Metabolic syndrome: treatment of hypertensive patients

Insulin-resistance in paediatric age: Its magnitude and implications

Insulin resistance (IR) is insulin failure in normal plasma levels to adequately stimulate glucose uptake by the peripheral tissues. IR is becoming more common in children and adolescents than before. There is a strong association between obesity in children and adolescents, IR, and the metabolic syndrome components. IR shows marked variation among different races, crucial to understanding the possible cardiovascular risk, specifically in high-risk races or ethnic groups. Genetic causes of IR include insulin receptor mutations, mutations that stimulate autoantibody production against insulin receptors, or mutations that induce the formation of abnormal glucose transporter 4 molecules or plasma cell membrane glycoprotein-1 molecules; all induce abnormal energy pathways and end with the development of IR. The parallel increase of IR syndrome with the dramatic increase in the rate of obesity among children in the last few decades indicates the importance of environmental factors in increasing the rate of IR. Most patients with IR do not develop diabetes mellitus (DM) type-II. However, IR is a crucial risk factor to develop DM type-II in children. Diagnostic standards for IR in children are not yet established due to various causes. Direct measures of insulin sensitivity include the hyperinsulinemia euglycemic glucose clamp and the insulin-suppression test. Minimal model analysis of frequently sampled intravenous glucose tolerance test and oral glucose tolerance test provide an indirect estimate of metabolic insulin sensitivity/resistance. The main aim of the treatment of IR in children is to prevent the progression of compensated IR to decompensated IR, enhance insulin sensitivity, and treat possible complications. There are three main lines for treatment: Lifestyle and behavior modification, pharmacotherapy, and surgery. This review will discuss the magnitude, implications, diagnosis, and treatment of IR in children.

Catestatin peptide of chromogranin A as a potential new target for several risk factors management in the course of metabolic syndrome

Obesity, lipodystrophy, diabetes, and hypertension collectively constitute the main features of Metabolic Syndrome (MetS), together with insulin resistance (IR), which is considered as a defining element. MetS generally leads to the development of cardiovascular disease (CVD), which is a determinant cause of mortality and morbidity in humans and animals. Therefore, it is essential to implement and put in place adequate management strategies for the treatment of this disease. Catestatin is a bioactive peptide with 21 amino acids, which is derived through cleaving of the prohormone chromogranin A (CHGA/CgA) that is co-released with catecholamines from secretory vesicles and, which is responsible for hepatic/plasma lipids and insulin levels regulation, improves insulin sensitivity, reduces hypertension and attenuates obesity in murine models. In humans, there were few published studies, which showed that low levels of catestatin are significant risk factors for hypertension in adult patients. These accumulating evidence documents clearly that catestatin peptide (CST) is linked to inflammatory and metabolic syndrome diseases and can be a novel regulator of insulin and lipid levels, blood pressure, and cardiac function. The goal of this review is to provide an overview of the CST effects in metabolic syndrome given its role in metabolic regulation and thus, provide new insights into the use of CST as a diagnostic marker and therapeutic target.

ACE-inhibition induces a cardioprotective transcriptional response in the metabolic syndrome heart

Cardiovascular disease associated with metabolic syndrome has a high prevalence, but the mechanistic basis of metabolic cardiomyopathy remains poorly understood. We characterised the cardiac transcriptome in a murine metabolic syndrome (MetS) model (LDLR−/−; ob/ob, DKO) relative to the healthy, control heart (C57BL/6, WT) and the transcriptional changes induced by ACE-inhibition in those hearts. RNA-Seq, differential gene expression and transcription factor analysis identified 288 genes differentially expressed between DKO and WT hearts implicating 72 pathways. Hallmarks of metabolic cardiomyopathy were increased activity in integrin-linked kinase signalling, Rho signalling, dendritic cell maturation, production of nitric oxide and reactive oxygen species in macrophages, atherosclerosis, LXR-RXR signalling, cardiac hypertrophy, and acute phase response pathways. ACE-inhibition had a limited effect on gene expression in WT (55 genes, 23 pathways), and a prominent effect in DKO hearts (1143 genes, 104 pathways). In DKO hearts, ACE-I appears to counteract some of the MetS-specific pathways, while also activating cardioprotective mechanisms. We conclude that MetS and control murine hearts have unique transcriptional profiles and exhibit a partially specific transcriptional response to ACE-inhibition.

