The Effects of Statin and Fibrate on Lowering Small Dense LDL- Cholesterol in Hyperlipidemic Patients with Type 2 Diabetes

Fibrate and the risk of cardiovascular disease among moderate chronic kidney disease patients with primary hypertriglyceridemia

Introduction

Hypertriglyceridemia is the most prevalent dyslipidemia in patients with chronic kidney disease (CKD). However, research about fibrate treatment in CKD patients is limited, and assessing its benefits becomes challenging due to the frequent concurrent use of statins. Thus, this study is aimed to investigate the role of fibrate in CKD stage 3 patients with hypertriglyceridemia who did not receive other lipid-lowering agents.

Methods

This study enrolled patients newly diagnosed CKD3 with LDL-C<100mg/dL and had never received statin or other lipid-lowering agents from Chang Gung Research Database. The participants were categorized into 2 groups based on the use of fibrate: fibrate group and non-fibrate group (triglyceride >200mg/dL but not receiving fibrate treatment). The inverse probability of treatment weighting was performed to balance baseline characteristics.

Results

Compared with the non-fibrate group (n=2020), the fibrate group (n=705) exhibited significantly lower risks of major adverse cardiac and cerebrovascular events (MACCEs) (10.4% vs. 12.8%, hazard ratios [HRs]: 0.69, 95% confidence interval [CI]: 0.50 to 0.95), AMI (2.3% vs. 3.9%, HR: 0.52, 95% CI: 0.37 to 0.73), and ischemic stroke (6.3% vs. 8.0%, HR: 0.67, 95% CI: 0.52 to 0.85). The risk of all-cause mortality (5.1% vs. 4.5%, HR: 1.09, 95% CI: 0.67 to 1.79) and death from CV (2.8% vs. 2.3%, HR: 1.07, 95% CI: 0.29 to 2.33) did not significantly differ between the 2 groups.

Conclusion

This study suggests that, in moderate CKD patients with hypertriglyceridemia but LDL-C < 100mg/dL who did not take other lipid-lowering agents, fibrates may be beneficial in reducing cardiovascular events.

Can Concurrent Fibrate Use Reduce Cardiovascular Risks among Moderate Chronic Kidney Disease Patients Undergoing Statin Therapy? A Cohort Study

The role of fibrates in treating hypertriglyceridemia in chronic kidney disease (CKD) patients to prevent cardiovascular disease (CVD) has been insufficiently investigated. Since statin is considered the first-line treatment for dyslipidemia in CKD patients, this study aims to evaluate the role of concurrent fibrate therapy with statins among moderate CKD patients. We recruited CKD3 patients from the Chang Gung Research Database who were receiving statin treatment but had not previously been administered ezetimibe or niacin. The participants were divided into two groups based on their use of fibrates (fibrate group) or those with triglyceride levels >200 mg/dL without fibrate treatment (non-fibrate group). The fibrate group (n = 954) only exhibited a significantly lower incidence of AMI (4.4% vs. 5.4%, HR: 0.77, 95% CI: 0.61 to 0.98). The risk of major adverse cardiovascular and cerebrovascular events (14.7% vs. 15.6%, HR: 0.91, 95% CI: 0.72 to 1.15) and all-cause mortality (5.7% vs. 6.1%, HR: 0.91, 95% CI: 0.63 to 1.30) did not significantly differ between the fibrate group and the non-fibrate group (n = 2358). In moderate CKD patients, combining fibrate therapy with statins may not offer additional cardiovascular protection compared to statin alone.

Prospective randomized comparative study of the effect of pemafibrate add-on or double statin dose on small dense low-density lipoprotein-cholesterol in patients with type 2 diabetes and hypertriglyceridemia on statin therapy

AIMS/INTRODUCTION

Small dense low-density lipoprotein (sdLDL) is a more potent atherogenic lipoprotein than LDL. As sdLDL-cholesterol (C) levels are determined by triglyceride and LDL-C levels, pemafibrate and statins can reduce sdLDL-C levels. However, it remains unclear whether adding pemafibrate or increasing statin doses would more effectively reduce sdLDL-C levels in patients receiving statin therapy.

