Differential effects of extended-release carvedilol and extended-release metoprolol on lipid profiles in patients with hypertension: results of the Extended-Release Carvedilol Lipid Trial

Carvedilol Ameliorates Experimental Atherosclerosis by Regulating Cholesterol Efflux and Exosome Functions

Carvedilol (Cav), a nonselective β-blocker with α1 adrenoceptor blocking effect, has been used as a standard therapy for coronary artery disease. This study investigated the effects of Cav on exosome expression and function, ATP-binding cassette transporter A1 (ABCA1) expression, and cholesterol efflux that are relevant to the process of atherosclerosis. Human monocytic (THP-1) cell line and human hepatic (Huh-7) cells were treated with Cav, and cholesterol efflux was measured. Exosomes from cell culture medium or mice serum were isolated using glycan-coated recognition beads. Low-density lipoprotein receptor knockout (ldlr^−/−) mice were fed with high-fat diet and treated with Cav. Cav accentuated cholesterol efflux and enhanced the expressions of ABCA1 protein and mRNA in both THP-1 and Huh-7 cells. In addition, Cav increased expression and function of exosomal ABCA1 in THP-1 macrophage exosomes. The mechanisms were associated with inhibition of nuclear factor-κB (NF-κB) and protein kinase B (Akt). In hypercholesterolemic ldlr^−/− mice, Cav enhanced serum exosomal ABCA1 expression and suppressed atherosclerosis by inhibiting lipid deposition and macrophage accumulation. Cav halts atherosclerosis by enhancing cholesterol efflux and increasing ABCA1 expression in macrophages and in exosomes, possibly through NF-κB and Akt signaling, which provides mechanistic insights regarding the beneficial effects of Cav on atherosclerotic cardiovascular disease.

Role of antioxidant property of carvedilol in mild to moderate hypertensive patients: A prospective open-label study

Objective:

Carvedilol is a nonselective third generation β-blocker that does not display the negative effects of traditional β-blockers. Regarding the antioxidant, anti-inflammatory and distinct metabolic properties of carvedilol which are similar to that of high-density lipoprotein (HDL) and paraoxonase 1 (PON1), the present study intends to investigate the effects of carvedilol treatment on malondialdehyde (MDA) and soluble lectin-like ox-low-density lipoprotein (LDL) receptor (sLOX-1) as markers of oxidative stress in association to lipid profiles, apolipoproteins (apo), and PON1 activity in hypertensive patients.

Patients and Methods:

This clinical trial study was performed on forty patients with mild to moderate essential hypertension. Subjects were studied before and after 2 months treatment with carvedilol, 25 mg daily. Lipids and lipoproteins were measured using a biochemistry analyzer. PON and arylesterase activity were assayed using paraoxon and phenyl acetate as substrates, respectively. MDA was quantified using a chemical colorimetric assay. ELISA was used to measure sLOX-1.

Results:

Our results showed that carvedilol treatment decreased systolic and diastolic blood pressure as much as forty and 16 mmHg, respectively (P < 0.001). It also increased HDL, total cholesterol, and serum PON1 activity (P < 0.05), but the levels of triglyceride, LDL, apo A-I, and apo B did not significantly change. There was an inverse correlation between serum PON1 activity and serum MDA.

Conclusion:

This study confirmed the antihypertensive effect of the drug and its beneficial metabolic effects through augmenting HDL and PON1 activity. We propose that the antioxidant effects of carvedilol can be partially attributed to increased PON-1 activity.

Hypolipidaemic Effects of Gymnema sylvestre on High Fat Diet Induced Dyslipidaemia in Wistar Rats

INTRODUCTION

Hyperlipidaemia is a well known risk factor for cardiovascular diseases. Lifestyle modification can be the initial step to reduce cholesterol levels. There are various drugs which are used to control dyslipidaemia. Treatment of lipid abnormalities is a lifelong battle. Moreover, the safety and effectiveness of long term lipid lowering treatment are questionable. Gymnema Sylvestre (GS) is a well known herb with various medicinal properties.

AIM

To explore the hypolipidaemic activity of GS leaves extract.

MATERIALS AND METHODS

Adult healthy female wistar rats, 30 in number, divided into five groups, weighing 150- 200 g were used. Dyslipidaemia was induced in rats by feeding them on high fat diet for four weeks. For the next four weeks GS extract was used as test drug while Atorvastatin was used as standard drug. Blood sample was collected for estimation of lipid profile on day 0, week 4 and week 8. Data was recorded as mean±SEM (Standard error of mean). Paired t-test and one way Analysis of Variance (ANOVA) followed by Dunnett's post hoc test was used for comparison. A p-value <0.05 was considered statistically significant. SPSS Statistics 20 (IBM software) was used for the analysis.

