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Background: A recent call-to-action highlighted that Australia is lagging behind high-income countries regarding hypertension control rates., Methods: We performed a systematic literature search of reports on prevalence, awareness, treatment and control rates since 2010. We also undertook an individual participant data meta-analysis of six population-based studies in the general population from 1980 to 2018 to understand the size of the problem and trajectories over time., Results: The aggregated data showed that after 2010, hypertension prevalence was 31% ]95% confidence interval (CI) 27-34%], and awareness, treatment, and control rates among people with hypertension were 56% (41-71%), 54% (46-62%) and 34% (22-47%), respectively. Since 1980, these figures have shown slight improvement. However, we noted a low availability of quality nationwide randomized databases for Australia., Conclusions: We require critical action to improve the prevention, detection and treatment of hypertension, and highlight the need for large-scale investment in tracking population health in order to produce vital health statistics for the nation., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Unlike noradrenaline, the sympathetic neurotransmitter which overflows to the circulation, adrenaline (ADR) is a secreted hormone, with a low plasma concentration, and plasma concentration for biological action a log order lower than that of noradrenaline. The venous drainage of the left adrenal medulla into the left renal vein does expose this vein to uniquely high plasma ADR concentrations and possible risk of thrombosis at high rates of ADR secretion. There is typically a different timeframe for adrenal medullary and sympathetic nervous system responses: ADR release is short term in contrast with sympathetic activation persisting for years in heart failure and hypertension. The historic view of Walter Cannon, subject to recent review, that the sympathoadrenal system is a unified biological system, was deconstructed further with demonstration of frequent mismatching of adrenal medullary and sympathetic nervous responses. Under gravity stimulation with standing, there is prompt sympathetic activation without ADR release. In many diseases, notably obesity, hypertension, heart failure and depressive illness, an activated sympathetic nervous system and silent adrenal medulla coexist. The therapeutic corollary of this is that ADR blockade is much less commonly needed clinically than pharmacological antagonism of the sympathetic nervous system., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Background: There is a need for an easily accessible biomarker of sympathetic nervous activation in essential hypertension, but none exists. Heart rate (HR) has been suggested, but requires validation, now doubly important as an elevated HR in hypertension has emerged as an independent cardiovascular risk factor., Methods: Isotope dilution methodology was used to measure total and regional noradrenaline spillover and adrenaline secretion rates in 30 patients with unmedicated essential hypertension and in a comparator group of 48 healthy participants with normal blood pressure. The particular interest was in the relationship of measured HR to cardiac noradrenaline spillover, the measure of cardiac sympathetic activity., Results: Sympathetic activation was present in the patients with essential hypertension, evident in significantly increased mean cardiac, renal and total noradrenaline spillover rates. Adrenaline secretion was normal. HR in hypertension correlated directly with cardiac noradrenaline spillover (r = 0.82, P = 9.3 × 10), but not with renal noradrenaline spillover or adrenaline secretion. 67% of the variance in HR was attributable to differences in cardiac sympathetic activity. Among hypertensive patients there was no internal correlation between cardiac noradrenaline spillover, renal noradrenaline spillover and adrenaline secretion; the sympathetic activation commonly was not 'global'. In healthy participants HR did not correlate with measures of sympathetic activity or adrenaline secretion., Conclusion: When sympathetic activation exists in essential hypertension it is differentiated, not necessarily involving all sympathetic outflows. An elevated HR proved to be a biomarker of cardiac sympathetic activation but not activation of the renal sympathetic outflow. Identifying activation of the cardiac sympathetic outflow as the prime mechanism of hypertension tachycardia is relevant to therapies which should now be considered to minimize cardiovascular risk in this clinical setting. Is an elevated HR a valid biomarker of sympathetic activation in essential hypertension? Yes, but only for the cardiac sympathetic outflow. The unavoidable principle is that regional differentiation of sympathetic responses in essential hypertension means that no simple test can ever represent each and every sympathetic outflow.

