Future Blood Pressure Research Articles

Heart rate and future blood pressure in school aged children

Heart rate and future blood pressure in school aged children

Isolated office hypertension: are there any markers of future blood pressure status?

The introduction of ambulatory blood pressure monitoring into clinical practice has defined a clinical condition called 'isolated office hypertension'. The aim of this study was to evaluate the long-term systolic and diastolic blood pressure changes in patients with isolated office hypertension and to identify the presence of markers capable of identifying which patients will develop sustained hypertension. All the 407 patients enrolled had a random office systolic or/and diastolic blood pressure of over 140/90mmHg and a mean daytime ambulatory blood pressure of 130/84mmHg or less. At enrollment, each patient underwent a 'baseline examination' made up of a physical evaluation, a 24h ambulatory blood pressure monitoring, and a mental arithmetic test performed at the end of the 24h ambulatory monitoring. Of the 173 patients finally studied, 102 (58.9%) developed sustained hypertension with an increase in both ambulatory systolic and diastolic blood pressure. At the time of the baseline examination, the patients were divided into two groups. Group A included patients with mean ambulatory systolic and diastolic blood pressures in the first hour of 130/84mmHg or less; group B included patients with mean ambulatory systolic and diastolic pressures in the first hour of greater than 130/84mmHg. During the mental arithmetic test, the systolic and heart rate values increased significantly only in group B patients. Of the 102 patients who had become hypertensive by the time of the follow-up examination, 84 (82%) belonged to group B. These data suggest that isolated office hypertension may indeed be a transitional state towards the development of sustained hypertension. Moreover, the mean ambulatory blood pressure value during the first hour can be considered to be a marker of a higher risk of developing sustained hypertension.

7-Year Stability of Blood Pressure in the Canadian Population

Background. The purpose of the study was to examine the 7-year stability of systolic (SBP) and diastolic (DBP) blood pressures in the Canadian population.Methods. The sample included 1,503 participants 7–69 years of age from the 1981 Canada Fitness Survey who were remeasured in Campbell's Survey of 1988. Both SBP and DBP were adjusted for the effects of body mass index (BMI) using regression procedures.Results. Interage correlations from baseline to follow-up ranged from −0.17 to 0.61 for SBP and from −0.22 to 0.51 for DBP. With few exceptions, correlations were positive and significant, and were highest and most consistent in adulthood. Further, between 27 and 39% of participants in the upper or lower quintiles in 1981 remained there in 1988. There were few differences in adiposity between those who remained in the upper or lower quintiles and those who did not. One exception was that males who remained in the upper quintile of SBP had greater values for BMI, sum of skinfolds, and waist circumference at baseline. Among adults, the best predictor of future blood pressure was baseline blood pressure, which accounted for between 12 and 34% of the variance in follow-up blood pressure, followed by age, follow-up BMI, and, in females, baseline physical activity levels.Conclusions. Blood pressure demonstrated low to moderate stability over 7 years in Canada, and baseline level of adiposity was related to the stability of SBP in males.

Heart rate as a predictor of future blood pressure in schoolchildren

Heart rate (HR) has been shown to predict future blood pressures (BP) in studies in adults. We explored the relation of HR to future BP levels in a cohort of 344 black and 456 white schoolchildren ages 5 to 19 years, to examine the hypothesis that HR predicts subsequent BP even very early in life. After making baseline measurements, BP was assessed longitudinally 1 to 24 additional times (mean = 8.25) after the baseline period, at intervals of approximately 6 months. We found that HR was significantly related to future diastolic BP in the black boys ( P = .016) after adjusting for baseline diastolic BP, age, and body mass index, but not in the black girls or in the white children. Because HR is reflective of sympathetic nervous system (SNS) activity that in turn can be related to the renin-angiotensin system (RAS), we also explored the relation of HR to the RAS by studying relationships to variants in the angiotensinogen gene and the angiotensin I-converting enzyme (ACE) gene. We found a significantly positive relationship of HR to the presence of the deletion allele of the ACE gene ( P = .0015), but, again, only in the black boys. Because blacks in general appear to retain additional sodium when compared with whites, the SNS, as reflected in the HR, may influence BP more when individuals have increased sodium retention. In summary, baseline HR predicted future diastolic BP in the black boys but not in the black girls or in the white children.

Persistent high job demands and reactivity to mental stress predict future ambulatory blood pressure.

