H. Neus

Ambulatory Blood Pressure in Children Followed for 3 Years: Influence of Sex and Family History of Hypertension

In 100 children (63 boys and 37 girls) aged 11.3 +/- 0.6 years ambulatory blood pressure (BP) was recorded by a semi-automatic device (Remler) 9 times per year over a period of 3 years. A sex difference in systolic BP was noted from the age of 13 years on with boys having higher values by about 6 mmHg (p less than .05). This could not be explained by differences in weight. In boys parental hypertension was associated with higher systolic values independent on age (p less than .05). Genetic and hormonal factors seem to influence BP during male puberty independently from each other.

Basal blood pressure variability and reactivity of blood pressure to emotional stress in essential hypertension

SummaryBlood pressure variability under basal conditions and blood pressure reactivity to emotional stress were studied in 38 hypertensives and 13 normotensives.Systolic basal blood pressure variability correlated with systolic blood pressure reactivity. Variability increased with higher basal blood pressure. Thus in the hypertension group the blood pressure variability was greater than in the normotension group. Besides, the hypertension group showed a greater reactivity of systolic blood pressure to emotional stress, too. An influence of age on basal blood pressure, blood pressure variability, and reactivity could be evaluated; but no influence of sex on these parameters was detected.The results indicate that variability and reactivity of blood pressure can be referred to a common central nervous blood-pressure-regulating mechanism. As both parameters are increased in hypertension, a greater lability of blood pressure must be assumed. This greater lability may be attributed to a stronger neurogenic influence or to structural changes of peripheral blood vessels.

