Increased arterial stiffness in children with a parental history of hypertension

The Association Between Body Mass Index and Parental History of Hypertension Among Young Indian Adults

BACKGROUND

Hypertension is a disease of multifactorial etiology. Individuals with parental history of hypertension (PHH) have also been observed to be at an increased risk of developing hypertension in their adult life. However, there is a dearth of studies among youth. Obesity is one of the risk factors, and studies conducted among adults of all age groups have observed that there is a highly significant correlation between hypertension and body mass index (BMI). Hence, the association between the two factors, viz., parental history of hypertension and BMI, among the young Indian male and female population was analyzed in this study.

METHOD

This cross-sectional study conducted in Central India comprised 100 young adults between 18 and 25 years of age. On the basis of parental history of hypertension, the subjects were divided into two groups: group 1 comprised youth with parental history of hypertension and group 2 comprised youth without parental history of hypertension, involving 32 and 68 subjects in each of these groups, respectively. Anthropometric measurements were done using standard methods, and BMI was calculated. Statistical analysis was done using Epi Info software.

RESULTS

The study subjects in both groups were comparable in age. The mean age of the study participants was 19.32 years and 19.45 years in group 1 and group 2, respectively. The study did not find any association between BMI and parental history of hypertension.

CONCLUSION

The association between parental history of hypertension and BMI, the non-modifiable and modifiable independent risk factors, respectively, needs to be further explored in light of the iceberg phenomenon, multifactorial causation, and natural history of disease. It is worth mentioning that parental history of hypertension and other risk factors should be considered even if the BMI is normal as per Asian Indian cutoff levels.

Familial tendency for hypertension is associated with increased vascular stiffness

OBJECTIVE

Hypertension is the leading cause of cardiovascular disease and premature death. New methods for early detection of hypertension and its consequences can reduce complications arising from uncontrolled hypertension. Pulse-wave velocity (PWV), a measure of arterial stiffness, has been recognized as a valuable tool in assessing risk for cardiovascular complications, although its use in clinical practice is currently limited. Here we examine whether brachial--ankle PWV (baPWV) and femoral--ankle PWV (faPWV) are elevated in nonhypertensive volunteers, with and without a history of familial hypertension.

METHODS

Volunteers were recruited and questioned as to their medical background and family history. Participants were divided into two groups based on history of familial hypertension and were measured for baPWV and faPWV. Carotid--femoral PWV was computed from these measurements.

RESULTS

A total of 82 healthy nonhypertensive volunteers (mean age 31.4 ± 9.6) were recruited. Among the study cohort, 43.7% had a history of familial hypertension. There were no between-group differences in any other clinical or demographic characteristics. Both baPWV and faPWV were significantly elevated in volunteers with a history of familial hypertension (10.86 ± 1.69 vs. 9.68 ± 1.52 m/s, P < 0.004, and 7.01 ± 1.65 vs. 6.28 ± 1.26 m/s, P < 0.028, respectively).

CONCLUSION

Volunteers with a history of familial hypertension present with elevated baPWV and faPWV. This is suggestive of increased central and peripheral arterial stiffness in susceptible individuals before the onset of hypertension. Routine measurement of these parameters may allow for early intervention and risk stratification, especially in persons with a history of familial hypertension.

Family history of cardiometabolic diseases and its association with arterial stiffness in the Malmö Diet Cancer cohort

OBJECTIVE

Arterial stiffening increases with age and is associated with increased cardiovascular risk. Several risk factors have been shown to predict the development of arterial stiffening; however, a positive family history (FH+) of cardiometabolic disease (CMD) and hypertension has not been extensively studied. We hypothesize that FH+ of CMD plays a significant role in the development of arterial stiffening in offspring.

METHODS

We used data from the population-based Malmö Diet Cancer study (n = 3056) examined in 1992-1996 and again in 2007-2012. Several variables were analysed, including anthropometrics, carotid-femoral pulse wave velocity and FH+. The association between FH+ of CMD and arterial stiffening in the offspring was analysed with analysis of covariance in SPSS. FH+ was subdivided into three categories: family history for cardiovascular events (FH-CVEs), family history for diabetes mellitus type 2 (FH-DM2) and family history for hypertension (FH-HT). The first analysis of covariance-model was adjusted for age, sex, mean arterial pressure and heart rate; the second model additionally adjusted for self-reported medical history in the offspring.

