Diurnal blood pressure patterns in normotensive and hypertensive children and adolescents

As abnormalities in diurnal ambulatory blood pressure (BP) have been associated with hypertensive target organ damage in adults, we investigated the diurnal systolic BP (SBP) and diastolic BP (DBP) patterns of 54 normotensive children, age 13.4 +/- 3.0 years, and 45 untreated borderline and mildly hypertensive children, age 14.4 +/- 2.6 years. Subjects wore the SpaceLabs 90207 ambulatory BP monitor for 24 h. BP was measured q 15 min from 08.00-21.00 h then q 30 min from 21.00-08.00 h. Nocturnal BP fall, the night-day ratio and cusum derived measures were calculated from time-weighted daytime and night-time SBP and DBP. The groups were compared using analysis of covariance with adjustment for age, race, gender and body mass index. The influence of age, gender and race on the diurnal BP profile was also examined. Nocturnal SBP fall was greater in hypertensive compared to normotensive subjects (17.1 +/- 6.7 vs 14.6 +/- 7.1 mm Hg; unadjusted mean +/- s.d., P = 0.022). Normotensive and hypertensive groups did not differ in nocturnal DBP fall or SBP or DBP night-day ratio. Race appeared to influence the diurnal BP pattern as black subjects had less nocturnal SBP fall (12.9 +/- 6.9 vs 17.1 +/- 6.5 mm Hg; P < 0.005) and a higher night-day SBP ratio (90.1 +/- 5.3 vs 86.7 +/- 4.6%; P < 0.005) than white subjects. In conclusion, hypertensive children and adolescents have a similar diurnal BP pattern as their normotensive counterparts, except that the entire BP profile is shifted upward with a greater absolute fall in SBP at night. Race also appears to influence the diurnal BP profile of normotensive and hypertensive children and adolescents.     

Postexercise decrease in arterial blood pressure, total peripheral resistance and in circulatory responses to brief hyperoxia in subjects with mild essential hypertension

The objective of our study was: (1) to compare the influence of moderate exercise on circulatory after-response in mildly hypertensive (n = 8) and normotensive male subjects (n = 9); (2) to examine the circulatory response to 3-min hyperoxic inactivation of arterial chemoreceptors at rest and during postexercise period in both groups. Hypertensive men (HTS) with a systolic blood pressure (SBP) 148 +/- 5 mm Hg, diastolic blood pressure (DBP) 92.4 +/- 4 mm Hg; and normotensive men (NTS), with a SBP 126 +/- 3 mm Hg, DBP 75.6 +/- 1.3 mm Hg, were submitted to 20-min of moderate exercise on a cycloergometer (up to the level of 55% of each subject's resting heart rate reserve). Finger arterial BP was recorded continuously with Finapres, impedance reography was used for recording stroke volume, cardiac output and arm blood flow. In HTS a significant decrease in SBP by 14.5 +/- 3.4 mm Hg, DBP by 8.9 +/- 1.9 mm Hg, total peripheral resistance (TPR) by 0.45 +/- 0.05 TPR u. (33.7 +/- 2.7%), and in arm vascular resistance (AVR) by 11.0 +/- 2.7 PRU u. (35.6 +/- 7%), was observed over a 60-min postexercise period. NTS exhibited insignificant changes in SBP, DBP, AVR except a significant decrease in TPR limited only to 20-min postexercise period. Hyperoxia decreased SBP, DBP and TPR in HTS. This effect was significantly attenuated during the postexercise period. Long-lasting antihypertensive effect of a single dynamic exercise in HTS suggests that moderate exercise may be applied as an effective physiological procedure to reduce elevated arterial BP in mild hypertension. We suggest also that the attenuation of the sympathoexcitatory arterial chemoreceptor reflex may contribute to a postexercise decrease in arterial BP and in TPR in mildly hypertensive subjects.     

Cardiovascular reactivity and central adiposity in older African Americans.

