The antihypertensive effect of arginine

Renal denervation ameliorated salt-induced hypertension by improving cardiac work, cardiac enzyme and oxidative balance in Sprague-Dawley rats

Background

Hypertension is associated with cardiovascular dysfunction, dysregulation of the antioxidant system and alteration of the level of some enzymes in the metabolic pathway. The possible modulatory effect of acute renal denervation (ARD) on cardiovascular function and the antioxidant system is still a subject of intense debate. This study sought to ascertain the ameliorative effects of ARD on cardiovascular parameters, antioxidant system, creatine kinase and lactate dehydrogenase levels.

Methods

Thirty-six Sprague-Dawley rats (5-6 weeks old) were divided into 6 groups of 6 animals each consisting of Normal Salt, High Salt, Normal Salt + Sham Denervation, High Salt + Sham Denervation, Normal Salt + Renal Denervation and High Salt + Renal Denervation. Induction of hypertension with 8 % salt in the diet lasted for 8 weeks. Renal or Sham denervation was thereafter done on selected groups. At the end of the experimental period, cardiovascular parameters, plasma antioxidant status, plasma creatine kinase (CK) and lactate dehydrogenase (LDH) levels were assessed. Significance level was set at p < 0.05.

Results

Salt-loading significantly increased systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MABP), rate pressure product (RPP) while reducing superoxide dismutase (SOD), reduced glutathione (GSH) and catalase (CAT). Acute renal denervation significantly (p < 0.0001) reduced SBP, DBP, MABP, RPP, LDH and norepinephrine level while increasing SOD, GSH and CAT. ARD did not significantly alter CK level.

Conclusion

Acute renal denervation, by reducing sympathetic activity, ameliorates cardiovascular and antioxidant functions as well as reduces LDH level without significantly altering CK level in salt-induced hypertension.

Anti-inflammatory role of extracellular l-arginine through calcium sensing receptor in human renal proximal tubular epithelial (HK-2) cells

Renal tubular epithelial cells are capable of synthesizing interleukins (IL) in response to a variety of proinflammatory cytokines. Moreover, elevated urinary levels of IL have been shown in patients with various forms of nephritic diseases. However, the underlying intracellular signaling mechanism is unclear. Here we show the immunological signaling role of l-Arginine (l-Arg) through Ca2+-sensing receptor (CaSR) in human kidney 2 (HK-2) renal proximal tubular epithelial cells, using Ca2+ imaging and patch clamp techniques and its mechanistic link to the downstream cellular function. Both pharmacological and siRNA inhibitors support the activation CaSR by extracellular l-Arg to induced Ca2+ entry via a Transient receptor potential canonical (TRPC) channel in HK-2 cells mainly through the receptor operated Ca2+ entry (ROCE). Activation of CaSR by l-Arg led to the rise in p-p38/p38 expression suggesting [Ca2+]i as a regulator for p38-signaling pathways. Notably, l-Arg activated CaSR-induced Ca2+ signaling reduced the expressions of key fibrotic, inflammatory, and apoptotic genes, suggesting its nephroprotective role via Ca2+ signaling through CaSR in HK-2 cells. Since we found that the IL-6 expressions were inversely proportional to the increasing concentrations of l-Arg in HK-2 cells, we measured the release of IL-6, which steadily decreased as the concentrations of l-Arg were elevated. Taken together, extracellular l-Arg is a negative regulator for IL-6-induced inflammatory process, through the activation of CaSR and TRPC channel by ROCE pathway and can have a potential to alleviate inflammatory renal diseases.

Eating more sardines instead of fish oil supplementation: Beyond omega-3 polyunsaturated fatty acids, a matrix of nutrients with cardiovascular benefits

Omega-3 polyunsaturated fatty acids (n-3 PUFA) play a significant role in the prevention and management of cardiometabolic diseases associated with a mild chronic pro-inflammatory background, including type 2 diabetes, hypertension, hypertriglyceridaemia, and fatty liver disease. The effects of n-3 PUFA supplements specifically, remain controversial regarding reducing risks of cardiovascular events. n-3 PUFA supplements come at a cost for the consumer and can result in polypharmacy for patients on pharmacotherapy. Sardines are a well-known, inexpensive source of n-3 PUFA and their consumption could reduce the need for n-3 PUFA supplementation. Moreover, sardines contain other cardioprotective nutrients, although further insights are crucial to translate a recommendation for sardine consumption into clinical practice. The present review discusses the matrix of nutrients contained in sardines which confer health benefits for cardiometabolism, beyond n-3 PUFA. Sardines contain calcium, potassium, magnesium, zinc, iron, taurine, arginine and other nutrients which together modulate mild inflammation and exacerbated oxidative stress observed in cardiovascular disease and in haemodynamic dysfunction. In a common serving of sardines, calcium, potassium, and magnesium are the minerals at higher amounts to elicit clinical benefits, whilst other nutrients are present in lower but valuable amounts. A pragmatic approach towards the consumption of such nutrients in the clinical scenario should be adopted to consider the dose-response relationship effects on physiological interactions. As most recommendations currently available are based on an indirect rationale of the physiological actions of the nutrients found in sardines, randomised clinical trials are warranted to expand the evidence on the benefits of sardine consumption.

