Prolonged-Release Nicotinic Acid

The potential prophylactic and therapeutic impacts of niacin on ischemia/reperfusion injury of testis

INTRODUCTION

The testicular ischemia-reperfusion (I/R) injury is characterized by the excessive aggregation of un-scavenged reactive oxygen species, leading to the heightened levels of oxidative stress. This phenomenon plays a pivotal role in the pathophysiology of testicular torsion damage.

OBJECTIVE

The current study aimed to detect the prophylactic and therapeutic effects of niacin on testicular I/R injury.

STUDY DESIGN

Twenty-four healthy adult male Sprague Dawley rats were randomly allocated into three groups as follows: (1) sham group, (2) torsion/detorsion (T/D) group, and (3) treatment group which received 200 mg/kg niacin along with testicular T/D. Torsion/detorsion was induced by 2 h of torsion followed by 10 days of reperfusion period. In the treatment group, niacin was injected 30 min before the reperfusion period intraperitoneally and continued for 10 days by oral gavage.

RESULTS

T/D was associated with marked decreases in terms of sperm count, viability, and kinematic parameters versus the sham group (P < 0.05), which niacin significantly reverted the kinematic parameters (P < 0.05). I/R injury caused a significant increase in the number of abnormal epididymal sperms compared to the sham group (P < 0.05). Niacin decreased the epididymal sperm abnormality significantly compared to the T/D group (P < 0.05). Tissue abnormalities in T/D group, such as edema, hyperemia, inflammation, and necrosis were completely visible histopathologically, while the histological changes in the niacin-treated group were better than those in the T/D group. Regarding the pathological parametric evaluations, I/R injury significantly reduced the mean testicular biopsy score (MTBS), germinal epithelial cell thickness (GECT), and mean seminiferous tubular diameter (MSTD), and increased the tubular hypoplasia/atrophy (THA) compared to the sham group (P < 0.05), which niacin treatment significantly improved the MTBS and GECT compared to the T/D group (P < 0.05). T/D significantly increased the oxidative stress index (OSI) and lipid peroxidation (MDA) (P < 0.05). Niacin significantly reduced the OSI and MDA levels compared to the T/D group (P < 0.05).

DISCUSSION

The current study found that niacin has preventive/therapeutic effects against the elevation of oxidative stress markers and depletion of antioxidants during I/R injury. Following administration of niacin, a reduction in histologic injury was observed in rats. In our study, we showed the antioxidant properties of niacin and its capacity to protect against I/R damage.

CONCLUSION

The findings of the present investigation revealed that niacin, as an antioxidant agent, can suppress the oxidative stress induced by testicular I/R injury, and can be used as a supplementary agent in the treatment of those undergoing testicular torsion surgery.

Adjunctive 5-Hydroxytryptophan Slow-Release for Treatment-Resistant Depression: Clinical and Preclinical Rationale

Serotonin transporter (SERT) inhibitors treat depression by elevating brain extracellular 5-hydroxytryptamine (5-HT_Ext). However, only one-third of patients respond adequately. Treatment-resistant depression (TRD) is a major unmet need. Interestingly, elevating 5-HT_Ext beyond what is achieved by a SERT inhibitor appears to treat TRD. Adjunctive administration of 5-hydroxytryptophan (5-HTP) safely elevates 5-HT_Ext beyond the SERT inhibitor effect in humans; however, 5-HTP cannot be a clinically viable drug because of its poor pharmacokinetics. A slow-release (SR) delivery mode would be predicted to overcome the pharmacokinetic limitations of 5-HTP, substantially enhancing the pharmacological action and transforming 5-HTP into a clinically viable drug. Animal studies bear out this prediction. Thus, adjunct 5-HTP SR could be an important new treatment for TRD. Here, we review the clinical and preclinical evidence for this treatment.

Effects of formulation design on niacin therapeutics: mechanism of action, metabolism, and drug delivery

Niacin is a highly effective, lipid regulating drug associated with a number of metabolically induced side effects such as prostaglandin (PG) mediated flushing and hepatic toxicity. In an attempt to reduce the development of these adverse effects, scientists have investigated differing methods of niacin delivery designed to control drug release and alter metabolism. However, despite successful formulation of various orally based capsule and tablet delivery systems, patient adherence to niacin therapy is still compromised by adverse events such as PG-induced flushing. While the primary advantage of orally dosed formulations is ease of use, alternative delivery options such as transdermal delivery or polymeric micro/nanoparticle encapsulation for oral administration have shown promise in niacin reformulation. However, the effectiveness of these alternative delivery options in reducing inimical effects of niacin and maintaining drug efficacy is still largely unknown and requires more in-depth investigation. In this paper, we present an overview of niacin applications, its metabolic pathways, and current drug delivery formulations. Focus is placed on oral immediate, sustained, and extended release niacin delivery as well as combined statin and/or prostaglandin antagonist niacin formulation. We also examine and discuss current findings involving transdermal niacin formulations and polymeric micro/nanoparticle encapsulated niacin delivery.

Extended-release niacin/laropiprant improves endothelial function in patients after myocardial infarction

Raising high-density lipoprotein cholesterol (HDL-C) is an important strategy for reducing residual cardiovascular risk. In the present study, we sought to assess the effect of extended-release niacin/laropiprant on endothelial function in patients after a myocardial infarction with target low-density lipoprotein cholesterol (LDL-C). In this double-blind, placebo-controlled trial, 63 men (35-60 years of age) after a myocardial infarction were randomized to either niacin/laropiprant (1000/20 mg daily for 4 weeks and 2000/40 mg daily thereafter) or placebo. Flow-mediated dilation (FMD) and nitroglycerin-induced (GTN) dilation of the brachial artery, total cholesterol (TC), LDL-C, HDL-C, triglycerides (TG), lipoprotein(a) [Lp(a)], and apolipoprotein (Apo) A1/B were measured at baseline and after 12 weeks of intervention. FMD significantly increased (from 3.9 ± 5.1 to 9.8 ± 4.4%, p < 0.001) in the niacin/laropiprant group, but not in the placebo group (4.6 ± 4.4 to 6.1 ± 4.4%, p = 0.16) (p = 0.02 for comparison of interventions). GTN dilation also increased in the niacin/laropiprant group (from 12.5 ± 6.1 to 16.7 ± 4.8%, p = 0.02), but not in the placebo group (13.4 ± 5.0 to 15.1 ± 5.2%, p = 0.18), (p = 0.60 for comparison of interventions). Niacin/laropiprant reduced TC and LDL-C (p = 0.05 for both) and increased HDL-C (p < 0.001) without influencing TG, with no changes in the placebo group. Lp(a) (p = 0.026) and ApoB (p = 0.014) were significantly lower in the niacin/laropiprant group, with no difference in the placebo group. ApoA1 did not change in either of the groups (p = 0.13; p = 0.26). FMD and GTN dilation improvements did not correlate with changes in the lipid profile. Niacin/laropiprant improves endothelium-dependent and endothelium-independent dilation of the brachial artery. This improvement does not correlate with changes in lipid parameters.