To test the hypothesis that work stress (persistent high job demands over 1 year) in combination with high reactivity to mental stress predict ambulatory blood pressure. Assessment of cardiovascular responses to standardized behavioural tasks, job demands, and ambulatory blood pressure over a working day and evening after 12 months. We studied 81 school teachers (26 men, 55 women), 36 of whom experienced persistent high job demands over 1 year, while 45 reported lower job demands. Participants were divided on the basis of high and low job demands, and high and low systolic pressure reactions to an uncontrollable stress task. Blood pressure and concurrent physical activity were monitored using ambulatory apparatus from 0900 to 2230 h on a working day. Cardiovascular stress reactivity was associated with waist/hip ratio. Systolic and diastolic pressure during the working day were greater in high job demand participants who were stress reactive than in other groups, after adjustment for age, baseline blood pressure, body mass index and negative affectivity. The difference was not accounted for by variations in physical activity. Cardiovascular stress reactivity and sustained psychosocial stress may act in concert to increase cardiovascular risk in susceptible individuals.

Predictors of future ambulatory blood pressure in youth

Objective: The objective of this study was to determine the predictors of future ambulatory blood pressure in normotensive youths with family histories of essential hypertension. Study design: Eighty-eight healthy youths (mean age 10.9 ± 2.5 years; 52 blacks, 36 whites; 45 boys) were studied. During an initial visit anthropometric variables and hemodynamics were measured at rest and before, during, and after three laboratory stressors: postural change, forehead cold, and video game challenge. The subjects' ambulatory blood pressure was monitored for 24 hours as part of a follow-up evaluation an average of 2.5 years later. Results: Anthropometric and demographic variables and measures of reactivity to laboratory stressors were related to future daytime and nighttime ambulatory blood pressure. Conclusion: These findings provide important information on the predictors of ambulatory blood pressure and underscore the importance of resting blood pressure and adiposity. These results support the guidelines of the Second Task Force, which recommend the measurement of blood pressure and adiposity in the context of ongoing health care. (J Pediatr 1998;132:693-8.)

P048 Value of childhood blood pressure measurements in predicting future adult elevated blood pressure

P048 Value of childhood blood pressure measurements in predicting future adult elevated blood pressure

Home Blood Pressure as a Predictor of Future Blood Pressure Stability in Borderline Hypertension: The Tecumseh Study

We evaluated time-related blood pressure trends in the Tecumseh study participants, none of whom received antihypertensive treatment. At baseline the blood pressures were measured in the field clinic and by self measurement at home (twice daily for 7 days). After a mean of 3.2 ± 0.42 years, the clinic and home pressure readings were repeated. Nine hundred forty-six subjects had clinic and home blood pressure readings at baseline. Of these 735 (380 men, 355 women; average age, 32 years) also completed the second examination. Blood pressure, morphometric data, and biochemical measures at the first examination were used as predictors of future clinic blood pressures. Five hundred ninety-six subjects were normotensive on both examinations (81%). Of 79 subjects (10.7%) with clinic hypertension (>140 mg Hg systolic or 90 mm Hg diastolic) at baseline, 38 remained hypertensive (“sustained hypertension”) and 41 became normotensive (“transient hypertension”) after 3 years. Another 60 normotensives at baseline (10.4%) became hypertensive on second examination (“de novo hypertensives”; incidence; 8.1%). The home blood pressure readings on both examinations were reproducible. The three hypertensive groups had elevated home blood pressure, were overweight, had dyslipidemia, and higher insulin values. Only the home blood pressure proved predictive of subsequent blood pressure trends. A home blood pressure of 128 and 83 mm Hg or higher detected “sustained” hypertension with a 48% sensitivity and 93% specificity. Readings of 120 and 80 mm Hg or lower predicted future normotension with a 45% sensitivity and a 91% specificity. We conclude that self determination of the blood pressure at home is useful in the management of borderline hypertension. An algorithm for the management of these patients is proposed.

Prediction of young adult blood pressure from childhood blood pressure, height, and weight

To assess the ability of childhood blood pressure, height, and weight to predict young adult blood pressure, the authors examined data obtained over multiple visits for four years on 339 children aged 8–18 years in East Boston, Massachusetts. These subjects were again seen 8–12 years later when they were aged 20–26 years. Multivariate regression models were used to predict true blood pressure in young adulthood from observed childhood measurements closest to age 10 ( n = 219), adjusting for within-person variability. Without adjusting for childhood blood pressure, childhood height, weight and body mass index were at least marginally associated with young adult systolic blood pressure in boys and girls, with similar coefficients for each gender. The strongest predictor was weight (β = 0.6 mmHg/10 Ibs for girls, and β = 0.7 mmHg/10 Ibs for boys), and height was no longer predictive with weight in the model. With childhood blood pressure included, neither childhood height nor weight were predictors of future systolic blood pressure. However, change in height and weight were predictors of future systolic blood pressure. Weight change was a stronger predictor in girls than boys with β = 0.9 mmHg/10 Ibs. For diastolic blood pressure, height and weight had limited predictive ability in these data. These models, which allow for both between- and within-person variability in young adulthood, may be used to estimate the predictive value for future high blood pressure of a child's current blood pressure, height and weight, as well as future change in height and weight. These data suggest that the effects of childhood height and weight on future blood pressure may be negligible given childhood blood pressure, but that later height and weight remain predictive.

