Drug treatment of lipid disorders

The pharmacokinetics and disposition of MK-0524, a Prostaglandin D2receptor 1 antagonist, in rats, dogs and monkeys

MK-0524 is a potent, selective and orally active Prosglandin D(2) Receptor 1 (DP(1)) antagonist currently under clinical development for the treatment of niacin-induced flushing. Experiments to study the pharmacokinetics, metabolism and excretion of MK-0524 were conducted in rats, dogs and monkeys. MK-0524 displayed linear kinetics and rapid absorption following an oral dose. Following intravenous (i.v.) administration of MK-0524 to rats and dogs (1 and 5 mg/kg), the mean Cl(p) was approximately 2 and approximately 6 ml/min/kg, the T(1/2) was approximately 7 and approximately 13 h and the Vd(ss) was approximately 1 and approximately 5 L/kg, respectively. In monkeys dosed i.v. at 3 mg/kg, the corresponding values were 8 ml/min/kg, 3 h and 1 L/kg, respectively. Following oral dosing of MK-0524 to rats (5, 25 and 100 mg/kg), dogs (5 mg/kg) and monkeys (3 mg/kg), the absorption was rapid with the mean C(max) occurring between 1 and 4 h. Absolute oral bioavailability values in rats, dogs and monkeys were 50, 70 and 8%, respectively. The major circulating metabolite was the acyl glucuronide of MK-0524 (M2), with ratios of glucuronide to the parent aglycone being highest in the monkey followed by dog and rat. In bile duct-cannulated rats and dogs, MK-0524 was eliminated primarily via acyl glucuronidation followed by biliary excretion of the acyl glucuronide, M2, the major drug-related entity in bile.

Simvastatin-ezetimibe-induced hepatic failure necessitating liver transplantation

Abstract Serum aminotransferase elevations are a commonly known adverse effect of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) therapy. However, hepatotoxic events have not been widely published with ezetimibe or the combination agent simvastatin-ezetimibe. We describe a 70-year-old Hispanic woman who developed fulminant hepatic failure necessitating liver transplantation 10 weeks after conversion from simvastatin 40 mg/day to simvastatin 10 mg-ezetimibe 40 mg/day. The patient's lipid panel had been maintained with simvastatin for 18 months before the conversion without evidence of hepatotoxicity. A routine laboratory work-up 10 weeks after conversion revealed elevated serum aminotransferase levels. Simvastatinezetimibe and escitalopram (which she was taking for depression) were discontinued, and other potential causes of hepatotoxicity were excluded. A repeat work-up revealed further elevations in aminotransferase levels, and liver biopsy revealed evidence of moderate-to-severe drug toxicity. She underwent liver transplantation with an uneventful postoperative course. Her aminotransferase levels returned to normal by postoperative day 23, and her 2-year follow-up showed no adverse events. Ezetimibe undergoes extensive glucuronidation by uridine diphosphate glucoronosyltransferases (UGT) in the intestine and liver and may have inhibited the glucuronidation of simvastatin hydroxy acid, resulting in increased simvastatin exposure and subsequent hepatotoxicity. To our knowledge, this is the first case report of simvastatin-ezetimibe-induced liver failure that resulted in liver transplantation. We postulate that the mechanism of the simvastatinezetimibe-induced hepatotoxicity is the increased simvastatin exposure by ezetimibe inhibition of UGT enzymes. Clinicians should be aware of potential hepatotoxicity with simvastatin-ezetimibe especially in elderly patients and should carefully monitor serum aminotransferase levels when starting therapy and titrating the dosage.

The psoriasis drug monomethylfumarate is a potent nicotinic acid receptor agonist

Nicotinic acid has been used for several decades to treat dyslipidemia. In mice, the lipid-lowing effect of nicotinic acid is mediated by the Gi coupled receptor PUMA-G. In humans, high (GPR109A) and low (GPR109B) affinity nicotinic acid receptors have been characterized. Here we identify monomethylfumarate as a GPR109A agonist. Monomethylfumarate is the active metabolite of the psoriasis drug Fumaderm. We show that monomethylfumarate activates GPR109A in a calcium based aequorin assay, cAMP assay and demonstrate competitive binding with nicotinic acid. We show that GPR109A is highly expressed in neutrophils and epidermal keratinocytes, and that its expression is increased in human psoriatic lesions. Our findings provide evidence that GPR109A is a target for the drug Fumaderm and suggest that niacin should be investigated to treat psoriasis in addition to its role in treating lipid disorders.

Discovery of pyrazolopyrimidines as the first class of allosteric agonists for the high affinity nicotinic acid receptor GPR109A

Pyrazolopyrimidines were discovered as the first class of allosteric agonists for the high affinity nicotinic acid receptor GPR109A. In addition to its intrinsic activity, compound 9n significantly enhances nicotinic acid binding to the receptor, thereby potentiating the functional efficacy of nicotinic acid.

Effect of ezetimibe coadministration with simvastatin in a Middle Eastern population: a prospective, multicentre, randomized, double-blind, placebo-controlled trial

OBJECTIVES

To assess the efficacy and safety of ezetimibe coadministered with simvastatin in patients with primary hypercholesterolaemia and coronary artery disease (CAD).

DESIGN AND SETTING

Prospective, multicentre, randomized, double-blind, placebo-controlled trial conducted in three Middle Eastern countries.

PATIENTS

Patients with known CAD, who were being treated with simvastatin 20 mg and had low-density lipoprotein cholesterol (LDL-C) concentrations of 2.6 to 4.1 mmol/l, were randomized to receive daily coadministration of ezetimibe 10 mg or placebo.

MAIN OUTCOME MEASURES

The primary outcome was percentage reduction of LDL-C after 6 weeks of randomization. Secondary endpoints included number of patients who achieved National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) LDL-C level and safety and tolerability.

RESULTS

We enrolled 144 patients of whom 120 had blood available for final analysis. The coadministration of ezetimibe with ongoing simvastatin therapy resulted in a statistically significant additional reduction in LDL-C concentration as compared with simvastatin monotherapy (-26.7 versus -9.1%, respectively; total additional reduction of 17.6%, P < 0.0001). More patients in the ezetimibe and simvastatin group achieved NCEP ATP III LDL-C target levels than in the simvastatin monotherapy group (70 versus 33%, respectively; P = 0.0001). The coadministration of ezetimibe with simvastatin was well tolerated with a safety profile similar to that of simvastatin monotherapy.

CONCLUSION

When coadministered with simvastatin therapy, ezetimibe resulted in significant additional reduction in LDL-C and enabled more patients to achieve NCEP ATP III LDL-C target levels. This was achieved safely and with excellent tolerability.

Does the addition of fibrates to statin therapy have a favorable risk to benefit ratio?

Statins effectively lower low-density lipoprotein cholesterol levels and the risk of cardiovascular disease (CVD) events, and because of this they have become a standard treatment for dyslipidemia and atheroprevention. Unfortunately, statin monotherapy may fail to normalize high triglycerides and low high-density lipoprotein cholesterol, and it prevents only a minority of CVD events. Further treatment of lipid disorders that remain after statin monotherapy should help reduce the residual CVD risk. Fibrate monotherapy lowers high triglyceride levels, raises low high-density lipoprotein cholesterol, and reduces CVD risk; therefore, fibrates are recommended as an adjunct to statins for treatment of residual dyslipidemia and residual CVD risk. This review provides an update on the benefits and risks of fibrate monotherapy and addresses the benefits and risks of adding fibrates to statins.