Pharmacogenetic landscape of Metabolic Syndrome components drug response in Tunisia and comparison with worldwide populations

Genetic variation is an important determinant affecting either drug response or susceptibility to adverse drug reactions. Several studies have highlighted the importance of ethnicity in influencing drug response variability that should be considered during drug development. Our objective is to characterize the genetic variability of some pharmacogenes involved in the response to drugs used for the treatment of Metabolic Syndrome (MetS) in Tunisia and to compare our results to the worldwide populations. A set of 135 Tunisians was genotyped using the Affymetrix Chip 6.0 genotyping array. Variants located in 24 Very Important Pharmacogenes (VIP) involved in MetS drug response were extracted from the genotyping data. Analysis of variant distribution in Tunisian population compared to 20 worldwide populations publicly available was performed using R software packages. Common variants between Tunisians and the 20 investigated populations were extracted from genotyping data. Multidimensional screening showed that Tunisian population is clustered with North African and European populations. The greatest divergence was observed with the African and Asian population. In addition, we performed Inter-ethnic comparison based on the genotype frequencies of five VIP biomarkers. The genotype frequencies of the biomarkers rs3846662, rs1045642, rs7294 and rs12255372 located respectively in HMGCR, ABCB1, VKORC1 and TCF7L2 are similar between Tunisian, Tuscan (TSI) and European (CEU). The genotype frequency of the variant rs776746 located in CYP3A5 gene is similar between Tunisian and African populations and different from CEU and TSI. The present study shows that the genetic make up of the Tunisian population is relatively complex in regard to pharmacogenes and reflects previous historical events. It is important to consider this ethnic difference in drug prescription in order to optimize drug response to avoid serious adverse drug reactions. Taking into account similarities with other neighboring populations, our study has an impact not only on the Tunisian population but also on North African population which are underrepresented in pharmacogenomic studies.

HDL Glycoprotein Composition and Site-Specific Glycosylation Differentiates Between Clinical Groups and Affects IL-6 Secretion in Lipopolysaccharide-Stimulated Monocytes

The goal of this pilot study was to determine whether HDL glycoprotein composition affects HDL’s immunomodulatory function. HDL were purified from healthy controls (n = 13), subjects with metabolic syndrome (MetS) (n = 13), and diabetic hemodialysis (HD) patients (n = 24). Concentrations of HDL-bound serum amyloid A (SAA), lipopolysaccharide binding protein (LBP), apolipoprotein A-I (ApoA-I), apolipoprotein C-III (ApoC-III), α-1-antitrypsin (A1AT), and α-2-HS-glycoprotein (A2HSG); and the site-specific glycovariations of ApoC-III, A1AT, and A2HSG were measured. Secretion of interleukin 6 (IL-6) in lipopolysaccharide-stimulated monocytes was used as a prototypical assay of HDL’s immunomodulatory capacity. HDL from HD patients were enriched in SAA, LBP, ApoC-III, di-sialylated ApoC-III (ApoC-III₂) and desialylated A2HSG. HDL that increased IL-6 secretion were enriched in ApoC-III, di-sialylated glycans at multiple A1AT glycosylation sites and desialylated A2HSG, and depleted in mono-sialylated ApoC-III (ApoC-III₁). Subgroup analysis on HD patients who experienced an infectious hospitalization event within 60 days (HD+) (n = 12), vs. those with no event (HD−) (n = 12) showed that HDL from HD+ patients were enriched in SAA but had lower levels of sialylation across glycoproteins. Our results demonstrate that HDL glycoprotein composition, including the site-specific glycosylation, differentiate between clinical groups, correlate with HDL’s immunomodulatory capacity, and may be predictive of HDL’s ability to protect from infection.