RESULTS

Data indicated that FH-CVE (F = 14.64, P < 0.001), FH-DM2 (F = 18.57, P < 0.001) and FH-HT (F = 13.92, P < 0.001) all significantly increased carotid-femoral pulse wave velocity levels. The results remained when additional adjustment was made for confounders and for self-reported CMD in the index participants, respectively, for FH-CVE (F = 12.47, P < 0.001), FH-DM2 (F = 7.62, P = 0.006) as well as for FH-HT (F = 7.30, P = 0.007).

CONCLUSION

These findings indicate that a FH+ of cardiometabolic conditions and hypertension affects arterial stiffness in offspring independently of haemodynamic factors and self-reported CMD in the offspring without sex differences.

Familial history of hypertension as a predictor of increased arterial stiffness in normotensive offspring

Background

Increased arterial stiffness can be used as a prognostic marker of arterial hypertension. The relationship between arterial stiffness and arterial hypertension seems to be reciprocal.

Objective

Evaluation of changes of the arterial elastic prosperities in normotensive subjects, with and without parental history of hypertension.

Subjects and Methods

One hundred and ten normotensive individuals, aged 20–30 years, were divided into two groups: group-A (n = 57) and group-B (n = 53) subjects with positive and negative parental history of hypertension, respectively. Systolic, diastolic and pulse pressures were measured using mercury sphygmomanometer. The elastic properties of the ascending aorta and the common carotid arteries were assessed using M-mode echo and B-mode imaging, respectively. Stiffness index of the digital volume pulse (SIDVP) was measured in the right index finger using photoplethysmography.

Results

Group A subjects showed higher aortic stiffness index (p = 0.002), carotid stiffness index (p = 0.001), carotid pulse wave velocity (p ⩽ 0.001) and stiffness index of digital volume pulse (p = 0.001). Group A subjects showed lower aortic distensibility (p = 0.001), aortic strain (p = 0.004), changes in aortic diameter (p = 0.022), carotid distension (p = 0.026), carotid distensibility coefficient (p ⩽ 0.001) and carotid compliance coefficient (p = 0.002).

Conclusion

The aortic and carotid stiffness parameters and SIDVP were higher in normotensive offspring of hypertensive parents. This finding could direct the attention towards the increased cardiovascular risk in this group and thus prompt earlier and tighter prevention of cardiovascular risk factors.

Family history of premature cardiovascular disease: blood pressure control and long-term mortality outcomes in hypertensive patients

AIMS

Current guidelines recommend early referral and initiation of intensive cardiovascular (CV) risk reduction in individuals with a positive family history of coronary heart disease (CHD). We hypothesized that a family history of premature CHD and stroke [CV disease (CVD)] would lead to earlier referral of hypertensive patients to secondary care clinic, leading to better control of risk factors, mitigating the excess risk seen in these individuals.

METHODS AND RESULTS

We studied the association of a positive family history of CVD in 10 787 individuals with longitudinal changes in risk factors and long-term cause-specific mortality in the Glasgow Blood Pressure Clinic using generalized estimating equations and the Cox proportional hazard models, respectively. The total time at risk was 193 756 person-years with a median survival time of 29.2 years. A positive family history of CVD was associated with an earlier presentation to the clinic, a lower burden of traditional CV risk factors, and similar longitudinal blood pressure reduction and drug adherence compared with those without. But despite these positive features, all-cause [hazard ratio (HR) = 1.12, 95% confidence interval 1.01-1.25] and CV (HR = 1.20, 1.04-1.38) mortality independent of baseline risk factors were worse. Consistent results were observed in propensity score-matched analysis. Inclusion of family history of CVD did not improve mortality risk discrimination over and above traditional risk factors.

CONCLUSION

Our study suggests that despite earlier referral and treatment of individuals with a positive family history of premature CVD, excess risk persists, indicating the need for continued and sustained efforts to reduce risk factors and drug adherence in these individuals.

Aortic stiffness and flow-mediated dilatation in normotensive offspring of parents with hypertension

OBJECTIVES

Although hypertension has been shown to be one of the most important risk factors for atherosclerosis, data about the presence of subclinical atherosclerosis in normotensive offspring with parental history of hypertension are scarce. Accordingly, the current study was designated to evaluate flow-mediated dilatation and aortic stiffness, which are early signs of atherosclerosis in young subjects with parental history of hypertension.

