Autonomic imbalance, hypertension, and cardiovascular risk

Brook, Robert D.; Julius, Stevo

doi:10.1016/s0895-7061(00)00228-4

Cited by 207 publications

(130 citation statements)

References 135 publications

Supporting

Mentioning

122

Contrasting

Unclassified

Order By: Relevance

“…Third, our results have a clinical implication, because the persistent sympathoexcitatory effect of sodium restriction may hamper the BP-lowering effects of this intervention, thereby being involved in its overall small hypotensive effects 33 as well as in the BP unresponsiveness or increase it shows in a number of individuals, 33,34 and aggravate the sympathetic hyperactivation already present in essential hypertension, thus enhancing its undesirable hemodynamic, metabolic, and structural consequences. 13,14 We can speculate that this may account, at least in part, for the recently reviewed adverse association between dietary sodium restriction or low sodium serum concentration and cardiovascular mortality. 35 …”

Section: Discussionmentioning

confidence: 99%

“…First, in hypertension, a marked reduction in dietary sodium content additionally enhances the sympathetic hyperactivity characterizing several patients with a high BP state, 5,9 -12 thereby aggravating its undesirable cardiovascular, metabolic, and hemorheologic effects. 13,14 Second, this occurs at least in part because of the impairment of a reflex mechanism of fundamental importance both for restraining sympathetic tone and for maintaining BP homeostasis. 15 Whether a more moderate restriction in dietary sodium intake triggers neuroadrenergic and reflex alterations similar to the ones seen during a marked sodium restriction is less certain.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Short- and Long-Term Neuroadrenergic Effects of Moderate Dietary Sodium Restriction in Essential Hypertension

et al. 2002

View full text Add to dashboard Cite

Background-In essential hypertension, marked restrictions in dietary sodium intake cause in the short-term period an increase in muscle sympathetic nerve traffic (MSNA) and a baroreflex impairment. The present study was set out to assess on a long-term basis the neuroadrenergic and reflex effects of moderate sodium restriction. Methods and Results-In 11 untreated mild to moderate essential hypertensive patients (age 42.0Ϯ2.6 years, meanϮSEM), we measured beat-to-beat blood pressure (Finapres), heart rate (ECG), and MSNA (microneurography) at rest and during stepwise intravenous infusions of phenylephrine and nitroprusside. Measurements were performed at regular sodium intake, after 1 and 8 weeks of low-sodium diet (80 mmol NaCl/d), and repeated again at regular sodium intake. After 1 week, urinary sodium excretion was markedly reduced. This was accompanied by a slight blood pressure reduction, no heart rate change, and a significant increase in plasma renin activity, aldosterone, and MSNA (ϩ23.0Ϯ4.6% PϽ0.05). Whereas baroreflex heart-rate control was unchanged, baroreflex modulation of MSNA was reduced by 46.8Ϯ5.1% (PϽ0.01). At the end of the 8-week low-sodium diet, the neurohumoral and baroreflex responses were similar to the ones observed after 1 week of the dietary intervention. All changes disappeared when regular sodium diet was restored. Conclusions-Thus, a moderate dietary sodium restriction triggers a sympathetic activation and a baroreflex impairment.Maintenance of low-sodium diet for several weeks does not attenuate these adverse adrenergic and reflex effects.

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Short- and Long-Term Neuroadrenergic Effects of Moderate Dietary Sodium Restriction in Essential Hypertension

et al. 2002

View full text Add to dashboard Cite

show abstract

“…Autonomic imbalance implying sympathetic overactivity and parasympathetic underactivity play a central role in the development and maintenance of essential hypertension (Brook and Julius 2003). Decreased HRV is associated with increased risk of hypertension (Liao et al 1996), coronary artery sclerosis (Huikuri et al 1999), acute cardiac events (Tsuji et al 1996), death from coronary artery disease (Tsuji et al 1996) and all-cause mortality (Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology 1996).…”