MATERIALS AND METHODS

A total of 97 patients with type 2 diabetes and hypertriglyceridemia who were treated with statins were randomly assigned to the pemafibrate 0.2 mg/day addition or statin dose doubled, and followed for 12 weeks. sdLDL-C was measured by our established homogenous assay.

RESULTS

The percentage and absolute reductions of sdLDL-C levels were significantly greater in the pemafibrate add-on group than the statin doubling group (-32.8 vs -8.1%; -16 vs -3 mg/dL, respectively). Triglyceride levels were reduced only in the pemafibrate add-on group (-44%), and LDL-C levels were reduced only in the statin doubling group (-8%), whereas levels of non-high-density lipoprotein-C and apolipoprotein B were similarly decreased (7-9%) in both groups. The absolute reductions of sdLDL-C levels were closely associated with decreased triglyceride, LDL-C, non-high-density lipoprotein-C and apolipoprotein B. In the subgroup analysis, the effect of pemafibrate add-on on sdLDL-C reductions was observed irrespective of baseline lipid parameters or statin type. No serious adverse effects were observed in both groups.

CONCLUSIONS

In patients with type 2 diabetes and hypertriglyceridemia, the addition of pemafibrate to a statin is superior to doubling a statin in reducing sdLDL-C without increasing adverse effects.

Saroglitazar, a Dual PPAR α/γ Agonist, Improves Atherogenic Dyslipidemia in Patients With Non-Cirrhotic Nonalcoholic Fatty Liver Disease: A Pooled Analysis

BACKGROUND & AIMS

Cardiovascular disease is the leading cause of mortality in nonalcoholic fatty liver disease (NAFLD). The aim of this study was to evaluate the effects of saroglitazar, a dual peroxisome proliferator-activated receptor α/γ agonist, on serum lipids in patients with NAFLD.

METHODS

A total of 221 patients (saroglitazar, 130; placebo, 91) with NAFLD from phase 2 and 3 double-blinded placebo-controlled randomized clinical trials were pooled to assess the impact of saroglitazar magnesium 4 mg on traditional lipids, very low density lipoprotein cholesterol (VLDL-C), and small dense LDL-C (sdLDL-C). Change from baseline in lipid parameters was performed by using analysis of covariance including treatment as fixed effect and baseline value, diabetes, hypertension, and statin use as covariates.

RESULTS

Treatment with saroglitazar significantly improved total cholesterol (-17 mg/dL, 95% confidence interval [CI], -24 to 9; P < .001), triglyceride (-45 mg/dL, 95% CI, -60 to 31; P < .001), low-density lipoprotein cholesterol (-8 mg/dL, 95% CI, -15 to -1; P = .01), and VLDL-C (-8 mg/dL, -14 to -3; P < .001). Saroglitazar improved serum lipids as early as 4-6 weeks of initiation of therapy, and these effects persisted for duration of therapy. Saroglitazar also improved the highly atherogenic sdLDL-C (-10 mg/dL, -17 to -2; P = .01). In subgroup analysis of patients with either diabetes or hypertension, saroglitazar significantly improved serum lipids.

CONCLUSIONS

Saroglitazar improved the serum atherogenic lipoprotein profile in patients with NAFLD, irrespective of comorbid conditions and statin use. Saroglitazar has the potential to not only positively affect liver disease but also reduce cardiovascular risk in patients with NAFLD. (Trials registrations: CTRI 2015/10/006236, CTRI 173300410A0106, NCT03863574, and NCT03061721).

Novel Selective PPARα Modulator Pemafibrate for Dyslipidemia, Nonalcoholic Fatty Liver Disease (NAFLD), and Atherosclerosis