METHODS

A total of 140 [corrected] healthy, non-obese subjects in the age group of 18-22 years were included in this study and divided into two groups. The first group included 70 offspring of hypertensive parents and the second group included 70 offspring of normotensive parents as controls. In all subjects, endothelium-dependent and endothelium-independent vasodilatation of the brachial artery and aortic elastic parameters were investigated using high-resolution Doppler echocardiography.

RESULTS

Offspring of hypertensive parents demonstrated higher values of aortic stiffness (7.1 plus or minus 1.88 and 6.42 plus or minus 1.56, respectively) but lower distensibility (9.47 plus or minus 1.33 and 11.8 plus or minus 3.36 square centimetres per dyne per 106) and flow-mediated dilatation (4.57 plus or minus 1.3 versus 6.34 plus or minus 0.83 percent, p equals 0.0001, respectively) than offspring of hypertensive parents.

CONCLUSION

We observed blunted endothelium-dependent dilatation and aortic stiffness in offspring of hypertensive parents compared with offspring of normotensive [corrected] parents. This is evident in the absence of overt hypertension and other diseases, suggesting that parental history of hypertension is a risk for subclinical atherosclerosis and it may contribute to the progression to hypertension and overt atherosclerosis in later life.

Parental blood pressure is related to vascular properties of their 5-year-old offspring

BACKGROUND

Adolescent offspring of hypertensive parents have increased carotid intima media thickness (CIMT) and arterial stiffness compared with offspring of normotensives. We assessed whether systolic blood pressure (SBP) of both parents is associated with the vasculature of their offspring as early as in childhood.

METHODS

In the first 306 5-year-old children of the Wheezing-Illnesses-Study-Leidsche-Rijn birth cohort, CIMT, distensibility, and elastic modulus (EM) were obtained ultrasonographically. In 204 of 306 (67%) children, complete data on both maternal and paternal SBP were obtained from the linked database of the Utrecht Health Project.

RESULTS

CIMT of the children was 0.58 µm (95% confidence interval (CI): 0.14, 1.0) greater with every 1-mm Hg higher maternal SBP. Maternal SBP and children's distensibility and EM were more strongly associated, negative and positive respectively, with increasing paternal SBP and vice versa (P value-for-interaction: 0.003 and 0.001, respectively). CIMT of children of whom both parents were in the highest SBP tertile was 17.9 µm (95% CI: 4.0, 31.9) greater compared with the CIMT of children of whom neither one of the parents had a SBP in the highest tertile. For EM and distensibility, these estimates were 20.1 kPa (95% CI: 1.1, 39.2) and -11.6 1/Mpa (95%-CI: -22.9, -0.31), respectively.

CONCLUSIONS

Higher maternal SBP is related to thicker arterial walls in their 5-year-old offspring. If both parents have higher SBP, the arterial wall of their offspring is thicker and stiffer.

Parental history of hypertension is associated with narrower retinal arteriolar caliber in young girls

We aimed to assess the associations between parental history of hypertension and indicators of cardiovascular risk (retinal vessel diameter, presence of obesity, and elevated blood pressure) in prepubertal children. There were 1739 (77.7% of those eligible) 6-year-old students (863 girls and 876 boys) who were examined from a random cluster sample of 34 Sydney schools. Parents completed questionnaires about their medical conditions, including whether they have/had hypertension. Retinal images were taken with a digital fundus camera, and retinal vessel caliber was quantified using computer software. Anthropometric (height, weight, percentage of body fat, and body mass index) and blood pressure measures were collected. There were 160 children (9.2%) with a positive parental history of hypertension (either biological mother and/or father). Children with a positive versus negative parental history of hypertension had significantly higher body mass index (16.8 versus 16.5 kg/m(2); P=0.04) and systolic blood pressure (101.3 versus 99.8 mm Hg; P=0.01). Girls with positive versus negative parental history of hypertension had significantly higher diastolic blood pressure (≈3.1 mm Hg; P=0.01) and narrower retinal arteriolar caliber (≈4.3 μm; P=0.0004). Positive parental history of hypertension was not associated with mean retinal vascular caliber among boys. We show that a positive parental history of hypertension in healthy prepubertal girls, but not boys, is associated with narrower retinal arteriolar vessels, likely conveying a predisposition to develop hypertension later in life. These findings may indicate the need for cardiovascular disease prevention measures starting early in life among offspring of hypertensive parents.

