Remodelado vascular excéntrico: su relación con trastornos metabólicos y el incremento de la masa corporal / Eccentric Vascular Remodeling: Its Relationship with Metabolic Disorders and Increased Body Mass

RESUMEN Introducción: Existe evidencia reciente que establecería a la hipoperfusión muscular como causa primaria de trastornos metabólicos en respuesta a la sobrealimentación. Esta concepción centrípeta del desarrollo de trastornos metabólicos podría implicar no solo alteraciones en la microvasculatura, sino también afectación en las arterias de conductancia. Objetivos: 1) Determinar la asociación entre diámetro basal de la arteria humeral (D-Hum) y la vasodilatación mediada por flujo (VDMF) 2) Analizar la asociación de ambos parámetros conforme aumenta de la masa corporal 3) Evaluar asociaciones entre el D-Hum/VDMF con componentes del síndrome metabólico (SM) 4) Evaluar la asociación independiente de ambas variables con el SM. Material y métodos: Se evaluaron 3493 pacientes. Se excluyeron pacientes < 18 y >80 años, con patología cardiovascular previa, insuficiencia renal crónica (IRC), colagenopatías, y tratados con estatinas. Se determinó presión arterial (PA), parámetros antropométricos y perfil metabólico, y se clasificó a los sujetos de acuerdo con la presencia de SM según AHA/NHLBI 2019. Se midieron D-Hum en mm y VDMF en %. Se analizó la asociación lineal entre D-Hum y VDMF y se analizaron ambas variables según decilos de índice de masa corporal (IMC). Se evaluaron asociaciones entre D-Hum/VDMF con la PA, glucemia (Glu), triglicéridos (TG) y colesterol de alta densidad (HDLc). Se realizaron dos regresiones logísticas con SM como variable dependiente y D-Hum o VDMF más edad, sexo, IMC y factores de riesgo coronario (FRC) como independientes. Resultados: Ingresaron 1995 pacientes (48,2 ± 11 años, 56 % hombres). El D-Hum y la VDMF presentaron una asociación inversa (r= -0,42; p < 0,0001). El D-Hum aumentó según decilos del IMC (p < 0,000001); la VDMF mostró relación inversa con los decilos crecientes de IMC (p < 0,000001). El D-Hum presentó correlación directa con PA, Glu y TG; e inversa con HDLc (p < 0,05 en todos los casos). La VDMF mostró correlación inversa con PA, Glu y TG; y directa con HDLc (p < 0,05 en todos los casos). El D-Hum se asoció en forma independiente con el SM ajustado por edad, sexo, IMC y FRC (OR 1,42, p = 0,0019), mientras que la VDMF no (OR 0,98, p = 0,217). Conclusión: El remodelado vascular excéntrico se asoció con un compromiso en la adaptación vascular ante aumentos en la demanda de flujo sanguíneo y con alteraciones metabólicas a lo largo del incremento de la masa corporal. Así, el compromiso dinámico de la vasculatura podría tener un rol determinante en el desarrollo de alteraciones metabólicas en forma sincrónica con la ganancia de peso.