Wax-matrix extended-release niacin vs inositol hexanicotinate: a comparison of wax-matrix, extended-release niacin to inositol hexanicotinate "no-flush" niacin in persons with mild to moderate dyslipidemia

BACKGROUND

Nicotinic acid (NA), long used for the treatment of dyslipidemia, has shown problems with undesirable side effects and safety issues. Wax-matrix, extended-release niacin (WMER) and inositol hexanicotinate (IHN) have both been formulated to increase patient tolerability. Several trials of WMER demonstrated good efficacy in improving dyslipidemia; however, there are few scientific data on the use of IHN.

OBJECTIVE

This study was designed to compare the efficacy and tolerability of WMER and IHN to each other and placebo to help clinicians make an informed choice of NA agents.

METHODS

This was a 6-week blinded, placebo-controlled trial comparing 1500 mg/d of WMER with 1500 mg/d IHN. Subjects with mild-to-moderate dyslipidemia (low-density lipoprotein = 130-190/dL) were randomized, after a 4-week diet lead-in period, to three parallel study arms (40 subjects/arm). Diet, pill compliance, and side effects were monitored as well as lipid and blood chemistry profiles (baseline, 6 weeks). A dose-reduction protocol was included for subjects who did not tolerate the 1500-mg dose of NA. A pharmacokinetic substudy was conducted on subjects from the WMER (n = 5) and IHN (n = 5) groups.

RESULTS

WMER demonstrated significant improvements in total cholesterol = -11%, low-density lipoprotein = -18%, high-density lipoprotein = +12%, and non-high-density lipoprotein = -15% (P < .001), whereas IHN and placebo showed no significant improvement in lipids. All groups had good medication compliance and treatment tolerance with only one dropout in the WMER group as the result of flushing. Blood chemistries showed small (24%-27%) mean increases in hepatic transaminases; six subjects completed the study at reduced dosage protocol with good lipid results. Pharmacokinetics demonstrated an intermediate release and absorption rate for WMER over 6 hours and IHN showed no evidence of bioavailability.

CONCLUSION

WMER demonstrated good tolerance and efficacy and extended-release kinetics. IHN was well tolerated but was no better than placebo in lipid improvement and showed no evidence of bioavailability.

Lipid-lowering agents in nonalcoholic fatty liver disease and steatohepatitis: human studies

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease which refers to the presence of hepatic steatosis without significant intake of alcohol. NAFLD is an asymptomatic disease that can progress to nonalcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and hepatocellular carcinoma. NAFLD is currently the most common cause of incidental abnormal liver tests and elevated serum liver enzyme activities in the developed world. Obesity, diabetes, and other components of the metabolic syndrome are frequently associated with the NAFLD. The treatment of NAFLD focuses on life-style modifications. Statins, fibrates, and other lipid-lowering agents have been proposed as effective lipid-lowering treatments in patients with NAFLD/NASH. However, clinicians are concerned that hyperlipidemic patients with NAFLD/NASH who are treated with statins could develop transaminitis. We assessed the efficacy and safety of lipid-lowering agents for NAFLD/NASH by reviewing reports of human studies including pilot, prospective, preliminary, and post hoc analysis studies on online databases during the period of 1980 to December 2012. The results of studies provide compelling evidence that lipid-lowering agents are safe and efficacious in patients with NAFLD/NASH and that some of these agents can induce a reduction in the extent of the hepatic steatosis. Well-designed randomized controlled studies of adequate size and duration with histological endpoints are needed in order to establish a suitable lipid-lowering treatment for hyperlipidemic patients with NAFLD/NASH, and for nonhyperlipidemic patients with NAFLD/NASH with a high risk for cardiovascular disease.

A systematic review on evidence of the effectiveness and safety of a wax-matrix niacin formulation

Niacin is a uniquely efficacious therapy in the treatment of dyslipidemia because of its broad spectrum of beneficial effects on every aspect of the lipid profile and because it has been shown to reduce both total mortality and coronary death. However, niacin therapy is hindered by its side-effect profile, which appears to be dependent on its formulation with immediate-release niacin, associated with a greater incidence of flushing, and sustained-release niacin, associated with greater liver function test (LFT) abnormalities and hepatotoxicity. One such sustained-release niacin nutritional supplement formulation, Endur-acin (Endurance Products Company, Tigard, OR), claims to have clinical evidence to support its use in the treatment of dyslipidemias, which prompted us to systematically review the literature. We identified four published papers in which the authors reported the results of two separate clinical trials and one pharmacokinetic study that fulfilled the inclusion criteria and were included in this review. Endur-acin significantly reduced total cholesterol, low-density lipoprotein cholesterol, and total cholesterol/high-density lipoprotein cholesterol ratio with mean reductions up to 19%, 26%, and 20%, respectively, at a dose of 2000 mg/day. Less-impressive benefits were also seen with high-density lipoprotein cholesterol (+10%) and serum triglycerides (-23%). Mean LFT elevations of up to 1.6-fold were seen at the 2000 mg per day dose, however, not exceeding three times the upper limit of normal, with abnormal results occurring at similar frequency in placebo and one patient experiencing marked gastrointestinal symptoms and a hepatitis-like syndrome with reversible elevated LFT. Short-term randomized controlled trials suggest Endur-acin is effective in modifying serum lipids, although study limitations prevent a comprehensive evaluation of safety.

Statins and their interactions with other lipid-modifying medications: safety issues in the elderly

Inhibitors of the enzyme 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, commonly known as statins, are widely used in both primary and secondary prevention of occlusive cardiovascular disease. Statins are effective not only in improving total and low-density lipoprotein cholesterol concentrations in blood but also in decreasing morbidity and mortality associated with cardiovascular diseases resulting from underlying atheroma. There is, however, evidence that statins are underutilized in elderly patients, possibly due to concerns about safety/tolerability issues or potential drug interactions, including interactions with other lipid-modifying medications, or both. In this review, we summarize the major adverse events associated with statin use, with particular reference to the elderly patient, including factors which might increase the risk of adverse effects. Potential drug interactions between statins and other lipid-modifying medications including fibrates, ezetimibe, nicotinic acid, bile acid sequestrants and omega-3-acid ethyl esters (fish oils) are specifically discussed. Clinical management strategies to avoid these drug interactions are outlined.