This study examined central adiposity, as measured by waist circumference (WC), in relation to mental-stress induced systolic (SBP) and diastolic blood pressure (DBP) and heart rate (HR) responses, body composition, the metabolic syndrome, and health practices in 22 older, African American men and women (ages 52–79 years). The high WC (>100 cm) group showed significantly greater SBP, DBP, and HR reactivity, greater fasting insulin levels, lower high density lipoprotein cholesterol levels, greater fat mass in both truncal and peripheral regions, and greater body mass index as compared to the low WC (     

Cigarette smoking, blood pressure and pulse rate in the Jerusalem Lipid Research Clinic Prevalence Study

The relationship between cigarette smoking and blood pressure (BP) and pulse rate (PR) was studied in a sample of 1,242 Jerusalem youngsters and 1,703 adults. Confounding effects of age, body mass, ethnic origin and season were controlled in the analysis. Both mean systolic (SBP) and diastolic blood pressure (DBP) were lower in smokers than in nonsmokers, with greater differences in both generations in females (women 4.5 mm Hg, P = 0.004 and girls 3.9 mm Hg, P less than 0.001 for SBP; women 2.3 mm Hg, P = 0.024 and girls 2.6 mm Hg, P = 0.002 for DBP) than among the males (men 1.5 mm Hg, P = 0.15 and boys 2.0 mm Hg, P = 0.022 for SBP; men 1.3 mm Hg, P = 0.05 and boys 1.8 mm Hg, P = 0.01 for DBP). The relative odds of being in the upper age, ethnic and body mass index-adjusted quintiles of SBP for nonsmokers were 1.3, 1.9, 2.1, and 3.5 for men, boys, women, and girls, respectively. For DBP they were 1.3, 1.7, 1.1, and 2.1, respectively. No significant trends for BP varying with number of cigarettes smoked were noted in either adults or youngsters. Only adult male smokers had slightly higher PRs. The relatively small differences in BP may be of pharmacologic or psychobehavioral interest, but do not counter the well-described deleterious effects of cigarette smoking.     

Severe manifestations in carrier females in X linked retinitis pigmentosa

The aim of this study was to assess the effect of menopause on circadian profile of blood pressure (BP) and heart rate (HR) in the normotensive pre- and postmenopausal women. Systolic BP (SBP), diagnostic BP (DBP) and HR were monitored every 30 min for 48 hrs using noninvasive ambulatory BP monitoring in 24 premenopausal and 40 postmenopausal women. Mean 48-hours, daytime (awake), and nighttime (sleeping) SBP, DBP and HR values were analyzed by reviewing the patients' diaries, and the nocturnal reduction rate (NRR) of SBP, DBP and HR were calculated according to the following formula. NRR (%9 = [(daytime mean-nighttime mean)/daytime mean] x 100. The study subjects were then divided into two groups according to the presence (dipper) or absence (nondipper) of a significant reduction in nocturnal BP (> 10%). Mean SBP, DBP and HR measured over 48 hours were similar between the premenopausal and the postmenopausal group. The NRR of DBP and HR in the postmenopausal group were significantly smaller than those in the premenopausal group (17.1 +/- 6.0% vs. 13.5 +/- 7.0%, 241.1 +/- 6.0% vs. 19.8 +/- 9.0%: p < 0.05). There tended to be higher prevalence of nondipper in the postmenopausal (37%) than in the premenopausal group (29%).     

Weight reduction regresses left ventricular mass regardless of blood pressure level in obese subjects