ABSTRACT Background: Recent evidence would establish muscle hypoperfusion as the primary cause of metabolic disorders in response to overfeeding. This centripetal concept on the development of metabolic disorders could involve not only alterations in the microvasculature, but also affect the conductance arteries. Objectives: The aim of this study was 1) to determine the association between baseline brachial artery diameter (BAD) and flow-mediated vasodilation (FMVD), 2) To analyze the association of both parameters throughout the increase in body mass, 3) To evaluate associations between BAD/FMVD with components of the metabolic syndrome (MS) and 4) To evaluate the independent association of both variables with MS. Methods: A total of 3493 patients were evaluated. Patients <18 and >80 years old, those with previous cardiovascular disease, chronic kidney disease (CKD), collagenopathies, or treated with statins were excluded from the study. Blood pressure (BP), anthropometric parameters and metabolic profile were determined, and the subjects were classified according to the presence of MS conforming AHA/NHLBI 2019 criteria. BAD was measured in mm and FMVD as percentage. The linear association between BAD and FMVD was assessed, and both variables were analyzed according to deciles of body mass index (BMI). Associations between BAD/FMVD with BP, glucose (Glu), triglycerides (TG) and high-density cholesterol (HDL-C) levels were evaluated. Two logistic regression analyses were performed with MS as dependent variable and BAD or FMVD plus age, gender, BMI, and coronary risk factors (CRF) as independent variables. Results: A total of 1995 patients (48.2 ± 11 years, 56% men) were admitted in the study. An inverse correlation was found between BAD and FMVD (r= -0.42; p < 0.0001). BAD increased according to deciles of BMI (p < 0.000001), while FMVD showed an inverse relationship with increasing deciles of BMI (p < 0.000001). BAD exhibited a direct correlation with BP, Glu and TG; and an inverse relationship with HDL-C (p < 0.05 in all cases). FMVD presented an inverse correlation with BP, Glu and TG; and a direct correlation with HDL-C (p < 0.05 in all cases). BAD was independently associated with MS adjusted for age, gender, BMI and CRF (OR 1.42, p=0.0019), while FMVD was not (OR 0.98, p = 0.217). Conclusion: Eccentric vascular remodeling was associated with vascular adaptation to increased blood flow demand and with metabolic alterations throughout the increase in body mass. Thus, the dynamic compromise of vasculature could play a decisive role in the development of metabolic alterations occurring synchronously with weight gain.

[Renal effects of GLP-1 agonists in type 2 diabetes]. / Efectos renales de los agonistas GLP-1 en la diabetes tipo 2.

The prevalence of type 2 diabetes mellitus (DM2) is increasing, generating a great impact both at individual and public health level. Nearly half of the patients with DM2 develop impaired renal function, so nephron-protection is highly important. The robust body of evidence that shifted the therapeutic focus from glycemic to cardio-renal metabolic therapy in DM2 led to the inclusion of new therapies with cardiovascular and renal benefits in international guidelines. Type 1 glucagon (GLP-1) receptor agonists have showed favorable effects on renal function and their potential protective actions are multifactorial, beyond glycemic control. These benefits have been demonstrated in efficacy and safety clinical studies, as well as in cardiovascular outcomes and real-life studies. This comprehensive review describes the direct and indirect effects of these molecules, as well as evidence obtained from pivotal clinical (LEADER, SUSTAIN 6 and REWIND) and real-life studies demonstrating their beneficial effects on renal function, and also introduces expectations of future results from ongoing studies with renal endpoints.

La prevalencia de diabetes mellitus tipo 2 (DM2) está en aumento, generando un gran impacto tanto a nivel individual como en salud pública. Cerca de la mitad de los pacientes con DM2 sufren un deterioro de la función renal, por esto la nefroprotección resulta de fundamental importancia. El conjunto de evidencia que cambió del enfoque terapéutico glucocéntrico al cardiorrenometabólico en la DM2 motivó la inclusión en las recomendaciones internacionales de nuevas terapias con beneficios cardiovasculares y renales. Los agonistas del receptor del péptido similar al glucagón tipo 1 (GLP-1) tienen efectos favorables sobre la función renal y sus posibles acciones protectoras son multifactoriales, más allá del control glucémico. Estos beneficios han sido demostrados en los estudios clínicos de eficacia y seguridad, así como también en los estudios de resultados cardiovasculares y de vida real. En esta revisión narrativa se describen los efectos directos e indirectos de estas moléculas, así como su evidencia en los principales estudios clínicos (LEADER, SUSTAIN 6 y REWIND) y de vida real que demuestran sus efectos beneficiosos sobre la función renal e introduce la expectativa de los resultados futuros de los estudios en curso con objetivos renales.

Efectos renales de los agonistas GLP-1 en la diabetes tipo 2 / Renal effects of GLP-1 agonists in type 2 diabetes

Resumen La prevalencia de diabetes mellitus tipo 2 (DM2) está en aumento, generando un gran impacto tanto a nivel individual como en salud pública. Cerca de la mitad de los pacientes con DM2 sufren un deterioro de la función renal, por esto la nefroprotección resulta de fundamental importancia. El conjunto de evidencia que cambió del enfoque terapéutico glucocéntrico al cardiorrenometabólico en la DM2 motivó la inclu sión en las recomendaciones internacionales de nuevas terapias con beneficios cardiovasculares y renales. Los agonistas del receptor del péptido similar al glucagón tipo 1 (GLP-1) tienen efectos favorables sobre la función renal y sus posibles acciones protectoras son multifactoriales, más allá del control glucémico. Estos beneficios han sido demostrados en los estudios clínicos de eficacia y seguridad, así como también en los estudios de re sultados cardiovasculares y de vida real. En esta revisión narrativa se describen los efectos directos e indirectos de estas moléculas, así como su evidencia en los principales estudios clínicos (LEADER, SUSTAIN 6 y REWIND) y de vida real que demuestran sus efectos beneficiosos sobre la función renal e introduce la expectativa de los resultados futuros de los estudios en curso con objetivos renales.