Cardiac and vascular consequences of pre-hypertension in youth

Hypertension is associated with increased left ventricular mass (LVM) and carotid intima-media thickness (cIMT), which predict cardiovascular (CV) events in adults. Whether target organ damage is found in pre-hypertensive youth is not known. The authors measured body mass index, blood pressure, fasting glucose, insulin, lipids and C-reactive protein, LVM/height(2.7) (LVM index), diastolic function, cIMT, carotid stiffness, augmentation index, brachial artery distensibility, and pulse wave velocity (PWV) in 723 patients aged 10 to 23 years (29% with type 2 diabetes mellitus). Patients were stratified by blood pressure level (normotensive: 531, pre-hypertensive: 65, hypertensive: 127). Adiposity and CV risk factors worsened across blood pressure group. There was a graded increase in cIMT, arterial stiffness, and LVM index and decrease in diastolic function from normotension to pre-hypertension to hypertension. In multivariable models adjusted for CV risk factors, status as pre-hypertension or hypertension remained an independent determinant of target organ damage for LVM, diastolic function, internal cIMT, and carotid and arterial stiffness. Pre-hypertension is associated with cardiovascular target organ damage in adolescents and young adults.

Age-related changes of regional pulse wave velocity in the descending aorta using Fourier velocity encoded M-mode

Aortic pulse wave velocity (PWV) is an independent determinant of cardiovascular risk. Although aortic stiffening with age is well documented, the interaction between aging and regional aortic PWV is still a debated question. We measured global and regional PWV in the descending aorta of 56 healthy subjects aged 25-76 years using a one-dimensional, interleaved, Fourier velocity encoded pulse sequence with cylindrical excitation. Repeatability across two magnetic resonance examinations (n = 19) and accuracy against intravascular pressure measurements (n = 4) were assessed. The global PWV was found to increase nonlinearly with age. The thoracic aorta was found to stiffen the most with age (PWV [thoracic, 20-40 years] = 4.7 ± 1.1 m/s; PWV [thoracic, 60-80 years] = 7.9 ± 1.5 m/s), followed by the mid- (PWV [mid-abdominal, 20-40 years] = 4.9 ± 1.3 m/s; PWV [mid-abdominal, 60-80 years] = 7.4 ± 1.9 m/s) and distal abdominal aorta (PWV [distal abdominal, 20-40 years] = 4.8 ± 1.4 m/s; PWV [distal abdominal, 60-80 years] = 5.7 ± 1.4 m/s). Good agreement was found between repeated magnetic resonance measurements and between magnetic resonance PWVs and the gold-standard. Fourier velocity encoded M-mode allowed to measure global and regional PWV in the descending aorta. There was a preferential stiffening of the thoracic aorta with age, which may be due to progressive fragmentation of elastin fibers in this region.

Autonomic nervous system and microvascular alterations in normotensives with a family history of hypertension

Autonomic nervous system and microvascular alterations at pre-hypertensive stage of hypertension have still not been fully elucidated. We aimed at addressing central and local influences on microvascular reactivity at pre-hypertensive stage of hypertension. To that end, we studied microvascular reactivity in 59 normotensives with a family history of hypertension and 46 controls. We measured laser-Doppler flow on the finger nailfold skin in the resting condition, after an 8-min occlusion of digital arteries and during local nitroglycerin application. Finger pressure, pulse and ECG were monitored by a Finapres device. Heart rate power spectral analysis was performed using Fast Fourier transformation. Baroreflex sensitivity was estimated by the sequence method. Normotensives with a family history of hypertension showed higher systolic pressure, decreased high-frequency power of the heart rate variability spectrum and reduced baroreflex sensitivity in the resting condition as well as decreased fundamental frequency of laser-Doppler flow oscillations during nitroglycerin application. We conclude that normotensives with a family history of hypertension exhibit altered sympathovagal balance with decreased parasympathetic activity at the cardiac level as well as increased myogenic microvascular reactivity.