Zur reaktion der fingerpulsamplitude auf belärmung

Summary1.Forty-three (30 male and 13 female) subjects were exposed to traffic noise of ca. 72 dB. Their reactions concerning blood pressure, pulse pressure, finger pulse amplitude and radialis pulse amplitude, heart rate, breathing rate, and integrated EMG were analyzed.2.Each of the circulatory parameters exhibited significant reactions in either direction in more than 40% of the subjects. The vasoconstrictive reaction in finger pulse amplitude was most outstanding. Moreover, pulse pressure, radialis pulse amplitude and, heart rate also tended to decrease whereas diastolic blood pressure tended to increase. Breathing rate and EMG remained mainly unchanged.3.Owing to the different direction of reactions the mean values of a sample can yield possibly misleading information. Furthermore, it is suggested that the reaction of finger pulse amplitude should be related to the standard deviation of the prestimulus resting period instead of to the mean value of this period.4.Male subjects react with a stronger decrease of heart rate than female subjects. Male subjects with higher diastolic casual blood pressure and heart rate values exhibit stronger decreases in finger pulse amplitude and heart rate. Older male subjects tend to react with an increase of heart rate.5.Within the male subjects, the reaction of finger pulse amplitude correlated positively with the reactions of pulse pressure and heart rate, but not with the reaction of radialis pulse amplitude. The attempt to distinguish between vasoactive and pressure-dependent components in finger pulse amplitude means of radialis pulse amplitude failed, which is probably a consequence of artifacts in radialis pulse amplitude.6.These results confirm the hypotheses that compensatory mechanisms influence the reactions caused by noise. There is no essential increase in blood pressure, sympathetic and parasympathetic activity being simultaneously increased.Zusammenfassung1.Dreiundvierzig Versuchspersonen (30 Männer und 13 Frauen) wurden mit Verkehrslärm von ca. 72 dB (A) belastet. Ihre Reaktionen in Blutdruck, Blutdruck-, Fingerpuls- und Radialispulsamplitude, Herzfrequenz, Atemfrequenz and Myointegral wurden untersucht.2.Jeder Kreislaufparameter zeigte in über 40% der Versuchspersonen signifikante Reaktionen in unterschiedlicher Richtung. Am deutlichsten war dabei ein Trend der Fingerpulsamplitude zur Verengung erkennbar. Blut druck- und Radialispulsamplitude sowie Herzfrequenz neigten ebenfalls zum Abfall, der diastolische Blutdruck zum Anstieg. Demgegenüber blieben Atemfrequenz und Myointegral weitgehend unverändert.3.Die unterschiedliche Richtung der Reaktionen läßt Mittelwertbildungen im Kollektiv als potentiell irreführend erscheinen. Weiterhin wird vorgeschlagen, die Fingerpulsreaktion auf die Standardabweichung der Vorruhe statt auf den Mittelwert der Vorruhe zu beziehen.4.Männer reagieren mit stärkeren Herzfrequenzabfällen als Frauen. Innerhalb der Männer zeigten Fingerpulsamplitude und Herzfrequenz bei erhöhten diastolischen Gelegenheitsblutdruckwerten und -herzfrequenzen stär kere Abnahmen. Ältere Männer reagieren eher mit Herzfrequenzanstiegen.5.Innerhalb der Männer korrelierte die Fingerpulsamplitude positiv mit der Reaktion von Blutdruckamplitude und Herzfrequenz, nicht aber mit der der Radialispulsamplitude. Der Versuch, mit Hilfe der Radialispulsamplitude vasoaktive und druckpassive Anteile der Fingerpulsamplitude zu trennen, zeigte keine befriedigenden Ergebnisse. Ursache ist vermutlich eine starke Artefaktanfälligkeit der Radial ispulsamplitude.6.Die dargestellten Ergebnisse stützen die Hypothese, daß Gegenregulationen die Reaktionen auf Dauerlärm beeinflussen. Bei gleichzeitiger sympathischer und parasympathischer Erregung kommt es zu keiner nennenswerten Blutdruckerhöhung.1. Forty-three (30 male and 13 female) subjects were exposed to traffic noise of ca. 72dB. Their reactions concerning blood pressure, pulse pressure, finger pulse amplitude and radialis pulse amplitude, heart rate, breathing rate, and integrated EMG were analyzed. 2. Each of the circulatory parameters exhibited significant reactions in either direction in more than 40% of the subjects. The vasoconstrictive reaction in finger pulse amplitude was most outstanding. Moreover, pulse pressure, radioalis pulse amplitude and, heart rate also tended to decrease whereas diastolic blood pressure tended to increase. Breathing rate and EMG remained mainly unchanged. 3. Owing to the different direction of reactions the mean values of a sample can yield possible misleading information. Furthermore, it is suggested that the reaction of finger pulse amplitude should be related to the standard deviation of the prestimulus resting period instead of to the mean value of this period. 4. Male subjects react with a stronger decrease of heart rate than female subjects. Male subjects with higher diastolic casual blood pressure and heart rate values exhibit stronger decreases in finger pulse amplitude and heart rate. Older male subjects tend to react with an increase of heart rate. 5. Within the male subjects, the reaction of finger pulse amplitude correlated positively with the reactions of pulse pressure and heart rate, but not with the reaction of radialis pulse amplitude. The attempt to distinguish between vasoactive and pressure-dependent components in finger pulse amplitude means of radialis pulse amplitude failed, which is probably a consequence of artifacts in radialis pulse amplitude.

Traffic noise and hypertension: An epidemiological study on the role of subjective reactions

SummaryTraffic noise is discussed as a possible risk factor for hypertension. However, no data are available concerning the moderating effect of the subjective reactions and the noise attitudes. In the present epidemiological study the relationship between these subjective factors and blood pressure was investigated separately for the inhabitants of two residential areas. One area had high traffic volumes, resulting in a high sound level (Leq > 73 db (A), noisy area); the other was socially comparable but with an essentially low sound level (Leq < 51 db (A), control area). The relationship between the subjective reactions and blood pressure was checked by analyzing the incidence of treatment for hypertension (n =919) and by analyzing the change of casual blood pressure after living 2.25 years in the respective residential area in a subgroup of those who had been normotensive (n = 36).The results obtained by either of these approaches indicate that the subjective factors do not modify the risk of hypertension in noisy areas, whereas they seem to be relevant for medium size stimuli. It is concluded that one can physiologically cope with low stimuli, but this is impossible for extreme stimuli. The results suggest also that the subjective reaction to extreme stimuli is strongly biased by attitudes which cannot be related to blood pressure. The family history of hypertension was found to be independent of the subjective reactions to noise.