Association of Major Dietary Protein Sources With All-Cause and Cause-Specific Mortality: Prospective Cohort Study

Background

Dietary recommendations regarding protein intake have been focused on the amount of protein. However, such recommendations without considering specific protein sources may be simplistic and insufficient.

Methods and Results

We included 102 521 postmenopausal women enrolled in the Women’s Health Initiative between 1993 and 1998, and followed them through February 2017. During 1 876 205 person‐years of follow‐up, 25 976 deaths occurred. Comparing the highest with the lowest quintile, plant protein intake was inversely associated with all‐cause mortality (hazard ratio [HR], 0.91 [0.86, 0.96]), cardiovascular disease mortality (HR, 0.88 [0.79, 0.97]), and dementia mortality (HR, 0.79 [0.67, 0.94]). Among major protein sources, comparing the highest with the lowest quintile of consumption, processed red meat (HR, 1.06 [1.01, 1.10]) or eggs (HR, 1.14 [1.10, 1.19]) was associated with higher risk of all‐cause mortality. Unprocessed red meat (HR, 1.12 [1.02, 1.23]), eggs (HR, 1.24 [1.14, 1.34]), or dairy products (HR, 1.11 [1.02, 1.22]) was associated with higher risk of cardiovascular disease mortality. Egg consumption was associated with higher risk of cancer mortality (HR, 1.10 [1.02, 1.19]). Processed red meat consumption was associated with higher risk of dementia mortality (HR, 1.20 [1.05, 1.32]), while consumption of poultry (HR, 0.85 [0.75, 0.97]) or eggs (HR, 0.86 [0.75, 0.98]) was associated with lower risk of dementia mortality. In substitution analysis, substituting of animal protein with plant protein was associated with a lower risk of all‐cause mortality, cardiovascular disease mortality, and dementia mortality, and substitution of total red meat, eggs, or dairy products with nuts was associated with a lower risk of all‐cause mortality.

Conclusions

Different dietary protein sources have varying associations with all‐cause mortality, cardiovascular disease mortality, and dementia mortality. Our findings support the need for consideration of protein sources in future dietary guidelines.

Impact of oral L-arginine supplementation on blood pressure dynamics in children with severe sickle cell vaso-occlusive crisis

Sickle cell anaemia (SCA) patients generally have lower blood pressures compared to those with the AA haemoglobin genotype. However, during vaso-occlusive crises (SCA-VOC), blood pressures (BP) may elevate transiently to levels beyond the 95^th percentile. The risk of stroke or even death increases with increasing systolic BP in SCA. Therefore, interventions targeted at BP reduction may be essential during severe vaso-occlusive episodes. Reduction in BP was achieved with arginine therapy in a meta-analysis of randomized controlled trials (RCT) in non-sickle cell adults. The impact of oral arginine (given for pain control) on the BP of children with SCA-VOC has not been documented.

METHODS

A double-blind RCT of oral _L-arginine hydrochloride as adjuvant therapy for pain reduction was conducted in children with SCA-VOC, aged 5-17 years, over a 2-year period. The mean change in BP and the time to achieve BP <90^th percentile was added as part of the outcome variables. The anthropometry, pain scores and mercury sphygmomanometry were done following standard procedures. BP percentiles were generated using the Fourth Report guidelines. Differences in the time to normalization of BP in the treatment arms were tested with Kaplan-Meier analysis.

