Treating hypertension while protecting the vulnerable islet in the cardiometabolic syndrome

Global dynamics for a model of amyloid fibril formation in pancreatic islet beta cells subjected to a therapy

Amyloid polypeptide (IAPP) fibril formation is the main cause of type II diabetes mellitus (T2DM) disease and cardiovascular disease (CVD). Therefore, implementing therapeutic interventions strategies to control IAPP fibril formation plays a crucial role in preventing and managing T2DM disease and CVD. For this purpose, in this paper, we make use of a mathematical model to investigate the effects of drug therapy on the dynamics of amyloid fibril formation (or amyloid plaques). The model is a hybrid system of differential equations consisting of ODEs and (hyperbolic) PDE. The (global) stability analysis is established through the construction of suitable Lyapunov functionals and application of Lasalle's invariance principle. Moreover, stability of the disease steady state is fully determined by a threshold condition, which is based on the total population of IAPP polymers.

Effect of livergol on the improvement of fatty liver in patients with cancer undergoing irinotecan- and oxaliplatin-based chemotherapy regimen

BACKGROUND

The aim of this study was to determine the effect of Livergol on the improvement of fatty liver in patients with cancer undergoing irinotecan- and oxaliplatin-based chemotherapy regimen.

MATERIALS AND METHODS

This was an add-on nonrandomized clinical trial study on thirty selected eligible cancer patients undergoing irinotecan (8 patients) and oxaliplatin (22 patients) with diagnosed fatty liver disease-based liver ultrasonography, as well as alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Patients in each group received Livergol at a dose of 140 mg daily for 1 month. ALT and AST levels as well as grade of fatty liver were evaluated before and after intervention.

RESULTS

In the oxaliplatin/Livergol group, 40% and 44.4% of patients who were in Grade 2 and 3 before intervention were altered to Grades 1 and 2, respectively (P = 0.005), and in irinotecan/Livergol group, the mentioned percentages were 80% and 66.7% (P = 0.014). The mean levels of ALT and AST enzymes were decreased in both groups after tacking Livergol; however, the observed decreases were not significantly different between groups.

CONCLUSION

It was concluded that the adding of Livergol to oxaliplatin and irinotecan regimens significantly improved the fatty liver of patients and none of them was superior.

Pinelliae Rhizoma Praeparatum Involved in the Regulation of Bile Acids Metabolism in Hepatic Injury

Pinelliae Rhizoma Praeparatum (PRP) as traditional Chinese medicine had been used for hepatic diseases in combinative forms. However, the effect of PRP was not clear when used alone. So to explore the hepatoprotective/hepatotoxin of PRP is necessary. The activities of PRP were investigated in acetaminophen-induced hepatic injury mice. Liver function markers, hepatic oxidative stress markers were evaluated. Bile acids metabolic transports and nuclear factor erythroid 2-related factor 2 (Nrf2) were detected. As a drug for the treatment of liver diseases, PRP slightly restored the parameters towards normal in model mice only in low dosage, and also had no antioxidant activity and regulate Nrf2. Cholestasis was significantly elevated in model mice when pretreatment with routine or high dosage of PRP, but had no effect on normal mice. Bile salt export pump (Bsep) and multidrug resistance-associated protein 2 (Mrp2) in model mice were markedly increased when pretreatment with low dose PRP, but significantly decreased when pretreatment in routine or high dosage. Mrp3 was significantly induced in model mice after pretreatment of PRP. But the adjustment effect to bile acids transporters by PRP was not significant in normal mice. These results reveal that PRP has the different effects on bile acids transporter in hepatic injury mice, and therefore, the dosage of PRP need to be paid attention to when it is used in clinical hepatic injury.

Barnidipine Real-Life Efficacy and Tolerability in Arterial Hypertension: Results from Younger and Older Patients in the BASIC-HT Study

Objective:

The aim of this study was to compare the efficacy and tolerability of barnidipine, a strong lipophilic calcium channel blocker, in younger (≤55 for efficacy or <65 years for adverse events) versus older (>55 or ≥65 years) patients with uncomplicated hypertension.

Methods:

20,275 patients received barnidipine, 10 or 20 mg/day, as monotherapy or in combination with other antihypertensive drug(s) in the observational BArnidipine real-life Safety and tolerability In Chronic HyperTension (BASIC-HT) study. Efficacy and tolerability were assessed over a 3-month period. The present paper describes results from prespecified subgroup analyses by age not reported elsewhere.