Blood Pressure Is Lower in Children and Adolescents With a Low-Saturated-Fat Diet Since Infancy

Blood pressure was measured in the prospective randomized Special Turku Coronary Risk Factor Intervention Project Study with an oscillometric method every year from 7 months to 15 years of age in 540 children receiving a low-saturated-fat, low-cholesterol diet and in 522 control children. Dietary intakes, family history of parental hypertension, and grandparental vascular disease were recorded. Systolic and diastolic blood pressures were 1.0 mm Hg lower (95% CI for systolic: −1.7 to −0.2 mm Hg; 95% CI for diastolic: −1.5 to −0.4 mm Hg) in children receiving low-saturated-fat counseling through childhood than in control children. Intakes of saturated fat were lower ( P <0.001), those of polyunsaturated fat higher ( P <0.001), and intakes of potassium slightly higher ( P =0.002) in the intervention group, but sodium intakes were not influenced by the intervention ( P =0.76). Children whose parents were hypertensive had 4- to 6-mm Hg higher systolic and 3- to 4-mm Hg higher diastolic blood pressures than children of normotensive parents ( P <0.001). Diastolic blood pressure of children with grandparental vascular disease, ie, early cardiovascular or cerebrovascular disease, tended to be higher than that of children with no grandparental disease ( P =0.051). We conclude that restriction of saturated fat from infancy until 15 years of age decreases childhood and adolescent blood pressure with a meaningful population-attributable amount. The importance of childhood lifestyle counseling and primary prevention of hypertension should be emphasized, especially in those children with a family history of hypertension or atherosclerotic vascular disease.

Family history of hypertension and arterial elasticity characteristics in healthy young people

Family history of hypertension is a primary predictor of high blood pressure (BP). This study attempted to determine whether there is a gradual increase in BP and an early change in arterial elasticity characteristics between young healthy individuals with or without a family history of hypertension and whether or not this increase is apparent in males as well as in females. A total of 270 normotensive healthy individuals (112 men and 158 women, aged 16 to 30 years) with or without a family history of hypertension, participated in conventional BP measurement and completed questionnaires covering basic information and a detailed family history of cardiovascular disease. Large arterial (capacitive) compliance (C1) and small arterial (oscillatory or reflective) compliance (C2) were derived from HDI/PulseWave CR-2000 (Hypertension Diagnostics, Minneapolis, USA). Based on family history information about parents and grandparents, three groups were formed: subjects with at least one hypertensive parent (group A), subjects with only hypertensive grandparents (group B), and subjects with normotensive parents and grandparents (group C). Men in group A had lower C1 and C2 along with higher systolic BP (SBP), diastolic BP (DBP), and heart rate than men in group C. Those in group B had intermediate C1, C2 and BP levels. C1 had a linear relationship with SBP, DBP, and heart rate. In the logistic regression model of family history of hypertension, C2 was lower in young normotensive males with parental hypertension (B = -0.315, exp B = 0.73, p = 0.03), independently of SBP, DBP, and heart rate. Among females, subjects with parental hypertension had higher systolic, mean arterial pressure, and pulse pressure (p < 0.05), and there were no significant differences in C1 and C2 between those with and those without parental hypertension. In conclusion, compared with normotensive offspring of normotensive parents, normotensive offspring of hypertensive parents had increased BP and impaired arterial properties, namely large and small arterial compliance as measured noninvasively by HDI. These differences were exhibited conspicuously in men but not in women. Alteration in arterial function in young non-hypertensive subjects may be a risk factor for hypertension and may contribute to the progression to hypertension later in life.

Arterial function in youth: window into cardiovascular risk

Noninvasive measures of arterial function, such as intima-media thickness (IMT), endothelial function, and arterial stiffness are associated with and are prognostic of cardiovascular events in adults. Postmortem evidence, however, has established that the atherosclerotic process starts in childhood. Furthermore, cardiovascular morbidities in childhood disrupt arterial health and may lead to adverse outcomes in adulthood. Thus it is important to examine the developmental changes in IMT, endothelial function, and arterial stiffness in healthy youth in contrast to the arterial health profile of youth with cardiovascular morbidities and to examine the effect of lifestyle interventions. In healthy youth, IMT may increase slightly, arterial stiffness increases, but there is no change in endothelial function from 5 to 20 years of age. In youth with cardiovascular risk factors there are larger increases in IMT and arterial stiffness, and reductions in endothelial function compared with healthy youth. The reduced arterial function in youth with cardiovascular risk factors may be related to the atherosclerotic process. Exercise and physical activity appear to exert a protective effect on arterial function, and exercise training can improve arterial function in children with cardiovascular risk factors. Furthermore, although diet alone can improve arterial function in children, the combination of exercise and diet appears to be more effective than either intervention alone. Future studies need to focus on the mechanism by which exercise and diet improve arterial function, the most effective types of diet and exercise, and if intervening in childhood leads to favorable outcomes in adulthood.