The emerging role of HDL in glucose metabolism

A low plasma level of HDL cholesterol is an atherosclerotic risk factor; however, emerging evidence suggests that low HDL levels might also contribute to the pathophysiology of type 2 diabetes mellitus (T2DM) through direct effects on plasma glucose. In the past decade, animal and clinical studies have uncovered a previously undescribed spectrum of HDL actions, indicating that HDL may control glucose homeostasis through mechanisms including insulin secretion, direct glucose uptake by muscle via the AMP-activated protein kinase, and possibly enhanced insulin sensitivity. These effects are mediated by multiple cell types via mechanisms including preservation of cell function through cellular lipid removal and also via direct signaling events. We suggest a paradigm shift from HDL being a bystander to being an active player in diabetic pathophysiology, which raises the possibility that HDL elevation could be a novel therapeutic avenue for T2DM. The entry of HDL-raising agents of the cholesteryl ester transfer protein (CETP) inhibitor class into late-phase clinical trials creates potential for rapid clinical translation. This Review will discuss the emerging evidence for a role of HDL-mediated glucose regulation in the pathophysiology of T2DM, and will also outline the therapeutic potential for HDL elevation for the prevention and management of T2DM.

Lipid lowering for secondary prevention of cardiovascular disease in older adults

A perceived lack of evidence for benefit and safety concerns may lead to underprescription of HMG-CoA reductase inhibitors (statins) in older adults. This article reviews clinical data regarding the effect of lipid-lowering therapies on cardiovascular outcomes in older adults with a focus on secondary prevention and safety considerations in this population. A literature search of the PubMed database (January 1984 to April 2009) was performed using search terms that included: 'aged' (MeSH heading), 'elderly', 'anticholesteremic agents', 'antilipemic agents', 'hydroxymethylglutaryl-CoA reductase inhibitors', 'cardiovascular diseases', 'randomized controlled trial', 'meta-analysis' and 'drug safety'. Results from large, randomized, controlled trials show that statin therapy lowers both all-cause and coronary heart disease mortality and reduces myocardial infarction, stroke and the need for revascularization in individuals aged ≥65 years who have a history of coronary heart disease. Given the high rate of recurrent cardiovascular events in older adults, there is substantial potential for statin treatment to provide benefits in this population. When older patients are prescribed statins, attention should be given to potential drug interactions, age-related changes in drug pharmacokinetics, adverse effects such as myopathy and risks arising from co-morbid conditions. Additional studies on the benefits and risks of lipid-lowering therapy in individuals aged ≥70 years who have no history of cardiovascular disease, and particularly in those aged ≥80 years, are needed. Other available lipid-modifying drugs - bile acid sequestrants (bile acid binding protein modulators), ezetimibe, niacin and fibrates (fibric acid derivatives) - may be required in patients who are statin-intolerant or have mixed dyslipidaemia, or in whom standard doses of statins may not be sufficient to achieve low-density lipoprotein cholesterol goals.

Recent advances in the treatment of atherogenic dyslipidemia in type 2 diabetes mellitus

Despite best treatment efforts reducing low-density lipoprotein cholesterol, a substantial number of type 2 diabetes mellitus patients still experience progression of cardiovascular risk. Even with intensification of statin therapy, a substantial residual cardiovascular risk remains and atherogenic dyslipidemia is an important driver of this so-called residual risk. Besides statin therapy, new strategies evaluate the role of intensive combination lipid treatment for the entire type 2 diabetic population. The results from the ACCORD (Action to Control Cardiovascular Risk in Diabetes) Lipid trial suggest that there is a lipid-related modifiable component to cardiovascular residual risk in statin-treated type 2 diabetic patients, and that further research should address patients with triglycerides above 204 mg/dl and high-density lipoprotein cholesterol below 34 mg/dl. Based on their respective lipid-modifying activity, the combination of a fibrate and statin is a logical approach to improving achievement of lipid targets in statin-treated patients with a glomerular filtration rate of >60 ml/min/1.73 m(2) and with residual atherogenic dyslipidemia. The link between dyslipidemia treatment and diabetic retinopathy, nephropathy and neuropathy is an emerging new field and microvascular complications are targets for new treatments.

Important considerations for treatment with dietary supplement versus prescription niacin products

Niacin is a water-soluble B vitamin (B3) known to have favorable effects on multiple lipid parameters, including raising high-density lipoprotein cholesterol (HDL-C) levels and lowering triglycerides (TGs), lipoprotein(a), and low-density lipoprotein cholesterol (LDL-C). Although LDL-C remains the primary target of lipid-altering therapy, current guidelines emphasize HDL-C and other modifiable lipid factors as key secondary targets. Thus, niacin is considered an important therapeutic option to help reduce the risk of cardiovascular disease in patients with mixed dyslipidemia who, in addition to high LDL-C, have elevated TGs and low HDL-C. Although available prescription niacin products, including immediate-release niacin (IR; Niacor) and an extended-release niacin formulation (Niaspan), have demonstrated safety and efficacy in randomized clinical trials, confusion remains among health care providers and their patients regarding the various commercially available nonprescription dietary supplement niacin products. These dietary supplements, which include IR, sustained-release (SR), and "no-flush" or "flush-free" niacin products, are not subject to the same stringent US Food and Drug Administration regulations as prescription drugs. In fact, both the American Heart Association and the American Pharmacists Association recommend against the use of dietary supplement niacin as a substitute for prescription niacin. Although some dietary supplement IR and SR niacin products have demonstrated a lipid response in clinical trials, products labeled as "no-flush" or "flush-free" that are intended to avoid the common niacin-associated adverse effect of flushing generally contain minimal or no free, pharmacologically active niacin and therefore lack beneficial lipid-modifying effects. To clarify important differences between available prescription and dietary supplement niacin products, this article contrasts current regulatory standards for dietary supplements and prescription drugs and provides an overview of available clinical data from key trials of niacin.

Lipid control in patients with diabetes mellitus

Patients with diabetes mellitus are at increased risk of cardiovascular disease (CVD). Dyslipidemia, an important component of the insulin resistance syndrome and type 2 diabetes, is strongly related to CVD risk and is open to therapeutic intervention. Statins have proved to be safe, very-well tolerated, and highly effective in reducing the levels of LDL cholesterol and apolipoprotein B. Primary and secondary CVD prevention trials have shown that use of statins leads to highly significant reductions in the incidence of major CVD events. A wealth of data on the outcomes of statin therapy is now available to guide clinical practice in the population of patients with type 2 diabetes. Statin therapy in patients with type 1 diabetes seems to have a similar benefit to that seen in patients with type 2 diabetes. However, despite statin therapy, high CVD risk persists in these populations. More-intensive statin therapy produces greater reduction in the incidence of CVD events, but a more-global approach to lipid management is likely to result in further risk reduction. After reductions in the levels of LDL cholesterol and apolipoprotein B, the next target of lipid-lowering therapy is to increase HDL-cholesterol levels, which tend to be low in patients with type 2 diabetes. The most effective HDL-cholesterol-raising agent currently available for use in clinical practice is niacin. Trials with surrogate end points have pointed to the cardiovascular benefit of adding niacin to statin therapy. Large CVD end point trials, which include many patients with diabetes, are underway to test the combination of a statin and niacin versus a statin alone.