Tetrahydro anthranilic acid as a surrogate for anthranilic acid: application to the discovery of potent niacin receptor agonists

The design, synthesis, and biological activity of a series of cycloalkene acid-based niacin receptor agonists are described. This led to the discovery that tetrahydro anthranilic acid is an excellent surrogate for anthranilic acid. Several compounds were identified that were potent against the niacin receptor, had enhanced cytochrome P450 selectivity against subtypes CYP2C8 and CYP2C9, and improved oral exposure in mice.

Comprehensive lipid management versus aggressive low-density lipoprotein lowering to reduce cardiovascular risk

Five lines of evidence justify comprehensive lipoprotein management over aggressive low-density lipoprotein (LDL) lowering alone in most cases of cardiovascular disease (CVD) prevention. First, lipoprotein lipid transport consists of a single, recycling system involving very-low-density lipoprotein, LDL, and high-density lipoprotein (HDL). Single lipid interventions affect all lipoprotein classes to varying degrees. These effects can be expanded by using different drug classes in combination. Second, observational studies support the unitary nature of lipoprotein risk. A family of curves describes increasing CVD risk from increasing LDL as other risk factors are present. Conversely, a family of curves describes increasing CVD risk from decreasing levels of HDL in mirror image to LDL. The LDL and HDL risks are additive. Third, clinical trials that raise HDL and lower triglyceride ameliorate CVD, as does lowering LDL. Lowering LDL prevents heart disease, but by only 22%-36% with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor therapy. Studies indicate that better CVD prevention is obtained when drugs for triglyceride and HDL reduction are combined with LDL reduction. Fourth, HDL and its apolipoprotein (apo), apo A-I, as well as apo A-I analogues, decrease atherosclerosis. Each modality decreases atherosclerosis in animal models, and apo A-I Milano acutely decreases human coronary luminal stenosis. Apo A-I analogues have similar promise. Fifth, combined hyperlipidemia is the most common lipid disorder, has the strongest risk for CVD, and combines elevated LDL, hypertriglyceridemia, and low HDL. This condition requires the comprehensive treatment approach described above. In conclusion, 5 lines of evidence justify comprehensive diet and drug treatment for combined hyperlipidemia and, at lesser LDL elevations, the atherogenic dyslipidemias of obesity, diabetes mellitus, and the metabolic syndrome.

Lipid-altering efficacy of ezetimibe/simvastatin 10/40 mg compared with doubling the statin dose in patients admitted to the hospital for a recent coronary event: the INFORCE study

BACKGROUND

The aim of this study was to investigate the efficacy and safety profile of switching to ezetimibe/simvastatin (Eze/Simva) 10/40 mg compared with doubling the statin dose upon discharge in patients taking a statin and admitted to the hospital for the investigation of a coronary event.

DESIGN

This phase IV, multi-centre, randomised, open-label, active-controlled, parallel group study enrolled 424 patients (aged >/= 18 years) hospitalised for an acute coronary event and taking a stable dose of a statin (>/= 6 weeks) that could be doubled per the product label. Upon discharge from the hospital, patients were stratified by their statin dose/potency (high, medium and low) and randomised 1 : 1 to doubling of the statin dose (n = 211) or Eze/Simva 10/40 mg (n = 213) for 12 weeks. The primary efficacy variable was the absolute low-density lipoprotein cholesterol (LDL-C) value (mmol/l) at study end-point.

RESULTS

Mean baseline LDL-C for the two treatment groups were 2.48 and 2.31 mmol/l for the Eze/Simva and statin groups respectively. At study end-point, least squares mean LDL-C values were 1.74 mmol/l in the Eze/Simva group and 2.22 mmol/l in the statin group resulting in a significant between-group difference of -0.49 mmol/l (p </= 0.001). Eze/Simva 10/40 mg also produced significantly lower total cholesterol (-0.49 mmol/l), non-high-density lipoprotein cholesterol [(non-HDL-C); -0.53 mmol/l] and apolipoprotein B (-0.14 mmol/l) values compared with doubling the statin dose (p </= 0.001 for all). Both treatments produced similar effects on triglycerides, C-reactive protein and HDL-C; the between treatment group differences were not significant (p >/= 0.160). Significantly more patients achieved LDL-C levels < 2.5 (< 100 mg/dl; 86% vs. 72%), < 2.0 (< 77 mg/dl; 70% vs. 42%) and < 1.8 mmol/l (< 70 mg/dl; 60% vs. 31%) with Eze/Simva than statin (all p </= 0.001). Eze/Simva was generally well tolerated, with a safety profile similar to statin. There were no differences in the incidences of liver transaminases >/= 3 x upper limit of normal (ULN) or creatine kinase >/= 10 x ULN between the groups.

CONCLUSIONS

In patients taking a statin and admitted to the hospital for investigation of a coronary event, treatment with Eze/Simva 10/40 mg for 12 weeks produced greater improvements in lipids with a similar safety profile compared with doubling of the statin dose.

Atorvastatin increases HDL cholesterol by reducing CETP expression in cholesterol-fed APOE*3-Leiden.CETP mice

OBJECTIVE

In addition to lowering low-density lipoprotein (LDL)-cholesterol, statins modestly increase high-density lipoprotein (HDL)-cholesterol in humans and decrease cholesteryl ester transfer protein (CETP) mass and activity. Our aim was to determine whether the increase in HDL depends on CETP expression.

METHODS AND RESULTS

APOE*3-Leiden (E3L) mice, with a human-like lipoprotein profile and a human-like responsiveness to statin treatment, were crossbred with mice expressing human CETP under control of its natural flanking regions resulting in E3L.CETP mice. E3L and E3L.CETP mice were fed a Western-type diet with or without atorvastatin. Atorvastatin (0.01% in the diet) reduced plasma cholesterol in both E3L and E3L.CETP mice (-26 and -33%, P<0.05), mainly in VLDL, but increased HDL-cholesterol only in E3L.CETP mice (+52%). Hepatic mRNA expression levels of genes involved in HDL metabolism, such as phospholipid transfer protein (Pltp), ATP-binding cassette transporter A1 (Abca1), scavenger receptor class B type I (Sr-b1), and apolipoprotein AI (Apoa1), were not differently affected by atorvastatin in E3L.CETP mice as compared to E3L mice. However, in E3L.CETP mice, atorvastatin down-regulated the hepatic CETP mRNA expression (-57%; P<0.01) as well as the total CETP level (-29%) and cholesteryl esters (CE) transfer activity (-36%; P<0.05) in plasma.

CONCLUSIONS

Atorvastatin increases HDL-cholesterol in E3L.CETP mice by reducing the CETP-dependent transfer of cholesterol from HDL to (V)LDL, as related to lower hepatic CETP expression and a reduced plasma (V)LDL pool.