Abstract The prevalence of type 2 diabetes mellitus (DM2) is increasing, generating a great impact both at individual and public health level. Nearly half of the patients with DM2 develop impaired renal function, so nephron-protection is highly important. The robust body of evidence that shifted the therapeutic focus from glycemic to cardio-renal metabolic therapy in DM2 led to the inclusion of new therapies with cardiovascular and renal benefits in international guidelines. Type 1 glucagon (GLP-1) receptor agonists have showed favorable effects on renal function and their potential protective actions are multifactorial, beyond glycemic control. These benefits have been demonstrated in efficacy and safety clini cal studies, as well as in cardiovascular outcomes and real-life studies. This comprehensive review describes the direct and indirect effects of these molecules, as well as evidence obtained from pivotal clinical (LEADER, SUSTAIN 6 and REWIND) and real-life studies demonstrating their beneficial effects on renal function, and also introduces expectations of future results from ongoing studies with renal endpoints.

Chronic Kidney Disease and Arterial Stiffness: A Two-Way Path.

The kidney-heart relationship has raised interest for the medical population since its vast and complex interaction significantly impacts health. Chronic kidney disease (CKD) generates vascular structure and function changes, with significant hemodynamic effects. The early arterial stiffening in CKD patients is a consequence of the interaction between oxidative stress and chronic vascular inflammation, leading to an accelerated deterioration of left ventricular function and alteration in tissue perfusion. CKD amplifies the inflammatory cascade's activation and is responsible for altering the endothelium function, increasing the vascular tone, wall thickening, and favors calcium deposits in the arterial wall. Simultaneously, the autonomic imbalance, and alteration in other hormonal systems, also favor the overactivation of inflammatory and fibrotic mediators. Thus, hormonal disarrangement also contributes to structural and functional lesions throughout the arterial wall. On the other hand, a rise in arterial stiffening and volume overload generates high left ventricular afterload. It increases the left ventricular burden with consequent myocardial remodeling, development of left ventricular hypertrophy and, in turn, heart failure. It is noteworthy that reduction in glomerular mass of renal diseases generates a compensatory glomerular filtration overdriven associated with large-arteries stiffness and high cardiovascular events. Furthermore, we consider that the consequent alterations of the arterial system's mechanical properties are crucial for altering tissue perfusion, mainly in low resistance. Thus, increasing the knowledge of these processes may help the reader to integrate them from a pathophysiological perspective, providing a comprehensive idea of this two-way path between arterial stiffness and renal dysfunction and their impact at the cardiovascular level.

Blood pressure control is not enough to normalize endothelial repair by progenitor cells.