Evaluation of the Measurement Properties of Self-reported Medication Adherence Instruments Among People at Risk for Metabolic Syndrome: A Systematic Review

PURPOSE

The purpose of this study was to present a systematic review of available published studies that evaluated the measurement properties of self-reported instruments assessing global medication adherence in adults at risk for metabolic syndrome.

METHODS

The authors searched PubMed, EMBASE, PsycINFO, and CINAHL in January 2015 for appropriate studies. The methodological quality (based on reliability, validity, responsiveness, and interpretability) of selected studies was assessed with the COSMIN checklist (Consensus-Based Standards for the Selection of Health Measurement Instruments).

RESULTS

Of the 44 studies reviewed, 32 used classical test theory, and 14 used self-reported medication adherence instruments. More than half the studies included patients with hypertension, followed by diabetes, dyslipidemia, and increased body mass index. Among the measurement properties, internal consistency, hypothesis testing, and structural validity were frequently assessed items, whereas only 1 study evaluated responsiveness, and none evaluated measurement error. The MMAS-8 (Morisky Medication Adherence Scale-8 items) and the Hill-Bone scale were the most frequently used instruments. They were found to be well validated, with strong evidence for internal consistency and strong positive evidence for reliability, structural validity, hypothesis testing, and criterion validity.

CONCLUSIONS

The MMAS-8 and Hill-Bone scale seem to be well-validated instruments for assessing medication adherence in adults at risk for metabolic syndrome. These findings may assist clinicians with selecting the appropriate instruments for assessing medication adherence in this population. However, further studies might be needed to define concepts to better understand the dimensions of each medication adherence instrument.

The cost-effectiveness of irbesartan for hypertension

High blood pressure is a very common problem in the adult and elderly population, both in developed and developing countries. A relatively large number of drug classes are available to treat this condition and prevent its complications, which are not only more frequent in the aforementioned patients but also those affected by metabolic syndrome and/or Type 2 diabetes. Irbesartan is an angiotensin-receptor blocker class drug with good antihypertensive efficacy and specific pharmacological characteristics, whose efficacy has been more deeply evaluated in metabolically complex hypertensive patients. In this review, the authors will analyze its effectiveness in preventing or delaying organ damage in hypertensive patients, with a closer look at the economic implications of treating hypertension with irbesartan in the context of available antihypertensive drugs.

A comprehensive review on metabolic syndrome

Metabolic syndrome is defined by a constellation of interconnected physiological, biochemical, clinical, and metabolic factors that directly increases the risk of cardiovascular disease, type 2 diabetes mellitus, and all cause mortality. Insulin resistance, visceral adiposity, atherogenic dyslipidemia, endothelial dysfunction, genetic susceptibility, elevated blood pressure, hypercoagulable state, and chronic stress are the several factors which constitute the syndrome. Chronic inflammation is known to be associated with visceral obesity and insulin resistance which is characterized by production of abnormal adipocytokines such as tumor necrosis factor α , interleukin-1 (IL-1), IL-6, leptin, and adiponectin. The interaction between components of the clinical phenotype of the syndrome with its biological phenotype (insulin resistance, dyslipidemia, etc.) contributes to the development of a proinflammatory state and further a chronic, subclinical vascular inflammation which modulates and results in atherosclerotic processes. Lifestyle modification remains the initial intervention of choice for such population. Modern lifestyle modification therapy combines specific recommendations on diet and exercise with behavioural strategies. Pharmacological treatment should be considered for those whose risk factors are not adequately reduced with lifestyle changes. This review provides summary of literature related to the syndrome's definition, epidemiology, underlying pathogenesis, and treatment approaches of each of the risk factors comprising metabolic syndrome.

