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Biomedical subjects

H J Naumann

Publications and source records attributed to H J Naumann.

At least 19 recordsLinked to original sources
PubMed1999

Hypertriglyceridaemia in mild hypertension: impact on cardiovascular and hormonal reactivity under different stress tests.

OBJECTIVES: We investigated the significance of hypertriglyceridaemia (HTG) for associated components of the metabolic syndrome and stress reactivity in subjects with mild hypertension. METHODS: Seventeen asymptomatic subjects with mild hypertension assessed by 24-h blood pressure (BP) measurement plus HTG (TG >2.3 mmol/l) were recruited and compared with age- and sex-matched subjects with hypertension alone and healthy controls. Cardiovascular and hormonal stress reactivity were tested in a standardised programme consisting of 6 min mental stress, 3 min finger grip and a submaximal bicycle ergometry. RESULTS: The hypertensive patients with HTG exhibited significantly higher fasting insulin, uric acid and gamma-GT levels and lower HDL-cholesterol. The cardiovascular reactivity was similar in all three tests with respect to brachial and peripheral BP in the groups. Peripheral BP during the tests was found to be higher particularly in subjects with hypertension alone. The correlations between BP parameters were disturbed in hypertensives with HTG. Latter group showed significantly higher dopamine, noradrenaline, as well as ACTH levels and an increased ACTH/cortisol ratio. CONCLUSION: HTG in mild hypertension is indicative for insulin resistance accompanied by a modified vascular reactivity as well as elevated catecholamines and ACTH.

Adult↗
PubMed1996

Leukocyte responsiveness to substances that activate the respiratory burst is not altered in borderline and essential hypertension.

Activated leukocytes have been implicated in the pathogenesis of hypertension and its complications. The present study investigated the activity stage of leukocytes for production of reactive oxygen species (ROS) in 17 normotensive controls and subjects with borderline (n = 17) or essential hypertension (n = 17) using different biological materials (whole blood and isolated polymorphonuclear leukocytes (PMNLs)), stimuli (zymosan and formyl-methionyl-leucyl-phenylalanine (FMLP)) and ROS detection assays (chemiluminescence, hydrogen peroxide and superoxide anion determination). Neither the capacity for extracellular generation of oxygen metabolites nor the production of ROS with an intracellular origin were significantly different in isolated PMNLs between controls and hypertensive subjects. There were no significant differences in the luminol-amplified zymosan- or FMLP-stimulated whole blood chemiluminescence response. In addition, the leukocyte count did not differ between the groups. The results suggest that circulating leukocytes of controls and hypertensives existed in a resting state in our experimental conditions. We did not find any evidence of enhanced basal leukocyte free radical activity in patients with mild or severe hypertension.

Adult↗
PubMed1996

Brachial and digital artery pulse pressures in hypertensive and normotensive subjects.

OBJECTIVES AND PATIENTS: To determine whether or not the pulsatile component of blood pressure (BP) measured centrally and peripherally allows a separation between hypertensive and normal subjects, as well as within hypertensive and normal subjects, as well as within hypertensive patients. We tested the hypothesis that the difference in central and peripheral pulse pressures is increased in hypertensive, compared to normotensive persons, and that this component is influenced by genetic variance. We studied 46 hypertensive patients and 56 age-matched normal subjects, as well as 10 hypertensive families with 74 members of the same age range. DESIGN: Pulse pressure was measured at the brachial artery and the digital artery in the standing and supine position. The difference in the pulse pressures between these sites was calculated. Further, digital volume-pulse amplitude and stroke volume measurements were determined with impedance plethysmography. RESULTS: The differences between central and peripheral pulse pressures were similar in hypertensive patients compared to normal subjects, regardless of posture. However, in the standing position the frequency distribution of this variable in hypertensive patients was bimodal and split into two significantly different distributions (P < 0.05) with peaks at -24 mm Hg and -1 mm Hg, compared to a single peak at -11 mm Hg in normal subjects. Furthermore, these two subgroups of hypertensive patients differed in their brachial systolic BP (127 +/- 10 vs 134 +/- 12 mm Hg; P < 0.05), their brachial pulse pressures (32 +/- 8 vs 42 +/- 8 mm Hg; P < 0.05), and in their peripheral compliance (1.59 +/- 0.92 vs 2.21 +/- 1.00 microliter/mm Hg per 100 ml tissue; P < 0.05). The frequency distribution of pulse pressure differences was also bimodal in members of hypertensive families, even though most (46 out of 74) were normotensive. CONCLUSION: The difference between the digital and brachial pulsatile component may be a useful intermediary phenotype in essential hypertension. Furthermore, the nonuniform decreases in arterial compliance exhibited by our patients may be of pathogenic significance.

Adult↗
PubMed1987

Behaviour of heart rate and electrical muscle activity in the simultaneous dynamic action of larger and smaller sets of muscles in the permanent performance threshold range.

This study was undertaken to assess more comprehensively and with greater differentiation the reduction in the absolute electrical muscle activity (aEA) determined by different investigations in the permanent performance threshold range of the cardiovascular system (HKS) by means of the behaviour of the aEA of the highly stressed leg muscles and little stressed forearm muscles. Six healthy, untrained male subjects operated a hand ergograph alone in one test, and, in four more tests, in combination with a constant bicycle ergometer load of 40, 60, 80, and 100 W, respectively. As a result of these tests, a relative reduction in aEA for the leg muscles and an absolute reduction in aEA for the forearm muscles could be identified in the permanent performance threshold range of the HKS. Therefore, aEA is also considered to be an indicator of general stress that can define the permanent performance threshold range of the HKS more completely. The reduction in aEA is probably an expression of a negative feedback from the cardiovascular system to the neuromuscular system induced by the central nervous system.

Adult↗