Laboratory markers of cardiovascular risk in pediatric SLE: the APPLE baseline cohort

As part of the Atherosclerosis Prevention in Pediatric Lupus Erythematosus (APPLE) Trial, a prospective multicenter cohort of 221 children and adolescents with systemic lupus erythematosus (SLE) (mean age 15.7 years, 83% female) underwent baseline measurement of markers of cardiovascular risk, including fasting levels of high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides (TG), lipoprotein A (Lpa), homocysteine and high-sensitivity C-reactive protein (hs-CRP). A cross-sectional analysis of the baseline laboratory values and clinical characteristics of this cohort was performed. Univariable relationships between the cardiovascular markers of interest and clinical variables were assessed, followed by multivariable linear regression modeling. Mean levels of LDL, HDL, Lpa, TG, hs-CRP and homocysteine were in the normal or borderline ranges. In multivariable analysis, increased Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), prednisone dose, and hypertension (HTN) were independently associated with higher LDL levels. Higher hs-CRP and creatinine clearance were independently related to lower HDL levels. Higher body mass index (BMI), prednisone dose, and homocysteine levels were independently associated with higher TG levels. Only Hispanic or non-White status predicted higher Lpa levels. Proteinuria, higher TG and lower creatinine clearance were independently associated with higher homocysteine levels, while use of multivitamin with folate predicted lower homocysteine levels. Higher BMI, lower HDL, and longer SLE disease duration, but not SLEDAI, were independently associated with higher hs-CRP levels. The R(2) for these models ranged from 7% to 23%. SLE disease activity as measured by the SLEDAI was associated only with higher LDL levels and not with hs-CRP. Markers of renal injury (HTN, proteinuria, and creatinine clearance) were independently associated with levels of LDL, HDL, and homocysteine, highlighting the importance of renal status in the cardiovascular health of children and adolescents with SLE. Future longitudinal analysis of the APPLE cohort is needed to further examine these relationships.

New evidence for nicotinic acid treatment to reduce atherosclerosis

Nicotinic acid (at a daily dose of grams) has been shown to induce potent anti-atherosclerotic effects in human and animal models. Evidence from clinical studies performed in the 1950s has shown that nicotinic acid treatment remarkably improves the plasma lipid profile. Large clinical studies showed that nicotinic acid improves clinical cardiovascular outcomes. Given the protective effects of niacin, basic research studies were designed to explore additional anti-atherosclerotic pathways, such as those involved in cardiovascular inflammation. After the discovery of the nicotinic acid receptor GPR109A on adipocytes and immune cells, novel direct immunomodulatory properties of nicotinic acid have been identified. Importantly, the regulation of the release of inflammatory mediators from adipose tissue was observed, independent of lipid level amelioration. Less is known about the possible direct anti-inflammatory activities of nicotinic acid in other cells (such as hepatocytes, endothelial and vascular cells) previously indicated as key players in atherogenesis. Thus, further studies are needed to clarify this promising topic. Emerging evidence from clinical and basic research studies indicates that novel direct anti-atherosclerotic properties might mediate nicotinic acid-induced cardiovascular protection. Despite some limitations in its clinical use (mainly due to the incidence of adverse events, such as cutaneous flushing and hepatotoxicity), nicotinic acid should be considered as a very potent therapeutic approach to reduce atherosclerosis. Promising research developments are warranted in the near future.

Pharmacological effects of lipid-lowering drugs on circulating adipokines

The cardioprotective effects of lipid-lowering drugs have been primarily attributed to their effects on blood lipid metabolism. However, emerging evidence indicates that lipid-lowering drugs also modulate the synthesis and secretion of adipose tissue-secreted proteins referred to as adipokines. Adipokines influence energy homeostasis and metabolism and have also been shown to modulate the vascular inflammatory cascade. The purpose of this review will be to examine the reported effects of commonly used lipid-lowering drugs (statins, fibrates, niacin and omega-3-fatty acids) on the circulating concentrations of leptin, adiponectin, tumor necrosis-factor-α (TNF-α), Retinol binding protein 4 (RBP4) and resistin. Overall, the lipid-lowering drugs reviewed have minimal effects on leptin and resistin concentrations.Conversely, circulating adiponectin concentrations are consistently increased by each lipid-lowering drug reviewed with the greatest effects produced by niacin. Studies that have examined the effects of statins, niacin and omega-3-fatty acids on TNF-α demonstrate that these agents have little effect on circulating TNF-α concentrations. Niacin and fibrates appear to lower RBP4 but not resistin concentrations. The results of the available studies suggest that a strong relationship exists between pharmacological reductions in blood lipids and adiponectin that is not obvious for other adipokines reviewed.

Pyrido pyrimidinones as selective agonists of the high affinity niacin receptor GPR109A: optimization of in vitro activity

Pyrido pyrimidinones are selective agonists of the human high affinity niacin receptor GPR109A (HM74A). They show no activity on the highly homologous low affinity receptor GPR109B (HM74). Starting from a high throughput screening hit the in vitro activity of the pyrido pyrimidinones was significantly improved providing lead compounds suitable for further optimization.

Niacin and fibrates in atherogenic dyslipidemia: pharmacotherapy to reduce cardiovascular risk

Although statin therapy represents a cornerstone of cardiovascular disease (CVD) prevention, a major residual CVD risk (60-70% of total relative risk) remains, attributable to both modifiable and non-modifiable risk factors. Among the former, low levels of HDL-C together with elevated triglyceride (TG)-rich lipoproteins and their remnants represent major therapeutic targets. The current pandemic of obesity, metabolic syndrome, and type 2 diabetes is intimately associated with an atherogenic dyslipidemic phenotype featuring low HDL-C combined with elevated TG-rich lipoproteins and small dense LDL. In this context, there is renewed interest in pharmacotherapeutic strategies involving niacin and fibrates in monotherapy and in association with statins. This comprehensive, critical review of available data in dyslipidemic subjects indicates that niacin is more efficacious in raising HDL-C than fibrates, whereas niacin and fibrates reduce TG-rich lipoproteins and LDL comparably. Niacin is distinguished by its unique capacity to effectively lower Lp(a) levels. Several studies have demonstrated anti-atherosclerotic action for both niacin and fibrates. In contrast with statin therapy, the clinical benefit of fibrates appears limited to reduction of nonfatal myocardial infarction, whereas niacin (frequently associated with statins and/or other agents) exerts benefit across a wider range of cardiovascular endpoints in studies involving limited patient numbers. Clearly the future treatment of atherogenic dyslipidemias involving the lipid triad, as exemplified by the occurrence of the mixed dyslipidemic phenotype in metabolic syndrome, type 2 diabetes, renal, and auto-immune diseases, requires integrated pharmacotherapy targeted not only to proatherogenic particles, notably VLDL, IDL, LDL, and Lp(a), but also to atheroprotective HDL.