Results:

Both age groups showed a clinically meaningful decrease in blood pressure (BP) over time (p<0.0001). The mean systolic and diastolic BP after approximately 3 months of barnidipine therapy was well below the target value of <140/90 mmHg for individual patients, with no notable differences between age groups. The decrease in mean pulse pressure was greater in patients >55 years (-10.8 mmHg) than in patients ≤55 years (-8.7 mmHg) (p<0.0001) and the proportion of patients with pulse pressure >60 mmHg decreased from 61.1% at baseline to 24.8% at Visit 3 in patients >55 years and from 47.7% to 16.5% in patients ≤55 years (p<0.0001).

The overall incidence of adverse events was low, leading to treatment discontinuation in only 3.0-3.6% of patients. Peripheral edema, a common adverse effect with calcium channel blockers in clinical practice, was reported by 2.7% of patients aged <65 years and by 4.6% of patients aged ≥65 years.

Conclusion:

The efficacy and tolerability profiles of barnidipine as monotherapy or in combination with other antihypertensive drugs were shown to be favorable in both younger and older patients in a real-life practice setting. Randomized double-blind controlled studies are needed to confirm these results.

Common Medications Which Lead to Unintended Alterations in Weight Gain or Organ Lipotoxicity

Obesity is one of the most common chronic conditions in the world. Its management is difficult, partly due to the multiple associated comorbidities including fatty liver, diabetes, hypertension, and hyperlipidemia. As a result, the choice of prescription medications in overweight and obese patients has important implications as some of them can actually worsen the fat accumulation and its associated metabolic complications. Several prescription medications are associated with weight gain with mechanisms that are often poorly understood and under-recognized. Even less data are available on the distribution of fat and lipotoxicity (the organ damage related to fat accumulation). The present review will discuss the drugs associated with weight gain, their mechanism of action, and the magnitude and timing of their effect.

Angiotensin II regulates islet microcirculation and insulin secretion in mice

OBJECTIVE

Angiotensin II causes potent increases in systemic and local pressure through its vasoconstrictive effect. Despite the importance of angiotensin II for local blood flow regulation, whether angiotensin II regulates the pancreatic islet microcirculation remains incompletely understood. We hypothesized that angiotensin II directly regulates the pancreatic islet microcirculation and thereby regulates insulin secretion. The aims of this study were to develop a new technique to visualize pancreatic islet hemodynamic changes in vivo and to analyze changes in islet circulation induced by angiotensin II or an angiotensin type 1 receptor blocker.

METHODS

Using an in vivo imaging method, we observed the pancreatic islet microcirculation. Various doses of angiotensin II or an angiotensin type 1 receptor blocker were injected intravenously, and changes in islet microcirculation were observed. Glucose-stimulated insulin secretion from the pancreas was measured from the hepatic portal vein.

RESULTS

We identified islet microcirculation using a fluorescent dye. Angiotensin II significantly induced blood vessel contraction in the islets in a dose-dependent manner. In contrast, the angiotensin type 1 receptor blocker induced vasodilation. Glucose-stimulated insulin secretion was decreased by angiotensin II infusion.

CONCLUSIONS

These results show that angiotensin II is involved in the regulation of pancreatic islet microcirculation and insulin secretion.

Hepatoprotective Effect of Silymarin (Silybum marianum) on Hepatotoxicity Induced by Acetaminophen in Spontaneously Hypertensive Rats

This study was aimed to investigate the effect of Silymarin (SLM) on the hypertension state and the liver function changes induced by acetaminophen (APAP) in spontaneously hypertensive rat (SHR). Animals normotensive (N) or hypertensive (SHR) were treated or not with APAP (3 g/kg, oral) or previously treated with SLM. Twelve hours after APAP administration, plasmatic levels of liver function markers: alanine aminotransferase (ALT), aspartate aminotransferase (AST), glucose (GLU), gamma glutamyl transferase (γ-GT), and alkaline phosphatase (ALP) of all groups, were determined. Liver injury was assessed using histological studies. Samples of their livers were then used to determine the myeloperoxidase (MPO) activity and nitric oxide (NO) production and were also sectioned for histological analysis. No differences were observed for ALT, γ-GT, and GLU levels between SHR and normotensive rats groups. However, AST and ALP levels were increased in hypertensive animals. APAP treatment promoted an increase in ALT and AST in both SHR and N. However, only for SHR, γ-GT levels were increased. The inflammatory response evaluated by MPO activity and NO production showed that SHR was more susceptible to APAP effect, by increasing leucocyte infiltration. Silymarin treatment (Legalon) restored the hepatocyte functional and histopathological alterations induced by APAP in normotensive and hypertensive animals.

Is diabetes mellitus-linked amino acid signature associated with β-blocker-induced impaired fasting glucose?