Genetic regulation of hemodynamic variables during dynamic exercise. The MCV twin study.

Both resting and exercise levels of blood pressure in individuals have been used as predictors of adult hypertension. One possible mechanism underlying the relation between childhood resting and exercise blood pressure and future blood pressure is a set of genes expressed in childhood that persists to regulate adult blood pressure. To investigate the genetic relation of blood pressure and heart rate during both rest and exercise, we asked: (1) Are the genes that regulate resting hemodynamic variables the same genes that regulate these variables during exercise? (2) How much of the variance in exercise hemodynamic variables is genetic and how much is environmental? (3) Do the genetic and environmental influences on hemodynamic responses change with increasing levels of exercise? To determine how genetic and environmental effects expressed at rest influenced responses during dynamic exercise, a genetic analysis was conducted by fitting a series of models to the covariance matrices with the use of the LISREL VII program. We found that all the genetic effects expressed at the later stages of exercise can be explained by genetic effects expressed at rest and at the first stage of exercise. The environmental effects appear to be workload specific and include errors of measurement.

The ability of active versus passive coping tasks to predict future blood pressure levels in normotensive men and women

Casual blood pressure (BP) after a 2-year follow-up interval was determined in 40 normotensive men and women (20 Blacks and 20 Whites), who had been initially tested for cardiovascular responses to a variety of active and passive coping tasks, including active speech, passive speech, reaction time, and forehead cold pressor tasks. Stepwise multiple regression analyses were used to identify the best model for predicting follow-up BP. Average systolic blood pressure (SBP) level during cold pressor stress was the single most powerful predictor of casual SBP over 2 years even after controlling for initial resting SBP. Other predictors of follow-up SBP were initial SBP, parental history of hypertension, and heart rate and SBP during passive speech (final model R(2) = .78). For follow-up diastolic blood pressure (DBP), the only significant predictors were initial DBP and male gender. These results contribute to a growing body of literature that suggests that cardiovascular measures observed during stressors have predictive validity above and beyond that of traditional predictor variables.

Anticipatory Blood Pressure Response to Exercise Predicts Future High Blood Pressure in Middle-aged Men

Increases in blood pressure during the period of emotional arousal attendant to impending exertion are well documented, yet the etiologic significance of these elevations is unknown. Research suggests that exaggerated cardiovascular responses to psychological stress may be importantly related to hypertension. We examined blood pressure reactivity in anticipation of an exercise stress test in relation to future hypertension in the Kuopio Ischemic Heart Disease Risk Factor Study, a population-based study of middle-aged men from Eastern Finland. Subjects were 508 unmedicated men with resting blood pressure less than 165/95 mm Hg who completed a bicycle ergometer stress test at baseline and whose hypertensive status was assessed at 4 years of follow-up. Systolic and diastolic reactivity were calculated as the difference between blood pressure measured after seated rest on the bicycle ergometer before initiation of exercise and mean seated resting blood pressure measured 1 week earlier. Logistic regression models adjusted for age and resting blood pressure revealed a graded association between quartiles of reactivity and risk of subsequent hypertension ( > or = 165/95 mm Hg), with men showing systolic responses greater than or equal to 30 mm Hg or diastolic responses greater than 15 mm Hg at nearly four times the risk of becoming hypertensive (odds ratios, 3.80 [95% confidence interval, 1.90 to 7.63] and 3.65 [95% confidence interval, 1.86 to 7.17], respectively) relative to the least-reactive groups (systolic response, < 10 mm Hg; diastolic response, < 5 mm Hg). Adjustments for traditional risk factors for hypertension did not alter these associations. Results demonstrate the clinical significance of the pressor response in anticipation of exercise and support the hypothesis that cardiovascular reactivity to psychological challenge plays a role in the etiology of hypertension.

Insulin and blood pressure among healthy children. Cardiovascular risk in young Finns.