Patients presenting with classical cardiovascular risk factors within acceptable or average value ranges often develop cardiovascular disease, suggesting that other risk factors need to be considered. Considering that endothelial progenitor cells (EPCs) contribute to endothelial repair, we investigated whether EPCs might be such a factor. We compared the ability of peripheral blood EPCs to attach to extracellular matrix proteins and to grow and function in culture, between controlled hypertensive patients exhibiting a Framingham score (FS) of <10% while showing severe vascular impairment (intima-media thickness/diameter, carotid-femoral pulse wave velocity, brachial artery flow-mediated dilation, carotid and femoral atherosclerotic plaque presence; vulnerable group, N = 30) and those with an FS of ≥10% and scarce vascular changes (protected group, N = 30). When compared with vulnerable patients, protected patients had significantly higher early and late-EPC and early and late-tunneling nanotube (TNT) numbers. Significant negative associations were found between vascular damage severity and early EPC, late-EPC, or late-TNT numbers, whereas EPC or TNT numbers and patient characteristics or cardiovascular risk factors were not associated. Except for protected patients, in all controlled hypertensive patients, early and late-EPC and early and late-TNT counts were significantly lower than those in the normotensive subjects studied (N = 30). We found that the disparity in vascular status between patients presenting with both an FS of ≥10% and scarce vascular changes and those presenting with both an FS of <10% and severe vascular impairment is related to differences in peripheral blood EPC and TNT numbers. These observations support the role of EPCs as contributors to vascular injury repair and suggest that EPC numbers may be a potential cardiovascular risk factor to be included in the FS calculation.NEW & NOTEWORTHY As individuals who present with risk factors within acceptable or average value ranges often develop cardiovascular (CV) disease, it has been suggested that other CV risk factors need to be considered in addition to those that are commonly combined in the Framingham score (FS) to estimate the risk of general CV disease. We investigated whether peripheral endothelial progenitor cells (EPCs) and tunneling nanotubes (TNTs) deserve to be considered. Here we report that EPCs and TNTs are significantly lower in controlled hypertensive patients versus normotensive subjects and that the disparity in vascular status between patients presenting with an FS of ≥10% with scarce vascular changes and those presenting with an FS of <10% with severe vascular impairment is related to differences in EPC and TNT numbers. These data point to EPC and TNT numbers as potential CV risk factors to be included in the FS calculation.

Displasia fibromuscular en la Argentina. Registro del grupo de trabajo de Hipertensión Secundaria de la Sociedad Argentina de Hipertensión Arterial (SAHARA-DF): proyecto de protocolo y resultados preliminares / Fibromuscular dysplasia in Argentina. A registry from the Secondary Hypertension working group of the Argentine Society of Hypertension (SAHARA-DF): project protocol and preliminary results

En la Argentina no existen datos epidemiológicos sobre displasia fibromuscular. La realización de un registro nacional puede aportar información que conduzca a una actualización de los consensos y recomendaciones para un correcto diagnóstico, evaluación y tratamiento. El Registro Argentino de Displasia Fibromuscular (SAHARA-DF) inició su actividad de recopilación de datos en octubre de 2015. Al año 2019 se confirmaron 49 pacientes (44 mujeres, 38 hipertensos, edad 45,3 ± 17,2 años, 12 con presentación neurológica). Veintidós pacientes tuvieron lesiones vasculares en más de un sitio, a pesar del sesgo diagnóstico por falta de estudios complementarios en casi la mitad de los casos. El sitio afectado más frecuente fue el renovascular, seguido por el carotídeo y el ilíaco, y las lesiones multifocales fueron más frecuentes que las unifocales (35 versus 14, respectivamente). Se constató la presencia de aneurismas asociados en 13 casos y disección arterial en 4 casos. De las 22 angioplastias renales realizadas, 14 fueron con colocación de stent (endoprótesis). En este estudio preliminar de una población argentina se evidencia el carácter sistémico de la enfermedad y se plantea un llamado a actuar en cuanto a la necesidad de debatir el algoritmo diagnóstico y el método de tratamiento. (AU)

In Argentina there are no epidemiological data regarding fibromuscular dysplasia. Building a National Registry may provide information leading to updated consensus and recommendations for a correct diagnosis, assessment and treatment. Data gathering for the Argentine Registry of Fibromuscular Dysplasia (SAHARA-DF) was initiated in October 2015. By 2019, 49 patients were confirmed (44 women, 38 hypertensives, age 45.3 ± 17.2 years, 12 with a neurological presentation). Twenty-two patients had multi-site vascular lesions, in spite of a diagnosis bias due to lack of supporting studies in almost half of the cases. The renovascular site was the most affected, followed by the carotid and iliac sites, and multifocal lesions were more frequent than unifocal (35 versus 14, respectively). Associated aneurysms were found in 13 cases, and arterial dissection in 4. Twenty-two renal angioplasties were performed, 14 with stent placement. In this preliminary study of an Argentinian population, the systemic nature of the disease is evidenced, and a call for action arises regarding the need for discussing the diagnostic algorithm and treatment method. (AU)

Blood pressure control and cardiovascular risk profile in hypertensive patients under specialist care in Argentina: Results from the CHARTER study.