RESULTS

Feeding rats with high fat diet for four weeks led to obesity and dyslipidaemia in rats. GS at both the doses (100mg/kg and 200mg/kg) significantly improved the lipid profile. Total Cholesterol (TC), Triglycerides (TG), Very Low Density Lipoprotein (VLDL) and Low Density Lipoprotein (LDL) values reduced significantly while that of High Density Lipoprotein (HDL) increased significantly. GS 200 mg/kg was found more effective than GS 100 mg/kg. GS improved the value of lipid profile significantly but the effect was found inferior to Atorvastatin.

CONCLUSION

From the present study it can be concluded that GS possess an effective hypolipidaemic effect. Hence it can be included as an add on therapy in dyslipidaemia after further confirmatory studies.

Effects of Carvedilol Compared to Nebivolol on Insulin Resistance and Lipid Profile in Patients With Essential Hypertension

Background and aim:

Beta-blockers have unfavorable effects on metabolic parameters in hypertensive treatment. New generation beta-blockers with vasodilatory capabilities are superior to traditional beta-blockers, but studies examining their effects on metabolic parameters are still lacking. This study aimed to compare the effects of 2 new generation beta-blockers, carvedilol and nebivolol, on insulin resistance (IR) and lipid profiles in patients with essential hypertension.

Methods:

This was a prospective, randomized, open-label, single-center clinical trial. A total of 80 patients were randomized into 2 groups: the carvedilol group (n = 40, 25 mg of carvedilol daily) and the nebivolol group (n = 40, 5 mg of nebivolol daily). Follow-up was performed for 4 months. Fasting plasma glucose, insulin levels, and the lipid profile (high-density lipoprotein [HDL], low-density lipoprotein [LDL], total cholesterol, triglyceride, apolipoprotein AI, and apolipoprotein B levels) were measured and IR was calculated by the homeostasis model assessment (HOMA) index. These variables were compared before and 4 months after treatment.

Results:

Blood pressure and heart rate were significantly and similarly reduced in the carvedilol and nebivolol groups after treatment compared to those before treatment (both P < .001). Serum glucose ( P < .001), insulin ( P < .01), HOMA-IR (P < .01), HDL ( P < .001), LDL ( P < .001), total cholesterol ( P < .001), and apolipoprotein B ( P < .05) levels decreased in a similar manner in the carvedilol and nebivolol groups after treatment compared to those before treatment. Serum triglyceride and apolipoprotein AI levels did not change after treatment with both drugs.

Conclusion:

New generation beta-blockers, carvedilol and nebivolol, efficiently and similarly decrease blood pressure. They have similar favorable effects on glucose, insulin, IR, and the lipid profile.

Carvedilol Compared With Metoprolol Succinate in the Treatment and Prognosis of Patients With Stable Chronic Heart Failure: Carvedilol or Metoprolol Evaluation Study

BACKGROUND

β-Blockers exert a prognostic benefit in the treatment of chronic heart failure. Their pharmacological properties vary. The only substantial comparative trial to date-the Carvedilol or Metoprolol European Trial-has compared carvedilol with short-acting metoprolol tartrate at different dose equivalents. We therefore addressed the relative efficacy of equal doses of carvedilol and metoprolol succinate on survival in multicenter hospital outpatients with chronic heart failure.

METHODS AND RESULTS

Four thousand sixteen patients with stable systolic chronic heart failure who were using either carvedilol or metoprolol succinate were identified in the Norwegian Heart Failure Registry and The Heart Failure Registry of the University of Heidelberg, Germany. Patients were individually matched on both the dose equivalents and the respective propensity scores for β-blocker treatment. During a follow-up for 17 672 patient-years, it was found that 304 (27.2%) patients died in the carvedilol group and 1066 (36.8%) in the metoprolol group. In a univariable analysis of the general sample, metoprolol therapy was associated with higher mortality compared with carvedilol therapy (hazard ratio, 1.49; 95% confidence interval, 1.31-1.69; P<0.001). This difference was not seen after multivariable adjustment (hazard ratio, 0.93; 95% confidence interval, 0.57-1.50; P=0.75) and adjustment for propensity score and dose equivalents (hazard ratio, 1.06; 95% confidence interval, 0.94-1.20; P=0.36) or in the propensity and dose equivalent-matched sample (hazard ratio, 1.00; 95% confidence interval, 0.82-1.23; P=0.99). These results were essentially unchanged for all prespecified subgroups.

CONCLUSIONS

In outpatients with chronic heart failure, no conclusive association between all-cause mortality and treatment with carvedilol or metoprolol succinate was observed after either multivariable adjustment or multilevel propensity score matching.

Marked hypertriglyceridemia in a woman receiving metoprolol succinate

β-blockers are commonly used therapies after acute myocardial infarction and in the management of congestive heart failure and hypertension. We report a case of a middle-aged woman with a history of mild hypertension who was placed on metoprolol succinate. Before initiation of the β-blocker, her triglyceride level was in the borderline-high range (150-199 mg/dL). On treatment, her triglyceride levels exceeded 1000 mg/dL. She developed fatigue and mild abdominal discomfort but without biochemical evidence of pancreatitis. After discontinuation of metoprolol succinate, her triglyceride levels receded. This case illustrates an uncommon side effect with a very commonly used therapy in clinical practice. Clinicians should closely evaluate medications and/or other therapies in patients presenting with new-onset hypertriglyceridemia especially when levels are sufficiently elevated to pose increased risk of pancreatitis.