Extended-release niacin (nicotinic acid)/laropiprant

Extended-release (ER) niacin (nicotinic acid)/laropiprant is a once-daily fixed-dose combination tablet that has been evaluated (with or without an HMG-CoA reductase inhibitor [statin]) in the treatment of adults with dyslipidaemia or primary hypercholesterolaemia. Niacin (vitamin B3) is a lipid-modifying drug and laropiprant is an anti-flushing agent, which reduces flushing induced by niacin. In a randomized, double-blind, placebo-controlled, multicentre, 24-week trial, a significant (p < 0.001) reduction (18.4%) in plasma low-density lipoprotein cholesterol (LDL-C) levels (primary endpoint) was achieved with ER niacin/laropiprant 2000 mg/40 mg once daily (after an initial 4-week 1000 mg/20 mg once-daily regimen) compared with placebo (weeks 12-24) in adults with primary hypercholesterolaemia or mixed dyslipidaemia. ER niacin/laropiprant 2000 mg/40 mg plus simvastatin 20 mg or 40 mg once daily (after an initial 4-week lower-dose regimen) produced significant (p < 0.05) improvements, from baseline, in LDL-C levels (primary endpoint) compared with once-daily ER niacin/laropiprant 2000 mg/40 mg or simvastatin alone at week 12 in a randomized, double-blind, multicentre, factorial trial in adults with primary hypercholesterolaemia or mixed dyslipidaemia. The incidence and intensity of flushing (an efficacy endpoint) were significantly (p < 0.05) reduced with ER niacin/laropiprant compared with ER niacin in randomized trials. ER niacin/laropiprant, alone or in combination with a statin, was generally well tolerated for up to 24 weeks by adults with dyslipidaemia or primary hyercholesterolaemia.

Drug-induced hepatotoxicity or drug-induced liver injury

Drug-induced hepatotoxicity is underreported and underestimated in the United States. It is an important cause of acute liver failure. Common classes of drugs causing drug-induced hepatotoxicity include antibiotics, lipid lowering agents, oral hypoglycemics, psychotropics, antiretrovirals, acetaminophen, and complementary and alternative medications. Hepatotoxic drugs often have a signature or pattern of liver injury including patterns of liver test abnormalities, latency of symptom onset, presence or absence of immune hypersensitivity, and the course of the reaction after drug withdrawal.

Niacin extended-release/simvastatin

Niacin extended-release (ER)/simvastatin is a once-daily, fixed-dose combination of the HMG-CoA reductase inhibitor simvastatin and an ER formulation of niacin (a B-complex vitamin). In healthy volunteers who were given niacin ER/simvastatin 2000 mg/40 mg, niacin exposure was similar to that with niacin ER 2000 mg, while simvastatin exposure was increased compared to that with simvastatin 40 mg. In patients with elevated non-high-density lipoprotein cholesterol (non-HDL-C) but with low-density lipoprotein cholesterol (LDL-C) at or below the National Cholesterol Education Program (NCEP) goal after a > or = 2-week simvastatin 20 mg/day run-in period (SEACOAST I), 24 weeks of niacin ER/simvastatin 1000 mg/20 mg or 2000 mg/20 mg per day reduced median plasma non-HDL-C levels to a significantly greater extent than simvastatin 20 mg/day. In patients with elevated non-HDL-C and LDL-C at any level after a > or = 2-week simvastatin 40 mg/day run-in period (SEACOAST II), 24 weeks of niacin ER/simvastatin 1000 mg/40 mg or 2000 mg/40 mg per day was noninferior to simvastatin 80 mg/day in reducing median plasma non-HDL-C levels. Compared with simvastatin monotherapy, there was no significant difference in reduction in plasma LDL-C levels with niacin ER/simvastatin in SEACOAST I, and the noninferiority criterion for LDL-C was not met in SEACOAST II. However, plasma HDL-C levels increased more and triglyceride levels were lowered more than with simvastatin monotherapy (SEACOAST I and II). Niacin ER/simvastatin was generally well tolerated, with flushing being the most common adverse reaction.

Effects of niacin on cell adhesion and early atherogenesis: biochemical and functional findings in endothelial cells

Atherosclerotic cardiovascular disease is a major cause of morbidity and mortality. Increased expression of cell adhesion molecules (CAM) and their ligands mediate essential processes in atherogenesis. Niacin reduces atherosclerotic cardiovascular complications and total mortality. Further understanding is needed on effects of niacin on CAM, and its functional consequences. The aim of this study was to evaluate the effects of niacin on CAM expression and monocyte adhesion in endothelial cells. Endothelial cells (HUVEC) were cultured to reach 80-90% confluence before experiments were initiated. Cells were exposed to DME/F12 with selected concentrations of niacin. To elicit the expression of CAM, cells were stimulated by addition of tumour necrosis factor (TNF)-alpha, interleukin (IL)-1 or interferon-gamma. Lysate from the conditioned media was assayed for CAM. The effect of niacin on mRNA expression of ICAM-1 was studied using semi-quantitative analysis of ICAM-1 mRNA. Adhesion assays were performed with flow cytometry to study the functional significance of the effects niacin on CAM expression. Niacin significantly reduced ICAM-1 and PECAM-1 protein levels basally, and reduced the cytokine-induced rise in ICAM-1, with a similar effect for TNF-alpha-induced PECAM-1 rise. The decrease in TNF-alpha-induced rise in ICAM-1 level was associated with a reduction of NF-kappaB activation, a reduction in mRNA expression of ICAM-1, and a functional reduction in monocyte adhesion to cultured endothelial cells. Niacin reduces CAM expression and monocyte adhesion to endothelial cells. Apart from its lipid-modifying effects, these pleiotropic effects of niacin may potentially contribute to the beneficial effects of risk reduction for atherosclerotic disease.

A review of the current status of the management of mixed dyslipidemia associated with diabetes mellitus and metabolic syndrome

Current treatment guidelines recommend lowering elevated low-density lipoprotein (LDL) cholesterol levels with a statin as the primary lipid-modifying intervention to reduce cardiovascular risk in patients with type 2 diabetes mellitus or metabolic syndrome. However, even with high-dose statin therapy or the combination of statin plus ezetimibe, many patients remain at substantial risk of a cardiovascular event. Increasingly, there is recognition of the importance of treating all components of the atherogenic dyslipidemic profile associated with both conditions, specifically low high-density lipoprotein cholesterol and elevated triglyceride levels, in addition to lowering LDL cholesterol. Both niacin (nicotinic acid) and fibrates are recommended as options for combination with a statin in this setting. Data from ongoing prospective outcomes studies are needed to evaluate the efficacy and safety of these combinations.