Statins, the intestinal cholesterol transporter inhibitor (ezetimibe), and PCSK9 inhibitors can reduce serum LDL-C levels, leading to a significant reduction in cardiovascular events. However, these events cannot be fully prevented even when maintaining very low LDL-C levels. Hypertriglyceridemia and reduced HDL-C are known as residual risk factors for ASCVD. Hypertriglyceridemia and/or low HDL-C can be treated with fibrates, nicotinic acids, and n-3 polyunsaturated fatty acids. Fibrates were demonstrated to be PPARα agonists and can markedly lower serum TG levels, yet were reported to cause some adverse effects, including an increase in the liver enzyme and creatinine levels. Recent megatrials of fibrates have shown negative findings on the prevention of ASCVD, which were supposed to be due to their low selectivity and potency for binding to PPAR α. To overcome the off-target effects of fibrates, the concept of a selective PPARα modulator (SPPARMα) was proposed. Kowa Company, Ltd. (Tokyo, Japan), has developed pemafibrate (K-877). Compared with fenofibrate, pemafibrate showed more favorable effects on the reduction of TG and an increase in HDL-C. Fibrates worsened liver and kidney function test values, although pemafibrate showed a favorable effect on liver function test values and little effect on serum creatinine levels and eGFR. Minimal drug-drug interactions of pemafibrate with statins were observed. While most of the fibrates are mainly excreted from the kidney, pemafibrate is metabolized in the liver and excreted into the bile. It can be used safely even in patients with CKD, without a significant increase in blood concentration. In the megatrial of pemafibrate, PROMINENT, for dyslipidemic patients with type 2 diabetes, mild-to-moderate hypertriglyceridemia, and low HDL-C and LDL-C levels, the incidence of cardiovascular events did not decrease among those receiving pemafibrate compared to those receiving the placebo; however, the incidence of nonalcoholic fatty liver disease was lower. Pemafibrate may be superior to conventional fibrates and applicable to CKD patients. This current review summarizes the recent findings on pemafibrate.

Fibrates Affect Levels of Phosphorylated p38 in Intestinal Cells in a Differentiation-Dependent Manner

Fibrates are widely used hypolipidaemic agents that act as ligands of the peroxisome proliferator-activated receptor α (PPARα). p38 is a protein kinase that is mainly activated by environmental and genotoxic stress. We investigated the effect of the PPARα activators fenofibrate and WY-14643 and the PPARα inhibitor GW6471 on the levels of activated p38 (p-p38) in the colorectal cancer cell lines HT-29 and Caco2 in relation to their differentiation status. Fibrates increased p-p38 in undifferentiated HT-29 cells, whereas in other cases p-p38 expression was decreased. HT-29 cells showed p-p38 predominantly in the cytoplasm, whereas Caco2 cells showed higher nuclear positivity. The effect of fibrates may depend on the differentiation status of the cell, as differentiated HT-29 and undifferentiated Caco2 cells share similar characteristics in terms of villin, CYP2J2, and soluble epoxide hydrolase (sEH) expression. In human colorectal carcinoma, higher levels of p-p38 were detected in the cytoplasm, whereas in normal colonic surface epithelium, p-p38 showed nuclear positivity. The decrease in p-p38 positivity was associated with a decrease in sEH, consistent with in vitro results. In conclusion, fibrates affect the level of p-p38, but its exact role in the process of carcinogenesis remains unclear and further research is needed in this area.

Lipid Messenger Phosphatidylinositol-4,5-Bisphosphate Is Increased by Both PPARα Activators and Inhibitors: Relevance for Intestinal Cell Differentiation

Simple Summary

Fibrates, such as fenofibrate, are widely used drugs for dyslipidaemia treatment. It is known that they activate peroxisome proliferator-activated receptor α (PPARα) which serves as a lipid sensor in the organism. This article addresses how activators and inhibitor of the PPARα could affect differentiation of intestinal cells. Carcinogenesis is a disruption of normal differentiation process and colorectal carcinoma is the third most common cancer in terms of incidence, but the secondp in terms of mortality. One of the important signalling pathways in intestinal cell differentiation as well as carcinogenesis is PI3K/Akt/PTEN. We showed that PPARα activators as well as inhibitor affected the levels of one member of this pathway called phosphatidylinositol-4,5-bisphosphate. This molecule is important for formation of microvilli, the essential structures of fully differentiated intestinal cells.