Section: Introductionmentioning

confidence: 99%

Low vagal tone is associated with impaired post stress recovery of cardiovascular, endocrine, and immune markers

et al. 2010

View full text Add to dashboard Cite

Reduced heart rate variability (HRV) and delayed blood pressure recovery are associated with increased cardiovascular risk. Besides this evident link, the vagus is thought to play an inhibitory role in the regulation of other allostatic systems, including inflammation and the hypothalamic-pituitary-adrenal (HPA) axis. However, human evidence is scarce. To further explore these associations and with special regard to the postulated mediating role of the vagus, we hypothesised that subjects with low vagal tone as indexed by reduced resting HRV would show impaired post-stress recovery of cardiovascular, endocrine and immune system markers involved in cardiovascular pathology. 44 healthy men underwent a standardised mental stress test. Besides continuous measurement of systolic and diastolic blood pressure (SBP, DBP), heart rate (HR), and HRV serum cortisol, tumour necrosis factoralpha (TNF-alpha), and interleukin-6 (IL-6) were measured before, after, 20, and 60 min after stress. Low versus high HRV groups was defined by median split on resting HRV (RMSSD). The task elicited significant time effects for SBP, DBP, HR, HRV, cortisol, and TNF-alpha. Subjects with low baseline HRV showed almost no modulation of HRV coupled with overall reduced HRV levels, and impaired recovery of DBP, cortisol, and TNF-alpha. Confirming our hypothesis, low vagal tone was associated with impaired recovery of cardiovascular, endocrine, and immune markers in healthy males. The data support an inhibitory role of the vagus in the regulation of allostatic systems as described in the neurovisceral integration model. We posit reduced resting HRV as a risk marker for future cardiovascular and other stress-related disease.

show abstract

“…In line with previous observations, we found in the present study that the a 2C Del322-325 allele carriers presented with sympathetic predominance as reflected in the HRV indices. In cardiovascular diseases including heart failure, sympathetic overactivation is closely involved in disease exacerbation and increased morbidity and mortality (Brook and Julius 2000), and it has been suggested that sympathetic predominance can also contribute to prospective pathogenesis of hypertension and CVD (Liao et al 1996(Liao et al , 1997.…”

Section: Discussionmentioning

confidence: 99%

Alpha-adrenoceptor gene variants and autonomic nervous system function in a young healthy Japanese population

et al. 2006

View full text Add to dashboard Cite

a 1A -adrenergic receptor (a 1A -AR) regulates the cardiac and peripheral vascular system through sympathetic activation, and a 2A -AR and a 2C -AR subtypes are essential for presynaptic feedback regulation of catecholamine release from the central and peripheral sympathetic nerve. Genetic variations in each human a-AR subtype gene have been identified and have been implicated in hypertension and cardiovascular disease. It is not yet clear whether these genetic variations actually have an effect on sympatho-vagal modulation. The aim of the present study was to evaluate the relation between the five representative genetic polymorphisms of a-AR subtypes (Arg347Cys of a 1A -AR; C-1291G, Asn251Lys, and DraI RFLP of a 2A -AR; and Del322-325 of a 2C -AR) and autonomic nervous system (ANS) function in young and healthy Japanese males. One hundred forty-nine subjects were genotyped for each a-AR polymorphism, and underwent evaluation of ANS function by power spectral analysis of heart rate variability (HRV) during supine rest and in a standing position. In a supine position, the a 1A -AR 347Cys allele was significantly associated with lower HRV sympathetic index (normalized low frequency power [LF(%)] and LF:HF ratio) and higher HRV parasympathetic index [HF(%)]. Meanwhile, subjects with the a 2C -AR Del322-325 allele had markedly higher LF(%) and LF:HF ratio and lower HF(%) than noncarriers. Thus, the a 1A -AR and a 2C -AR genetic variations influence sympatho-vagal balance even in young and healthy normotensive states, which could be postulated to constitute an intermediate phenotype for future pathological episodes of various ANS dysfunction-related diseases.

show abstract

Autonomic imbalance, hypertension, and cardiovascular risk

Cited by 207 publications

References 135 publications

Short- and Long-Term Neuroadrenergic Effects of Moderate Dietary Sodium Restriction in Essential Hypertension

Short- and Long-Term Neuroadrenergic Effects of Moderate Dietary Sodium Restriction in Essential Hypertension

Low vagal tone is associated with impaired post stress recovery of cardiovascular, endocrine, and immune markers

Alpha-adrenoceptor gene variants and autonomic nervous system function in a young healthy Japanese population

Contact Info

Product

Resources

About