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

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 42.0±2.6 years, mean±SEM), 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 (+23.0±4.6% P <0.05). Whereas baroreflex heart-rate control was unchanged, baroreflex modulation of MSNA was reduced by 46.8±5.1% ( P <0.01). 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

Sympathetic Control of Circulation in Hypertension and Congestive Heart Failure

Adrenergic overactivity is a common hallmark of both essential hypertension and congestive heart failure. Indirect and direct measures of sympathetic function have clearly shown that sympathetic activation characterizes essential hypertension. This adrenergic overactivity appears to be related to the severity of the hypertensive state, being detectable in its early stages and showing a progressive increase with the severity of the disease. Essential hypertension is also associated with an impaired baroreflex control of vagal activity, whereas baroreceptor modulation of sympathetic nerve traffic remains unaltered, although undergoing a resetting phenomenon. In contrast, secondary hypertension is not associated with an increased adrenergic activity, thus suggesting that an enhancement in efferent sympathetic outflow is a peculiar feature of essential hypertension. Congestive heart failure is a condition also characterized by sympathetic activation, whose degree is proportional to the clinical severity of the disease. This is paralleled by an impairment in arterial baroreceptor modulation of both vagal and sympathetic activity, thus suggesting that the adrenergic overactivity in congestive heart failure is triggered by a reduced afferent restraint on the vasomotor centre. Chronic angiotensin-converting enzyme inhibition reduces the degree of both sympathetic activation and baroreflex dysfunction occurring in heart failure patients, a finding which documents that the neurohumoral abnormalities can be at least partially reversed by pharmacologic treatment

Comparative study of different functionalized graphene-nanoplatelet aqueous nanofluids for solar energy applications

The optical properties of nanofluids are peculiar and interesting for a variety of applications. Among them, the high light extinction coefficient of nanofluids can be useful in linear parabolic concentrating solar systems, while their properties under high light irradiation intensities can be exploited for direct solar steam generation. The optical characterization of colloids, including the study of non-linear optical properties, is thus a needed step to design the use of such novel materials for solar energy exploitation. In this work, we analysed two different types of nanofluids, consisting of polycarboxylate chemically modified graphene nanoplatelets (P-GnP) and sulfonic acid-functionalized graphene nanoplatelets (S-GnP) dispersed in water, at three concentrations from 0.005 wt% to 0.05 wt%. Moderately stable nanofluids were achieved with favourable light extinction properties, as well as a non-linear optical behaviour under high input solar intensities

Serum Uric Acid Predicts All-Cause and Cardiovascular Mortality Independently of Hypertriglyceridemia in Cardiometabolic Patients without Established CV Disease: A Sub-Analysis of the URic acid Right for heArt Health (URRAH) Study

High serum uric acid (SUA) and triglyceride (TG) levels might promote high-cardiovascular risk phenotypes across the cardiometabolic spectrum. However, SUA predictive power in the presence of normal and high TG levels has never been investigated. We included 8124 patients from the URic acid Right for heArt Health (URRAH) study cohort who were followed for over 20 years and had no established cardiovascular disease or uncontrolled metabolic disease. All-cause mortality (ACM) and cardiovascular mortality (CVM) were explored by the Kaplan-Meier estimator and Cox multivariable regression, adopting recently defined SUA cut-offs for ACM (&gt;= 4.7 mg/dL) and CVM (&gt;= 5.6 mg/dL). Exploratory analysis across cardiometabolic subgroups and a sensitivity analysis using SUA/serum creatinine were performed as validation. SUA predicted ACM (HR 1.25 [1.12-1.40], p &lt; 0.001) and CVM (1.31 [1.11-1.74], p &lt; 0.001) in the whole study population, and according to TG strata: ACM in normotriglyceridemia (HR 1.26 [1.12-1.43], p &lt; 0.001) and hypertriglyceridemia (1.31 [1.02-1.68], p = 0.033), and CVM in normotriglyceridemia (HR 1.46 [1.23-1.73], p &lt; 0.001) and hypertriglyceridemia (HR 1.31 [0.99-1.64], p = 0.060). Exploratory and sensitivity analyses confirmed our findings, suggesting a substantial role of SUA in normotriglyceridemia and hypertriglyceridemia. In conclusion, we report that SUA can predict ACM and CVM in cardiometabolic patients without established cardiovascular disease, independent of TG levels

Gaia Early Data Release 3: Structure and properties of the Magellanic Clouds

We compare the Gaia DR2 and Gaia EDR3 performances in the study of the Magellanic Clouds and show the clear improvements in precision and accuracy in the new release. We also show that the systematics still present in the data make the determination of the 3D geometry of the LMC a difficult endeavour; this is at the very limit of the usefulness of the Gaia EDR3 astrometry, but it may become feasible with the use of additional external data. We derive radial and tangential velocity maps and global profiles for the LMC for the several subsamples we defined. To our knowledge, this is the first time that the two planar components of the ordered and random motions are derived for multiple stellar evolutionary phases in a galactic disc outside the Milky Way, showing the differences between younger and older phases. We also analyse the spatial structure and motions in the central region, the bar, and the disc, providing new insights into features and kinematics. Finally, we show that the Gaia EDR3 data allows clearly resolving the Magellanic Bridge, and we trace the density and velocity flow of the stars from the SMC towards the LMC not only globally, but also separately for young and evolved populations. This allows us to confirm an evolved population in the Bridge that is slightly shift from the younger population. Additionally, we were able to study the outskirts of both Magellanic Clouds, in which we detected some well-known features and indications of new ones