Lipid lowering in diabetes mellitus

PURPOSE OF REVIEW

The purpose of this review is to present recent information on lipid lowering in diabetes mellitus. New information from randomized clinical trials will be discussed together with implications for clinical practice. Residual risk persists despite statin therapy and additional approaches, particularly in relation to increasing HDL cholesterol will be discussed.

RECENT FINDINGS

Recent RCTS have shown evidence of benefit and safety of more intensive LDL cholesterol lowering in patients with diabetes and established cardiovascular disease supporting guidelines for a more intensive LDL goal of therapy. A recent meta-analysis has confirmed benefit on major coronary events and ischaemic stroke in many diabetic patient subgroups, including those with type 1 disease.Despite statin treatment, cardiovascular disease residual risk remains high. After LDL the next lipoprotein goal is to increase HDL. Although there has been disappointment with the first cholesterol ester transfer protein inhibitor, there is encouraging evidence that increasing HDL with the peroxisome proliferator activator receptor (PPAR) gamma agonist, pioglitazone and nicotinic acid derivatives may contribute beyond statin therapy.

SUMMARY

In summary the benefits of statin therapy in diabetes has been confirmed and extended such that the overwhelming majority of diabetic patients should be considered for this therapy. Increasing HDL might provide additional benefit that may further reduce cardiovascular disease risk.

A quercetin containing supplement reduces niacin-induced flush in humans

Coronary artery disease is associated with increased serum levels of cholesterol, triglycerides and LDL, but low levels of HDL. The most potent agent capable of reversing this trend is the vitamin nicotinic acid (niacin). However, compliance even with extended-release preparations and addition of acetylsalicylic acid (ASA) is hampered by the development of a feeling of erythema and burning ("flush"), especially on the face. We recently showed that the natural flavonoids quercetin and luteolin can eliminate "flush", as well as inhibit both niacin-induced plasma prostaglandin D2 (PGD2) and serotonin increase in an animal model. We conducted a pilot clinical study in humans. Four normal male subjects received (a) 1 g immediate release niacin either alone or after (b) the dietary formulation (Algonot-plus) containing 150 mg quercetin per capsule. Subjects completed a visual scale (1 = no, 5 = worst response) symptom assessment. Erythema and burning sensation scores were both 4.75+/-0.50 and lasted for 3.63+/-1.11 hours. After Algonot-plus administration, both scores were reduced to 2.5+/-0.58 and lasted only for 1.68+/-0.70 hours. Quercetin also inhibited methylnicotinate-induced human mast cell PGD2 release. These preliminary results suggest that quercetin could reduce niacin-induced "flush" in humans.

The Residual Risk Reduction Initiative: a call to action to reduce residual vascular risk in dyslipidaemic patient

Despite current standards of care aimed at achieving targets for low-density lipoprotein (LDL) cholesterol, blood pressure and glycaemia, dyslipidaemic patients remain at high residual risk of vascular events. Atherogenic dyslipidaemia, specifically elevated triglycerides and low levels of high-density lipoprotein (HDL) cholesterol, often with elevated apolipoprotein B and non-HDL cholesterol, is common in patients with established cardiovascular disease, type 2 diabetes, obesity or metabolic syndrome and is associated with macrovascular and microvascular residual risk. The Residual Risk Reduction Initiative (R3I) was established to address this important issue. This position paper aims to highlight evidence that atherogenic dyslipidaemia contributes to residual macrovascular risk and microvascular complications despite current standards of care for dyslipidaemia and diabetes, and to recommend therapeutic intervention for reducing this, supported by evidence and expert consensus. Lifestyle modification is an important first step. Additionally, pharmacotherapy is often required. Adding niacin, a fibrate or omega-3 fatty acids to statin therapy improves achievement of all lipid risk factors. Outcomes studies are evaluating whether these strategies translate to greater clinical benefit than statin therapy alone. In conclusion, the R3I highlights the need to address with lifestyle and/or pharmacotherapy the high level of residual vascular risk among dyslipidaemic patients who are treated in accordance with current standards of care.

Niacin-induced "flush" involves release of prostaglandin D2 from mast cells and serotonin from platelets: evidence from human cells in vitro and an animal model

Niacin lowers serum cholesterol, low-density lipoprotein, and triglycerides, and it raises high-density lipoprotein. However, most patients experience cutaneous warmth and vasodilation (flush). Acetylsalicylic acid (ASA) can reduce this flush, presumably by decreasing prostaglandin D(2) (PGD(2)) release from macrophages. Here, we show that methylnicotinate induces significant PGD(2) release from human mast cells and serotonin from human platelets. Intradermal injection of methylnicotinate induces rat skin vasodilation and vascular permeability. Niacin increases plasma PGD(2) and serotonin in a rat model of flush. The phenothiazine prochlorperazine, the H(1), serotonin receptor antagonist cyproheptadine, and the specific serotonin receptor-2A antagonist ketanserin inhibit niacin-induced temperature increase by 90% (n = 5, p < 0.05), 90 and 50% (n = 3, p < 0.05), and 85% (n = 6, p = 0.0008), respectively, in this animal model. These results indicate that niacin-induced flush involves both PGD(2) and serotonin, suggesting that drugs other than ASA are required to effectively inhibit niacin-induced flush.

Effects of oral niacin on endothelial dysfunction in patients with coronary artery disease: results of the randomized, double-blind, placebo-controlled INEF study

High-density-lipoproteins-cholesterol (HDL-C) is invertedly related to the incidence of cardiovascular events. Recent studies suggest that HDL-C directly improves endothelial function. Nicotinic acid (niacin) effectively raises serum HDL-C. We therefore hypothesized that treatment with niacin improves endothelial dysfunction in patients with coronary artery disease (CAD). One hundred seven patients with CAD were randomly assigned to double-blinded treatment for 12 weeks with extended-release (ER)-niacin 1000 mg/day (N) or placebo (C), respectively. Flow-mediated dilation (FMD) of the brachial artery, nitroglycerin-mediated endothelium-independent dilation (NMD) and serum lipid concentrations were measured before and after treatment. Triglycerides (P=0.013), low-density-lipoprotein-cholesterol (LDL-C) (P=0.013) and HDL-C (P<0.0001) were altered by N compared to C. Niacin treatment was without effect on FMD or NMD, respectively, compared to placebo. However, post-hoc subgroup analysis revealed an improvement in FMD in patients with low HDL-C at baseline (absolute change in FMD (mean+/-S.D.) N: +3.25+/-3.88%, C: +1.03+/-2.71% in low tertile HDL-C <or=45 mg/dl. P=0.047). The present findings indicate that ER-niacin treatment improves endothelial dysfunction in patients with CAD and low HDL-C, but not with normal HDL-C.