Telmisartan suppresses food intake in mice via the melanocortin pathway

SUMMARY

Telmisartan, an angiotensin type 1 receptor blocker, is widely used for the treatment of hypertension and related cardiovascular and organ damage. We here describe the effects of telmisartan on food intake and body weight using C57BL/6N mice, KKAy mice that overexpress agouti protein (a mouse model of type 2 diabetes with obesity), and mice deficient for angiotensin II-1a receptor. Telmisartan combined with a high-fat diet significantly reduced food intake and body weight gain in the three groups of mice compared with respective control animals that were fed the high-fat diet without telmisartan. Telmisartan did not induce taste aversion or affect energy expenditure. Intracerebroventricular administration of agouti-related protein, a potent antagonist of the melanocortin 3 receptor (MC3-R) and melanocortin 4 receptor (MC4-R), did not stimulate feeding in telmisartan-treated mice. Telmisartan administration enhanced the alpha-melanocyte stimulating hormone-induced suppression of food intake. This study highlights a potential role for telmisartan in hypothalamic feeding regulation, including melanocortin receptors-mediated suppression of food intake and body weight gain.:

50 years of thiazides: should thiazide diuretics be considered third-line hypertension treatment?

The purpose of this report is to review available and emerging antihypertensive treatment options in light of current guidelines and evidence from large clinical trials. The published literature was reviewed for evidence regarding first-line options for antihypertensive agents, including thiazide-type diuretics, as monotherapy or as part of combination therapy. Current guidelines recommend using thiazide-type diuretics as first-line therapy alone or in combination with another agent. Other commonly used antihypertensive agents include calcium channel blockers, β-adrenergic receptor blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and the direct renin inhibitor, aliskiren. These agents are associated with varying degrees of evidence that they may provide protection from cardiovascular or renal disease beyond that associated with blood pressure reduction. Thiazide diuretics are inexpensive and effective but may not be preferable to other classes of antihypertensives that reduce blood pressure to a similar extent with a better safety profile and superior reductions in cardiovascular event rates. However, calcium channel blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and direct renin inhibitors also show promise as initial monotherapy or as part of a combination therapy regimen. In patients requiring additional blood pressure reduction, add-on therapy with a diuretic could provide additional blood pressure-lowering efficacy.

The role of irbesartan in the treatment of patients with hypertension: a comprehensive and practical review

Irbesartan is an orally active angiotensin II type 1 receptor antagonist (angiotensin receptor blocker [ARB]) whose pharmacological profile differs significantly from those of many other compounds of the same class. In particular, according to its pharmacokinetic and pharmacodynamic profile, irbesartan has a high bioavailability, a long duration of action and a small potential for pharmacological interactions due to the nature of the enzymatic pathway involved in its metabolic process. Morbidity data with irbesartan have been mainly accumulated in patients with renal impairment where the drug has demonstrated the most remarkable evidence of efficacy among the ARBs class, regardless of the stage of the renal disease (from early to late) and the length of the observational period. The efficacy of irbesartan has also been demonstrated in patients with left ventricular hypertrophy and congestive heart failure. The drug is indicated for the treatment of hypertension and renal impairment in patients with type 2 diabetes mellitus (T2D) and hypertension, and its tolerability and safety profile have been extensively investigated and reported to be similar to placebo. From the pharmacoeconomic point of view, treating patients with T2D, hypertension and overt nephropathy using irbesartan was both a cost- and life-saving procedure compared with the use of amlodipine and standard antihypertensive treatment in an Italian setting. The role of irbesartan in the management of hypertension with or without T2D and renal impairment is clearly recognized by national and international guidelines and largely acknowledged by the medical community according to the efficacy of the drug in the prevention of cardiovascular risk in addition to and beyond kidney prevention.

The effects of phentolamine on fructose-fed rats

Metabolic syndrome (MS) is a combination of medical disorders that increase the risk of developing cardiovascular disease and diabetes. MS is associated with obesity, increased blood pressure, hyperlipidemia, and hyperglycemia. This study was designed to investigate the pharmacological profile of phentolamine, a nonselective α adrenergic receptor antagonist, in the prevention of increased blood pressure in fructose-fed rats. Phentolamine prevented the fructose-induced increase in systolic blood pressure without affecting insulin sensitivity and major metabolic parameters. The levels of plasma noradrenaline and angiotensin II, 2 proposed contributors to the development of fructose-induced elevated blood pressure, were examined. Neither noradrenaline nor angiotensin II levels were affected by phentolamine treatment. Since overproduction of nitric oxide has been shown to lead to an elevation in peroxynitrite, the role of oxidative stress, a proposed mechanism of fructose-induced elevated blood pressure and insulin resistance, was examined by measuring plasma levels of total nitrate/nitrite. Plasma nitrate/nitrite was significantly elevated in all fructose-fed animals, regardless of treatment with phentolamine. Another proposed contributor toward fructose-induced MS is an elevation in uric acid levels. In this experiment, plasma levels of uric acid were found to be increased by dietary fructose and were unaffected by phentolamine treatment.