We evaluated the role of insulin in regulating and predicting blood pressure among 3596 to 2799 Finnish children and adolescents aged 3 to 18 years who were followed from 1980 to 1986. Blood pressure, weight, and height were measured in three surveys 3 years apart. Fasting blood samples were drawn and serum insulin was analyzed. The effect of insulin on blood pressure was evaluated in each of the 3 study years, together with the effect of fasting insulin on future blood pressure and the effect of insulin on the change in blood pressure. We also analyzed the correlation between insulin and blood pressure in different age groups and the correlation between change in insulin and change in blood pressure. A constant positive correlation was found between insulin and both systolic and diastolic (Korotkoff's fifth phase) blood pressures measured in the respective years (correlation coefficients 0.10 to 0.41 and partial correlation coefficients 0.02 to 0.15), except between insulin and diastolic blood pressure in the first two surveys in terms of partial correlation and multiple regression analysis. Similarly insulin and blood pressure correlated positively in every age group. Insulin measured in 1980 or 1983 predicted systolic blood pressure as measured 3 and 6 years later (correlation coefficients 0.30 to 0.47 and partial correlation coefficients 0.06 to 0.13), and likewise diastolic blood pressure as measured 3 and 6 years later (correlation coefficients 0.17 to 0.35 and partial correlation coefficients 0.05 to 0.08), except among the males in 1983. Correlation between insulin and the change in blood pressure was not significant or remained marginal. Similarly, the correlation between change in insulin and change in blood pressure was not significant or remained marginal. We suggest that insulin seems to regulate actual blood pressure within the normal range and to predict future blood pressure among children and adolescents, independently of age and weight. However, insulin does not enhance the rise in blood pressure.

Pressor reactions to psychological stress and prediction of future blood pressure: data from the Whitehall II study

To examine whether reactions of blood pressure to psychological stress predict future blood pressure. Blood pressure was recorded at a medical screening examination after which pressor reactions to a psychological stress task were determined. Follow up measurement of blood pressure was undertaken, on average, 4.9 years later. 20 civil service departments in London. 1003 male civil servants aged between 35 and 55 years at entry to the study. Blood pressure at follow up screening. Reactions of systolic blood pressure to stress correlated positively with systolic blood pressure at follow up screening (r = 0.22, P < 0.01). The dominant correlate of follow up blood pressure was blood pressure at initial screening (r = 0.60; P < 0.01 between initial and follow up systolic blood pressure; r = 0.59, P < 0.01 between initial and follow up diastolic blood pressure). Stepwise multiple regression analysis indicated that reactions to the stressor provided minimal prediction of follow up blood pressure over and above that afforded by blood pressure at initial screening. In the case of follow up systolic blood pressure, systolic reactions to stress accounted for only 1% of follow up variance; systolic blood pressure at initial screening accounted for 34%. With regard to diastolic blood pressure at follow up, the independent contribution from diastolic reactions to stress was less than 1%. Pressor reactions to psychological stress provide minimal independent prediction of blood pressure at follow up. Measurement of reactivity is not a useful clinical index of the course of future blood pressure.

New perspectives in childhood blood pressure.

Ambulatory blood pressure monitoring is a new technique available to the pediatric cardiologist, and several studies have investigated its usefulness. Investigators are now providing data for both normal values and reproducibility. Other authors have examined the effects of hypertension in mothers upon their offspring, which include small birthweight and possible developmental delay. New data, particularly from the Bergen Blood Pressure Study, indicate that maternal hypertension may be a precursor for future blood pressure elevation in offspring. It is known that obese people are more likely to be hypertensive. A study performed in China in a lean population, including individuals who were relatively obese, showed the positive relation of body weight to blood pressure. Furthermore, data now emerging indicate that both retinal vessels and renal arteries in children suffer changes with persistently elevated blood pressure. This clearly is something to follow. Other articles examined in this review investigate the relation of atherosclerosis to hypertensive disease.

Predictors of blood pressure and left ventricular mass in the young: the Hypertension in Pregnancy Offspring Study.

The present study evaluates potential predictors for the future blood pressure and left ventricular mass in children. Fifty-two children were studied at mean age 12.6 +/- 1.5 years and reexamined after 5.6 years. Thirty-six children were born to mothers who had hypertension during pregnancy and 16 children were born after normotensive pregnancies by mothers who remained normotensive at follow-up. Blood pressure was measured at rest and during physical exercise. Left ventricular mass was calculated from M-mode echocardiography, and erythrocyte sodium and potassium concentrations were determined. A stepwise multiple linear regression analysis was used to predict subsequent blood pressure and left ventricular mass. Final systolic blood pressure was best explained by initial systolic blood pressure, erythrocyte potassium concentration, gender, and erythrocyte sodium concentration. Final diastolic blood pressure was best explained by erythrocyte potassium concentration. Gender and initial left ventricular mass were predictors of left ventricular mass at follow-up. This prospective study corroborates previous findings that blood pressure measured in children predicts their future blood pressure. Furthermore, an independent inverse relationship between childhood erythrocyte potassium concentration and adolescent blood pressure is demonstrated. Male gender and an early increased left ventricular mass are independent predictors of an increased left ventricular mass in adolescents.