Serum lipid profiles and their relationship to cardiovascular disease in the elderly: the PREV-ICTUS study

OBJECTIVE

To assess the relationship between different serum lipid profiles and the prevalence of established cardiovascular disease (CVD) in an elderly population.

RESEARCH DESIGN AND METHODS

An analysis was undertaken of the PREV-ICTUS population-based study on Spanish subjects aged > or =60 years. The following definitions were used: abnormal LDL cholesterol (LDL-C): > or =130 mg/dl (> or =3.3 mmol/L), or > or =100 mg/dl (> or =2.5 mmol/L) in those with diabetes or CVD, or treatment with any hypolipidaemic drug; low HDL cholesterol (HDL-C): <40 mg/dl (<1 mmol/L) (men), or <50 mg/dl (<1.3 mmol/L) (women), and abnormal triglycerides (TG): > or =150 mg/dl (> or =1.7 mmol/L) or treatment with fibrates. We defined eight groups: A (normal lipid profile), B (isolated abnormal LDL-C), C (isolated abnormal TG), D (isolated low HDL-C), E (abnormal LDL-C and HDL-C), F (abnormal LDL-C and TG), G (abnormal TG and HDL-C), H (abnormal LDL-C, HDL-C and TG). A multivariate analysis was performed to assess the relationship between each lipid profile and CVD.

RESULTS

A total of 6010 subjects (mean age 71.7 years, 53.5% women, 73.2% with hypertension, 29.2% with diabetes mellitus, 24.3% with CVD), were included in the analysis. LDL-C elevation was present in 78.1%, 23.3% had low HDL-C and 35.7% abnormal TG. Combined dyslipidaemias were frequent (40.3%). Odds ratios (95% confidence intervals) for CVD, compared with those with a normal lipid profile, were 2.07 (1.24-3.46) for abnormal HDL-C (p = 0.005), 4.09 (3.10-5.39) for abnormal LDL-C; 6.41 (4.59-8.95) for abnormal LDL-C plus HDL-C, 5.33 (3.98-7.14) for abnormal LDL-C plus TG and 7.59 (5.51-10.5) for those with the three parameters altered (all p < 0.001). Compared with those with isolated LDL-C elevation, those with abnormal LDL-C plus HDL-C had 1.57 (1.30-1.97) higher odds of having CVD (p < 0.001), the figures being 1.30 (1.11-1.53) for those with abnormal LDL-C plus TG and 1.86 (1.52-2.28) for those with abnormal LDL-C, TG plus HDL-C (p < 0.001).

CONCLUSIONS

Lipid abnormalities are frequent in the elderly, and are associated with the presence of CVD. Low HDL-C and/or abnormal TG levels, when added to abnormal LDL-C, are associated with a higher prevalence of CVD, suggesting the advisability of a comprehensive lipid evaluation and treatment earlier in life.

Comparison of the efficacy and safety of a combination tablet of niacin extended-release and simvastatin with simvastatin 80 mg monotherapy: the SEACOAST II (high-dose) study

BACKGROUND

The number of patients with multiple lipid abnormalities is increasing. Lipid treatment guidelines are established for low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol (non-HDL-C). The importance of treating HDL-C and triglycerides is gaining recognition.

OBJECTIVE

To determine, in patients who had been treated previously with simvastatin 40 mg/day, the efficacy, safety, and tolerability of two regimens of a combination of proprietary niacin, extended-release core, coated with 40 mg/day simvastatin (NER/S), compared to 80 mg/day simvastatin monotherapy (S80).

METHODS

High-risk patients (n = 343) with dyslipidemia were treated for 24 weeks with NER/S (1000/40 mg/day or 2000/40 mg/day) or S80.

RESULTS

Median percentage change from baseline to week 24 in non-HDL-C in either NER/S group was noninferior to S80 (-11.3%, -17.1%, and -10.1%, respectively). Changes in LDL-C were comparable (-8.6%, -11.6%, and -12.7%, respectively). Doubling the dose of simvastatin (S80) did not alter HDL-C, triglycerides, or lipoprotein(a); however, both NER/S doses resulted in significant improvements in all three parameters (+21.9%, -31.8%, and -21.0%, respectively, for NER/S 2000/40 mg/day). The safety of NER/S was consistent with the safety profile of each individual component. Treatment with both doses of NER/S was well tolerated; 59% of patients experienced flushing, 78% of flushing was mild or moderate in intensity, 49% of those who flushed during dose titration did not flush during weeks 13 to 24, and only 4.6% of patients discontinued because of flushing.

CONCLUSION

NER/S provides similar reductions in non-HDL-C and LDL-C compared to doubling the simvastatin dose to 80 mg; however, only NER/S resulted in improvements in HDL-C, triglycerides, and lipoprotein(a).

The flavonoid luteolin inhibits niacin-induced flush

BACKGROUND AND PURPOSE

Sustained release niacin effectively lowers serum cholesterol, LDL and triglycerides, while raising HDL. However, 75% of patients experience cutaneous warmth and itching known as flush, leading to discontinuation. Acetylsalicylic acid (aspirin) reduces this flush only by about 30%, presumably through decreasing prostaglandin D2 (PGD2). We investigated whether niacin-induced flush in a rat model involves PGD2 and 5-HT, and the effect of certain flavonoids.

EXPERIMENTAL APPROACH

Three skin temperature measurements from each ear were recorded with an infrared pyrometer for each time point immediately before i.p. injection with either niacin or a flavonoid. The temperature was then measured every 10 min for 60 min.

KEY RESULTS

Niacin (7.5 mg per rat, equivalent to a human dose of 1750 mg per 80 kg) maximally increased ear temperature to 1.9+/-0.2 degrees C at 45 min. Quercetin and luteolin (4.3 mg per rat; 1000 mg per human), administered i.p. 45 min prior to niacin, inhibited the niacin effect by 96 and 88%, respectively. Aspirin (1.22 mg per rat; 325 mg per human) inhibited the niacin effect by only 30%. Niacin almost doubled plasma PGD2 and 5-HT, but aspirin reduced only PGD2 by 86%. In contrast, luteolin inhibited both plasma PGD2 and 5-HT levels by 100 and 67%, respectively. CONCLUSIONS AND IMPLICATIONS. Niacin-induced skin temperature increase is associated with PGD2 and 5-HT elevations in rats; luteolin may be a better inhibitor of niacin-induced flush because it blocks the rise in both mediators.