Metabolic syndrome: definition and therapeutic implications

The collection of impaired glucose metabolism, central obesity, elevated blood pressure, and dyslipidemia is identified as metabolic syndrome (MetS). It is estimated that approximately 25% of the world's population has MetS. In the United States, MetS is more common in men and Hispanics, and its incidence increases with age. Metabolic syndrome increases the risk of developing cardiovascular disease and type 2 diabetes mellitus. The underlying risk factors include insulin resistance and abdominal obesity. Confusion about MetS exists in part due to the lack of a consensus definition and treatment protocol. Treatment of MetS begins with therapeutic lifestyle changes and then pharmacologic treatment of the syndrome's individual components. Effective interventions include diet modification, exercise, and use of pharmacologic agents to treat risk factors. Weight loss and increasing physical activity significantly improve all aspects of MetS. A diet that includes more fruits, vegetables, whole grains, monounsaturated fats, and low-fat dairy products will benefit most patients with MetS. Physicians can be most effective in advising patients by customizing specific lifestyle recommendations after assessing patients for the presence of risk factors.

Blood Pressure and Metabolic Effect of a Combination of Lercanidipine with Different Antihypertensive Drugs in Clinical Practice

The aim of this study is to assess the blood pressure (BP) and metabolic effects of lercanidipine when combined with other classes of first-line antihypertensive drugs in day-to-day clinical practice. For this study, we consecutively enrolled 162 patients with uncomplicated primary hypertension, who are partial responders to the treatment with lercanidipine over a period of 24 months. Patients were then allocated to the combination of lercanidipine (10–20 mg/day) with β-blockers, diuretics, angiotensin-converting enzyme inhibitors, and angiotensin-II receptor blockers according to compelling indications (if any) and/or suggestions of European Society of Hypertension–European Society of Cardiology (ESH–ESC) guidelines. All the enrolled patients completed the study and no adverse drug reaction was registered during the research period. The association of a second drug with lercanidipine determined an additional BP decrease of either systolic BP or diastolic BP independently from the type of drug added (P always <0.05). The additional effect of lercanidipine appears widely distributed with no significant differences in the size of BP decrease. From the metabolic point of view, the addition of a second drug did not determine a significant variation in the serum levels of total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol (P always >0.05). Conversely, a significant decrease in fasting plasma glucose and serum levels of triglycerides has been observed in patients where lercanidipine has been combined with an angiotensin-converting enzyme inhibitor or an angiotensin-II receptor blocker. In conclusion, in our study we observed that lercanidipine-based protocols are well tolerated and efficacious in reducing BP. Moreover, the association of lercanidipine with renin–angiotensin system blockers is also associated with significant improvements in triglycerides and fasting plasma glucose.

Hypoglycemic and hypolipidemic effects of Coriandrum sativum L. in Meriones shawi rats

ETHNOPHARMACOLOGICAL RELEVANCE

The use of an aqueous extract of coriander (Coriandrum sativum L.; Apiaceae, Umbelliferae) seeds (CS-extract) in Moroccan traditional treatment of diabetes remains to be experimentally validated.

AIM OF THE STUDY

The study aim was to investigate potential hypoglycemic (and hypolipidemic) activity of CS-extract after a single oral dose and after daily dosing for 30 days (sub-chronic study) in normal and obese-hyperglycemic-hyperlipidemic (OHH) Meriones shawi rats.