Tracking of blood pressure in children and youth.

Part of a preventive pediatric strategy against cardiovascular diseases is the early identification of hypertension in childhood. There is a clearly established relationship between blood pressure measured during childhood and at later periods for the same individual. This relationship was investigated in studies of blood pressure tracking in children over the past two decades. This report reviews longitudinal studies that analysed tracking of blood pressure between the ages of 4 and 20 years. The results confirm the existence of tracking, but the statistical relationship seems too weak to justify preventive pediatric strategies based on blood pressure in childhood. However, during adolescence, tracking of blood pressure is affected by the processes of growth and maturation. Methodological problems may have also resulted in underestimation of the amount of tracking. An increase in the number of blood pressure measurements and the use of vertex-corrected blood pressure values would probably improve tracking. It is important to analyse the improvement in tracking coefficients when these new methods are used in order to determine the maximal extent to which blood pressure in childhood can predict future levels. Recently, several studies that were able to relate blood pressure values from childhood to adulthood suggested that tracking seems to persist over this long period. Together with comparable results from future analyses of studies considered in this review, more detailed information will become available about the predictability of blood pressure in children. Although blood pressure is the best single predictor of future blood pressure, results of this review indicate that its predictability is not sufficiently strong for preventive strategies in childhood. Therefore, the development of blood pressure predictors based on more than one parameter is recommended. © 1994 Wiley-Liss, Inc.

Ambulatory blood pressure: a predictor of left ventricular mass and future blood pressure in subjects predisposed for hypertension.

Twenty-four-hour ambulatory blood pressure (SpaceLab 5200) and a single laboratory blood pressure were measured in a population-derived sample of normotensive men (mean age 36 years) with (n = 13) or without (n = 16) a positive family history of hypertension. The aim was to determine whether ambulatory monitoring was a better predictor than clinical measurements for echocardiographic derived indices of left ventricular mass and for future blood pressure. At the initial examination ambulatory blood pressure could discriminate between the groups, showing significant differences that were not evident from the clinical blood pressure measurement. After 5 years the blood pressure had increased in the group with a family predisposition for hypertension but only one subject had overt hypertension. The correlation between the average day-time blood pressure and the clinical blood pressure at follow-up was only marginally better than the correlation for the initial clinical blood pressure. In contrast to the clinical blood pressure, both day-time and night-time blood pressure averages were significantly correlated to left ventricular mass at the initial examination. It is concluded that in still normotensive subjects, ambulatory monitoring is a better predictor than clinical measurements for left ventricular mass but not for future blood pressure.

Blood pressure increases in response to feeding in the term neonate.

We studied blood pressure and heart rate of 18 medically well newborn babies before, during, and after feeding. Seven were breast-fed and 11 bottle-fed and all were studied between 24 and 92 hr of age. There was an increase in heart rate associated with sucking on a pacifier but no additional increase with feeding. By 30-60 min after feeding, heart rate had returned to baseline value. Blood pressure, however, did increase in response to feeding and showed a greater increase in the breast-fed group than in the bottle-fed group. Systolic blood pressure rose from 72 mmHg in the basal state to 85 mmHg during the first 3 min of feeding in the bottle-fed babies and from 73 to 99 mmHg during comparable periods in the breast-fed babies. The results for diastolic blood pressure were similar except that changes within the bottle-fed group were not statistically significant. Bottle-fed babies rose only from 42 to 47 mmHg while breast-fed babies rose from 42 to 61 mmHg from basal conditions to feeding. Blood pressure responses to feeding may have implications for susceptibility to necrotizing enterocolitis, for future blood pressure liability in adulthood and for later hypertensive disease.

Challenge Response Predictors

Environmental challenges offer a potential method for predicting hypertension. They could be nutritional (eg, an increased salt load), behavioral (eg, a mental arithmetic task), or physical (eg, an exercise test) in nature. An ideal challenge test should be simple to administer, easily standardized, and with a response that can be precisely quantified. The response is best expressed as a change score from the baseline level, and should be reproducible over time. For the prediction of hypertension, blood pressure is the usual response measure, although others, such as heart rate, are possible. The response should have predictive value independently of other known predictors, including the baseline level. The dependent variables might be future blood pressure, target organ damage, or morbid events.