Worldwide, hypertension control rate is far from ideal. Some studies suggest that patients treated by specialists have a greater chance to achieve control. The authors aimed to determine the BP control rate among treated hypertensive patients under specialist care in Argentina, to characterize patients regarding their cardiovascular risk profile and antihypertensive drug use, and to assess the variables independently associated with adequate BP control. The authors included adult hypertensive patients under stable treatment, managed in 10 specialist centers across Argentina. Office BP was measured thrice with a validated oscillometric device. Adequate BP control was defined as an average of the three readings <140/90 mm Hg (and <150/90 in patients older than 80 years). The authors estimated the proportion of adequate BP control and the variables independently associated with it through a multiple conditional logistic regression model. Among the 1146 included patients, 48.2% were men with a mean age of 63.5 (±13.1) years old. Mean office BP was 135.3 (±14.8)/80.8 (±10) mm Hg, with a 64.8% (95% CI: 62%-67.6%) of adequate control. The mean number of antihypertensive drugs was 2.1 per participant, the commonest being angiotensin receptor blockers and calcium channel blockers. In multivariable analysis, only female sex was a predictor of adequate BP control (OR 1.33 [95% CI 1.02-1.72], P = .04). In conclusion, almost 65% of hypertensive patients treated in specialist centers in Argentina have adequate BP control. The challenge for future research is to define strategies in order to translate this control rate to the primary care level, where most patients are managed.

Predictores de fuerza de presión palmar en hemodiálisis en un centro único en Argentina / Predictors of handgrip strength in hemodialysis patients at a single center in Argentina

INTRODUCCIÓN: Existe una alta incidencia de fracturas en pacientes con enfermedad crónica terminal. Esto se debe en parte a la enfermedad óseo mineral del enfermo renal crónico y en parte a la alta prevalencia de debilidad muscular en esta población. OBJETIVO: Nuestro objetivo fue evaluar cuáles son los determinantes de fuerza muscular medida por fuerza de prensión palmar (FPP) en nuestra población de pacientes en hemodiálisis crónica. MATERIAL Y MÉTODOS: Estudio de corte transversal en adultos de un centro de hemodiálisis. Se registró la FPP y el índice de masa magra (IMM). Se registraron los valores de albumina, magnesio y otros parámetros serológicos. Utilizamos un análisis de regresión lineal múltiple para evaluar los predictores de FPP. RESULTADOS: Analizamos 139 pacientes (hombres: mujeres = 88:51, edad 60.7 ± 16), 18 fueron excluidos. La media de albúmina: 3.8 +/- 0.47 mg/dl, la mediana de tiempo en hemodiálisis: 37 meses (15-83), 25% (n= 35) fueron definidos como sarcopénicos y 21.5% (n= 30) tenían antecedentes de diabetes. En el análisis univariado el magnesio presentó correlación positiva con la FPP (ß 0.19 p 0.02). En el análisis multivariado todas las siguientes continuaron siendo correlativas con la FPP y estadísticamente significativas (R2 0.61 p <0.001): albumina (ß:.4.36 p 0.02), IMM (ß: 1.44 p <0.001), edad (ß -0.10 p 0.04), sexo (ß 6.21 p 0.007), diabetes (ß -5,08 p 0.005). CONCLUSIÓN: Edad, diabetes, albúmina, sexo e IMM están independientemente asociados con la FPP en pacientes en hemodiálisis. Los niveles séricos de magnesio presentaron asociación en el análisis univariado

INTRODUCTION: There is a great incidence of fractures in patients suffering from end-stage chronic disease. This is partly caused by chronic kidney disease-mineral bone disorder and partly by the high prevalence of muscle weakness in these patients. OBJECTIVE: Our objective was to identify the determining factors of muscle strength measured by means of handgrip strength (HGS) in chronic hemodialysis patients. METHODS: A cross-sectional study was conducted on adult patients in a hemodialysis center. Handgrip strength (HGS) and lean mass index (LMI) were measured, as well as albumin and magnesium values and other serological parameters. Multiple linear regression was used to assess HGS predictors. RESULTS: We analyzed 139 patients (88 men and 51 women; age: 60.7 ± 16); 18 subjects were excluded. Mean albumin values: 3.8 +/- 0.47 mg/dL; median hemodialysis time: 37 months (15-83). From the total number of patients, 25% (n=35) were found to be sarcopenic and 21.5% (n=30) had a history of diabetes. The univariate analysis showed a positive correlation between magnesium and HGS (ß 0.19 p 0.02). According to the multivariate analysis, all the following showed a correlation with HGS and were statistically significant: (R2 0.61 p <0.001): albumin (ß:.4.36 p 0.02); LMI (ß: 1.44 p <0.001); age (ß -0.10 p 0.04); sex (ß 6.21 p 0.007); diabetes (ß -5,08 p 0.005). CONCLUSION: Age, diabetes, albumin values, sex and LMI are independently associated with HGS in hemodialysis patients. Serum magnesium levels showed an association in the univariate analysis