Abstract

We investigated the effects of PPARα activators fenofibrate and WY-14643 as well as the PPARα inhibitor GW6471 on the PI3K/Akt/PTEN pathway of intestinal cell differentiation. Our previous study showed that all these compounds increased the expression of villin, a specific marker of intestinal cell differentiation in HT-29 and Caco2 cells. Our current results confirmed the central role of lipid messenger phosphatidylinositol-4,5-bisphosphate (PIP2), a known player in brush border formation, in mediating the effects of tested PPARα ligands. Although all tested compounds increased its levels, surprisingly, each of them affected different PIP2-metabolizing enzymes, especially the levels of PIP5K1C and PTEN. Moreover, we found a positive relationship between the expression of PPARα itself and PIP2 as well as PIP5K1C. By contrast, PPARα was negatively correlated with PTEN. However, the expression of antigens of interest was independent of PPARα subcellular localization, suggesting that it is not directly involved in their regulation. In colorectal carcinoma tissues we found a decrease in PTEN expression, which was accompanied by a change in its subcellular localization. This change was also observed for the regulatory subunit of PI3K. Taken together, our data revealed that fenofibrate, WY-14643, and GW6471 affected different members of the PI3K/Akt/PTEN pathway. However, these effects were PPARα-independent.

Metabolic Properties of Lowdensity Lipoprotein (LDL) Triglycerides in Patients with Type 2 Diabetes, Comparison with Small Dense LDL-Cholesterol

AIMS

Abnormal compositional changes in low-density lipoprotein (LDL) particles, such as triglyceride (TG) enrichment and size reduction, are common in patients with diabetes. Several cohort studies have demonstrated that LDL-TG and sdLDL-cholesterol (C) are sensitive biomarkers for predicting atherosclerotic cardiovascular diseases beyond LDL-C. Although sdLDL has been extensively studied, little is known about the properties of LDL-TG. We investigated similarities or differences between LDL-TG and sdLDL-C.

METHODS

Fasting plasma was obtained from 1,085 patients with type 2 diabetes who were enrolled in the diabetes regional cohort study (ViNA Cohort). LDL-TG and sdLDL-C concentrations were measured using a homogeneous assay established by us. In a subset of subjects, LDL-TG and sdLDL-C levels were measured postprandially or after treatment with lipid-lowering drugs.

RESULTS

In a quartile analysis, higher LDL-TG quartiles were associated with higher frequency of female and fibrate users, whereas sdLDL-C quartiles were associated with frequency of men, drinking, and metabolic syndrome-related measurements. Higher quartiles of LDL-TG/LDL-C were associated with smoking, drinking, fibrate users, and statin users. LDL-TG was significantly correlated with TG, LDL-C, sdLDL-C, and apolipoprotein (apo) B, with apoB being the primary determinant. LDL-TG correlated to high sensitive C-reactive protein (CRP) independently of other lipids. Mean LDL-TG did not change with fasting/non-fasting. Statin treatment reduced LDL-TG, whereas fibrates increased it, but these drugs reduced sdLDL-C equally.

CONCLUSIONS

LDL-TG levels were more tightly regulated by the number of LDL particles than plasma TG levels were. SdLDL-C was closely associated with metabolic syndrome-related factors, whereas LDL-TG was associated with low-grade systemic inflammation.

Small Dense Low-Density Lipoprotein Cholesterol and Cardiovascular Risk in Statin-Treated Patients with Coronary Artery Disease

Aim: We investigated the relationship between small dense low-density cholesterol (sdLDL-C) and risk of major adverse cardiovascular events (MACE) in patients treated with high- or low-dose statin therapy.

Methods: This was a prospective case-cohort study within the Randomized Evaluation of Aggressive or Moderate Lipid-Lowering Therapy with Pitavastatin in Coronary Artery Disease (REAL-CAD) study, a randomized trial of high- or low-dose (4 or 1 mg/d pitavastatin, respectively) statin therapy, in patients with stable coronary artery disease (CAD). Serum sdLDL-C was determined using an automated homogenous assay at baseline (randomization after a rule-in period, ＞1 month with 1 mg/d pitavastatin) and 6 months after randomization, in 497 MACE cases, and 1543 participants randomly selected from the REAL-CAD study population.

Results: High-dose pitavastatin reduced sdLDL-C by 20% than low-dose pitavastatin (p for interaction ＜0.001). Among patients receiving low-dose pitavastatin, baseline sdLDL-C demonstrated higher MACE risk independent of LDL-C (hazard ratio [95% confidence interval], 4th versus 1st quartile, 1.67 [1.04–2.68];p for trend=0.034). High-dose (versus low-dose) pitavastatin reduced MACE risk by 46% in patients in the highest baseline sdLDL-C quartile (＞34.3 mg/dL; 0.54 [0.36–0.81];p=0.003), but increased relative risk by 40% in patients with 1st quartile (≤ 19.5 mg/dL; 1.40 [0.94–2.09];p=0.099) and did not alter risk in those in 2nd and 3rd quartiles (p for interaction=0.002).

