sexual stimulus content, which prompted greater reactivity in men than in women. These findings extend prior research on gender differences in autonomic responding to emotional visual stimuli and suggest that BP changes might reflect sexual peripheral arousal more than other autonomic measures.