MATERIALS AND METHODS

After a single oral dose of CS-extract (20mg/kg; predetermined as optimum), plasma glucose, insulin, total cholesterol (TC), and triglycerides (TG) were measured in normal and OHH rats (hypercaloric diet and forced limited physical activity); glibenclamide (GLB; 2.5mg/kg) was used as reference. In the sub-chronic study, the effect of CS-extract and GLB (at the above doses) on body weight (BW), plasma glucose, insulin, TC, LDL-cholesterol, HDL-cholesterol, TG, urea and creatinine was determined in normal and OHH rats; insulin resistance (IR as HOMA-IR), atherosclerotic and cardioprotective indices were calculated.

RESULTS

A single dose of CS-extract or GLB suppressed hyperglycemia in OHH rats, and normo-glycemia was achieved at 6-h post-dose; there was no effect on lipids, TG or insulin, but IR decreased significantly. The hypoglycemic effect was lower in normal rats. In the sub-chronic study in OHH rats, the test substances (CS-extract>GLB) reduced plasma glucose (normoglycemia on Day 21), insulin and IR, TC, LDL-cholesterol, and TG. Atherosclerotic index decreased while cardioprotective indices increased only by CS-extract, with no effect on BW, urea or creatinine.

CONCLUSION

Sub-chronic administration of CS-extract in OHH Meriones shawi rats normalized glycemia and decreased the elevated levels of insulin, IR, TC, LDL-cholesterol and TG. Since, the CS-extract decreased several components of the metabolic syndrome and decreased atherosclerotic and increased cardioprotective indices, CS-extract may have cardiovascular protective effect. The present study validates the traditional use of coriander in diabetes.

Low-Intensity swimming training after weaning improves glucose and lipid homeostasis in MSG hypothalamic obese mice

Low-intensity swimming training, started at an early age, was undertaken to observe glycemic control in hypothalamic obese mice produced by neonatal monosodium l-glutamate (MSG) treatment. Although swimming exercises by weaning pups inhibited hypothalamic obesity onset and recovered sympathoadrenal axis activity, this event was not observed when exercise training is applied to young adult mice. However, the mechanisms producing this improved metabolism are still not fully understood. Current work verifies whether, besides reducing fat tissue accumulation, low-intensity swimming in MSG-weaned mice also improves glycemic control. Although MSG and control mice swam for 15 min/day, 3 days a week, from the weaning stage up to 90 days old, sedentary MSG and normal mice did not exercise at all. After 14 h of fasting, animals were killed at 90 days of age. Retroperitonial fat accumulation was measured to estimate obesity. Fasting blood glucose and insulin concentrations were also measured. Mice were also submitted to ipGTT. MSG obese mice showed fasting hyperglycemia, hyperinsulinemia, and glucose intolerance and insulin resistance. However, the exercise was able to block MSG treatment effects. Higher total cholesterol and triglycerides observed in MSG mice were normalized by exercise after weaning. Exercised MSG animals had higher HDLc than the sedentary group. Data suggest that early exercise training maintains normoglycemia, insulin tissue sensitivity, and normal lipid profile in mice programmed to develop metabolic syndrome.

The relationship between antihypertensive combination therapies comprising diuretics and/or beta-blockers and the risk of new-onset diabetes: a retrospective longitudinal cohort study

We investigate the associations of antihypertensive drugs in double and triple combination regimens comprising diuretics and/or beta-blockers on the development of new-onset diabetes (NOD). This study was a retrospective cohort study carried out using data from claim forms provided to the central regional branch of the Bureau of National Health Insurance (BNHI) in Taiwan from January 2001 to December 2006. We estimated the odds ratios (ORs) of NOD associated with antihypertensive combination therapy use; non-NOD individuals served as the reference group. A total of 2361 NOD cases were identified among the 12,386 hypertensive patients (6143 men and 6243 women, aged 28-86 years (mean age: 68+11)) during the study period. The risk of NOD was higher after adjusting for age and sex among users of double combinations of diuretics plus beta-blockers (adjusted OR, 1.25; 95% confidence interval (CI): 1.12-1.58), diuretics plus calcium channel blockers (CCBs; adjusted OR: 1.14; 95% CI: 1.06-1.26) and beta-blockers plus calcium channel blockers (adjusted OR: 1.12; 95% CI: 1.04-1.29) than that among non-users. Patients who took angiotensin-converting enzyme (ACE) inhibitors, or alpha-blockers as part of a double-drug regimen were at a lower risk of developing NOD than were non-users. Double- or triple-drug combinations comprising angiotensin receptor blockers (ARBs) and vasodilators were not associated with risk of NOD. The results of this study suggest that users of double-drug combination therapies containing diuretics and/or beta-blockers and an ACE inhibitor or alpha-blocker are at a significantly lower risk of developing NOD than are other classes.