Intermittent ambulatory blood pressure recordings in children: Methodological aspects and influence of family history on hypertension

SummaryIn 100 children of different school classes (10–12 years, participation rate ca. 50%) ambulatory blood pressure (BP) was recorded by a semi-automatic non-invasive device (Remler system). BP was measured every 1/2 h between 2 and 7.30 p.m. During each measurement the children protocolled their activity. These BP recordings were repeated five times at monthly intervals in 86 children. In the same children casual and near basal BP was determined. The mean ambulatory BP was 103/64±7/6 mm Hg. The average retest reliability of the monthly mean values wasr=0.57 for systolic andr=0.45 for diastolic BP. The variability of BP (standard deviation) was not reproducible. Data recording failed in 32% of all single systolic and in 42% of all single diastolic BP measurements. These drop-outs were caused by inappropriate use rather than technical problems. There was a relationship between procolled activities and systolic BP. On average, ambulatory BP was lower than BP under standardized conditions. Under all conditions, children with hypertensive parents exhibited a 6 mm Hg higher systolic BP than children without a similar family history. No sex differences were found.

Blutdruckreaktivität unter emotionalem Streß bei unkomplizierten Formen des Hochdrucks

SummaryBlood pressure behavior under basal conditions and emotional stress was examined in 48 patients with elevated casual blood pressure values who had no hypertensive cardiovascular complications and in 48 normotensives of the same age. In order to study possible interactions with age and sex each group was divided in two age and two sex subgroups respectively.Under basal conditions the blood pressure values of the hypertensive group were within the normal range but markedly higher than the values of the normotensive group. During stress the difference between both groups increased because the hypertensive group exhibited a stronger reactivity of blood pressure. There was an interaction between sex and hypertension in that in contrast to the hypertensive group normotensive women had lower blood pressure values at rest and under emotional stress than men. There was an influence of age consisting in a stronger blood pressure reactivity of the older subjects; this effect could be found in the hypertensive as well as in the normotensive group.Patients with uncomplicated forms of hypertension exhibit a blood pressure hyperreactivity on emotional stress independendly of age and sex. According to previous investigations normotensive subjects with a family history of hypertension show stronger blood pressure reactivity, too. Therefore this phenomenon must be regarded as important in the pathogenesis of essential hypertension.ZusammenfassungBei 48 Patienten mit erhöhten Gelegenheitsblutdruckwerten ohne hypertoniebedingte kardiovaskuläre Komplikationen und 48 altersgleichen normotonen Vergleichsprobanden wurde das Blutdruckverhalten unter strengen Ruhebedingungen und emotionalem Streß untersucht. Um dabei gleichzeitig mögliche Wechselwirkungen mit Alter und Geschlecht zu erfassen, wurden die beiden Gruppen in jeweils zwei Alters- und zwei Geschlechtsgruppen unterteilt.Die hypertone Gruppe wies unter strengen Ruhebedingungen zwar einen im Normbereich liegenden Blutdruck auf; dieser lag aber deutlich höher als bei der normotonen Gruppe. Während der Streßphase war dieser Unterschied noch deutlicher ausgeprägt, da die hypertone Gruppe einen stärkeren Blutdruckanstieg auf den emotionalen Streß zeigte als die normotone Gruppe. Eine Wechselwirkung zwischen Geschlecht und Hypertonie bestand insofern, als normotone Frauen in Ruhe und während Belastung einen niedrigeren Blutdruck aufwiesen als normotone Männer, in der hypertonen Gruppe aber keine Geschlechtsunterschiede des Blutdrucks bestanden. Ein Alterseffekt war in der bei den älteren Probanden verstärkten Blutdruckreaktivität feststellbar; dieser Effekt war sowohl bei der normotonen wie bei der hypertonen Gruppe zu finden.Personen mit unkomplizierten Formen des Hochdrucks weisen also unabhängig von Alter und Geschlecht eine Blutdruckhyperreaktivität unter emotionalem Streß auf. Da nach früheren Untersuchungen auch bei normotonen Personen mit einer hereditären Hypertoniebelastung die verstärkte Blutdruckreaktivität besteht, muß diesem Phänomen eine besondere Bedeutung in der Pathogenese der essentiellen Hypertonie zugemessen werden.

