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Salt sensitivity is a powerful risk factor for cardiovascular (CV) disease and mortality in both normotensive and hypertensive patients. We investigated the predictive value of the salt sensitivity phenotype in the development of CV events and hypertensive target organ damage (TOD) among essential hypertensive patients.Eight hundred forty-four naive hypertensive patients were recruited and underwent an acute saline test during which blood pressure (BP) displayed either no substantial variation (salt-resistant, SR individuals), an increase (salt-sensitive, SS), or a paradoxical decrease (inverse salt-sensitive, ISS). Sixty-one patients with the longest monitored follow-up (median 16 years) for blood pressure and organ damage were selected for the present study. A clinical score for TOD development based on the severity and the age of onset was set up by considering hypertensive heart disease, cerebrovascular damage, microalbuminuria, and vascular events.CV events were significantly higher among SS and ISS than in SR patients. The relative risk of developing CV events was 12.67 times higher in SS than SR and 5.94 times higher in ISS than SR patients. The development of moderate to severe TOD was 10-fold higher in SS and over 15-fold higher in ISS than in SR patients. Among the three phenotypes, changes in plasma endogenous ouabain were linked with the blood pressure effects of saline.Salt sensitivity and inverse salt sensitivity appear to be equivalent risk factors for CV events. The response to an acute saline test is predictive of CV damage for newly identified ISS individuals.

Objective:Worldwide blood pressure control is achieved only in 40–50% of patients treated for hypertension, despite the availability of a considerable number of antihypertensive drugs from different pharmacological classes. Although there are many reasons for insufficient control of blood pressure

Objective:For decades, it has been widely accepted that initiation of salt-induced hypertension involves a type of kidney dysfunction (natriuretic handicap) which causes salt-sensitive subjects to excrete less of a sodium load than normal subjects and to undergo abnormal increases in cardiac output

OBJECTIVE In the setting of normal sodium (Na) intake, many patients with hypertension have inappropriately elevated plasma aldosterone (Aldo) levels and may be at increased risk for tissue damage. Moreover, other adrenocortical steroids, including endogenous ouabain can stimulate tissue damage. As endogenous ouabain is often elevated in chronically Na-loaded states, is a vasoconstrictor, raises blood pressure (BP), and also promotes tissue fibrosis, we investigated the extent to which plasma Aldo and endogenous ouabain were coelevated among naive hypertensive patients (NHP). We also investigated the impact of an acute salt load on these steroids, BP, and renal function. METHODS NHP (590) were grouped in tertiles based on their baseline plasma Aldo (mean ± SEM first 7.59 ± 0.18, versus third 24.15 ± 0.31 ng/dl). Baseline plasma renin activity (2.4 ± 0.1 versus 1.2 ± 0.1 ng/ml per h, P

Thiazide diuretics have been recommended as a first-line antihypertensive treatment, although the choice of 'the right drug in the individual essential hypertensive patient' remains still empirical. Essential hypertension is a complex, polygenic disease derived from the interaction of patient's genetic background with the environment. Pharmacogenomics could be a useful tool to pinpoint gene variants involved in antihypertensive drug response, thus optimizing therapeutic advantages and minimizing side effects.We looked for variants associated with blood pressure response to hydrochlorothiazide over an 8-week follow-up by means of a genome-wide association analysis in two Italian cohorts of never-treated essential hypertensive patients: 343 samples from Sardinia and 142 from Milan. TET2 and CSMD1 as plausible candidate genes to affect SBP response to hydrochlorothiazide were identified. The specificity of our findings for hydrochlorothiazide was confirmed in an independent cohort of essential hypertensive patients treated with losartan. Our best findings were also tested for replication in four independent hypertensive samples of European Ancestry, such as GENetics of drug RESponsiveness in essential hypertension, Genetic Epidemiology of Responses to Antihypertensives, NORdic DILtiazem intervention, Pharmacogenomics Evaluation of Antihypertensive Responses, and Campania Salute Network-StayOnDiur. We validated a polymorphism in CSMD1 and UGGT2.This exploratory study reports two plausible loci associated with SBP response to hydrochlorothiazide: TET2, an aldosterone-responsive mediator of αENaC gene transcription; and CSMD1, previously described as associated with hypertension in a case-control study.