BACKGROUND

The 5-amino acid (AA) signature, including isoleucine, leucine, valine, tyrosine, and phenylalanine, has been associated with incident diabetes mellitus and insulin resistance. We investigated whether this same AA signature, single-nucleotide polymorphisms in genes in their catabolic pathway, was associated with development of impaired fasting glucose (IFG) after atenolol treatment.

METHODS AND RESULTS

Among 234 European American participants enrolled in the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) study and treated with atenolol for 9 weeks, we prospectively followed a nested cohort that had both metabolomics profiling and genotype data available for the development of IFG. We assessed the association between baseline circulating levels of isoleucine, leucine, valine, tyrosine, and phenylalanine, as well as single-nucleotide polymorphisms in branched-chain amino-acid transaminase 1 (BCAT1) and phenylalanine hydroxylase (PAH) with development of IFG. All baseline AA levels were strongly associated with IFG development. Each increment in standard deviation of the 5 AAs was associated with the following odds ratio and 95% confidence interval for IFG based on a fully adjusted model: isoleucine 2.29 (1.31-4.01), leucine 1.80 (1.10-2.96), valine 1.77 (1.07-2.92), tyrosine 2.13 (1.20-3.78), and phenylalanine 2.04 (1.16-3.59). The composite P value was 2×10(-5). Those with PAH (rs2245360) AA genotype had the highest incidence of IFG (P for trend=0.0003).

CONCLUSIONS

Our data provide important insight into the metabolic and genetic mechanisms underlying atenolol-associated adverse metabolic effects. Clinical Trial Registration- http://www.clinicaltrials.gov; Unique Identifier: NCT00246519.

The past, present and future of renin-angiotensin aldosterone system inhibition

The renin-angiotensin aldosterone system (RAAS) is central to the pathogenesis of cardiovascular disease. RAAS inhibition can reduce blood pressure, prevent target organ damage in hypertension and diabetes, and improve outcomes in patients with heart failure and/or myocardial infarction. This review presents the history of RAAS inhibition including a summary of key heart failure, myocardial infarction, hypertension and atrial fibrillation trials. Recent developments in RAAS inhibition are discussed including implementation and optimization of current drug therapies. Finally, ongoing clinical trials, opportunities for future trials and issues related to the barriers and approvability of novel RAAS inhibitors are highlighted.

Liraglutide ameliorates glycometabolism and insulin resistance through the upregulation of GLUT4 in diabetic KKAy mice

Liraglutide, a long-lasting glucagon‑like peptide‑1 analogue, has been used for the treatment of patients with type 2 diabetes mellitus since 2009. In this study, we investigated the anti-diabetic effects and mechanisms of action of liraglutide in a spontaneous diabetic animal model, using KK/Upj-Ay/J (KKAy) mice. The KKAy mice were divided into 2 groups, the liraglutide group (mice were treated with 250 µg/kg/day liraglutide) and the model group (treated with an equivalent amount of normal saline). C57BL/6J mice were used as the controls (treated with an equivalent amount of normal saline). The treatment period lasted 6 weeks. During this treatment period, fasting blood glucose (FBG) levels and the body weight of the mice were measured on a weekly basis. Our results revealed that liraglutide significantly decreased FBG levels, the area under the curve following a oral glucose tolerance test and insulin tolerance test, increased serum insulin levels, reduced homeostasis model assessment of insulin resistance and increased the insulin sensitivity index. Furthermore, liraglutide ameliorated glycometabolism dysfunction by increasing glycolysis via hexokinase and glycogenesis via pyruvate kinase activation. An ultrastructural examination of the pancreas revealed that liraglutide improved the damaged state of islet β cells and increased the number of insulin secretory granules. The real-time PCR results revealed that the gene expression of glucose transporter 4 (GLUT4) increased following treatment with liraglutide. Liraglutide also upregulated the protein expression of GLUT4 in liver tissue and skeletal muscle. Our results suggest that liraglutide ameliorates glycometabolism and insulin resistance in diabetic KKAy mice by stimulating insulin secretion, increasing glycogenesis and glycolysis and upregulating the expression of GLUT4.

Possible Mechanisms of Local Tissue Renin-Angiotensin System Activation in the Cardiorenal Metabolic Syndrome and Type 2 Diabetes Mellitus