Treatment of hypertension in metabolic syndrome: implications of recent clinical trials

Metabolic syndrome represents a constellation of hypertension, abdominal obesity, impaired fasting glucose, and dyslipidemia, and it has been shown to be a risk factor for cardiovascular disease. The components of metabolic syndrome are rapidly emerging as epidemics of the twenty-first century, and reduction of these underlying causes, such as obesity, physical inactivity, and atherogenic diet, is first-line therapy. Treatment of hypertension and other cardiometabolic risk factors of the syndrome is also required. Evidence demonstrates a relationship between hypertension, type 2 diabetes mellitus, and several vascular and metabolic abnormalities that are components of metabolic syndrome. Hypertension associated with metabolic syndrome has pathophysiologic characteristics that provide clinical challenges as well as opportunities for successful therapeutic interventions. This article reviews the treatment of hypertension as a metabolic and vascular disease and also opens a new paradigm for the treatment of metabolic syndrome, which affects nearly one quarter of the world's population.

The metabolic syndrome

The "metabolic syndrome" (MetS) is a clustering of components that reflect overnutrition, sedentary lifestyles, and resultant excess adiposity. The MetS includes the clustering of abdominal obesity, insulin resistance, dyslipidemia, and elevated blood pressure and is associated with other comorbidities including the prothrombotic state, proinflammatory state, nonalcoholic fatty liver disease, and reproductive disorders. Because the MetS is a cluster of different conditions, and not a single disease, the development of multiple concurrent definitions has resulted. The prevalence of the MetS is increasing to epidemic proportions not only in the United States and the remainder of the urbanized world but also in developing nations. Most studies show that the MetS is associated with an approximate doubling of cardiovascular disease risk and a 5-fold increased risk for incident type 2 diabetes mellitus. Although it is unclear whether there is a unifying pathophysiological mechanism resulting in the MetS, abdominal adiposity and insulin resistance appear to be central to the MetS and its individual components. Lifestyle modification and weight loss should, therefore, be at the core of treating or preventing the MetS and its components. In addition, there is a general consensus that other cardiac risk factors should be aggressively managed in individuals with the MetS. Finally, in 2008 the MetS is an evolving concept that continues to be data driven and evidence based with revisions forthcoming.

Metabolic syndrome patient compliance with drug treatment

OBJECTIVES

1) To evaluate the compliance with drug treatment in patients with metabolic syndrome. 2) To determine association between access to and use of medicines, as well as the level of knowledge of cardiovascular risk factors and compliance.

INTRODUCTION

Low compliance has been one of the greatest challenges for the successful treatment of chronic diseases. Although this issue has been widely studied in patients with isolated hypertension, diabetes and dyslipidemia, compliance studies involving patients with these concomitant diseases or with metabolic syndrome diagnosis are scarce.

METHODS

This was a cross-sectional study involving patients who have been diagnosed with metabolic syndrome according to the IDF criteria. Patients were being treated in a Health-Medical School Center bound to the Public Brazilian Healthcare System. This study was conducted in two phases. Phase I was characterized by analyzing medical records and Phase II involved interviewing the patients. A variation of the Morisky-Green Test was used to evaluate compliance. Compliance was the dependent variable and the independent variables included access to medicines, the use of medicines and the level of knowledge concerning cardiovascular risk factors.

RESULTS

Two hundred and forty-three patients were identified as being eligible for Phase II, and 75 were included in the study. The average level of compliance was 5.44 points (standard deviation of 0.68), on a scale ranging from 1.00 to 6.00 points. There was no statistically meaningful association between independent variables and compliance. The level of patient knowledge of diet and dyslipidemia was considered to be low.