Conclusions: These findings associate sdLDL-C and cardiovascular risk, independent of LDL-C, in statin-treated CAD patients. Notably, high-dose statin therapy reduces this risk in those with the highest baseline sdLDL-C.

Dyslipidemia in diabetic kidney disease classified by proteinuria and renal dysfunction: A cross-sectional study from a regional diabetes cohort

AIMS/INTRODUCTION

Diabetic kidney disease (DKD) exacerbates dyslipidemia and increases the incidence of atherosclerotic cardiovascular disease. DKD is a concept that includes typical diabetic nephropathy and an atypical phenotype without proteinuria. We investigated dyslipidemia in different DKD phenotypes that have not been fully studied.

MATERIALS AND METHODS

Fasting plasma was obtained from 1,073 diabetes patients enrolled in the regional diabetes cohort (ViNA cohort). Non-proteinuric and proteinuric DKD were defined as an estimated glomerular filtration rate <60 mL/min/1.73 m² in the absence or presence of urinary albumin-to-creatinine ratio >300 mg/g. Novel lipid risk factors, low-density lipoprotein (LDL) triglyceride (TG) and small dense LDL cholesterol were measured using our established homologous assay.

RESULTS

The proportion of atherosclerotic cardiovascular disease patients was higher in non-proteinuric DKD and even higher in proteinuric DKD than in non-DKD. Increased estimated glomerular filtration rate grade and albuminuric stage were independently correlated with higher TG, TG-rich lipoprotein cholesterol and apolipoprotein CIII. Therefore, proteinuric DKD had the highest of these levels. Small dense LDL cholesterol and LDL-TG were higher in the proteinuria without renal dysfunction group in the lipid-lowering drug-free subset. Lipoprotein(a) was higher in DKD regardless of proteinuria.

CONCLUSIONS

Proteinuria was associated with an atherogenic subspecies of LDL, whereas renal dysfunction was associated with increased lipoprotein(a). Proteinuria and renal dysfunction independently exacerbated TG-rich lipoprotein-related dyslipidemia. This is in good agreement with the results of large-scale clinical studies in which proteinuria and renal dysfunction synergistically increased the risk of atherosclerotic cardiovascular disease in populations with diabetes.

When Activator and Inhibitor of PPARα Do the Same: Consequence for Differentiation of Human Intestinal Cells

Peroxisome proliferator-activated receptor α (PPARα) is a ligand-dependent transcription factor that plays a role in various processes including differentiation of several cell types. We investigated the role of PPARα in the differentiation of intestinal cells using HT-29 and Caco2 cell lines as a model as well as human normal colon and colorectal carcinoma tissues. We detected a significant increase in PPARα expression in differentiated HT-29 cells as well as in normal surface colon epithelium where differentiated cells are localised. Thus, it seems that PPARα may play a role in differentiation of intestinal cells. Interestingly, we found that both PPARα activators (fenofibrate and WY-14643) as well as its inhibitor (GW6471) regulated proliferation and differentiation of HT-29 cells in vitro in the same way. Both compounds led to a decrease in proliferation accompanied by a significant increase in expression of villin, intestinal alkaline phosphatase (differentiation markers). Moreover, the same trend in villin expression was observed in Caco2 cells. Furthermore, villin expression was independent of subcellular localisation of PPARα. In addition, we found similar levels of PPARα expression in colorectal carcinomas in comparison to adjacent normal epithelium. All these findings support the hypothesis that differentiation of intestinal epithelium is PPARα-independent.

Fenofibrate Delays the Need for Dialysis and Reduces Cardiovascular Risk Among Patients With Advanced CKD

CONTEXT

Fenofibrate provides limited cardiovascular (CV) benefits in the general population; however, little is known about its benefit among advanced chronic kidney disease (CKD) patients.

OBJECTIVE

This study compared outcomes among advanced CKD patients treated with fenofibrate, statins, a combination of both, and none of these.