The efficacy of statin monotherapy uptitration versus switching to ezetimibe/simvastatin: results of the EASEGO study

OBJECTIVE

To assess the incremental low-density lipoprotein-cholesterol (LDL-C) lowering efficacy of doubling the statin dose or switching to the ezetimibe/simvastatin 10/20 mg combination tablet (EZE/SIMVA) in patients on simvastatin 20 mg or atorvastatin 10 mg not at LDL-C target < 2.5 mmol/L.

STUDY DESIGN AND METHODS

Patients with documented coronary heart disease (CHD) and/or type 2 diabetes (DM2) with LDL-C > or = 2.5 and < 5.0 mmol/L despite treatment with atorvastatin 10 mg or simvastatin 20 mg were randomized to (1) double statin dose or (2) switch to ezetimibe/simvastatin 10/20, according to a PROBE study design. LDL-C, lipoprotein subfractions and safety data were assessed during the study.

RESULTS

119 of 178 (67%) patients in the EZE/SIMVA group and 49 of 189 (26%) in the doubling statin group reached target LDL-C < 2.5 mmol/L. The odds ratio of success for EZE/SIMVA versus doubling statin treatment in reaching the LDL-C target of < 2.5 mmol/L was 5.7 (95% CI: 3.7-9.0, p < 0.0001). A reduction in total cholesterol (TC), total/high density lipoprotein (HDL) cholesterol ratio and apolipoprotein B was observed in both groups, but this reduction was significantly more pronounced in the EZE/SIMVA group as compared with the doubling statin dose group. Treatment was well tolerated and no difference was observed between the two groups with regard to adverse effects.

CONCLUSIONS

In CHD/DM2 patients treated with simvastatin or atorvastatin with LDL-C persistently > or = 2.5 mmol/L, switching to the EZE/SIMVA was more effective in attaining the LDL-C target of < 2.5 mmol/L than doubling the statin dose.

Efficacy and tolerability of fluvastatin XL 80 mg alone, ezetimibe alone, and the combination of fluvastatin XL 80 mg with ezetimibe in patients with a history of muscle-related side effects with other statins

Although statin treatment is generally well tolerated, it is estimated that 5% to 10% of patients develop muscle-related side effects (MRSEs), resulting in less effective nonstatin alternatives or cessation of lipid-lowering therapy completely. This study was designed to assess the efficacy and tolerability of extended-release fluvastatin (fluvastatin XL) and ezetimibe alone or in combination in patients with previous MRSEs with other statins. This was a double-blinded, double-dummy trial of 199 mostly moderate- or high-risk dyslipidemic patients randomized to fluvastatin XL 80 mg/day (n = 69), ezetimibe 10 mg/day (n = 66), or fluvastatin XL 80 mg/day plus ezetimibe 10 mg/day (n = 64) for 12 weeks. Fluvastatin XL lowered low-density lipoprotein (LDL) cholesterol by 32.8% compared with 15.6% with ezetimibe (between-group difference -17.1%, 95% confidence interval -23.6 to -10.7, p <0.0001); the fluvastatin XL/ezetimibe combination lowered LDL cholesterol by 46.1% (between-group difference vs ezetimibe -30.4%, 95% confidence interval -37.0 to -23.8, p <0.0001). Proportions of patients achieving their National Cholesterol Education Program Adult Treatment Panel III target LDL cholesterol were 84% with the fluvastatin XL/ezetimibe combination, 59% with fluvastatin XL, and 29% with ezetimibe (p <0.001 for fluvastatin XL monotherapy or combination therapy vs ezetimibe monotherapy). Incidences of MRSEs were 24% in the ezetimibe group, 17% in the fluvastatin XL group, and 14% in the combination group. There were no instances of creatine kinase increases >or=10 times upper limit of normal. In conclusion, in patients with a history of statin-associated MRSEs, fluvastatin XL alone or in combination with ezetimibe offers an effective and well-tolerated lipid-lowering option.

Dyslipidaemia and cardiorenal disease: mechanisms, therapeutic opportunities and clinical trials

Dyslipidaemia is an important risk factor for the development of chronic kidney disease (CKD) and cardiovascular disease (CVD). CKD generates an atherogenic lipid profile, characterised by high triglycerides, low high-density lipoprotein (HDL) cholesterol and accumulation of small dense low-density lipoprotein (LDL) particles, comparable to that in the metabolic syndrome. These changes are due specifically to the effects of CKD on key enzymes, transfer proteins and receptors involved in lipid metabolism. Dyslipidaemia is further compounded by dialysis, immunosuppressive drugs, and concomitant diseases such as diabetes mellitus. Post hoc analyses from large intervention trials suggest the benefit of statins in patients with early CKD, but prospective clinical trials in haemodialysis (HD) and renal transplant recipients have not conclusively shown improvements in hard cardiovascular end-points. The lack of efficacy of statins in late-stage CKD could be a consequence of other disease processes, such as calcific arteriopathy and insulin resistance, which are not modified by lipid-lowering agents. Despite uncertainty and pending the results of ongoing statin trials such as Study of Heart and Renal Protection (SHARP) and AURORA (A study to evaluate the Use of Rosuvastatin in subjects On Regular haemodialysis: an Assessment of survival and cardiovascular events), major international guidelines continue to support statin therapy in CKD and renal transplant patients to reduce cardiovascular risk burden. Because of increased risk of toxicity, particularly myopathy, statins and other lipid-regulating agents should be used cautiously in CKD and renal transplant recipients.

Diaqua-bis(5-phenyl-1H-pyrazole-3-carboxyl-ato)copper(II)

In the centrosymmetric title compound, [Cu(C₁₀H₇N₂O₂)₂(H₂O)₂], the Cu^II ion occupies an inversion centre and exhibits a distorted octa­hedral geometry. The phenyl and pyrazole rings of the ligand are twisted by an angle of 11.36 (8)°. In the crystal structure, mol­ecules are linked into a two-dimensional network parallel to the (010) plane by O—H⋯O and N—H⋯O hydrogen bonds.

Impact of metformin versus the prandial insulin secretagogue, repaglinide, on fasting and postprandial glucose and lipid responses in non-obese patients with type 2 diabetes

OBJECTIVE

Non-obese patients with type 2 diabetes (T2DM) are characterized by predominant defective insulin secretion. However, in non-obese T2DM patients, metformin, targeting insulin resistance, is non-inferior to the prandial insulin secretagogue, repaglinide, controlling overall glycaemia (HbA1c). Whether the same apply for postprandial glucose and lipid metabolism is unknown. Here, we compared the effect of metformin versus repaglinide on postprandial metabolism in non-obese T2DM patients.

DESIGN

Single-centre, double-masked, double-dummy, crossover study during 2x4 months involving 96 non-obese (body mass index < or = 27 kg/m2) insulin-naïve T2DM patients. At enrolment, patients stopped prior oral hypoglycaemic agents therapies and after a 1-month run-in period on diet-only treatment, patients were randomized to repaglinide (2 mg) thrice daily followed by metformin (1 g) twice daily or vice versa each during 4 months with 1-month washout between interventions.

METHODS

Postprandial metabolism was evaluated by a standard test meal (3515 kJ; 54% fat, 13% protein and 33% carbohydrate) with blood sampling 0-6 h postprandially.