CONCLUSIONS

Patients involved in this study exhibited a high level of compliance with drug treatment. Further research is needed to better elucidate the compliance behavior of patients who have been diagnosed with metabolic syndrome.

Neuropeptide Y and alpha-melanocyte-stimulating hormone: interaction in obesity and possible role in the development of hypertension

AIM

Obesity and hypertension frequently coexist and both represent important risk factors for cardiovascular disease. The mechanisms implicated in the regulation of food intake have not been completely elucidated. Recent data suggests that peripheral and central neuropeptides play an important role in the maintenance of energy balance. More specifically, leptin, neuropeptide Y (NPY) and alpha-melanocyte-stimulating hormone (a-MSH) appear to be implicated in the pathogenesis of obesity and also contribute to the development of hypertension in obesity.

METHODS

Analysis of the pertinent bibliography published in PubMed database.

RESULTS

Leptin is produced in the adipose tissue directly correlated with fat tissue mass. Leptin acts on two distinct neural populations in the hypothalamus: the first expresses the orexigenic peptides NPY and agouti-related protein (AgRP), the second pro-opiomelanocortin (POMC). The activation of POMC neurons increases the production of the anorexigenic hormone a-MSH and inhibits the release of NPY and AgRP. In addition, the hypothalamus integrates the neuroendocrine systems with the autonomic nervous system and controls the activity of the latter. Stimulation of hypothalamic nuclei elicits sympathetic responses including blood pressure elevation. Both NPY and a-MSH appears to be implicated in the hypothalamic regulation of sympathetic nervous system (SNS) activity.

CONCLUSION

Alterations in leptin, NPY and a-MSH are frequently observed in obesity and might stimulate SNS activity, contributing to the development of hypertension in obese patients. These neuropeptides might provide a pathophysiologic link between excess weight and hypertension. However, more research is needed before the pharmacologic manipulation of these complex neuroendocrine systems can be applied in the treatment of obesity and hypertension.

Cardiovascular Consequences of Obesity and Targets for Treatment

Obesity is a risk factor for cardiovascular disease, including coronary artery disease and heart failure, but the mechanisms by which it may cause them are not completely clear. Currently, therapies aimed at obesity-related cardiovascular disease include weight loss strategies and reduction of the other risk factors that are associated with obesity and cardiovascular disease. Other pathways with for potential drug development for obesity-related CVD are also discussed.

Effect of the angiotensin receptor blocker irbesartan on metabolic parameters in clinical practice: the DO-IT prospective observational study

Aims

A number of intervention studies have shown that therapy with angiotensin receptor blockers, such as irbesartan, can improve metabolic parameters and reduce the incidence of diabetes mellitus. It is unknown whether this observation also holds true in routine clinical settings.

Methods

We evaluated the effect of irbesartan (150 mg or 300 mg/d) together with or without hydrochlorothiazide (12.5 mg/d) in 3259 German patients. A total of 750 primary care physicians evaluated up to 5 subsequent patients with metabolic syndrome (58.9% diabetic), in whom irbesartan therapy was newly initiated (87%) or continued (13%).

Results

Six months of irbesartan therapy decreased systolic blood pressure by 14% (157.4 ± 14.7 vs. 135.0 ± 10.7 mmHg) and diastolic blood pressure by 13% (92.9 ± 9.2 vs. 80.8 ± 6.8 mmHg). This was associated with a decrease in body weight (-2.3%), fasting glucose (-9.5%), HbA1c (-4.6%), LDL-cholesterol (-11%), triglycerides (-16%) and gamma-GT (-12%) and an increase in HDL-cholesterol (+5%). These changes were somewhat more pronounced in male than in female patients and in obese than in lean patients. Changes in glucose concentration and HbA1c were much more prominent in diabetic patients.

Conclusion

Irbesartan therapy improves metabolic parameters in routine clinical settings. Thus, our study confirms previously published results from large intervention trials and extends the findings to routine clinical practice.