Age, hypertension and arterial function

1. Ageing exerts a marked effect on the cardiovascular system and, in particular, the large arteries. Using a variety of techniques to assess arterial stiffness, many cross-sectional studies have demonstrated a significant relationship between age and aortic stiffness, although the age-related changes observed in peripheral arteries appear to be less marked. 2. The relationship between arterial stiffness and hypertension is more complex. The distending, or mean arterial, pressure is an important confounder of measurements of arterial stiffness and, therefore, must be taken into consideration when assessing arterial stiffness in hypertensive subjects or investigating the effect of antihypertensive agents. Current methods for correcting for differences in distending pressure involve pharmacological manipulation, statistical correction or mathematical manipulation of stiffness indices. 3. Many studies have provided evidence that both peripheral (muscular) and central (elastic) arteries are stiffer in subjects with mixed (systolic/diastolic) hypertension compared with normotensive subjects. However, it is unclear to what extent differences in mean arterial pressure explain the observed differences in hypertensive subjects. In contrast, isolated systolic hypertension is associated with increased aortic, but not peripheral artery, stiffness, although the underlying mechanisms are somewhat unclear. 4. Traditional antihypertensive agents appear to reduce arterial stiffness, but mostly via an indirect effect of lowering mean pressure. Therefore, therapies that target the large arteries to reduce stiffness directly are urgently required. Agents such as nitric oxide donors and phosphodiesterase inhibitors may be useful in reducing stiffness via functional mechanisms. In addition, inhibitors or breakers of advanced glycation end-product cross-links between proteins, such as collagen and elastin, hold substantial promise.

Increased arterial stiffness in children on haemodialysis

BACKGROUND

Measures of aortic stiffness--aortic pulse wave velocity (PWV) and augmentation index (AIx)--have been shown to be powerful predictors of survival in adult haemodialysis (HD) patients. Very few data have been reported regarding arterial stiffness in paediatric renal populations.

METHODS

PWV and aortic AIx were determined from contour analysis of arterial waveforms recorded by applanation tonometry using a SphygmoCor device in 14 children on HD (age = 14.1 years) and in 15 age, height matched children controls.

RESULTS

Pre-HD AIx (29.7 +/- 15.4%) and PWV (6.6 +/- 1.0 m/s) were significantly higher compared with children controls (8.3 +/- 8.0% and 5.4 +/- 0.6 m/s, respectively, P < 0.0001). The only significant difference between normal and HD children was BP level: 103/61 vs 114/72 mmHg, P < 0.05. In children of HD patients, a multiple linear regression model including BP, age, height, weight, Ca and P levels as independent variables accounted for 57% of the variability in AIx. Dialysis had no impact on AIx (post-HD: 28.5 +/- 12.7%) or on PWV (post-HD: 6.7 +/- 0.8 m/s).

CONCLUSIONS

We show, in this first-ever report of increased arterial stiffness in children on dialysis, that end-stage renal disease is associated with abnormalities in arterial wall elastic properties, comparable with adult levels, even in childhood. Most importantly, the absence of a discernible amelioration with dialysis implies that purely structural and not functional alterations lie behind the increased arterial stiffness.