RESULTS

Sixty-six children (57.6% male) were randomized into _L-arginine (35 patients) or placebo (31 patients) arm. The prevalence of hypertension (BP ≥95^th percentile) at presentation tended to increase as the pain scores increased, from a prevalence of 50% in patients with a score of 7 to 65% in those with score of 10 (systolic hypertension) and from 44.4% in patients with pain score of 7 to 50% in patients with pain score of 10 (diastolic hypertension). Patients that received arginine recorded a 12.8±3.2 mmHg decline in mean systolic BP compared to the placebo group, where a mean difference of 7.6±1.5 mmHg was observed, P<0.001. Similarly, the mean diastolic BP reduced by 13% in the arginine group and 7.5% in the placebo group, P<0.001. Children who received arginine tended to achieve BP normalization much faster than the placebo group (P=0.112), and no serious adverse events were documented related to the hypertension or arginine administration.

CONCLUSIONS

High blood pressure (≥95^th percentile) is common amongst children with SCA-VOC and are mostly asymptomatic. Administration of oral arginine given for pain control achieves a reduction of the BP at a faster rate in children compared to placebo and it is safe.

Total Nut, Tree Nut, and Peanut Consumption and Metabolic Status in Southern Italian Adults

Background: Nut consumption has been associated with cardio-metabolic health benefits. However, studies conducted in the Southern Italian population, where adherence to the Mediterranean diet has been reported being relatively high, are rather scarce. The aim of this study was to test the association between consumption of total and specific types of nuts and metabolic status among adults living in Sicily, Southern Italy. Methods: Demographic and dietary characteristics of 2044 adults living in Southern Italy were analyzed. Multivariate logistic regression analyses were performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs) of the association between nut consumption and metabolic status adjusting for potential confounding factors. Results: The energy-adjusted model revealed that higher nut intake was inversely associated with occurrence of hypertension, type-2 diabetes, and dyslipidemia. However, the association did not remain significant for the latter after adjusting for the main background characteristics, while an inverse association was stably confirmed for hypertension (OR = 0.61, 95% CI: 0.46–0.80 and OR = 0.44, 95% CI: 0.26–0.74, respectively) even after adjusting for adherence to the Mediterranean diet. Among individual nut types, most of the associations were null except for higher almond intake, which was inversely associated with occurrence of hypertension (OR = 0.70, 95% CI: 0.49–0.99). Conclusions: Higher nut consumption is associated with overall better metabolic status in individuals living in the Mediterranean area.

Levels of endothelial substances in patients with newly identified hypertension compared with healthy controls

INTRODUCTION

Endothelial dysfunction occurs at the very beginning of hypertension. The primary goal of our study was to determine plasmatic levels of multiple endothelial substances in otherwise healthy patients with primary hypertension and compare them to healthy individuals. Secondary goals were to determine the change in NOx levels after initiation of treatment and to compare the NOx levels in patients with established resistant hypertension.

MATERIALS AND METHODS

87 consecutive patients were enrolled. In the exploratory cohort of 22 healthy and 28 hypertensive individuals, plasmatic levels of big endotelin-1, asymmetric dimethylarginin, osteopontin, oxidized LDL, 3-nitro-L-tyrosine, growth/differentiation factor 15, intercellular adhesion molecule, vascular cell adhesion molecule, tumor necrosis factor-α, vascular endothelial growth factor, interleukins -1β, -6 and nitric oxide levels (NO, expressed as NOx) were determined. The remaining 27 individuals were used as a validation cohort. Ten patients with established resistant hypertension were enrolled from our Hypertension Clinic.

RESULTS

There was a statistically significant difference in NOx levels between healthy controls and hypertensive patients/resistant hypertensive patients: 45.164 µmol/L ± 48.627 vs 17.763 µmol/L ± 10.333 (P=0.00004)/14.36 µmol/L ± 7.194 (P=0.00007).

CONCLUSION

We identified a decrease in total NOx plasmatic levels in otherwise healthy patients with primary hypertension that was more profound in patients with resistant hypertension. Plasmatic levels of other determined endothelial substances did not differ among the groups. However, due to the significant variability of plasmatic NOx levels even in healthy controls and many factors that affect it, we cannot recommend it to be used to assess endothelial function routinely.

The impact of type of dietary protein, animal versus vegetable, in modifying cardiometabolic risk factors: A position paper from the International Lipid Expert Panel (ILEP)