Reliability and Validity of Ambulatory Blood Pressure Recording in Children

We investigate whether ambulatory BP (aBP) recording in children reflects situational variations and whether aBP depicts the impact of heightened cardiovascular reactivity under mental challenge, and gender on changes in BP. Results of 19 aBP protocols (2 to 7.30 p.m. after school; 30 min intervals) in 86 children, performed during 2 years of follow-up show that repetitive ambulatory blood pressure (aBP) recording reflects the great variability of environmental stimuli in children. Mean aBP is highly correlated with self-reported physical activity. Systolic aBP correlates with cardiovascular changes under mental arithmetic and - to a lesser degree - during bicycle exercise. Ambulatory BP recording is a sensitive method to detect the influence of hyperreactivity and gender on BP development in children at the age of 10-13 yrs.

Effects ofβ-blockers on type-A coronary-prone behaviour

SummaryThe influence of coronary-prone behaviour on coronary heart disease is well established, but the link between behavioural and pathophysiological processes is still unknown. Aβ-adrenergic hyper-reactivity of type-A subjects is assumed. In this investigation the influence ofβ-blockers on the type-A behaviour pattern was tested in an inter-individual comparison. Sixteen male hypertensive subjects (stage I or II) were divided at random into two therapeutic groups (β-blockers vs diuretics). Each patient was given a type-A interview before therapy and at a minimum of 4 weeks after the onset of therapy. Subjects in both groups were similar in age and before therapy they had similar blood pressure at rest as well as similar cardiovascular reactivity and type-A behaviour pattern. After therapy, subjects in the group treated withβ-blockers exhibited less type-A behaviour than those in the group treated with diuretics. The possible influence of the attenuation of the type-A behaviour on the risk of coronary heart disease should be investigated in a prospective study.ZusammenfassungDie Wirkung koronargefährdender Verhaltensweisen (Typ-A-Verhalten) für die koronare Herzerkrankung ist bekannt. Eineβ-sympathomimetische Übererregbarkeit bei Typ-A-Personen wird vermutet, wenn auch der pathophysiologische Mechanismus noch nicht vollständig geklärt wurde. Bei der jetzigen Untersuchung wurde der Einfluß vonβ-Blockern auf das Typ-A-Verhalten in einem interindividuellen Vergleich gemessen. 16 männliche Hypertoniker wurden randomisiert in 2 Therapiegruppen (β-Blocker und Diuretika) aufgeteilt. Das Typ-A-Interview wurde bei jedem Patienten einmal vor Therapie durchgeführt und frühestens 4 Wochen nach Therapiebeginn wiederholt. Bezüglich Alter, Ruheblutdruck, kardiovaskulärer Reaktivität und Typ-A-Verhalten vor Therapie zeigten sich zwischen diesen beiden Gruppen keine Unterschiede. Nach Therapie waren bei der Gruppe, die mitβ-Blockern behandelt wurde, die Typ-A-Verhaltensweisen im Vergleich zu der Gruppe, die mit Diuretika behandelt wurde, geringer ausgeprägt. Die klinische Bedeutung dieser Ergebnisse im Hinblick auf die koronare Herzerkrankung muß in einer prospektiven Studie geklärt werden.

Selected Topics in the Methodology of Stress Testing: Time Course, Gender and Adaptation

The time course of haemodynamic reactions to mental stress has not received much attention in the psychophysiological literature. However, the data suggest that the time course of cardiovascular adaptation to active coping tasks might be important to the analysis of cardiovascular control mechanisms. With mental arithmetic, a steady state of circulatory parameters is reached after one to two minutes of stress exposure, so that representative stress values can be calculated. In the first two minutes transient changes occur. Evidence is presented that the arterial baroreflex and autoregulation contribute to these changes. The initial peak generally seen in heart rate seems to be indicative of sympathetic drive to the heart and functional hyperreactivity.

Cardiovascular reactivity to methacholine in normotensives with genetic risk of hypertension.

Hemodynamic reactivity to methacholine (0,1 mg/kg bodyweight) was studied in 10 normotensives with genetic risk of hypertension (mean age: 25,4 +/- 2,6 years) in comparison with 8 controls (mean age: 25,0 +/- 2,3 yrs). Due to peripheral vasodilatation this substance led to an initial blood pressure fall which was the same in the investigated and in the control group. In the phase of counterregulation the secondary rise of blood pressure was higher in the group with family history of hypertension. As evidenced by correlation statistical analysis the increases of heart rate and cardiac output were responsible for the rise of systolic blood pressure. The hemodynamic response to methacholine in the group with genetic risk of hypertension has been attributed to a higher sympathetic reactivity.