The lord of the ring: mandatory role of the kidney in drug therapy of hypertension

Strong evidence supports the idea that total peripheral resistance (TPR) is increased in all forms of human and experimental hypertension. Although the etiological participation of TPR in the origin and long-term maintenance of hypertension has been extensively debated, it now seems clear that the renal, nonadaptive, infinite gain-working, pressure-sensitive natriuresis and diuresis is the main mechanism of blood pressure control in the long term. The tissue, cellular, biochemical, and genetic sensors and executors of this process have not been fully identified yet, but the role of the renal medulla has gained growing attention as the physiopathological scenario in which the key regulatory elements reside. Specifically, the functionality of the renomedullary vasculature seems to be highly responsible for blood pressure control. The vasculature of the renal medulla becomes a new and more specific target for the therapeutic intervention of hypertension. Recent data on the effect of baroreceptor-controlled renal sympathetic activity on the long-term regulation of blood pressure are integrated. The renomedullary effects of the main antihypertensive drugs are discussed, and new perspectives for the therapeutic intervention of hypertension are outlined. Comparison of the genetic program of the renal medulla before and after the development of hypertension in spontaneously hypertensive and experimentally induced animal models might provide a mechanism for identifying the key genes that become activated or suppressed in the development of high blood pressure. These genes, their encoded proteins, or other elements related to their signalling and genetic pathways might serve as new and more specific targets for the pharmacological treatment of abnormally elevated blood pressure. Besides, proteins specifically located to the luminal side of the renomedullary vascular endothelium may serve as potential targets for site-directed drug and gene therapy.

Cardiovagal autonomic function in sedentary and trained offspring of hypertensive parents

In young normotensive subjects, parental hypertension is associated with stiffening of the carotid artery and reduction in cardiovagal outflow and baroreflex gain. In subjects without parental hypertension regular exercise training was found to attenuate age-related reduction in carotid compliance and baroreflex gain. The aim of the present study was to test the hypothesis that regular physical activity is associated with better parameters of carotid artery elasticity, increased cardiovagal outflow and higher baroreflex gain in normotensive offspring of hypertensive parents. We studied 98 healthy, sedentary or endurance exercise trained subjects (49 men, 18-27 years of age) with or without family history of hypertension (FH(+) and FH(-), respectively) in a cross-sectional design. In the sedentary group spontaneous baroreflex indices (sequence method and spectral techniques) were lower in FH(+) subjects than in their FH(-) peers, while in trained subjects these indices were not different between FH(+) and FH(-). Furthermore, in the FH(+) group trained subjects had higher baroreflex indices than their sedentary peers, while in the FH(-) group no significant differences were found. Carotid compliance and distensibility coefficient (echo-tracking ultrasound and applanation tonometry) were not different in FH(-) sedentary and trained subjects, but were higher in FH(+) trained subjects as compared to their sedentary peers. Significant but modest relationships were found between spontaneous baroreflex indices and carotid artery elastic parameters across all subjects. Our present data indicate that in subjects with parental hypertension aerobic exercise training is associated with higher levels of cardiovagal outflow and baroreflex gain, which finding, however, is not explained by greater elasticity of the carotid artery.

Cardiovascular reactivity to work stress predicts subsequent onset of hypertension: the Air Traffic Controller Health Change Study

OBJECTIVE

The hypothesis that increased blood pressure reactivity to stress is an early risk marker of hypertension was tested in a 1994 follow-up of the 1974 to 1978 Air Traffic Controller Health Change Study sample.

METHODS

Assessments in 1974 to 1978 included physical examinations and recordings (every 20 minutes for 5 hours) of both workload (planes within controller airspace) and blood pressure reactivity. Individual differences in reactivity were used to predict 1994 self-report of ever having been told by a physician to take antihypertensive medication, assessed in a telephone survey of 218 respondents who were normotensive or stage 1 hypertensive in 1974 to 1978.

RESULTS

Each SD increase in baseline systolic reactivity was associated with a 1.7 (p <.019) increase in the relative-odds of 1994 hypertension, after controlling for age, body mass index, and clinic systolic and diastolic blood pressure at clinical examination, with effects comparable for baseline normotensives and stage 1 hypertensives.

CONCLUSION

A 20-year follow-up of originally normotensive and stage I hypertensive workers suggests that increased systolic blood pressure reactivity to work stress is associated with long-term risk of hypertension.

The Atherosclerosis Risk in Young Adults (ARYA) study: rationale and design

INTRODUCTION

Despite recent advances in treatment, cardiovascular disease (CVD) is still health problem number one in western societies. Aiming at specific prevention strategies for high-risk individuals and shifting the available prevention programs towards younger age groups might increase the success of primary prevention. However, before addressing age-specific prevention programs, more insight in the determinants of early vascular damage and increased cardiovascular risk is warranted as well as insight in determinants increased cardiovascular risk, including vascular damage, at an early age. The Atherosclerosis Risk in Young Adults (ARYA) study was specifically designed to address this issue.