β-AR polymorphisms and glycemic and lipid parameters in hypertensive individuals receiving carvedilol or metoprolol

BACKGROUND

β-Blocker therapy and β-adrenergic receptor (β-AR) polymorphisms are associated with increases in glucose and lipid levels. We investigated associations of common β1 and β2-AR single-nucleotide polymorphisms (SNPs) with metabolic and lipid variables, and examined interactions with β-blocker treatment assignment to affect these parameters.

METHODS

This was a post hoc analysis of a double-blinded clinical trial of nondiabetic, hypertensive individuals that were randomized to receive carvedilol or metoprolol succinate. Fasting glucose, insulin, and lipid levels were measured at baseline, 3 months, and after 6 months. Genotypes for β1-AR SNPs Ser49Gly & Gly389Arg and β2-AR Arg16Gly & Gln27Glu were determined. Multivariable mixed models were used to examine associations between β-AR polymorphisms, metabolic parameters, and SNP interactions with β-blocker therapy (p(interaction)).

RESULTS

The 322 subjects were mean (s.d.) 51.5 (11.2) years old. After 6 months, insulin levels increased by 35.6% on metoprolol and 9.9% on carvedilol (P = 0.015). In univariate models, the Gln27Gln genotype had higher overall insulin levels with β-blockade compared to the Glu27Glu genotype (P = 0.006). Both Arg16Gly (P = 0.012) and Gln27Glu (P = 0.037) SNPs were associated with higher triglycerides levels. An interaction between the Arg16Gly SNP and treatment was identified (p(int) = 0.048).

CONCLUSIONS

These data suggest that insulin and triglycerides may be influenced by β2-AR polymorphisms in patients taking β blockers.

Use of carvedilol in hypertension: an update

β-blockers are effective antihypertensive agents and, together with diuretics, have been the cornerstone of pioneering studies showing their benefits on cardiovascular morbidity and mortality as a consequence of blood pressure reduction in patients with hypertension. However, evidence from recent meta-analyses have demonstrated no benefit afforded by atenolol compared with placebo in risk of mortality, myocardial infarction, or stroke, and a higher risk of mortality and stroke with atenolol/propranolol compared with other antihypertensive drug classes. Thus, the effect of these agents on cardiovascular morbidity and mortality in hypertensive patients, especially their use in uncomplicated hypertension, has remained largely controversial. However, it is recognized that the clinical studies used in these meta-analyses were mainly based on the older second-generation β-blockers, such as atenolol and metoprolol. Actually, considerable heterogeneity in, eg, pharmacokinetic, pharmacological, and physicochemical properties exists across the different classes of β-blockers, particularly between the second-generation and newer third-generation agents. Carvedilol is a vasodilating noncardioselective third-generation β-blocker, without the negative hemodynamic and metabolic effects of traditional β-blockers, which can be used as a cardioprotective agent. Compared with conventional β-blockers, carvedilol maintains cardiac output, has a reduced prolonged effect on heart rate, and reduces blood pressure by decreasing vascular resistance. Studies have also shown that carvedilol exhibits favorable effects on metabolic parameters, eg, glycemic control, insulin sensitivity, and lipid metabolism, suggesting that it could be considered in the treatment of patients with metabolic syndrome or diabetes. The present report provides an overview of the main clinical studies concerning carvedilol administered as either monotherapy or in combination with another antihypertensive or more frequently a diuretic agent, with particular focus on the additional benefits beyond blood pressure reduction.

Hypertension, dyslipidemia, and insulin resistance in patients with diabetes mellitus or the cardiometabolic syndrome: benefits of vasodilating β-blockers

Hypertension frequently coexists with diabetes and the cardiometabolic syndrome. β-Blockers have been a mainstay for controlling blood pressure for nearly 4 decades. However, β-blockers are perceived to cause glucose and lipid metabolism dysregulation, including hypoglycemia masking, reduced glycemic control, insulin resistance, and dyslipidemia. It should be noted, however, that β-blockers are diverse in their effects on glucose and lipid metabolism. Potential mechanisms that contribute to these metabolic effects include hemodynamic differences, anti-inflammatory and anti-oxidative pathways, and/or weight changes. Traditional β-blockers decrease cardiac output while peripheral vascular resistance increases or remains unchanged, which may result in glucose and lipid abnormalities. In contrast, vasodilating β-blockers reduce peripheral vascular resistance but have little effect on cardiac output. Vasodilating β-blockers may therefore result in less impact on insulin sensitivity and glycemic control, a reduced new-onset diabetes risk, and improved dyslipidemia compared with traditional β-blockers. Because of these effects, vasodilating β-blockers may represent a favorable option in the treatment of high-risk patients with hypertension.