The "J curve" problem revisited: Old and new findings

This paper critically addresses the issue of the "J-curve" paradox-the finding described in studies performed about 30 years ago indicating that treatment-induced systolic blood pressure values below 120 or 125 mm Hg and diastolic blood pressure values below 75 mm Hg are characterized by an increase, rather than a reduction, in the incidence of coronary events. This paper focuses on four major subjects: 1) the benefits of a lower blood pressure target during treatment; 2) the historical background of the "J-curve" phenomenon; 3) the evidence collected in recent clinical trials regarding the existence of a "J-curve" in treated hypertensive patients; and 4) the recent recommendations by the Task Force Committee of the European Society of Hypertension on blood pressure goals to be achieved during treatment. © 2010 Springer Science+Business Media, LLC

A comprehensive physical profile for aqueous dispersions of carbon derivatives as solar working fluids

The application of nanofluids in direct solar absorption, heat transfer or direct solar steam generation entails carrying out a comprehensive study taking into account several physical quantities. Long-term stability, rheological, thermophysical and optical properties of dispersions must be known to assess their potential for envisaged applications. Two low-concentration nanofluids, 0.005 and 0.05 wt%, of sulfonic acid-functionalized and polycarboxylate chemically modified graphene nanoplatelets in water were considered in this work. Elemental analyses of the nanopowders and pH evaluations of the colloids were carried out. The rheological behaviour of dispersions at different temperatures was studied by rotational rheometry. Thermal conductivities were measured by the transient hot wire method and densities by the oscillating U-tube technique. Additionally, a brief report of the optical properties was included to provide a comprehensive physical analysis.Ministerio de Economía, Industria y Competitividad (España) | Ref. ENE2017-86425-C2-1-REuropean Commissio

Association between Berlin questionnaire index and blood pressure, organ damage and metabolic profilein a general population

Abstract We evaluated the relationships between Berlin questionnaire (BQ) scores, hypertension and other metabolic variables in 598 subjects (age: 65.8 ± 10 years, mean ± SD) enrolled in the PAMELA (Pressioni Arteriose Monitorate E Loro Associazioni) study representative of the general population, treated or untreated with antihypertensive drugs. Two hundred and eleven subjects (35%) had a positive BQ with two or more positive categories of the inquiry. Compared to those without sleep disorders these subjects showed a greater male prevalence (55.9%), worse serum cholesterol, triglycerides and glucose profile, greater body mass index (BMI) (28.9 ± 4.9 vs. 24.9 ± 3.4 kg/m2), higher office (and to a lesser extent 24‐h) BP and HR values, higher serum creatinine values and greater rate of echocardiographic left ventricular (LV) hypertrophy (25% vs. 13%). These differences were not detected when the data analysis was restricted to treated hypertensive patients. Thus, BQ scores allow to identify among subjects belonging to a general population those with elevated BP, organ damage and altered metabolic. When antihypertensive drug treatment is present, however, the approach fails to detect differences between groups with low or high BQ index

Comparison of electrocardiographic versus echocardiographic detection of left ventricular mass changes over time and evaluation of new onset left ventricular hypertrophy

Abstract We assessed the value of 3 electrocardiographic (EKG) voltage criteria in detecting variations of left ventricular mass (LVM) over time, taking echocardiographic (ECHO) LVM as reference, in the Pressioni Arteriose Monitorate E Loro Associazioni study. In 927 subjects (age 47 ± 13 years on entry, 49.9% men) an ECHO evaluation of LVM and EKG suitable for measurement of EKG‐LVH criteria (Sokolow‐Lyon voltage, Cornell voltage and R‐wave voltage in aVL) were available at baseline and at a 2nd evaluation performed 10 years later. Δ (delta) LVM, Δ LVMI, and Δ EKG parameters values were calculated from 2nd evaluation to baseline. The sensitivity of the EKG criteria in the diagnosis of LVH, poor at baseline, becomes even worse after 10 years, reaching very low values. Only the sensitivity of R‐wave amplitude exhibited slight increase over time but with unsatisfactory absolute values. Despite the prevalence of ECHO‐LVH at the 2nd evaluation was threefold increased compared to baseline (29.3% and 33.7% for LVM indexed to BSA and height2.7, respectively), the prevalence of EKG‐LVH was unchanged when evaluated by Sokolow‐Lyon criteria, significantly reduced when assessed by Cornell voltage index, while significantly increased using R‐wave voltage in aVL criteria. Despite an ECHO‐LVM increase over the time, mean EKG changes were of opposite sign, except for R‐wave amplitude in aVL. Our study highlights the discrepancy between ECHO and EKG in monitoring LVM changes over the time, especially for Sokolow‐Lyon and Cornell voltage. Thus, EKG is an unsuitable method for the longitudinal evaluation of LVM variations