METHODS

This national cohort study was based on Taiwan's National Health Insurance Research Database. Patients younger than 20 years with advanced CKD were identified and further divided into 4 groups according to treatment. The inverse probability of treatment weighting was used to balance baseline characteristics. Patients received fenofibrate, statins, a combination of fenofibrate and statins, or none of these in the 3 months preceding the advanced CKD date. Main outcome measures included all-cause mortality, CV death, and incidence of permanent dialysis.

RESULTS

The fenofibrate and statin groups exhibited a lower risk of CV death (fenofibrate vs nonuser: hazard ratio [HR]: 0.84; 95% CI, 0.75-0.94; statins vs nonuser: HR: 0.94; 95% CI, 0.90-0.97) compared with the nonuser group. The fenofibrate group further exhibited the lowest incidence of permanent dialysis (fenofibrate vs nonuser: subdistribution HR [SHR]: 0.78; 95% CI, 0.77-0.80; statins vs fenofibrate: SHR: 1.27; 95% CI, 1.26-1.29; combination vs fenofibrate: SHR: 1.15; 95% CI, 1.13-1.17). Furthermore, the combined administration of fenofibrate and high-intensity statins exhibited a lower risk of major adverse cardiac and cerebrovascular events.

CONCLUSION

For patients with advanced CKD, continuing fenofibrate may provide a protective effect on CV outcomes equal to that of statins, and it may further delay the need for permanent dialysis. The combination of fenofibrate and high-intensity statins may have additional benefits.

Effects of Pitavastatin on Lipoprotein Subfractions and Oxidized Low-density Lipoprotein in Patients with Atherosclerosis

It has been demonstrated that pitavastatin can significantly reduce low-density lipoprotein (LDL) cholesterol (LDL-C), but its impact on lipoprotein subfractions and oxidized low-density lipoprotein (oxLDL) has not been determined. The aim of the present study was to investigate the potential effects of pitavastatin on subfractions of LDL and high-density lipoprotein (HDL) as well as oxLDL in untreated patients with coronary atherosclerosis (AS). Thirty-six subjects were enrolled in this study. Of them, 18 patients with AS were administered pitavastatin 2 mg/day for 8 weeks and 18 healthy subjects without therapy served as controls. The plasma lipid profile, lipoprotein subfractions and circulating oxLDL were determined at baseline and 8 weeks respectively. The results showed that pitavastatin treatment indeed not only decreased LDL-C, total cholesterol (TC), triglycerides (TG) and apolipoprotein B (ApoB) levels, and increased HDL cholesterol (HDL-C), but also reduced the cholesterol concentration of all of the LDL subfractions and the percentage of intermediate and small LDL subfractions. Meanwhile, pitavastatin could decrease plasma oxLDL levels. Furthermore, a more close correlation was found between oxLDL and LDL-C as well as LDL subfractions after pitavastatin treatment. We concluded that a moderate dose of pitavastatin therapy not only decreases LDL-C and oxLDL concentrations but also improves LDL subfractions in patients with AS.

Pemafibrate, a New Selective PPARα Modulator: Drug Concept and Its Clinical Applications for Dyslipidemia and Metabolic Diseases

PURPOSE OF REVIEW

Reduction of serum low-density lipoprotein cholesterol (LDL-C) levels by statins, ezetimibe and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors has been shown to significantly reduce cardiovascular events risk. However, fasting and postprandial hypertriglyceridemia as well as reduced high-density lipoprotein cholesterol (HDL-C) remain as residual risk factors of atherosclerotic cardiovascular diseases (ASCVD). To treat patients with hypertriglyceridemia and/or low HDL-C, drugs such as fibrates, nicotinic acids, and n-3 polyunsaturated fatty acids have been used. However, fibrates were demonstrated to cause side effects such as liver dysfunction and increase in creatinine levels, and thus large-scale clinical trials of fibrates have shown negative results for prevention of ASCVD. The failure could be attributed to their low selectivity and potency for binding to peroxisome proliferator-activated receptor (PPAR) α. To resolve these issues, the concept of selective PPARα modulator (SPPARMα) with a superior balance of efficacy and safety has been proposed and pemafibrate (K-877) has been developed.