Proteins play a crucial role in metabolism, in maintaining fluid and acid-base balance and antibody synthesis. Dietary proteins are important nutrients and are classified into: 1) animal proteins (meat, fish, poultry, eggs and dairy), and, 2) plant proteins (legumes, nuts and soy). Dietary modification is one of the most important lifestyle changes that has been shown to significantly decrease the risk of cardiovascular (CV) disease (CVD) by attenuating related risk factors. The CVD burden is reduced by optimum diet through replacement of unprocessed meat with low saturated fat, animal proteins and plant proteins. In view of the available evidence, it has become acceptable to emphasize the role of optimum nutrition to maintain arterial and CV health. Such healthy diets are thought to increase satiety, facilitate weight loss, and improve CV risk. Different studies have compared the benefits of omnivorous and vegetarian diets. Animal protein related risk has been suggested to be greater with red or processed meat over and above poultry, fish and nuts, which carry a lower risk for CVD. In contrast, others have shown no association of red meat intake with CVD. The aim of this expert opinion recommendation was to elucidate the different impact of animal vs vegetable protein on modifying cardiometabolic risk factors. Many observational and interventional studies confirmed that increasing protein intake, especially plant-based proteins and certain animal-based proteins (poultry, fish, unprocessed red meat low in saturated fats and low-fat dairy products) have a positive effect in modifying cardiometabolic risk factors. Red meat intake correlates with increased CVD risk, mainly because of its non-protein ingredients (saturated fats). However, the way red meat is cooked and preserved matters. Thus, it is recommended to substitute red meat with poultry or fish in order to lower CVD risk. Specific amino acids have favourable results in modifying major risk factors for CVD, such as hypertension. Apart from meat, other animal-source proteins, like those found in dairy products (especially whey protein) are inversely correlated to hypertension, obesity and insulin resistance.

Safety issues and harmful pharmacological interactions of nutritional supplements in Duchenne muscular dystrophy: considerations for Standard of Care and emerging virus outbreaks

At the moment, little treatment options are available for Duchenne muscular dystrophy (DMD). The absence of the dystrophin protein leads to a complex cascade of pathogenic events in myofibres, including chronic inflammation and oxidative stress as well as altered metabolism. The attention towards dietary supplements in DMD is rapidly increasing, with the aim to counteract pathology-related alteration in nutrient intake, the consequences of catabolic distress or to enhance the immunological response of patients as nowadays for the COVID-19 pandemic emergency. By definition, supplements do not exert therapeutic actions, although a great confusion may arise in daily life by the improper distinction between supplements and therapeutic compounds. For most supplements, little research has been done and little evidence is available concerning their effects in DMD as well as their preventing actions against infections. Often these are not prescribed by clinicians and patients/caregivers do not discuss the use with their clinical team. Then, little is known about the real extent of supplement use in DMD patients. It is mistakenly assumed that, since compounds are of natural origin, if a supplement is not effective, it will also do no harm. However, supplements can have serious side effects and also have harmful interactions, in terms of reducing efficacy or leading to toxicity, with other therapies. It is therefore pivotal to shed light on this unclear scenario for the sake of patients. This review discusses the supplements mostly used by DMD patients, focusing on their potential toxicity, due to a variety of mechanisms including pharmacodynamic or pharmacokinetic interactions and contaminations, as well as on reports of adverse events. This overview underlines the need for caution in uncontrolled use of dietary supplements in fragile populations such as DMD patients. A culture of appropriate use has to be implemented between clinicians and patients' groups.

Norvaline Reduces Blood Pressure and Induces Diuresis in Rats with Inherited Stress-Induced Arterial Hypertension

Growing evidence suggests that increased arginase activity affects vital bioprocesses in various systems and universally mediates the pathogenesis of numerous metabolic diseases. The adverse effects of arginase are associated with a severe decline in L-arginine bioavailability, which leads to nitric oxide synthase substrate insufficiency, uncoupling, and, eventually, superoxide anion generation and substantial reduction of nitric oxide (NO) synthesis. In cooperation, it contributes to chronic oxidative stress and endothelial dysfunction, which might lead to hypertension and atherosclerosis. Recent preclinical investigations point arginase as a promising therapeutic target in ameliorating metabolic and vascular dysfunctions. In the present study, adult rats with inherited stress-induced arterial hypertension (ISIAH) were used as a model of hypertension. Wistar rats served as normotensive controls. Experimental animals were intraperitoneally administered for seven days with nonproteinogenic amino acid L-norvaline (30 mg/kg/day), which is a potent arginase inhibitor, or with the vehicle. Blood pressure (BP), body weight, and diuresis were monitored. The changes in blood and urine levels of creatinine, urea, and NO metabolites were analyzed. We observed a significant decline in BP and induced diuresis in ISIAH rats following the treatment. The same procedure did not affect the BP of control animals. Remarkably, the treatment had no influence upon glomerular filtration rate in two experimental groups, just like the daily excretion of creatinine and urea. Conversely, NO metabolite levels were amplified in normotonic but not in hypertensive rats following the treatment. The data indicate that L-norvaline is a potential antihypertensive agent and deserves to be clinically investigated. Moreover, we suggest that changes in blood and urine are causally related to the effect of L-norvaline upon BP regulation.