RESULTS

Fasting levels and total area under the curve (AUC) for plasma glucose, triglycerides and free fatty acids (FFA) changed equally between treatments. In contrast, fasting levels and AUC of total cholesterol, low-density lipoprotein (LDL) cholesterol, non-high-density lipoprotein (non-HDL) cholesterol and serum insulin were lower during metformin than repaglinide (mean (95% confidence intervals), LDL cholesterol difference metformin versus repaglinide: AUC: -0.17 mmol/l (-0.26; -0.08)). AUC differences remained significant after adjusting for fasting levels.

CONCLUSIONS

In non-obese T2DM patients, metformin reduced postprandial levels of glycaemia, triglycerides and FFA similarly compared to the prandial insulin secretagogue, repaglinide. Furthermore, metformin reduced fasting and postprandial cholesterolaemia and insulinaemia compared with repaglinide. These data support prescription of metformin as the preferred drug in non-obese patients with T2DM targeting fasting and postprandial glucose and lipid metabolism.

Achieving lipid goals with rosuvastatin compared with simvastatin in high risk patients in real clinical practice: a randomized, open-label, parallel-group, multi-center study: the DISCOVERY-Beta study

The aim of this multi-center, open-label, randomized, parallel-group trial was to compare the efficacy of rosuvastatin with that of simvastatin in achieving the 1998 European Atherosclerosis Society (EAS) lipid treatment goals. 504 patients (> or =18 years) with primary hypercholesterolemia and a 10-year cardiovascular (CV) risk >20% or history of coronary heart disease (CHD) or other established atherosclerotic disease were randomized in a 2:1 ratio to receive rosuvastatin 10 mg or simvastatin 20 mg once daily for 12 weeks. A significantly higher proportion of patients achieved 1998 EAS low-density lipoprotein cholesterol (LDL-C) goal after 12 weeks of treatment with rosuvastatin 10 mg compared to simvastatin 20 mg (64 vs 51.5%, p < 0.01). Similarly, significantly more patients achieved the 1998 EAS total cholesterol (TC) goal and the 2003 EAS LDL-C and TC goals (p < 0.001) with rosuvastatin 10 mg compared with simvastatin 20 mg. The incidence of adverse events and the proportion of patients who discontinued study treatment were similar between treatment groups. In conclusion, in the DISCOVERY-Beta Study in patients with primary hypercholesterolemia greater proportion of patients in the rosuvastatin 10 mg group achieved the EAS LDL-C treatment goal compared with the simvastatin 20 mg group. Drug tolerability was similar across both treatment groups.

Use of propensity score technique to account for exposure-related covariates: an example and lesson

BACKGROUND

In observational research, propensity score techniques can be used to account for baseline differences between compared therapies. Although propensity scores are used increasingly often, their limitations in settings without complete data may not be recognized.

OBJECTIVES

We sought to evaluate the ability of propensity score matching to mitigate confounding by indication in an observational study of the effect of statin therapy on acute myocardial infarction (AMI). Matching was performed at random, and with propensity scores that incorporated a reduced or expanded set of variables. RESEARCH DESIGN/SUBJECTS: This was a propensity score matched cohort study using members of a health insurer database.

MEASURES

Exposure to statin therapy was assessed at the beginning of follow-up with all cohort members being statin initiators or noninitiators, and the outcome of AMI was identified on the basis of claims codes.

RESULTS

Matching on the basis of the propensity score provided results that are similar in magnitude to randomized clinical trials, suggesting that confounding was mitigated. However, matching on a propensity score created on a reduced set of variables yielded a result that suggested no effect of statin therapy, and demonstrated substantial imbalance on some variables that were not part of the propensity score.

CONCLUSIONS

Propensity score matching can balance with respect to variables not explicitly included in the score, but external data are required to evaluate this.

Discovery of biaryl anthranilides as full agonists for the high affinity niacin receptor

Biaryl anthranilides are reported as potent and selective full agonists for the high affinity niacin receptor GPR109A. The SAR presented outlines approaches to reduce serum shift and both CYPCYP2C8 and CYP2C9 liabilities, while improving PK and maintaining excellent receptor activity. Compound 2i exhibited good in vivo antilipolytic efficacy while providing a significantly improved therapeutic index over vasodilation (flushing) with respect to niacin in the mouse model.

Efficacy and safety of high-dose pravastatin in hypercholesterolemic patients with well-compensated chronic liver disease: Results of a prospective, randomized, double-blind, placebo-controlled, multicenter trial

The hepatotoxic potential of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors in patients with underlying chronic liver disease remains controversial. We performed a multicenter, randomized, double-blind, placebo-controlled, parallel-group trial that compared pravastatin (80 mg) to a placebo administered once daily to hypercholesterolemic subjects greater than 18 years of age with at least a 6-month history of compensated chronic liver disease and with a low-density lipoprotein cholesterol (LDL-C) level greater than or equal to 100 mg/dL and a triglyceride (TG) level lower than 400 mg/dL. The efficacy was determined by the percentage change in LDL-C [along with the total cholesterol (TC), high-density lipoprotein cholesterol, and TG] from the baseline to week 12. The safety was analyzed by the proportion of subjects who developed at least 1 alanine aminotransferase (ALT) value greater than or equal to 2 times the upper limit of normal for those with normal ALT at the baseline or a doubling of the baseline ALT for those with elevated ALT at the baseline during 36 weeks of treatment. A total of 630 subjects were screened, and 326 subjects were randomized; nonalcoholic fatty liver disease was present in 64%, and chronic hepatitis C was present in 23%. In the intent-to-treat population, pravastatin (80 mg/day) significantly lowered the mean LDL-C, TC, and TG values at week 12 and at other times (weeks 4, 8, 24, and 36) in comparison with the placebo. The incidence of subjects who met the primary prespecified ALT event definition was lower in the pravastatin group at all times over the 36 weeks of therapy in comparison with the placebo group, although the difference was not statistically significant. No differences were seen on the basis of the baseline ALT values or among the different liver disease groups.

CONCLUSION

High-dose pravastatin (80 mg/day) administered to hypercholesterolemic subjects with chronic liver disease significantly lowered LDL-C, TC, and TGs in comparison with the placebo and was safe and well tolerated. The concern over an increased potential for statin-induced hepatotoxicity in patients with chronic liver disease appears to be lessened on the basis of these results.

Treatment of the dyslipidemia of insulin resistance

The increase in ischemic cardiovascular mortality and morbidity in persons with insulin resistance has been adequately documented elsewhere in this issue. Some of the most important risk factors for this increased mortality and morbidity are the lipid abnormalities, which form two out of five criteria for defining the metabolic syndrome, a definition focusing on risk factors for ischemic cardiovascular disease. This article explores the description, pathophysiology, and treatment of these atherogenic lipid abnormalities.

Discovery of orally bioavailable and novel urea agonists of the high affinity niacin receptor GPR109A

A urea class of high affinity niacin receptor agonists was discovered. Compound 1a displayed good PK, better in vivo efficacy in reducing FFA in mouse than niacin, and no vasodilation in a mouse model. Compound 1q demonstrated equal affinity to GPR109A as niacin.