The effects of weight reduction on left ventricular mass in obese normotensive and hypertensive subjects were investigated. Previous studies have shown that weight reduction in hypertensive (HT) obese patients is associated with decreased left ventricular mass (LVM) and decreased blood pressure (BP). This study was performed to examine whether weight reduction would also regress LVM in normotensive (NT) obese subjects and to clarify the mechanisms of these effects if they occurred. A weight-reduction program consisted of mild exercise and mild hypocaloric intake. M-mode echocardiography was performed to estimate the LVM. After the 12-week intervention, the mean reductions in body weight (BW) in the NT (n = 11) and HT (n = 11) groups were 4.9 kg (p < 0.005) and 4.6 kg (p < 0.0005), respectively. Systolic, diastolic, and mean BP were significantly reduced by 13, 9, and 11 mm Hg, respectively, in the HT group. By contrast, no significant changes in systolic, diastolic, or mean BP were observed in the NT group. LVM was significantly reduced from 176 +/- 26 gm to 159 +/- 26 gm (p < 0.05) in the HT group and from 167 +/- 33 gm to 145 +/- 34 gm (p < 0.02) in the NT group. These results suggest that weight reduction in obese subjects by mild exercise and mild hypocaloric intake can lead to a reduction in LVM, regardless of whether the subjects have normal or high blood pressure.     

Cardiovascular reactivity and interpersonal influence: Active coping in a social context.

Previous studies have demonstrated that effortful attempts to secure positive outcomes or avoid negative outcomes produce significant increases in systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR). Although these effects of active coping on cardiovascular reactivity are central in current psychosomatic theories, virtually all of the research to date has used impersonal, asocial tasks. Our two studies examined the cardiovascular effects of effortful attempts to influence other people. In Study 1, male subjects attempting to influence the opinions of their discussion partner to improve their own chances of winning money displayed significantly greater SBP, DBP, and HR reactivity. In Study 2, we obtained similar effects on SBP and DBP reactivity in men and women, while both preparing an influence attempt and making that attempt. Furthermore, reactivity levels were larger as the magnitude of incentive for successful persuasion increased. Implications of this interpersonal equivalent of active coping for the development of cardiovascular disease are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ultrasound diagnosis in primary staging of head-neck tumors

The purpose of this study was to determine the minimum number of consecutive blood pressure cuff inflations required to obtain seated stable resting baseline measurements of heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP). Sixty male college students aged 18 to 31 years volunteered as study subjects. Thirteen observations of HR, SBP, DBP, and MAP were recorded at 90-second intervals for each subject using a Critikon-Dinamap monitor. Stable readings for SBP and MAP were obtained in 6.5 minutes or 3 to 5 cuff inflations in the population tested. Using this procedure, additional age- and gender-specific norms could be established for normal and hypertensive subjects. Knowing the approximate quantity and frequency of blood pressure cuff inflations needed to generate baseline minimum measurements of HR, SBP, DBP, and MAP will be helpful in studies of cardiovascular reactivity, as well as for clinical and psychophysiologic treatment of hypertension.     

Intensive training and cardiac autonomic control in high level athletes

The bioavailability of propranolol depends on the degree of liver metabolism. Orally but not intravenously administered propranolol is heavily metabolized. In the present study we assessed the pharmacokinetics and pharmacodynamics of sublingual propranolol. Fourteen severely hypertensive patients (diastolic blood pressure (DBP) > or = 115 mmHg), aged 40 to 66 years, were randomly chosen to receive a single dose of 40 mg propranolol hydrochloride by sublingual or peroral administration. Systolic (SBP) and diastolic (DBP) blood pressures, heart rate (HR) for pharmacodynamics and blood samples for noncompartmental pharmacokinetics were obtained at baseline and at 10, 20, 30, 60 and 120 min after the single dose. Significant reductions in BP and HR were obtained, but differences in these parameters were not observed when sublingual and peroral administrations were compared as follows: SBP (17 vs 18%, P = NS), DBP (14 vs 8%, P = NS) and HR (22 vs 28%, P = NS), respectively. The pharmacokinetic parameters obtained after sublingual or peroral drug administration were: peak plasma concentration (CMAX): 147 +/- 72 vs 41 +/- 12 ng/ml, P < 0.05; time to reach CMAX (TMAX): 34 +/- 18 vs 52 +/- 11 min, P < 0.05; biological half-life (t1/2b): 0.91 +/- 0.54 vs 2.41 +/- 1.16 h, P < 0.05; area under the curve (AUCT): 245 +/- 134 vs 79 +/- 54 ng h-1 ml-1, P < 0.05; total body clearance (CLT/F): 44 +/- 23 vs 26 +/- 12 ml min-1 kg-1, P = NS. Systemic availability measured by the AUCT ratio indicates that extension of bioavailability was increased 3 times by the sublingual route. Mouth paresthesia was the main adverse effect observed after sublingual administration. Sublingual propranolol administration showed a better pharmacokinetic profile and this route of administration may be an alternative for intravenous or oral administration.     