RECENT FINDINGS

Pemafibrate, one of SPPARMsα, was synthesized by Kowa Company, Ltd. for better efficiency and safety. Clinical trials in Japan have established the superiority of pemafibrate on effects on serum triglycerides (TG) reduction and HDL-C elevation as well safety. Although available fibrates showed worsening of liver and kidney function test values, pemafibrate indicated improved liver function test values and was less likely to increase serum creatinine or decrease estimated glomerular filtration rate (eGFR). Very few drug-drug interactions were observed even when used concomitantly with statins. Furthermore, pemafibrate is metabolized in the liver and excreted into the bile, while many of available fibrates are mainly excreted from the kidney. Therefore, pemafibrate can be used safely even in patients with impaired renal function since there is no significant increase in its blood concentration. A large-scale trial of pemafibrate, PROMINENT, for dyslipidemic patients with type 2 diabetes is ongoing. Pemafibrate is one of novel SPPARMsα and has superior benefit-risk balance compared to conventional fibrates and can be applicable for patients for whom the usage of existing fibrates is difficult such as those who are taking statins or patients with renal dysfunction. In the current review, all the recent data on pemafibrate will be summarized.

Available oral lipid-lowering agents could bring most high-risk patients to target: an estimate based on the Dyslipidemia International Study II-Italy

AIMS

The analysis evaluated the contemporary percentage of patients with established coronary heart disease (CHD) reaching the European guidelines recommended LDL-cholesterol (LDL-C) levels of less than 70 mg/dl and the threshold required for proprotein convertase subtlisin/kexin type 9 reimbursement in Italy (100 mg/dl). It also assessed how these percentages would change in case of diffuse use of ezetimibe.

METHODS

The Dyslipidemia International Study II enrolled CHD patients aged at least 18 either on lipid-lowering therapy (LLT) for at least 3 months or not on LLT at the time of the lipid profile. Distribution of LLTs and LDL-C target attainment were assessed. Multivariate logistic regression evaluated predictors of LDL-C target attainment. A 24% LDL-C lowering was modeled in patients not taking ezetimibe to assess its potential effects.

RESULTS

Among 676 Italian CHD patients enrolled, LDL-C concentrations were lower among the 631 patients (93.3%) who were on LLT (82 versus 118 mg/dl; P < 0.001). The LDL-C target was attained by 35.4% of patients. Statin dose (median atorvastatin dose 40 mg/day) was the sole significant predictor of LDL-C target attainment. The simple addition of ezetimibe in the model reduced the percentage of patients more than 70 and 100 mg/dl from 64.6 to 37.9% and from 25.1 to 11.8%, respectively.

CONCLUSION

Despite treatment in more than 90%, only one-third of Italian stable CHD patients attained the recommended LDL-C target. Statin dose was the sole predictor of the target achievement. The addition of ezetimibe would almost double patients at target and halve the potential candidates for reimbursement of more expensive agents such as proprotein convertase subtlisin/kexin type 9 inhibitors.

Molecular Actions of PPARα in Lipid Metabolism and Inflammation

Peroxisome proliferator-activated receptor α (PPARα) is a nuclear receptor of clinical interest as a drug target in various metabolic disorders. PPARα also exhibits marked anti-inflammatory capacities. The first-generation PPARα agonists, the fibrates, have however been hampered by drug-drug interaction issues, statin drop-in, and ill-designed cardiovascular intervention trials. Notwithstanding, understanding the molecular mechanisms by which PPARα works will enable control of its activities as a drug target for metabolic diseases with an underlying inflammatory component. Given its role in reshaping the immune system, the full potential of this nuclear receptor subtype as a versatile drug target with high plasticity becomes increasingly clear, and a novel generation of agonists may pave the way for novel fields of applications.