Do we need a statin-nicotinic acid-aspirin mini-polypill to treat combined hyperlipidaemia?

This review considers the treatment for combined hyperlipidaemia (CH) with a combination formulation of three drugs: a statin, nicotinic acid (NA) and aspirin--a mini-polypill. CH is a highly atherogenic dyslipidaemia manifested either as familial combined hyperlipidaemia or dyslipidaemia related to the metabolic syndrome or Type 2 diabetes mellitus. These types of dyslipidaemia are highly prevalent in the general population. Statin plus extended-release NA is a promising treatment option for the normalisation of these atherogenic lipid alterations, regression of atherosclerosis, as well as for primary or secondary prevention of cardiovascular disease (CVD) events. The addition of aspirin might prove a useful adjunct that might reduce the cutaneous side effects of NA while also acting as an antiplatelet agent in high-CVD-risk patients. However, the effective dose of aspirin may need to be at least 160 mg/day. This triple combination might improve patient compliance when compared with the three drugs administered separately.

Effectiveness of statins in Medicare-eligible patients and patients < 65 years using clinical practice data

OBJECTIVE

This study compared effectiveness of rosuvastatin (RSV) with other statins on lowering LDL-C and LDL-C goal attainment among Medicare-eligible patients (age >or= 65 years) and patients with age < 65 years treated in usual clinical practice to provide evidence of real-world effectiveness of statins.

METHODS

Retrospective cohort study was conducted in patients, newly prescribed statin therapy during August 2003 to May 2005. Patient inclusion criteria: no prior prescription for dyslipidaemic medication in the preceding 12 months, continuously enrolled for >or= 15 months and >or= 90-day supply of statin. Effectiveness of RSV in reducing LDL-C and attaining LDL-C goal when compared with other statins was evaluated using multivariate regression, adjusting for baseline LDL-C, age, gender, smoking, hypertension, coronary heart disease (CHD), systolic blood pressure and therapy duration.

RESULTS

Adjusted per cent LDL-C reduction was significantly greater (p < 0.05) with RSV (24.3% for >or= 65 and 28.5% for < 65) compared with ATV (17.5%, 21.3%), SMV (14.8%, 18.4%), PRV (11.3%, 15.8%), FLV (10.7%, 20.6%) and LOV (13.3%, 14.4%). Among patients in both age groups at high or moderate CHD risk, a greater proportion of RSV patients attained LDL-C goal (76.0% for age group >or= 65 years and 78.4% for age group < 65 years) vs. 50.5-73.0% for >or= 65 and 51.3-71.5% for < 65 years of age on other statins (p < 0.0001).

CONCLUSIONS

Rosuvastatin is more effective in lowering LDL-C in Medicare-eligible patients and patients < 65 years of age when compared with other statins in usual clinical practice. Moreover, RSV patients had higher LDL-C goal attainment rates when compared with other statins in high- and moderate-risk patients. The study results have implications for clinicians in selecting the optimal statin to meet individual patient care needs.

Ezetimibe: an update on the mechanism of action, pharmacokinetics and recent clinical trials

Elevated serum cholesterol is a known risk factor for the development of coronary artery disease. Circulating cholesterol is a product of both cholesterol absorption from the gut and cellular cholesterol production. Ezetimibe is a novel cholesterol-lowering drug that acts at the brush border of the small intestine. Recent studies have further identified the molecular target as the Niemann-Pick C1-like transporter. Ezetimibe blocks the absorption of dietary and biliary cholesterol and plant sterols resulting in intracellular cholesterol depletion. Clinical studies have demonstrated beneficial improvements in the lipid profile with ezetimibe as monotherapy, but dramatic effects are seen when ezetimibe is combined with other lipid-lowering drugs, particularly 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins). Combination studies of ezetimibe with statins, bile acid sequestrants, fenofibrate and niacin all demonstrate significant total and low density lipoprotein cholesterol lowering. An excellent safety and tolerability profile combined with once-daily dosing make this attractive adjunct therapy for the treatment of hypercholesterolemia.

A multi-centre, randomised, double-blind 14-week extension study examining the long-term safety and efficacy profile of the ezetimibe/simvastatin combination tablet

The objective of this study was to compare the efficacy and safety profile of ezetimibe/simvastatin (EZE/SIMVA) tablet and SIMVA monotherapy. This was an extension study of a randomised, double-blind, placebo-controlled study in patients with primary hypercholesterolaemia. Protocol-compliant patients who completed the 12-week base study were eligible to enter a randomised, double-blind, 14-week extension study and were administered 1 of 8 daily treatments: EZE/SIMVA 10/10-, 10/20-, 10/40- or 10/80-mg, or SIMVA 10-, 20-, 40- or 80-mg. Patients receiving these treatments during the base study remained on the same treatment in the extension. Patients administered placebo or EZE 10-mg monotherapy during the base study were re-randomised to EZE/SIMVA 10/10 mg or SIMVA 80 mg. The primary analysis was mean per cent change in low-density lipoprotein cholesterol (LDL-C) from baseline to extension study end-point. Mean changes from baseline in LDL-C of -38.8% and -53.7% were observed for pooled SIMVA and pooled EZE/SIMVA respectively. The between treatment difference of -14.9% (95% confidence interval: -16.4, -13.3) was statistically significant (p < 0.001). The incremental LDL-C lowering effect of EZE/SIMVA compared with the corresponding dose of SIMVA alone was consistent across the dose range (p < 0.001 for each between-group comparison). More patients receiving EZE/SIMVA than SIMVA achieved LDL-C concentrations < 100 mg/dl and < 70 mg/dl (p < 0.001 for both goals). EZE/SIMVA was generally well tolerated with a safety profile similar to SIMVA monotherapy. There were no significant between-group differences in the incidences of clinically significant elevations in liver transaminase or creatine kinase levels. In conclusion, EZE/SIMVA had a comparable safety and tolerability profile and was more efficacious than SIMVA monotherapy for up to 6 months.

New dimension of statin action on ApoB atherogenicity

Newer, more effective statins are powerful agents for reducing elevated levels of low-density lipoprotein (LDL) cholesterol and thereby lowering the risk of coronary heart disease (CHD) and related adverse events. Although LDL remains the primary target of therapy for reducing CHD risk, increased interest is focusing on apolipoprotein B (apoB)-containing lipoprotein subfractions--particularly very-low-density lipoprotein (VLDL). VLDL remnants, and intermediate-density lipoproteins (IDL)--as secondary targets of therapy. Elevated apoB is known to be an important risk factor for CHD, and dysregulation of the metabolism of apoB-containing lipoproteins is involved in the progression of atherosclerosis. Statins reduce circulating concentrations of atherogenic apoB-containing lipoproteins by decreasing the production of VLDL in the liver and, thus, the production of VLDL remnants and LDL. Statins also increase the clearance of these particles through upregulation of LDL receptors in the liver. Efforts to develop statins with enhanced lipid-modifying properties are ongoing. The optimal statin would offer a high degree of inhibition of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, a prolonged duration of action, hepatic selectivity for maximal upregulation of LDL receptors, and a low potential for drug-drug interactions. Recent studies have shown that rosuvastatin, a new agent in this class, demonstrates these qualities. Rosuvastatin is a highly effective inhibitor of HMG-CoA reductase, is relatively nonlipophilic, has a half-life of approximately 20 h, exhibits hepatic selectivity, has little systemic availability, and has a low potential for drug-drug interactions because of its limited degree of metabolism by the cytochrome P450 system. A recent double-blind, crossover study revealed that treatment with rosuvastatin resulted in marked reductions in apoB-containing lipoproteins in patients with type IIa or IIb dyslipidemia. By reducing the number of atherogenic lipoprotein particles, rosuvastatin decreases the atherosclerotic burden in hyperlipidemic patients at high risk for CHD and related adverse outcomes.