OBJECTIVES

The ARYA study started off with studies evaluating (1) whether it is possible to predict cardiovascular risk at young adulthood by routinely measured adolescent data, and (2) evaluating the role of birth characteristics and adolescent characteristics to the development of vascular damage at young adulthood.

METHODS

The ARYA study comprises of two cohorts of young adults. The Utrecht cohort includes 750 young adults, aged 27-30 years. The Hague-cohort includes 261 young adults born between 1963 and 1968. Data on birth characteristics, growth in early infancy as well as adolescent anthropometry, blood pressure, lipids, body mass index were obtained from the original medical records of the Municipal Health Service. In 1999/2001, the extent of subclinical vascular damage was measured using carotid wall thickness and aortic stiffness. Also, data on adult cardiovascular risk profile, bone density and central blood pressure were assessed, fasting blood was drawn and timed overnight urine samples were collected.

CONCLUSION

The ARYA study is aimed to provide data on early determinants of cardiovascular risk, including vascular damage, at an early age. This knowledge enhances the understanding of atherosclerosis development and CVD risk and is needed to improve the available primary prevention programs.

Rarefaction of skin capillaries in normotensive offspring of individuals with essential hypertension

BACKGROUND

Rarefaction of skin capillaries in people with intermittent borderline essential hypertension suggests a primary or an early abnormality that may antedate the onset of sustained hypertension.

OBJECTIVE

To compare skin capillary density in subjects with and without a family history of essential hypertension.

SUBJECTS

21 normotensive individuals, one or both of whose parents had essential hypertension (mean age 39.3 years; blood pressure 124/79 mm Hg); 21 normotensive controls with no family history of hypertension (age 46.3 years; blood pressure 124/78 mm Hg).

METHODS

The skin of the dorsum of the fingers was examined by intravital capillary microscopy before and after venous congestion at 60 mm Hg for two minutes.

RESULTS

By analysis of variance, both baseline and maximum skin capillary density were lower in subjects with a family history of essential hypertension than in those with no family history (baseline: 67 v 79 capillaries per field, p = 0.008; maximum: 74 v 93 capillaries per field, p < 0.0005).

CONCLUSIONS

Capillary rarefaction in essential hypertension may occur before the increase in blood pressure and could, at least in part, reflect a primary rather than a secondary abnormality.

Effect of angiotensin II on pulse wave velocity in humans is mediated through angiotensin II type 1 (AT(1)) receptors

The objective of this study was to examine the effect of angiotensin II (Ang II) and angiotensin II type 1 (AT(1)) receptor blockade on pulse wave velocity (PWV) in healthy humans. We studied nine young male volunteers in a double-blind randomised crossover design. Carotid-femoral PWV (an index of arterial stiffness) was measured by using a Complior machine. Subjects were previously treated for 3 days with once-daily dose of either a placebo or valsartan 80 mg. On the third day, they were infused with either placebo or 5 ng/kg/min of Ang II over 30 min. Subjects thus received placebo capsule + placebo infusion (P), valsartan + placebo infusion (V), placebo + Ang II infusion (A), and valsartan + Ang II infusion (VA) combinations. Heart rate (HR), blood pressure and PWV were recorded at baseline and then every 10 min during infusion and once after the end of infusion. There were significant increases in systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) with A compared with P (P = 0.002, P = 0.002, P = 0.001 respectively). These rises in blood pressure were completely blocked by valsartan. A significant rise in PWV by A was seen compared with P (8.38 +/- 0.24 vs 7.48 +/- 0.24 m/sec, P = 0.013) and was completely blocked by valsartan; VA compared with P (7.27 +/- 0.24 vs 7.48 +/- 0.24 m/sec, P = NS). Multiple linear regression analysis showed that blockade of Ang II induced increase in blood pressure by valsartan contributed to only 30% of the total reduction in Ang II induced rise in PWV (R(2) = 0.306). The conclusions were that valsartan completely blocks the effect of Ang II on PWV. The effect of Ang II on PWV is mediated through AT(1)receptors. Reduction in PWV by Ang II antagonist is not fully explained by its pressure lowering effect of Ang II and may be partially independent of its effect on blood pressure.