The basolateral Na pump drives renotubular reabsorption. In cultured renal cells, mutant adducins, as well as sub-nanomolar ouabain concentrations, stimulate the Na-K pump.To determine whether these factors interact and affect Na handling and blood pressure (BP) in vivo, we studied 155 untreated hypertensive patients subdivided on the basis of their plasma endogenous ouabain or alpha-adducin genotype (ADD1 Gly460Trp-rs4961).Under basal conditions, proximal tubular reabsorption and plasma Na were higher in patients with mutated Trp ADD1 or increased endogenous ouabain (P = 0.002 and 0.05, respectively). BPs were higher in the high plasma endogenous ouabain group (P = 0.001). Following volume loading, the increment in BP (7.73 vs. 4.81 mmHg) and the slopes of the relationship between BP and Na excretion were greater [0.017 +/- 0.002 vs. 0.009 +/- 0.003 mmHg/(muEq min)] in ADD1 Trp vs. ADD1 Gly carriers (P0.05). BP changes were similar, whereas the slopes of the relationship between BP and Na excretion were lower [0.016 +/- 0.003 vs. 0.008 +/- 0.002 mmHg/(muEq min)] in patients with low vs. high endogenous ouabain (P0.05). In patients with high endogenous ouabain, volume loading increased the BP in the ADD1 Trp group but not in the Gly group (P0.05). Thus, patients with ADD1 Trp alleles are sensitive to salt and tubular Na reabsorption remains elevated after volume expansion.With saline loading, BP changes are similar in high and low endogenous ouabain patients, whereas tubular Na reabsorption increases in the high endogenous ouabain group. Saline loading unmasks differences in renal Na handling in patients with mutant adducin or high endogenous ouabain and exposes an interaction of endogenous ouabain and Trp alleles on BP.

Objective : To investigate the role of ouabain in human hypertension and to establish whether immunoreactive endogenous ouabain is secreted by the adrenal gland under the influence of dopaminergic regulation. Methods : We measured plasma levels of endogenous ouabain by immunoassay, together with other variables, including plasma renin activity and aldosterone levels, in 91 clinically selected hypertensives and 19 healthy volunteers. We also measured endogenous ouabain in adrenal venous blood and the effect of DA 2 dopaminergic receptor blockade and stimulation. After a thorough clinical evaluation, 64 patients were diagnosed with essential hypertension and 24 with primary aldosteronism. Results : Plasma levels of endogenous ouabain were higher in essential hypertensives than in controls. Multiple regression analysis showed a significant relationship of mean blood pressure with plasma endogenous ouabain, age and body mass index, but not with other measured parameters. The plasma levels of endogenous ouabain were more than two standard deviations above the mean value for normotensives in 45% of patients with essential hypertension in whom plasma renin activity was normal. Higher plasma levels of endogenous ouabain were found in patients with aldosterone excess, specifically affecting 56% of 17 patients with surgically confirmed adrenal cortical adenoma and one (14%) of seven patients with idiopathic causes. Removal of adenomas lowered blood pressure in half of the patients in whom plasma levels of endogenous ouabain normalized after surgery. Plasma endogenous ouabain levels were similar in venous blood from the adrenal and inferior vena cava, and plasma levels were not influenced by DA 2 dopaminergic blockade and stimulation. Conclusion : Approximately half of Caucasian patients with essential hypertension and with hyperaldosteronism exhibit elevated circulating levels of endogenous ouabain. The latter do not appear to be secondary to hypertension, are unrelated to plasma renin activity, and may not involve adrenal type-2 dopaminergic receptors.

An endogenous ouabain has been isolated and conclusively identified from several mammalian tissues, including human plasma, by a number of independent laboratories. Substantial evidence from independent laboratories in several continents is consistent with an adrenal source for most if not all of the circulating endogenous ouabain. Accumulating evidence suggests that circulating levels of endogenous ouabain in humans are modulated by dietary salt and chronic volume status. Endogenous ouabain is linked significantly with vascular function in hypertension and likely impacts the pathogenesis of heart and renal failure. Moreover, the molecular mechanism of endogenous ouabain-linked hypertension involves the sodium pump/sodium-calcium exchange duet. The outstanding analytical issues include the elucidation of distal events in the biosynthetic pathway for endogenous ouabain and identification of molecular mechanisms that regulate its secretion and clearance.