State of the Art Reviews: Health Benefits Related to Exercise in Patients With Chronic Low-Grade Systemic Inflammation

Today, there is substantial evidence to suggest that regular exercise has health-promoting effects, which are beyond its effect on weight control. Regular exercise offers protection against all-cause mortality, and there is evidence from randomized intervention studies that physical training is effective as a treatment in patients with chronic heart diseases, type 2 diabetes, and symptoms related with the metabolic syndrome. Chronic diseases such as cardiovascular disease and type 2 diabetes are associated with chronic low-grade systemic inflammation. This review focuses on the anti-inflammatory effects of exercise that are mediated by muscle-derived cytokines (myokines). It is suggested that myokines may be involved in mediating the health-beneficial effects of exercise and that these in particular are involved in the protection against chronic diseases associated with low-grade inflammation.

Absorption, metabolism, and excretion of [(14)C]MK-0524, a prostaglandin D(2) receptor antagonist, in humans

[(3R)-4-(4-Chlorobenzyl)-7-fluoro-5-(methylsulfonyl)-1,2,3,4-tetrahydrocyclopentaindol-3-yl]acetic acid (MK-0524) is a potent orally active human prostaglandin D(2) receptor 1 antagonist that is currently under development for the prevention of niacin-induced flushing. The metabolism and excretion of [(14)C]MK-0524 in humans were investigated in six healthy human volunteers following a single p.o. dose of 40 mg (202 microCi). [(14)C]MK-0524 was absorbed rapidly, with plasma C(max) achieved 1 to 1.5 h postdose. The major route of excretion of radioactivity was via the feces, with 68% of the administered dose recovered in feces. Urinary excretion averaged 22% of the administered dose, for a total excretion recovery of approximately 90%. The majority of the dose was excreted within 96 h following dosing. Parent compound was the primary radioactive component circulating in plasma, comprising 42 to 72% of the total radioactivity in plasma for up to 12 h. The only other radioactive component detected in plasma was M2, the acyl glucuronic acid conjugate of the parent compound. The major radioactive component in urine was M2, representing 64% of the total radioactivity. Minor metabolites included hydroxylated epimers (M1/M4) and their glucuronic acid conjugates, which occurred in the urine as urea adducts, formed presumably during storage of samples. Fecal radioactivity profiles mainly comprised the parent compound, originating from unabsorbed parent and/or hydrolyzed glucuronic acid conjugate of the parent compound. Therefore, in humans, MK-0524 was eliminated primarily via metabolism to the acyl glucuronic acid conjugate, followed by excretion of the conjugate into bile and eventually into feces.

A pravastatin dose-escalation study in systemic lupus erythematosus

Statin medications have been suggested for widespread use in patients with systemic lupus erythematosus (SLE). We studied the dose effectiveness and tolerability of pravastatin in SLE. We compared 41 SLE subjects in a two-month open-label dose-titration study of pravastatin to 22 SLE controls. Lipids, ALT, CPK, CRP, adverse effects were assessed. Linear mixed models assessed changes in lipids and CRP, comparing pravastatin subjects to controls. After 1 month of pravastatin 10 mg a day, total cholesterol decreased by 16% (+/-12.1%) and LDL by 24% (+/-17%), compared with 1.8% (+/-7.5%) and 2.6% (+/-8.6%) decreases in controls (P < 0.001). CRP did not decline. Glucocorticoids appeared to decrease pravastatin effectiveness. Serum CPK increased in one subject. Pravastatin reduced LDL and total cholesterol levels approximately the same degree observed in normal individuals, but the effect appeared blunted in those on modest doses of glucocorticoids and those with higher BMI.

Effects of fenofibrate and xuezhikang on high-fat diet-induced non-alcoholic fatty liver disease

1. Fenofibrate and xuezhikang are two types of drugs widely used in the treatment of dyslipidaemia in China. The main purpose of present study was to test the efficacies and explore the potential mechanisms of action of the two lipid-lowering agents on high-fat diet-induced non-alcoholic fatty liver disease (NAFLD). 2. Rats were randomly divided into four groups, with eight rats per group. One group was given normal diet, whereas the other three groups were fed a high-fat diet. Forty-two days later, two of the high-fat diet-fed groups were administered fenofibrate (100 mg/kg, p.o.) and xuezhikang (300 mg/kg, p.o.) for another 42 consecutive days. The other two groups were administered placebo (saline) by gavage. 3. Typical pathological symptoms of NAFLD occurred in the high-fat diet groups. Fenofibrate and xuezhikang treatment markedly improved NAFLD, ameliorating dyslipidaemia and fat accumulation in the liver, improving insulin resistance and ameliorating oxidative stress. Hepatic steatosis, necro-inflammation and collagen deposition were lessened in the drug-treated groups. However, both xuezhikang and fenofibrate failed to reverse hepatomegaly and fenofibrate even aggravated it. Xuezhikang reversed aminotransferase abnormalities, but fenofibrate had less of an effect. 4. The common therapeutic mechanism of action of fenofibate and xuezhikang likely involves inhibition of the hepatic expression of tumour necrosis factor-alpha. Fenofibrate upregulated mRNA levels of peroxisome proliferator-activated receptor (PPAR) alpha in the liver, whereas xuezhikang had no effect on the hepatic expression of PPARalpha and this may explain, in part, their different effects on the NAFLD rats. 5. The results suggest that fenofibrate and xuezhikang may have potential clinical application in the treatment of NAFLD. However, the side-effects of fenofibrate and the underlying constituents of xuezhikang need to be determined and investigated further.

Effects of statins on cognitive function in patients with Alzheimer's disease in galantamine clinical trials

BACKGROUND AND OBJECTIVE

A number of reports have been published on the possible involvement of changes in brain cholesterol metabolism in the origin of Alzheimer's disease (AD) and the potential for influencing these changes by administration of HMG-CoA reductase inhibitors ('statins'). The aim of this study was to evaluate a potential association between use of statins and maintenance of cognitive function in patients with AD in galantamine clinical trials.

METHOD

A post hoc analysis was conducted on data pooled from three double-blind, placebo-controlled, clinical trials of galantamine in patients with AD. Patients were divided into four treatment groups: statin plus galantamine (n = 42), statin alone (n = 50), galantamine alone (n = 614) or neither galantamine nor statin (n = 619).

RESULTS

Galantamine was associated with a significant beneficial effect on cognitive status (p < 0.001). The association of use of statins with changes in cognitive status was not significant (p = 0.083). There was no significant interaction between the effects on cognition of statins and galantamine (p = 0.183) and no statistically significant changes in adverse effect rates were observed.