l-arginine Supplementation Increased Only Endothelium-Dependent Relaxation in Sprague-Dawley Rats Fed a High-Salt Diet by Enhancing Abdominal Aorta Endothelial Nitric Oxide Synthase Gene Expression

Background

Abnormal vascular reactivity and reduced expression of endothelial nitric oxide synthase (eNOS) gene are hallmark of salt-induced hypertension in rats. Although l-arginine is an established vasodilator, the mechanism by which it modulates vascular reactivity in salt-induced hypertension is not clearly understood.

Objectives

This study was designed to investigate the mechanism by which oral l-arginine supplementation modulates vascular reactivity and eNOS gene expression in Sprague-Dawley rats fed a high-salt diet.

Methods

Forty-eight weaned male Sprague-Dawley rats of weight range 90 to 110 g were randomly divided into 6 groups of 8 rats per group. Group I was fed normal rat chow ad libitum and served as the Normal Diet group. Group II was fed a diet that contained 8% NaCl. Groups III and IV took normal and high-salt diet, respectively, and then received oral l-arginine supplementation (100 mg/kg/day), while groups V and VI took normal and high-salt diet, respectively, and then were co-administered with both l-arginine and l-nitro-arginine methyl ester (L-NAME; 100 mg/kg/day and 40 mg/kg/day, respectively) orally. At the end of 12-week experimental period, the animals were sacrificed to assess vascular reactivity and gene expression level.

Results

Our results show that high-salt diet significantly reduced (P < .05) endothelium-dependent relaxation response to acetylcholine and qualitatively reduced eNOS gene expression in the abdominal aorta of the rats. However, l-arginine supplementation improved the impaired endothelium-dependent relaxation and nitric oxide level while ameliorating the reduced eNOS gene expressions.

Conclusion

This study suggests that oral supplementation of l-arginine enhances endothelial-dependent relaxation in rats fed a high-salt diet by ameliorating eNOS gene expression in the abdominal aorta of the rats.

Enzymatic hydrolysis of insectAlphitobius diaperinustowards the development of bioactive peptide hydrolysates

Edible insects are a promising protein source for the future generation, due to their nutritional composition, sustainability and low environmental impact.

Phosphorylation Mechanism of N-Acetyl-l-glutamate Kinase, a QM/MM Study

In microorganisms and plants, N-acetyl-l-glutamate kinase (NAGK) catalyzes the second step in l-arginine synthesis, the phosphorylation of N-Acetyl-l-glutamate (NAG) to give N-acetyl-l-glutamate-5-phosphate. NAGK is only present in microorganisms and plants but absent in mammals, which makes it an attractive target for antimicrobial or biocidal development. Understanding the substrate binding mode and reaction mechanism of NAGK is crucial for targeting the kinase to develop potential therapies. Here, the substrate binding mode was studied by comparing the conformational change of NAGK in the presence and in the absence of the NAG substrate based on molecular dynamics simulations. We revealed that with substrate binding, the catalytic site of the kinase involving three loops in NAGK exhibits a closed conformation, which is predominantly controlled by an interaction between Arg98 and the α-COO^- of NAG. Lys41 is found to guide phosphate transfer through the interactions with the β-,γ-, and γ-phosphate oxygen atoms of adenosine 5'-triphosphate surrounded by two highly conserved glycine residues (Gly44 and Gly76), while Arg98 helps to position the NAG substrate in the catalytic site, which facilitates the phosphate transfer. Furthermore, we elucidated phosphate-transfer reaction mechanism using hybrid density functional theory-based quantum mechanics/molecular mechanics calculations (B97D/AMBER99) and found that the catalysis follows a dissociative mechanism.

Arginase upregulation and eNOS uncoupling contribute to impaired endothelium-dependent vasodilation in a rat model of intrauterine growth restriction