Blood pressure reactivity in adult male twins.

Examined possible genetic contributions to cardiovascular reactivity by contrasting patterns of association in 82 monozygotic (MZ) and 88 dizygotic adult male twin pairs (aged 21–61 yrs). Systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were recorded during baseline and during a mental arithmetic task. The task produced significant elevations in all 3 cardiovascular measures. Levels of SBP and DBP reactivity were significantly correlated in MZ pairs only. Statistical tests suggest a heritability estimate of about 50% that was marginally significant for SBP and DBP changes during the task. There was no indication of a genetic influence on HR reactivity. Resting level and static task period measures of SBP, DBP, and HR demonstrated statistically significant heritability estimates of 60–80%. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Left ventricular diastolic function in young men with high normal blood pressure

OBJECTIVE: Abnormalities in left ventricular (LV) diastolic filling have been reported in hypertensive patients. This study was designed to compare LV diastolic filling between individuals with high normal blood pressure (HNBP) and optimal blood pressure (OBP). SUBJECTS AND DESIGN: From a survey of 219 young male individuals (age 21 +/- 0.1 years), two groups were selected according to their BP (group A: systolic BP [SBP] 120 mmHg and diastolic BP [DBP] 80 mmHg, n = 23 and group B: SBP 130 to 139 mmHg and/or DBP 85 to 89 mmHg, n = 21). Subjects habits, anthropometric characteristics, LV structure and systolic and diastolic function were compared. RESULTS: No differences were detected between the two groups in habits, systolic function or early diastole. LV mass index (LVMI) was higher in group B (103.6 +/- 4.58 g/m2 versus 90.49 +/- 3.27 g/m2 in group A, P < 0.05), though the values were not high enough to indicate LV hypertrophy. The pattern of LV late filling was different between the two groups. The peak late diastolic flow velocity (A) was 0.45 +/- 0.02 m/s in group B and 0.52 +/- 0.03 m/s in group A (P < 0.05). The early peak velocity (E):A ratio was 1.82 +/- 0.08 in group A and 1.59 +/- 0.08 in group B (P < 0.05). The early filling fraction also demonstrated a significant shift to more prominent late diastolic filling in group B (0.68 +/- 0.01% versus 0.73 +/- 0.01% in group A, P < 0.05). This pattern in LV filling did not correlate to inheritance, age, sex, heart rate, habits or body mass index. CONCLUSIONS: This shift in filling pattern to a late flow in young men with HNBP seemed to be an early indicator of an increased dependence of LV filling on atrial contraction and may reflect an impairment in LV relaxation.     