CONCLUSION

These findings suggest the need for larger long-term trials to confirm or refute possible effects of statins on cognitive function and the potential interaction of statins with acetylcholinesterase inhibitors in the treatment of AD.

Cholesterol distribution, not total levels, correlate with altered amyloid precursor protein processing in statin-treated mice

There are now a number of studies that suggest that cholesterol might regulate the processing of the amyloid precursor protein to form the neurotoxic peptide Abeta. This research has opened the possibility that cholesterol-lowering drugs might be efficacious as anti-Abeta drugs for use in Alzheimer's disease. The use of HMG-CoA reductase inhibitors (commonly called statins) in vitro and in vivo has proven them to be Abeta-lowering agents, however, the mechanism of action of these drugs is not yet known. One possible mechanism is that they reduce Abeta levels indirectly by reducing cholesterol in the central nervous system (CNS). In this study, we administered three different statins (simvastatin, lovastatin, and atorvastatin) to nontransgenic mice. We found that all three compounds had similar effects on Abeta, reducing both Abeta40 and Abeta42. The statins decreased beta-cleaved C-terminal fragment (CTF) although having no effect on alpha-CTF levels. However, the drugs did not have a similar effect on cholesterol in the CNS. Only lovastatin significantly reduced total cholesterol in isolated plasma membranes. As cholesterol is not distributed evenly in the plasma membrane, we examined bilayer distribution of cholesterol and found that all three statins caused CNS cholesterol to translocate from the cytofacial leaflet to the exofacial leaflet. This data suggests that cholesterol distribution and not total cholesterol levels may be important to Abeta production in the CNS.

Safety of Rosuvastatin: Update on 16,876 Rosuvastatin-Treated Patients in a Multinational Clinical Trial Program

BACKGROUND

The safety and tolerability of rosuvastatin were assessed using data from 16,876 patients who received rosuvastatin 5-40 mg in a multinational phase II/III/IIIb/IV program, representing 25,670 patient-years of continuous exposure to rosuvastatin.

METHODS

An integrated database, consisting of 33 trials whose databases were locked up to and including September 16, 2005, was used to examine adverse events and laboratory data.

RESULTS

In placebo-controlled trials, adverse events irrespective of causality assessment occurred in 52.1% of patients receiving rosuvastatin 5-40 mg (n = 931) and 51.8% of patients receiving placebo (n = 483). In all controlled clinical trials with comparator statins, rosuvastatin 5-40 mg was associated with an adverse event profile similar to profiles for atorvastatin 10-80 mg, simvastatin 10-80 mg, and pravastatin 10-40 mg. Clinically significant elevations in alanine aminotransferase (> 3 times the upper limit of normal [ULN] on at least 2 consecutive occasions) were uncommon (< or = 0.2%) in the rosuvastatin and comparator statin groups. Elevated creatine kinase > 10 times ULN occurred in < or = 0.3% of patients receiving rosuvastatin or other statins. Myopathy (creatine kinase > 10 times ULN with muscle symptoms) possibly related to treatment occurred in 0.03% of patients taking rosuvastatin at doses < or = 40 mg. The frequency of dipstick-positive proteinuria at rosuvastatin doses < or = 20 mg was comparable to that seen with other statins, and the development of proteinuria was not predictive of acute or progressive renal disease. Both short- and long-term rosuvastatin treatment were associated with small increases in estimated glomerular filtration rate, with improvements appearing to be somewhat greater in those patients beginning treatment with greater renal impairment. In the phase II-IV program, no deaths were attributed to rosuvastatin; at doses of rosuvastatin < or = 40 mg, 1 case of rhabdomyolysis occurred in a patient who received rosuvastatin 20 mg and concomitant gemfibrozil treatment.

CONCLUSION

In summary, rosuvastatin was well tolerated by a broad range of patients with dyslipidemia, and its safety profile was similar to those of comparator statins investigated in the clinical program. (Nota bene: The clinical development program for rosuvastatin initially evaluated rosuvastatin doses up to 80 mg. Following completion of the phase III/IIIb program, a decision was made not to pursue marketing approval for the 80-mg dose because the additional lipid-modifying benefits of this dose did not justify the potential risks for use in the general population of patients with dyslipidemia.)

Statins in elderly patients with acute coronary syndrome: an analysis of dose and class effects in typical practice

OBJECTIVE

To compare the effectiveness of statins of different treatment intensity used to treat elderly patients with acute coronary syndrome (ACS) in typical care settings.

DESIGN

Retrospective cohort study using linked hospital and pharmacy claims data.

SETTING

Statewide pharmacy benefits programmes in Pennsylvania and New Jersey.

PARTICIPANTS

18,311 Medicare patients discharged alive after ACS who received a prescription for a statin within 90 days of hospital discharge.

MAIN OUTCOME MEASURES

Using multivariable and propensity-matched Cox proportional hazards regression models, patients who were prescribed high-intensity and moderate-intensity statins were compared based on the drug-dose combination that they initially received. Individual drug-dose combinations were also compared. Our primary outcome was the composite of all-cause death or recurrent ACS.

RESULTS

Patients who received moderate-intensity statins were as likely to experience a primary outcome as patients treated with high-intensity statins (adjusted HR 1.02, 95% CI 0.96 to 1.08). Propensity matching did not change the results. Individually, all moderate-intensity statins were as effective as high-intensity atorvastatin with the exception of lovastatin (adjusted HR 1.22, 95% CI 1.09 to 1.36). Similarly, all high-intensity statins seem as effective as high-intensity atorvastatin but the CIs surrounding these estimates were wide.

CONCLUSIONS

This analysis of elderly patients with ACS treated in typical care settings does not demonstrate the superiority of high-intensity over moderate-intensity statin treatment or significant differences among individual statins.

Statins and dietary fish oils improve lipid composition in bone marrow and joints

There have been numerous efforts to alter the lipid content of cardiovascular tissues. Although equally important, only limited information is available about musculoskeletal tissues. I characterized joint and bone marrow lipids in patients having joint replacement surgery and explored the effects of fish oils and statins on lipid composition in bone marrow and joint fluid. Joint drainage catheters were used to collect marrow lipids from 84 patients having 128 hip and knee replacements for osteoarthritis, osteonecrosis, and femoral neck fractures (osteoporosis). Statins reduced the amount of lipid by 22% in patients with osteoporosis, 26% in patients with osteoarthritis, and 41% in patients with osteonecrosis compared with pretreatment lipid levels in the same patients. Taking fish oils reduced the amount of lipid in bone marrow by 20%. Lipid profiles of disturbed marrow and joint fluid from patients who took statins or dietary fish oil showed an increase in the proportion of unsaturated fatty acids and longer-chain fatty acids relative to pretreatment profiles. The ability to change the amount and character of bone and joint lipids may have major importance for strengthening bone, reducing the severity or preventing osteonecrosis, and enhancing joint lubrication.