Individuals born after intrauterine growth restriction (IUGR) are at increased risk of developing cardiovascular diseases in adulthood, notably hypertension (HTN). Alterations in the vascular system, particularly impaired endothelium-dependent vasodilation, may play an important role in long-term effects of IUGR. Whether such vascular dysfunction precedes HTN has not been fully established in individuals born after IUGR. Moreover, the intimate mechanisms of altered endothelium-dependent vasodilation remain incompletely elucidated. We therefore investigated, using a rat model of IUGR, whether impaired endothelium-dependent relaxation precedes the development of HTN and whether key components of the l-arginine-nitric oxide (NO) pathway are involved in its pathogenesis. Pregnant rats were fed with a control (CTRL, 23% casein) or low-protein diet (LPD, 9% casein) to induce IUGR. Systolic blood pressure (SBP) was measured by tail-cuff plethysmography in 5- and 8-wk-old male offspring. Aortic rings were isolated to investigate relaxation to acetylcholine, NO production, endothelial NO synthase (eNOS) protein content, arginase activity, and superoxide anion production. SBP was not different at 5 wk but significantly increased in 8-wk-old offspring of maternal LPD (LP) versus CTRL offspring. In 5-wk-old LP versus CTRL males, endothelium-dependent vasorelaxation was significantly impaired but restored by preincubation with l-arginine or the arginase inhibitor S-(2-boronoethyl)-l-cysteine; NO production was significantly reduced but restored by l-arginine pretreatment; total eNOS protein, dimer-to-monomer ratio, and arginase activity were significantly increased; superoxide anion production was significantly enhanced but normalized by pretreatment with the NO synthase inhibitor N^ω-nitro-l-arginine. In this model, IUGR leads to early-impaired endothelium-dependent vasorelaxation, resulting from arginase upregulation and eNOS uncoupling, which precedes the development of HTN.

Association of Animal and Plant Proteins Intake with Hypertension in Iranian Adult Population: Isfahan Healthy Heart Program

Background:

There is evidence regarding the relationship between dietary proteins intake and blood pressure (BP), but they had inconsistent results. Therefore, this study was designed to assess the association between different kinds of protein intake (animal and plant protein) and BP.

Materials and Methods:

Data were collected from Isfahan Healthy Heart Program. We performed a cross-sectional study among 9660 randomly selected Iranian adults aged ≥19-year-old that they were selected from three large Iranian regions in 2007. A simplified validated 48-item-food frequency questionnaire was used to assess dietary intake including all kinds of protein. Systolic and diastolic BPs were measured in duplicate by trained personnel using a standard protocol. Multivariable regressions were applied to assess the relationship between protein intake and BP levels and the presence of hypertension (HTN).

Results:

More frequent consumption of animal, plant, and total protein intake were inversely associated with BP in a crude model (P < 0.001); however, after adjustment for potential confounders this relationship remained only for plant protein (P = 0.04). The risk of HTN occurrence decreased in the highest quintile of total and plant protein consumption by 19% (odds ratio [OR] = 0.81; confidence interval [CI]: [0.65–0.96]; P for trend = 0.004) and 18% (OR = 0.82; [CI: (0.67–0.94]; P for trend = 0.03), respectively.

Conclusions:

More frequent protein intake, especially plant protein consumption was inversely associated with BP and risk of HTN among Iranian adults.

The effects of dietary approaches to stop hypertension diet on weight loss, anti-Müllerian hormone and metabolic profiles in women with polycystic ovary syndrome: A randomized clinical trial

OBJECTIVE

This study was designed to evaluate the effects of the dietary approaches to stop hypertension (DASH diet) on weight loss, anti-Müllerian hormone (AMH) and metabolic profiles in women with polycystic ovary syndrome (PCOS).

DESIGN, PATIENTS AND MEASUREMENTS

A randomized controlled clinical trial was conducted among 60 overweight or obese patients with PCOS. Patients were randomly assigned to receive either low-calorie DASH (N=30) or control diet (N=30) for 12 weeks. The DASH and control diets were consisted of 52%-55% carbohydrates, 16%-18% proteins and 30% total fats; however, the DASH diet was designed to be rich in fruits, vegetables, whole grains, low-fat dairy products, cholesterol and refined grains. Both diets were equicaloric.

RESULTS

Adherence to the DASH diet, compared to the control diet, resulted in a significant decrease in BMI (-1.6±0.5 vs -1.2±0.7 kg/m2 , P=.02). Significant decreases in AMH (-1.1±3.1 vs +0.3±0.7 ng/mL, P=.01), insulin (-25.2±51.0 vs -1.2±28.8 pmol/L, P=.02), homoeostasis model of assessment-estimated insulin resistance (-0.9±2.0 vs -0.1±1.0, P=.02), free androgen index (FAI; -0.03±0.09 vs +0.06±0.21, P=.02) and malondialdehyde (MDA) levels (-0.5±0.4 vs +0.2±0.3 μmol/L, P<.001), and significant increases in quantitative insulin sensitivity check index (+0.01±0.03 vs -0.004±0.01, P=.02), sex hormone-binding globulin (SHBG; +3.7±8.5 vs -1.5±7.2 nmol/L, P=.01) and nitric oxide (NO; +9.0±4.9 vs +0.6±2.3 μmol/L, P<.001) were also seen in the DASH group compared with the control group.