Indomethacin does not attenuate the hypotensive effect of trandolapril

This is a randomised, double-blind, placebo-controlled, four-way crossover study to determine if indomethacin attenuates the hypotensive effect of trandolapril. Twenty-three hypertensive patients (diastolic blood pressure (DBP) 95-115) requiring NSAID were recruited. Seventeen completed the study. Three week treatment periods: trandolapril 2 mg od and indomethacin 25 mg tds, trandolapril 2 mg and placebo, indomethacin and placebo, placebo and placebo. Clinic and ambulatory BP after 3 weeks of each treatment. Study had 85% power to detect a 5 mm Hg difference in BP (s.d. 7 mm Hg). End of treatment clinic BPs were: 152.9/98 mm Hg (95% CI 147.2, 158.6/95.8, 101.4) with placebo and placebo; 150.4/94.9 mm Hg (95% CI 144.7, 156.1/92.1, 97.7) with trandolapril and indomethacin; 148.2/96.5 mm Hg (95% CI 142.5, 153.9/93.7, 99.3) with trandolapril and placebo; and 156.6/97.4 mm Hg (95% CI 150.9, 162.3/94.6, 100.2) with indomethacin and placebo. There were no significant interactions between trandolapril and indomethacin for clinic systolic BP (SBP) (P = 0.79) or clinic DBP (P = 0.87). When trandolapril treatments (placebo or with indomethacin) were compared to treatments without trandolapril (placebo or indomethacin), trandolapril lowered clinic SBP by 5.4 mm Hg (P = 0.047) and DBP by 2.3 mm Hg (P = 0.08). Mean ambulatory BP was: 140.6/88.2 mm Hg (trandolapril and placebo); 142.8/89.7 mm Hg (trandolapril and indomethacin); 149.6/95.0 mm Hg, (indomethacin and placebo); 147.7/94.0 mm Hg (placebo and placebo). Compared with placebo, trandolapril and placebo lowered BP by 6.5/7.5 mm Hg (P < 0.001, SBP; P < 0.001, DBP). Compared with indomethacin, trandolapril and indomethacin lowered BP by 5.0/5.5 mm Hg (P = 0.001, SBP; P < 0.001, DBP). In the present study trandolapril 2 mg lowered clinic SBP and ambulatory BP, but indomethacin did not attenuate this. Indomethacin had no significant effect on either clinic or ambulatory BP. The antihypertensive effects of trandolapril in this study were modest. Patient selection factors may have contributed to the observed responses, but it seems unlikely from these data that a clinically important drug interaction has occurred.     

The relationship of blood lead and dietary calcium to blood pressure in the normative aging study

BACKGROUND: Previous studies have demonstrated a positive relationship between elevated blood lead (BPb) and blood pressure (BP), but few have additionally examined the role of dietary calcium. METHODS: The cross-sectional relationship between BPb and BP and the possible protective influence of increased dietary calcium on that relationship was examined among 798 male participants in the Normative Aging Study (NAS), a cohort of older men with relatively low BPb levels. RESULTS: The age range of these subjects was 43-93 years (mean = 66.1, SD = 7.4 years) and blood lead concentrations ranged form 0.5 to 35 mcg/dl (median = 5.6 mcg/dl). For the cohort overall, neither ln blood lead nor dietary calcium were significantly correlated with BP. In multivariate linear regression analyses that adjusted for age, body mass index, dietary calcium intake (adjusted for total calorie intake), alcohol intake, sitting heart rate, kilocalories/week expended in exercise, haematocrit, and smoking status, a unit increase in ln BPb predicted an increase on 1.2 mmHg diastolic blood pressure (DBP) (95% CI : 0.11, 2.2; P = 0.03). Adjusted calcium intake of 800 mg/day predicted a decrease of 3.2 mmHg systolic blood pressure (SBP) (95% CI : -5.6, -0.24, P = 0.03). There was no evidence of an interaction between dietary calcium intake and blood lead on BP. When the analyses were restricted to those men <=74 years old, a unit increase in ln BPb predicted an increase of 1.6 mmHg DBP (n = 681; 95% CI : 0.42, 2.7; P = 0.007). However, when men on antihypertensive medication (AHM) were excluded from the analyses, ln BPb was not significantly associated with increased DBP nor was adjusted calcium significantly associated with SBP. CONCLUSIONS: The study did support the hypothesis that increased BPb was associated with increased DBP in a cohort of older men with low blood lead, but there was no evidence of interaction between BPb and dietary calcium on BP. However, the relationship between increased BPb and DBP did not hold when those on anti-hypertensive medications were excluded.     