: The Lancet Commission on Hypertension identified that a key action to address the worldwide burden of high blood pressure (BP) was to improve the quality of BP measurements by using BP devices that have been validated for accuracy. Currently, there are over 3000 commercially available BP devices, but many do not have published data on accuracy testing according to established scientific standards. This problem is enabled through weak or absent regulations that allow clearance of devices for commercial use without formal validation. In addition, new BP technologies have emerged (e.g. cuffless sensors) for which there is no scientific consensus regarding BP measurement accuracy standards. Altogether, these issues contribute to the widespread availability of clinic and home BP devices with limited or uncertain accuracy, leading to inappropriate hypertension diagnosis, management and drug treatment on a global scale. The most significant problems relating to the accuracy of BP devices can be resolved by the regulatory requirement for mandatory independent validation of BP devices according to the universally-accepted International Organisation for Standardization Standard. This is a primary recommendation for which there is an urgent international need. Other key recommendations are development of validation standards specifically for new BP technologies and online lists of accurate devices that are accessible to consumers and health professionals. Recommendations are aligned with WHO policies on medical devices and universal healthcare. Adherence to recommendations would increase the global availability of accurate BP devices and result in better diagnosis and treatment of hypertension, thus decreasing the worldwide burden from high BP.

Objective: To examine Dickinson's hypothesis in mild essential hypertension, in which neurogenic mechanisms are believed to be particularly relevant, by combining measures of cerebral oxygen consumption with the concurrent assessment of sympathetic nervous activity., Design and Methods: Twenty-five untreated essential hypertensive subjects and 28 healthy age-matched volunteers underwent direct blood sampling using percutaneously inserted catheters advanced into the internal jugular vein, with cerebral blood flow scans to differentiate between cortical and subcortical venous drainage of the brain. Venoarterial blood gas measurements and internal jugular vein blood flows were used to calculate cerebral respiratory quotients and cerebral oxygen utilization. The total body rate of noradrenaline spillover into plasma was measured to assess relationships between cerebral oxidative metabolism and sympathetic nervous activity., Results: Compared with controls, the hypertensive subjects exhibited reductions in internal jugular vein blood flow (482 +/- 29 versus 410 +/- 15 ml/min), cerebral oxygen consumption (27 +/- 2 versus 23 +/- 1 ml/min) and cerebral oxygen supply (93 +/- 6 versus 78 +/- 3 ml/min). The cerebral respiratory quotients were identical (1.00 +/- 0.04 in normotensives and 0.98 +/- 0.03 in hypertensives). Technetium blood flow scans revealed that the reductions in internal jugular blood flow and cerebral oxygen consumption in the hypertensive patients were confined to cortical brain regions. Cortical blood flow was quantitatively linked to the matching respiratory quotient and oxygen consumption, neither of which bore any relation to the level of sympathetic nervous activity. The spillover of noradrenaline into the plasma for the body as a whole did not differ between the two groups., Conclusions: In accord with Dickinson's hypothesis, we have established a reduction in internal jugular vein blood flow and cerebral oxygen utilization in hypertension. These reductions were confined to cortical brain regions. However, cerebral respiratory quotients in our hypertensive study group were no different from those in our controls, suggesting that glucose remained as the major cerebral metabolic substrate in hypertension. We were not able to establish a link between cerebral metabolism and blood pressure or sympathetic nervous activity in mildly hypertensive patients.

Objective: To investigate the association of serum lipids with non-invasively assessed systemic arterial compliance in a group of newly diagnosed coronary artery disease patients and their matched controls., Design: Systemic arterial compliance is important in maintaining diastolic blood pressure and coronary perfusion, with decreased diastolic blood pressure in the presence of significant coronary artery disease suggested as contributing to increased morbidity. Decreased systemic arterial compliance is also associated with increased morbidity through its contribution to systolic hypertension. Despite the importance of arterial compliance, its association with biochemical factors is not certain., Patients and Methods: Twenty newly diagnosed coronary artery disease patients and disease-free controls were matched for age, sex, smoking status and total serum cholesterol level. Systemic arterial compliance was measured using applanation tonometry and Doppler velocimetry before instigation of treatment., Results: There was no difference in group low-density lipoprotein or high-density lipoprotein cholesterol levels. Systemic arterial compliance was significantly less in the coronary artery disease group. For the groups combined, a significant negative correlation was demonstrated between systemic arterial compliance and low-density lipoprotein; however, on separate group analysis the correlation was confined to the coronary artery disease group. A significant difference was found in the association between systemic arterial compliance and diastolic blood pressure for the two groups., Conclusions: Increasing low-density lipoprotein cholesterol levels are associated with decreasing systemic arterial compliance; however, the identified intergroup differences suggest that, presumably because of differences in lipid-vessel wall interactions, disease-free subjects exhibit relatively less alteration in aortic mechanical properties than those who develop coronary artery disease.