CONCLUSIONS

Adherence to the DASH diet for 12 weeks among PCOS women had beneficial effects on BMI, AMH, insulin metabolism, SHBG, FAI, NO and MDA levels.

Immunonutrition in patients with cyctic fibrosis leads to drop of serum amyloid A and increase of oxidative stress

The aim of the present study is to evaluate of the impact of immunonutrition on parameters of oxidative stress and inflammation in patients with cystic fibrosis and malnutrition. In the 30 patients with cystic fibrosis and long-term enteral nutrition support for malnutrition the effect of standard and immunonutrion sipping on oxidative stress and inflammatory activity parameters was compared. Malonyldialdehyde (MDA) as parameter of oxidative stress and serum amyloid A (SAA), interleukin 1 and 6, hsCRP, IgM, IgA, IgG as parameters of inflammatory activity were examined. Immunonutrition decreased SAA to 17.6 mg/L comparing to 25.6 mg/L when standard nutrition was given (p = 0.014). MDA was 0.66 µM on standard and 0.96 µM on immunonutrition support (p<0.01). The significant negative correlation was recorded between MDA and SAA, hs-CRP, interleukin 6, IgA and IgG. In conclusion, the application of immunonutrition in patients with cystic fibrosis and malnutrition is associated with drop of SAA but with the rise of MDA.

Beyond the Cholesterol-Lowering Effect of Soy Protein: A Review of the Effects of Dietary Soy and Its Constituents on Risk Factors for Cardiovascular Disease

The hypocholesterolemic effect of soy is well-documented and this has led to the regulatory approval of a health claim relating soy protein to a reduced risk of cardiovascular disease (CVD). However, soybeans contain additional components, such as isoflavones, lecithins, saponins and fiber that may improve cardiovascular health through independent mechanisms. This review summarizes the evidence on the cardiovascular benefits of non-protein soy components in relation to known CVD risk factors such as hypertension, hyperglycemia, inflammation, and obesity beyond cholesterol lowering. Overall, the available evidence suggests non-protein soy constituents improve markers of cardiovascular health; however, additional carefully designed studies are required to independently elucidate these effects. Further, work is also needed to clarify the role of isoflavone-metabolizing phenotype and gut microbiota composition on biological effect.

ADMA, SDMA and L-arginine may be Novel Targets in Pharmacotherapy for Complications due to Cardiopulmonary Bypass

Background

In this study, the effects of olmesartan therapy on asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), L-arginine and inducible nitric oxide synthase (iNOS) levels were investigated in patients undergoing cardiopulmonary bypass.

Methods

Patients were randomly allocated to two groups, control and olmesartan. Olmesartan was administered 30 mg once a day beginning from preoperative day 5 to postoperative day 28 and on operation day. Blood was drawn from all patients and ADMA, SDMA, L-arginine and iNOS levels were analyzed at six time points (T1: before anesthesia induction, T2: during cardiopulmonary bypass, T3: five min after the cross-clamp was removed, T4: after protamine infusion, T5: on postoperative day 3 and T6: on postoperative day 28).

Results

In the olmesartan treated group, iNOS levels exhibited significant decreases at T2, T3, T4, T5 and T6 time points compared with control group (p<0.001, p<0.05, p<0.001, p<0.01, p<0.05 respectively). ADMA levels were significantly lower in olmesartan treated group than in control group at T3, T4, T5 and T6 time points (p<0.05, p<0.05, p<0.05, p<0.01 respectively). SDMA levels at T2, T3 and T6 time points were higher in control group than olmesartan group. L-Arginine levels were significantly higher at T2 and T3 time points in olmesartan treated group than control group (p<0.001, p<0.01).

Conclusions

It was concluded that administration of olmesartan reduced plasma ADMA, SDMA, iNOS levels and enhanced L-arginine level in CPB time and it could reduce potential postoperative complications through reducing oxidative stress and inflammatory response in the postoperative period after coronary bypass surgery.