Probucol suppresses oxidant stress in hypertensive arteries. Immunohistochemical evidence

Oxy-free radicals may be involved in the pathogenesis of accelerated atherosclerosis in hypertension. We evaluated the direct antioxidant potential of probucol in hypertensive arteries by studying the spatial immunohistochemical distribution of three primary antioxidant enzymes (AEs). Nineteen normocholesterolemic New Zealand White rabbits were divided into two groups: normotensive controls (NT; n = 6) and 13 animals rendered hypertensive by surgical coarctation of abdominal aorta. The hypertensive group was subdivided into hypertensive alone (HT; n = 8) and hypertensive treated with 1% probucol (PO) for 9 weeks (HT-P; n = 5). Blood pressure rose significantly in both hypertensive groups (P < .005). At autopsy, both hypertensive groups showed similarly significant increases in mean arterial intima-media thickness (IMT) whether or not they were treated with probucol. However, only HT rabbits revealed significant increases in the intima-media depth penetration of glutathione peroxidase, superoxide dismutase, and catalase AEs. By contrast, in HT-P animals probucol produced significant reductions of immunostaining of all three AEs compared to the HT group (P < .05). Additionally, specific macrophage immunostaining revealed that the arterial wall of HT rabbits had numerous (10 to 12 per high power field) subintimal and medial macrophages as compared to the HT-P animals (1 to 2 per high power field). The blood pressure level correlated significantly with IMT in all three groups, but with depth penetration of the three AEs only in the NT and HT groups. Probucol, therefore, appears to act in concert with the native arterial antioxidant enzymes as a potent free radical scavenger to reduce oxidative stress and thus attenuate the macrophage invasive response in hypertensive arteries.     

Mental and physical stress as moderators of the postural response in insulin-dependent diabetic patients.

In 14 insulin-dependent diabetic patients (mean age 31.3 yrs) and in 15 normal controls (mean age 30.9 yrs), continuous measures were taken of heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and skin conductance (SC) during postural change under baseline and stressor conditions. Diabetic Ss without symptoms of neuropathy and healthy controls showed generally similar responses to postural change and to stressor conditions (mental arithmetic and isometric handgrip). SBP and DBP were more responsive to mental and physical stressors than were HR or SC, especially after standing. Two diabetics with postural hypotension showed significant increases in overall BP levels and less of a fall in BP during postural change under the stressor conditions, despite minimal HR or SC responses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Elevated plasma catecholamines without alteration in cardiovascular responsiveness in young men with borderline hypertension

Plasma catecholamines and cardiovascular responses to upright posture, exogenous noradrenaline (NA), and isoproterenol (IP) were examined in 20 young men with borderline hypertension and in 10 age-matched normotensive volunteers. Resting plasma NA and adrenaline (Ad) levels were higher in the borderline hypertensive patients. Significant correlations were found among plasma NA and mean blood pressure (MBP) or heart rate (HR), and between plasma Ad and HR in all individuals in the supine position. The increases in plasma NA were similar between groups for orthostatic positions. Pressor response to exogenous NA and chronotropic response to exogenous IP were not augmented in borderline hypertensives. A negative correlation was found between plasma NA before infusion and the increases of MBP produced by NA or the increases of HR produced by IP in all the individuals. Our observations suggest that there is hyperactivity of the sympathoadrenal system without enhancement in cardiovascular reactivity to catecholamines in young men with borderline hypertension.     

Dietary magnesium intake and blood pressure: a qualitative overview of the observational studies

Published reports of 30 separate sets of analyses from 29 observational studies relating dietary intake of magnesium to blood pressure (BP) were identified through a comprehensive search using MEDLINE and BIDS-EMBASE. Three studies were prospective, 24 cross-sectional (25 reports), of which four also contained a longitudinal component, and two were obtained from baseline data in a trial. Various dietary methodologies were used: 24-h dietary recall (n = 12), food-frequency questionnaire (8), food record (7), and duplicate diet (2). Twelve reports compared magnesium intake or BP level between subgroups. Seven showed a negative association between magnesium intake and BP level, and five reported no association. From 18 of the 30 sets of analyses either a regression estimate or a Pearson correlation coefficient was reported. Many reports also allowed identification of subgroups by sex, age and race. Ninety population samples and subgroups could thus be identified from the 30 reports. All 11 Pearson-r correlation coefficients reported for systolic BP (SBP) (three significant, P < 0.05) and 10 (out of 12) Pearson-r correlation coefficients reported for diastolic BP (DBP) (four significant) were negative. Seven reports (13 subgroups for SBP, 11 subgroups for DBP) gave partial regression coefficients after adjustment; 10 (seven significant) and eight (six significant) were negative for SBP and DBP, respectively. For 13 subgroups in five papers, Pearson-r correlation coefficients were reported after adjustment for confounding factors. Eight (out of 13) showed a negative relationship for SBP and DBP. This review points to a negative association between dietary magnesium intake and BP. A systematic quantitative overview is needed to reconcile the inconsistencies of the results of individual studies and to quantify the size of such relationship.     