Sympathetic predominance is associated with impaired endothelial progenitor cells and tunneling nanotubes in controlled-hypertensive patients.

Early endothelial progenitor cells (early EPC) and late EPC are involved in endothelial repair and can rescue damaged endothelial cells by transferring organelles through tunneling nanotubes (TNT). In rodents, EPC mobilization from the bone marrow depends on sympathetic nervous system activity. Indirect evidence suggests a relation between autonomic derangements and human EPC mobilization. We aimed at testing whether hypertension-related autonomic imbalances are associated with EPC impairment. Thirty controlled-essential hypertensive patients [systolic blood pressure/diastolic blood pressure = 130(120-137)/85(61-88) mmHg; 81.8% male] and 20 healthy normotensive subjects [114(107-119)/75(64-79) mmHg; 80% male] were studied. Mononuclear cells were cultured on fibronectin- and collagen-coated dishes for early EPC and late EPC, respectively. Low (LF)- and high (HF)-frequency components of short-term heart rate variability were analyzed during a 5-min rest, an expiration/inspiration maneuver, and a Stroop color-word test. Modulations of cardiac sympathetic and parasympathetic activities were evaluated by LF/HF (%) and HF power (ms(2)), respectively. In controlled-hypertensive patients, the numbers of early EPC, early EPC that emitted TNT, late EPC, and late EPC that emitted TNT were 41, 77, 50, and 88% lower than in normotensive subjects (P < 0.008), respectively. In controlled-hypertensive patients, late EPC number was positively associated with cardiac parasympathetic reserve during the expiration/inspiration maneuver (rho = 0.45, P = 0.031) and early EPC with brachial flow-mediated dilation (rho = 0.655; P = 0.049); also, late TNT number was inversely related to cardiac sympathetic response during the stress test (rho = -0.426, P = 0.045). EPC exposure to epinephrine or norepinephrine showed negative dose-response relationships on cell adhesion to fibronectin and collagen; both catecholamines stimulated early EPC growth, but epinephrine inhibited late EPC growth. In controlled-hypertensive patients, sympathetic overactivity/parasympathetic underactivity were negatively associated with EPC, suggesting that reducing sympathetic/increasing parasympathetic activation might favor endothelial repair.

Lack of RAAS inhibition by high-salt intake is associated with arterial stiffness in hypertensive patients.

HYPOTHESIS/INTRODUCTION: The relationship between salt intake, blood pressure and RAAS activation is still controversial, being that both high- and low-salt intakes are associated with cardiovascular events in a J-shaped curve pattern. We hypothesized that different patterns of RAAS response to dietary salt intake among hypertensives could be identified, while vascular damage would be related to high-salt intake plus absence of expected RAAS inhibition. OBJECTIVE: We aim to assess the relationship between sodium intake, RAAS and vascular stiffness in hypertension. MATERIALS AND METHODS: We screened 681 hypertensive patients for urinary/plasma electrolytes, renin, aldosterone and pulse wave velocity (PWV) under their usual salt intake level. RESULTS: After applying exclusion criteria, an inverse relation between urinary sodium and RAAS was observed in the 300 remaining subjects. Additionally, four types of response were identified: 1) Low (L) sodium (S)-Low RAAS, 2) LS-High (H) SRAAS, 3) HS-Low RAAS, 4) HS-High RAAS. We found no differences in age/BP among groups, but type 4 response individuals included more females and a higher pulse wave velocity. CONCLUSIONS: We showed a) an inverse salt-RAAS relation, b) an association between HS plus high RAAS with increased PWV that could identify a higher-risk hypertensive condition.