HDL-c is a powerful lipid predictor of cardiovascular diseases

RELATIONSHIP BETWEEN HDL-C AND CARDIOVASCULAR DISEASES: Beyond the role of low-density lipoprotein cholesterol (LDL-c) in the development of atherosclerosis, growing evidence suggest that high-density lipoprotein cholesterol (HDL-c) is a powerful predictor of cardiovascular disease. Indeed, epidemiological, mechanistic and intervention studies suggest that low HDL-c is a major cardiovascular risk factor and that increasing HDL-c plasma levels may be beneficial, particularly in patients with low HDL-c levels. The inverse association between HDL-c concentrations and cardiovascular risk is continuous without threshold value. Thus, any categorical definition of low HDL-c is arbitrary. PROTECTIVE EFFECTS OF HDL: HDL particles are highly heterogeneous in structure and intravascular metabolism. Antiatherogenic properties of HDL include its role in the reverse cholesterol transfer, besides its antioxidant, anti-inflammatory and antiapoptotic activities. WHAT SHOULD CLINICIANS DO?: From a practical point of view, HDL-c should be systematically measured to assess the cardiovascular risk in patients. The first step to consider in subjects with low HDL-c is to look for specific causes and give advice to change inappropriate lifestyle components associated with low HDL-c, such as smoking, lack of physical exercise and overweight. Patients with very low HDL-c need a thorough evaluation by specialist physicians. Statins are associated with a modest increase of HDL-c (5%) while fibrates and nicotinic acid increase HDL-c by 10% and 20% respectively.

Toxicity From the Use of Niacin to Beat Urine Drug Screening

Niacin (vitamin B3) is promoted for rapidly clearing the body of drugs of abuse, such as cocaine and cannabis, and is alleged to interfere with urine drug screening. We present 4 cases of such novel use associated with significant adverse effects. Two cases had isolated skin manifestations, whereas the other 2 presented with life-threatening manifestations, including nausea, vomiting, dizziness, hepatotoxicity, metabolic acidosis, and hypoglycemia evolving into hyperglycemia. One patient also had profound neutrophilia and QT(C)-interval prolongation. All patients improved after cessation of the drug use and supportive treatment. Health care providers should be aware of these potential adverse effects of niacin and of the misguided use of this vitamin by patients seeking to interfere with urine drug screening.

Cost-effectiveness of raising HDL cholesterol by adding prolonged-release nicotinic acid to statin therapy in the secondary prevention setting: a French perspective

AIM

To evaluate the cost-effectiveness of raising high-density lipoprotein cholesterol (HDL-C) with add-on nicotinic acid in statin-treated patients with coronary heart disease (CHD) and low HDL-C, from the French healthcare system perspective.

METHODS AND RESULTS

Computer simulation economic modelling incorporating two decision analytic submodels was used. The first submodel generated a cohort of 2000 patients and simulated lipid changes using baseline characteristics and treatment effects from the ARterial Biology for the Investigation of the Treatment Effects of Reducing cholesterol (ARBITER 2) study. Prolonged-release (PR) nicotinic acid (1 g/day) was added in patients with HDL-C < 40 mg/dl (1.03 mmol/l) on statin alone. The second submodel used standard Markov techniques to evaluate long-term clinical and economic outcomes based on Framingham risk estimates. Direct medical costs were accounted from a third party payer perspective [2004 Euros (euro)] and discounted by 3%. Addition of PR nicotinic acid to statin therapy resulted in substantial health gain and increased life expectancy, at a cost well within the threshold (< 50,000 euros per life year gained) considered good value for money in Western Europe.

CONCLUSIONS

Raising HDL-C by adding PR nicotinic acid to statin therapy in CHD patients was cost-effective in France at a level considered to represent good value for money by reimbursement authorities in Europe. This strategy was highly cost-effective in CHD patients with type 2 diabetes.

HDL-C in post-menopausal women: An important therapeutic target

Coronary heart disease is a major cause of mortality in women in Western industrialised countries, particularly after the age of 50 years, coinciding with the onset of the menopause and potentially adverse metabolic changes that occur during the transitional peri-menopausal and post-menopausal periods. Dyslipidaemia characterised by increases in plasma levels of low-density lipoprotein cholesterol (LDL-C), triglycerides and lipoprotein(a) and a decrease in high-density lipoprotein cholesterol (HDL-C) together with the emergence of other diagnostic features of the metabolic syndrome are key factors that increase cardiovascular risk. Treatment beyond LDL-C with a combination of different lipid-modifying therapies may therefore be of greater importance in women than men. Fibrates and nicotinic acid are two treatments that may be added to primary statin therapy. Fibrates are more effective in lowering elevated triglycerides, whereas nicotinic acid is more effective in raising HDL-C. Although there is clearly a need for clinical trials in women, the available data suggests that combination lipid-modifying therapy is a logical treatment strategy in this high-risk patient group.

Postprandial lipemia: an under-recognized atherogenic factor in patients with diabetes mellitus

Atherosclerotic disease is the leading cause of both morbidity and mortality in patients with type 2 diabetes. In these patients, postprandial dyslipidemia include not only quantitative but also qualitative abnormalities of lipoproteins which are potentially atherogenic and seems to be a significant risk factor for cardiovascular disease since there is evidence that it results in endothelial dysfunction and enhanced oxidative stress. The most common pattern of postprandial dyslipidemia in diabetes consists of high concentrations of triglycerides, higher VLDLs production by the liver and a decrease in their clearance, a predominance of small dense LDL particles, and reduced levels of HDL. The cause of this postprandial dyslipidemia in diabetes is complex and involves a variety of factors including hyperinsulinemia, insulin resistance, hyperglycemia and disturbed fatty acid metabolism. Numerous clinical studies have shown that postprandial dyslipidemia is associated with endothelial dysfunction in type 2 diabetes and with alterations in other surrogate markers in the cascade of atherosclerosis. Current published guidelines indicate that in diabetics the primary lipid target is LDL<100 mg/dL (70 mg/dL in very high-risk patients) and the most appropriate class of drugs are statins although the issue of postprandial dyslipidemia has not been specifically addressed so far. Moreover, several other classes of medications (fibrates, niacin and antidiabetic drugs) as well as non-pharmacological interventions (i.e. diet, smoking cessation and exercise) can be used to treat lipid and lipoprotein abnormalities associated with insulin resistance and type 2 diabetes. These type of interventions may be more appropriate to ameliorate postprandial dyslipidemia. However, this remains to be confirmed on clinical grounds.

Lipid-lowering agents that cause drug-induced hepatotoxicity

The effort to reduce cardiovascular risk factors, including hyperlipidemia, has led to the increased use of lipid-lowering agents. Hyperlipidemic patients often have underlying fatty liver disease, however, and thus may have elevated and fluctuating liver biochemistries. Therefore, caution should be applied before attributing elevated liver tests to lipid-lowering agents. Data indicate that patients who have chronic liver disease and compensated cirrhosis should not be precluded from receiving statins to treat hyperlipidemia. Several recent studies and expert opinion currently fully endorse statin use in patients who have nonalcoholic fatty liver disease and other chronic liver disease if clinically indicated.