The potential risk factors associated with acute viral hepatitis in children under 5 years old]

In studies of the effects of salt intake on blood pressure (SBP, MBP, DBP), influences on heart rate (HR) are usually neglected even though the longterm load on both left ventricle (LV) and systemic arteries (SA) is better related to the product of HR x SBP (or MBP) than to pressure alone. After all, altered salt intakes often induce considerable volume-related changes in HR, and the heart operates more economically at low HR and high stroke volume (SV). Thus, about 3/4 of LV metabolism is used for the build-up of systolic tension, while the cost for SV expulsion, or for SV increases, is far lower. Moreover, low HR prolongs the diastolic period, so important for LV coronary supply. Against this background we have used results from studies in both rats and man, in which both BP and HR were followed during marked changes in salt intake, to explore how this affected the HR x SBP (or HR x MBP) product. Briefly, in ordinarily salt-resistant organisms, whether normo- or hypertensive, salt intake increases, which in man ranged from 10-20 to 250-300 mM (in rats over 100-fold), if anything reduced the computed longterm load (HR x SBP, or MBP) on LV and SA, as consequences of an efficient reflex volume control. By contrast, in salt-sensitive man, HR reflex reductions to increased salt intake were almost absent despite substantial SBP elevations, suggesting the influence of a CNS suppression of bulbar reflex centres combined with CNS neurohormonal interference with renal salt volume excretion, as in SHR.     

Cardiovascular Intraindividual Variability in Later Life: The Influence of Social Connectedness and Positive Emotions.

Healthy normotensive men and women (N = 33) underwent a 60-day diary assessment of emotions and cardiovascular functioning. Individual differences in social connectedness and mood were measured in questionnaires, and positive emotions, negative emotions, systolic blood pressure (SBP), and diastolic blood pressure (DBP) were assessed daily for 60 consecutive days. Results confirmed that the cardiovascular undoing effect of positive emotions is evident primarily in the context of negative emotional arousal. The daily associations between positive emotions and cardiovascular outcomes were linked to individual differences in social connectedness. Controlling for individual differences in mood levels, multilevel regression analyses showed that social connectedness predicted extended positive emotion, diminished SBP and DBP reactivity, and more rapid SBP recovery from daily negative emotional states. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychological Stress Tasks in the Prediction of Blood Pressure Level and Need for Antihypertensive Medication: 9-12 Years of Follow-Up.

Increased blood pressure (BP) reactivity to subtypes of psychological stimuli may differentially predict the development of future BP elevation or hypertension. The authors present the 9-12-year follow-up results of 82 (86%) of 95 male participants with different BP levels. They were healthy, untreated, and age-matched volunteers from a routine health checkup carried out on all 35-, 40-, and 45-year-olds from a medium-sized city. Intra-arterial systolic blood pressure (SBP) during the psychological tasks improved the prediction of future casual SBP and noninvasive 24-hr ambulatory SBP compared with predictions from casual diagnostic measurements. Diastolic blood pressure (DBP) was very useful when added to casual DBP in predicting the need for antihypertensive medication. Reactivity to active tasks especially predicts the need for antihypertensive medication. (PsycINFO Database Record (c) 2010 APA, all rights reserved)