Sodium intake is associated with parasympathetic tone and metabolic parameters in mild hypertension.

BACKGROUND: Although the impairment of parasympathetic cardiac control was described in hypertensives submitted to a high salt diet, the impact of this autonomic abnormality on metabolic and inflammation markers in patients with mild hypertension has not been explored. METHODS: Four hundred and ninety mild essential hypertensive patients (144 ± 9/94 ± 9 mm Hg, 49.5 ± 13.9 years, 67.9 % male) were studied. Dietary sodium intake was estimated by measuring 24-h urinary sodium excretion (UNa), and the patients were classified according to UNa levels as follows: low (<50 mEq/l), medium (50-99 mEq/l), and high UNa (≥100 mEq/l). Parasympathetic tone was evaluated by assessing heart rate recovery (HRR) after an exercise stress test. HRR, plasma lipids, glucose metabolism, and inflammatory biomarkers were compared across UNa groups. RESULTS: HRR and high-density lipoprotein (HDL)-cholesterol were progressively lower, and insulin (INS), homeostasis model assessment of insulin resistance (HOMAir), ultrasensitive-C-reactive protein (usCRP) were progressively higher across increasing UNa groups. In the low and medium UNa groups, HDL-cholesterol was higher and CRP was lower than that in high UNa (P < 0.01 and P < 0.05, respectively) (Dunnett post-hoc test). In the low UNa group, triglycerides (TGs), INS, and HOMAir were lower than that in high UNa (P < 0.05). Multiple linear regression analysis showed that UNa, HOMAir, and heart rate (HR) were negatively associated with HRR (P < 0.0001, P < 0.0001, and P = 0.001, respectively). CONCLUSIONS: In the essential hypertensive patients studied high sodium intake is associated with parasympathetic inhibition, lipid disturbances, and inflammation. Studies designed to assess causality between sodium intake and metabolic and autonomic status are needed to evaluate the relevance of controlling sodium intake, especially in hypertensive patients.

Are plasma renin activity and aldosterone levels useful as a screening test to differentiate between unilateral and bilateral renal artery stenosis in hypertensive patients?

OBJECTIVE: To evaluate the serum aldosterone (Ald)/plasmatic renin activity (PRA) ratio as a surrogate marker of renin-angiotensin-aldosterone system status in unilateral (Uni)- and bilateral (Bi)-renal artery stenosis (RAS). METHODS: Seven hundred and eight hypertensive patients (HTP) were studied. Intermediate and high pretest risk of RAS was detected in 66 HTP who subsequently underwent renal gadolinium-enhanced magnetic resonance and arteriography. After application of exclusion criteria 51 HTP remained: 16 with Uni-RAS, 16 with Bi-RAS and 19 essential hypertensives with normal arteries. Nineteen normotensive individuals were also studied. Ald and PRA were determined before and after stenosis resolution by balloon angioplasty and stent implantation. RESULTS: Ald/PRA (ng/dl per (ng/ml per h(-1))) was markedly high in Bi-RAS (5.92 +/- 2.30, P < 0.001), and markedly low in Uni-RAS (0.38 +/- 0.17, P < 0.001) versus essential hypertensives (1.52 +/- 2.02). Multilevel likelihood ratios for Bi-RAS were positive for Ald/PRA higher than 3.6, negative for Ald/PRA lower than 0.2, and neutral for Ald/PRA at least 0.2 and 3.6 or less. ROC analysis identified Ald/PRA lower than 0.5 and Ald/PRA higher than 3.7 to have the best sensitivity and specificity to detect Uni-RAS and Bi-RAS, respectively. In Uni-RAS, but not in Bi-RAS, postinterventional PRA was significantly lower than basal PRA. In Uni-RAS and Bi-RAS, postinterventional Ald was approximately 30% and approximately three times lower than basal Ald, respectively. In essential hypertensives, PRA and Ald showed no changes in the same period. CONCLUSION: In the population studied, Ald, PRA and Ald/PRA were significantly different among essential hypertensives, and HTP with Uni-RAS or Bi-RAS. Studies with a higher number of patients will allow exploration of the usefulness of pharmacologic aldosterone blockade in Bi-RAS, and to assess the relevance of Ald/PRA to differentiate Uni-RAS from Bi-RAS.