Increased plasma levels of oxysterols, in vivo markers of oxidative stress, in patients with familial combined hyperlipidemia: reduction during atorvastatin and fenofibrate therapy

Familial combined hyperlipidemia (FCHL), the most common inherited disorder of lipid metabolism, is associated with an increased risk of atherosclerosis that is not fully explained by the metabolic disturbances of these patients. Oxidative damage to lipid components accumulating in the plasma of FCHL patients might contribute to explaining this lack of evidence. Cholesterol is one of the preferential targets of oxidation in LDL and this may contribute to setting a proatherogenetic phenotype in FCHL. We investigated plasma oxysterols (7-ketocholesterol and 7beta-hydroxycholesterol) and alpha-tocopherol as in vivo hallmarks of lipid-related oxidative stress. Oxidative stress hallmarks were measured in 45 FCHL patients and 54 sex- and age-matched healthy controls; in FCHL patients, oxidative stress and lipid profile parameters were also assessed in response to lipid-lowering drugs in a 24-week randomized, open-label trial with atorvastatin or fenofibrate. FCHL patients showed markedly increased levels of oxysterols (p < 0.001) and reduced alpha-tocopherol/total lipids (p < 0.001) compared to controls. These differences were independent of the presence of clinical atherosclerosis and persisted after correction for hyperlipidemia. Atorvastatin and fenofibrate significantly improved the lipid profile and caused a comparable decrease in plasma oxysterols, with the normalization of 7-ketocholesterol and a significant reduction of 7beta-hydroxycholesterol (p < 0.001). These drugs also decreased the ratio of alpha-tocopherol/total lipids by more than 30% (p < 0.001). In conclusion, FCHL patients showed increased hallmarks of cholesterol oxidation and decreased levels of alpha-tocopherol/total lipids. Atorvastatin and fenofibrate displayed comparable efficiency in decreasing oxysterols, but they further decreased lipid-corrected alpha-tocopherol levels in plasma. More research work is needed to understand the clinical meaning of these findings, which may help to understand the role of oxidative stress in FCHL and lipid-lowering therapy.

Fibrates: What Have We Learned in the Past 40 Years?

The prominent use of fibric acid derivatives has lessened over the years because of unimpressive results in major clinical trials, safety concerns, and the emergence of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins). Clofibrate was widely used in the 1970s, but after publication of results from two major trials demonstrating only modest reductions in the rate of coronary heart disease (CHD) and concerns regarding an increase in the frequency of gallstones and overall mortality, its use subsided dramatically. With the introduction of gemfibrozil in the 1980s came a renewed interest in the class, which was also supported by the published results of the Helsinki Heart Study; however, despite a significant reduction in CHD events and a sound safety profile, overall mortality was comparable to that with placebo. Again, in the 1990s, awareness of the fibrates was heightened with the availability of fenofibrate and the findings of another major trial using gemfibrozil, the Veterans Affairs High-Density Lipoprotein Cholesterol Intervention Trial (VA-HIT), which demonstrated impressive results in reducing cardiovascular events. To further strengthen the VA-HIT results, numerous post hoc analyses were performed on the data of major trials of fibrate therapy among patients with mixed dyslipidemia, with similar findings. Recently, however, data from the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study were published, indicating mixed results. Nearly 40 years after the introduction of the fibrates, practitioners are still contemplating the role of these agents in the treatment of CHD.

Management of Cardiovascular Risk in Patients With Type 2 Diabetes Mellitus as a Component of the Cardiometabolic Syndrome

Heart disease and stroke are the most life-threatening consequences of diabetes mellitus, with mortality rates up to two to four times higher for persons with diabetes vs. those without and accounting for up to 65% of deaths. The cardiometabolic syndrome is a potent indicator of future risk of type 2 diabetes and concomitant increased potential for cardiovascular morbidity and mortality. Pharmacologic treatment is usually necessary to improve blood pressure and lipids, thereby decreasing the risk of cardiovascular disease. The reduction of cardiovascular and renal risk with type 2 diabetes and elevated blood pressure are compelling indications for thiazide diuretics, blockers, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, and calcium channel blockers. Nevertheless, most patients with type 2 diabetes and elevated blood pressure will require two or more agents to lower blood pressure to the recommended goal of <130/80 mm Hg, and combination therapy may be beneficial. In patients with the cardiometabolic syndrome without type 2 diabetes, the present goal is to maintain BP <140/90 mm Hg, although recent data suggest potential decrease in the progression of prehypertension to hypertension with antihypertensive medication. Furthermore, blockers of the renin-angiotensin system may actually prevent newonset diabetes. It is reasonable for patients with type 2 diabetes and cardiovascular disease to achieve an optional low-density lipoprotein cholesterol (LDL-C) goal <70 mg/dL, and statin therapy should be considered regardless of baseline LDL-C level. In patients with the cardiometabolic syndrome without type 2 diabetes and calculated moderately high-risk status (two or more risk factors; 10-year risk, 10%-20%), the present goal for LDL-C is <130 mg/dL, with perhaps a therapeutic option of <100 mg/dL, and in patients with the cardiometabolic syndrome at lower risk, the LDL-C goal remains <160 mg/dL. Multifactorial management must be utilized to prevent progression of cardiovascular risk with the cardiometabolic syndrome and the ravages of cardiovascular disease in persons with type 2 diabetes, including antiplatelet therapy with aspirin.

Metabolism of MK-0524, a prostaglandin D2 receptor 1 antagonist, in microsomes and hepatocytes from preclinical species and humans

(3R)-4-(4-Chlorobenzyl)-7-fluoro-5-(methylsulfonyl)-1,2,3,4-tetrahydrocyclopenta[b]indol-3-yl acetic acid (MK-0524) is a potent orally active human prostaglandin D(2) receptor 1 antagonist that is currently under development for the prevention of niacin-induced flushing. The major in vitro and in vivo metabolite of MK-0524 is the acyl glucuronic acid conjugate of the parent compound, M2. To compare metabolism of MK-0524 across preclinical species and humans, studies were undertaken to determine the in vitro kinetic parameters (K(m) and V(max)) for the glucuronidation of MK-0524 in Sprague-Dawley rat, beagle dog, cynomolgus monkey, and human liver microsomes, human intestinal microsomes, and in recombinant human UDP glucuronosyltransferases (UGT). A comparison of K(m) values indicated that UGT1A9 has the potential to catalyze the glucuronidation of MK-0524 in the liver, whereas UGT1A3 and UGT2B7 have the potential to catalyze the glucuronidation in the intestine. MK-0524 also was subject to phase I oxidative metabolism; however, the rate was significantly lower than that of glucuronidation. The rate of phase I metabolism was ranked as follows: rat approximately monkey > human intestine > dog > human liver with qualitatively similar metabolite profiles across species. In all the cases, the major metabolites were the monohydroxylated epimers (M1 and M4) and the keto-metabolite, M3. Use of inhibitory monoclonal antibodies and recombinant human cytochromes P450 suggested that CYP3A4 was the major isozyme involved in the oxidative metabolism of MK-0524, with a minor contribution from CYP2C9. The major metabolite in hepatocyte preparations was the acyl glucuronide, M2, with minor amounts of M1, M3, M4, and their corresponding glucuronides. Overall, the in vivo metabolism of MK-0524 is expected to proceed via glucuronidation, with minor contributions from oxidative pathways.