Salt-sensitive hypertension: mechanisms and effects of dietary and other lifestyle factors

Salt sensitivity, which is an increase in blood pressure in response to high dietary salt intake, is an independent risk factor for cardiovascular disease and mortality. It is associated with physiological, environmental, demographic, and genetic factors. This review focuses on the physiological mechanisms of salt sensitivity in populations at particular risk, along with the associated dietary factors. The interplay of mechanisms such as the renin-angiotensin aldosterone system, endothelial dysfunction, ion transport, and estrogen decrease in women contributes to development of salt sensitivity. Because of their effects on these mechanisms, higher dietary intakes of potassium, calcium, vitamin D, antioxidant vitamins, and proteins rich in L-arginine, as well as adherence to dietary patterns similar to the DASH (Dietary Approaches to Stop Hypertension) diet, can be beneficial to salt-sensitive populations. In contrast, diets similar to the typical Western diet, which is rich in saturated fats, sucrose, and fructose, together with excessive alcohol consumption, may exacerbate salt-sensitive changes in blood pressure. Identifying potential mechanisms of salt sensitivity in susceptible populations and linking them to protective or harmful dietary and lifestyle factors can lead to more specific guidelines for the prevention of hypertension and cardiovascular disease.

The effects of DASH diet on weight loss and metabolic status in adults with non-alcoholic fatty liver disease: a randomized clinical trial

BACKGROUND & AIMS

This study was designed to determine the effects of the Dietary Approaches to Stop Hypertension (DASH) diet on weight loss and metabolic status in overweight patients with non-alcoholic fatty liver disease (NAFLD).

METHODS

This randomized controlled clinical trial was done among 60 overweight and obese patients with NAFLD. Patients were randomly allocated to consume either the control (n = 30) or the DASH eating pattern (n = 30) for 8 weeks. Both diets were designed to be calorie-restricted. Both diets were consisted of 52-55% carbohydrates, 16-18% proteins and 30% total fats; however, the DASH diet was designed to be rich in fruits, vegetables, whole grains, and low-fat dairy products and low in saturated fats, cholesterol and refined grains.

RESULTS

Adherence to the DASH eating pattern, compared to the control diet, weight (P = 0.006), BMI (P = 0.01), alanine aminotransferase (ALT) (P = 0.02), alkalin phosphatase (ALP) (P = 0.001), insulin levels (P = 0.01), homoeostasis model of assessment-estimated insulin resistance (HOMA-IR) (P = 0.01) significantly decreased and quantitative insulin sensitivity check index (QUICKI) (P = 0.004) significantly increased. Compared with the control diet, the DASH diet has resulted in significant reductions in serum triglycerides (P = 0.04) and total-/HDL-cholesterol ratio (P = 0.01). Finally, decreased concentrations of serum high-sensitivity C-reactive protein (hs-CRP) (P = 0.03), malondialdehyde (MDA) (P = 0.04), increased levels of nitric oxide (NO) (P = 0.01) and glutathione (GSH) (P = 0.009) were found in the DASH group compared with the control group.

CONCLUSIONS

Consumption of DASH diet for 8 weeks among patients with NAFLD had beneficial effects on weight, BMI, ALT, ALP, triglycerides, markers of insulin metabolism, inflammatory markers, GSH and MDA.

Antihypertensive effects of dietary protein and its mechanism

Hypertension is a leading cause of morbidity and mortality worldwide. Individuals with hypertension are at increased risk of stroke, heart disease and kidney failure. Both genetic and lifestyle factors, particularly diet, have been attributed an important role in the development of hypertension. Reducing dietary sugar and salt intake can help lower blood pressure; similarly, adequate protein intake may also attenuate hypertension. Observational, cross-sectional and longitudinal epidemiological studies, and controlled clinical trials, have documented significant inverse associations between protein intake and blood pressure. Human and animal studies have shown that specific amino acids within proteins may have antihypertensive effects. Cysteine, glutathione (a tripeptide), glutamate and arginine attenuate and prevent alterations that cause hypertension including insulin resistance, decreased nitric oxide bioavailability, altered renin angiotensin system function, increased oxidative stress and formation of advanced glycation end products. Leucine increases protein synthesis in skeletal muscle and improves insulin resistance by modulating hepatic gluconeogenesis. Taurine and tryptophan attenuate sympathetic nervous system activity. Soy protein helps lower blood pressure through its high arginine content and antioxidant activity exhibited by isoflavones. A diet containing an ample amount of protein may be a beneficial lifestyle choice for individuals with hypertension; one example is the Dietary Approaches to Stop Hypertension (DASH) diet, which is low in salt and saturated fat; includes whole grains, lean meat, poultry, fish and nuts; and is rich in vegetables, fruits and low-fat dairy products, which are good sources of antioxidant vitamins, minerals and fibre. Including an adequate supply of soy in the diet should also be encouraged.