The role of local tissue renin-angiotensin system (tRAS) activation in the cardiorenal metabolic syndrome (CRS) and type 2 diabetes mellitus (T2DM) is not well understood. To this point, we posit that early redox stress-mediated injury to tissues and organs via accumulation of excessive reactive oxygen species (ROS) and associated wound healing responses might serve as a paradigm to better understand how tRAS is involved. There are at least five common categories responsible for generating ROS that may result in a positive feedback ROS-tRAS axis. These mechanisms include metabolic substrate excess, hormonal excess, hypoxia-ischemia/reperfusion, trauma, and inflammation. Because ROS are toxic to proteins, lipids, and nucleic acids they may be the primary instigator, serving as the injury nidus to initiate the wound healing process. Insulin resistance is central to the development of the CRS and T2DM, and there are now thought to be four major organ systems important in their development. In states of overnutrition and tRAS activation, adipose tissue, skeletal muscle (SkM), islet tissues, and liver (the quadrumvirate) are individually and synergistically related to the development of insulin resistance, CRS, and T2DM. The obesity epidemic is thought to be the driving force behind the CRS and T2DM, which results in the impairment of multiple end-organs, including the cardiovascular system, pancreas, kidney, retina, liver, adipose tissue, SkM, and nervous system. A better understanding of the complex mechanisms leading to local tRAS activation and increases in tissue ROS may lead to new therapies emphasizing global risk reduction of ROS resulting in decreased morbidity and mortality.

Impact of abdominal obesity on incidence of adverse metabolic effects associated with antihypertensive medications

We assessed adverse metabolic effects of atenolol and hydrochlorothiazide among hypertensive patients with and without abdominal obesity using data from a randomized, open-label study of hypertensive patients without evidence of cardiovascular disease or diabetes mellitus. Intervention included randomization to 25 mg of hydrochlorothiazide or 100 mg of atenolol monotherapy followed by their combination. Fasting glucose, insulin, triglycerides, high-density lipoprotein cholesterol, and uric acid levels were measured at baseline and after monotherapy and combination therapy. Outcomes included new occurrence of and predictors for new cases of glucose > or =100 mg/dL (impaired fasting glucose), triglyceride > or =150 mg/dL, high-density lipoprotein < or =40 mg/dL for men or < or =50 mg/dL for women, or new-onset diabetes mellitus according to the presence or absence of abdominal obesity. Abdominal obesity was present in 167 (58%) of 395 patients. Regardless of strategy, in those with abdominal obesity, 20% had impaired fasting glucose at baseline compared with 40% at the end of study (P<0.0001). Proportion with triglycerides > or =150 mg/dL increased from 33% at baseline to 46% at the end of study (P<0.01). New-onset diabetes mellitus occurred in 13 patients (6%) with and in 4 patients (2%) without abdominal obesity. Baseline levels of glucose, triglyceride, and high-density lipoprotein predicted adverse outcomes, and predictors for new-onset diabetes mellitus after monotherapy in those with abdominal obesity included hydrochlorothiazide strategy (odds ratio: 46.91 [95% CI: 2.55 to 862.40]), female sex (odds ratio: 31.37 [95% CI: 2.10 to 468.99]), and uric acid (odds ratio: 3.19 [95% CI: 1.35 to 7.52]). Development of adverse metabolic effect, including new-onset diabetes mellitus associated with short-term exposure to hydrochlorothiazide and atenolol was more common in those with abdominal obesity.

Cardiovascular therapies and associated glucose homeostasis: implications across the dysglycemia continuum

Certain cardiovascular drugs have adverse effects on glucose homeostasis, which may lead to important long-term implications for increased risks of adverse outcomes. Thiazide diuretics, niacin, and beta-adrenergic blockers impair glucose homeostasis. However, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers have demonstrated beneficial metabolic effects. The newer vasodilating beta-blocking agents and calcium antagonists appear to be metabolically neutral. These considerations, in addition to meticulous attention to blood pressure control and lifestyle changes, have the potential to beneficially modify glycemia and long-term risks. These considerations have particular importance in younger patients who may also have pre-diabetes or the metabolic syndrome and who are likely to require therapy over the course of decades.

Attenuation of endocrine-exocrine pancreatic communication in type 2 diabetes: pancreatic extracellular matrix ultrastructural abnormalities

Ultrastructural observations reveal a continuous interstitial matrix connection between the endocrine and exocrine pancreas, which is lost due to fibrosis in rodent models and humans with type 2 diabetes mellitus (T2DM). Widening of the islet-exocrine interface appears to result in loss of desmosomes and adherens junctions between islet and acinar cells and is associated with hypercellularity consisting of pericytes and inflammatory cells in T2DM pancreatic tissue. Organized fibrillar collagen was closely associated with pericytes, which are known to differentiate into myofibroblasts-pancreatic stellate cells. Of importance, some pericyte cellular processes traverse both the connecting islet-exocrine interface and the endoacinar interstitium of the exocrine pancreas. Loss of cellular paracrine communication and extracellular matrix remodeling fibrosis in young animal models and humans may result in a dysfunctional insulino-acinar-ductal-incretin gut hormone axis, resulting in pancreatic insufficiency and glucagon-like peptide deficiency, which are known to exist in prediabetes and overt T2DM in humans.