The Opportunities and Challenges of Peroxisome Proliferator-Activated Receptors Ligands in Clinical Drug Discovery and Development

Peroxisome proliferator-activated receptors (PPARs) are a well-known pharmacological target for the treatment of multiple diseases, including diabetes mellitus, dyslipidemia, cardiovascular diseases and even primary biliary cholangitis, gout, cancer, Alzheimer's disease and ulcerative colitis. The three PPAR isoforms (α, β/δ and γ) have emerged as integrators of glucose and lipid metabolic signaling networks. Typically, PPARα is activated by fibrates, which are commonly used therapeutic agents in the treatment of dyslipidemia. The pharmacological activators of PPARγ include thiazolidinediones (TZDs), which are insulin sensitizers used in the treatment of type 2 diabetes mellitus (T2DM), despite some drawbacks. In this review, we summarize 84 types of PPAR synthetic ligands introduced to date for the treatment of metabolic and other diseases and provide a comprehensive analysis of the current applications and problems of these ligands in clinical drug discovery and development.

Effect of pitavastatin and atorvastatin on regression of atherosclerosis assessed using intravascular ultrasound: a meta-analysis

BACKGROUND

The aim of this study is to compare the efficacy and safety of pitavastatin and atorvastatin using data from randomized-controlled trial pooled together by means of a meta-analysis and decide which is better.

METHODS

PubMed, CENTRAL, Web of Knowledge, and ClinicalTrials.gov website were searched for randomized-controlled trials published until October 2016. Eligible studies comparing pitavastatin with atorvastatin head to head and reporting the outcome of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), glycated hemoglobin, and intravascular ultrasound evaluation were enrolled. Heterogeneity was assessed by using the I statistic, and the extracted data were estimated by fixed-effects model.

RESULTS

Eleven trials including a total number of 1733 participants were identified. Compared with atorvastatin, changes in the mean differences of LDL-C and HDL-C were 2.51 [95% confidence interval (CI): 1.17-3.86; I=48%; P=0.0003] and 2.17 (95% CI: 1.42-2.91; I=40%; P<0.00001), respectively, for pitavastatin. The changes in the mean differences of glycated hemoglobin was -0.15 (95% CI: -1.44-1.15; I=0%; P=0.83) for pitavastatin compared with atorvastatin. For plaque volume, lumen volume, and external elastic membrane, the changes are -0.93 (95% CI: -3.04-1.19; I=50%; P=0.39), 0.17 (95% CI: -2.91-3.26; I=0%; P=0.91), and -0.43 (95% CI: -1.96-1.11; I=4%; P=0.58), respectively, for pitavastatin versus atorvastatin.

CONCLUSION

In this study, pitavastatin seems to be less effective in reducing LDL-C and elevating HDL-C level compared with atorvastatin. Moreover, there is no significant difference in changes of glycated hemoglobin and intravascular ultrasound evaluation between pitavastatin and atorvastatin.

Reference values assessment in a Mediterranean population for small dense low-density lipoprotein concentration isolated by an optimized precipitation method

Background

High serum concentrations of small dense low-density lipoprotein cholesterol (sd-LDL-c) particles are associated with risk of cardiovascular disease (CVD). Their clinical application has been hindered as a consequence of the laborious current method used for their quantification.

Objective

Optimize a simple and fast precipitation method to isolate sd-LDL particles and establish a reference interval in a Mediterranean population.

Materials and methods

Forty-five serum samples were collected, and sd-LDL particles were isolated using a modified heparin-Mg²⁺ precipitation method. sd-LDL-c concentration was calculated by subtracting high-density lipoprotein cholesterol (HDL-c) from the total cholesterol measured in the supernatant. This method was compared with the reference method (ultracentrifugation). Reference values were estimated according to the Clinical and Laboratory Standards Institute and The International Federation of Clinical Chemistry and Laboratory Medicine recommendations. sd-LDL-c concentration was measured in serums from 79 subjects with no lipid metabolism abnormalities.

Results

The Passing–Bablok regression equation is y = 1.52 (0.72 to 1.73) + 0.07x (−0.1 to 0.13), demonstrating no significant statistical differences between the modified precipitation method and the ultracentrifugation reference method. Similarly, no differences were detected when considering only sd-LDL-c from dyslipidemic patients, since the modifications added to the precipitation method facilitated the proper sedimentation of triglycerides and other lipoproteins. The reference interval for sd-LDL-c concentration estimated in a Mediterranean population was 0.04–0.47 mmol/L.

Conclusion

An optimization of the heparin-Mg²⁺ precipitation method for sd-LDL particle isolation was performed, and reference intervals were established in a Spanish Mediterranean population. Measured values were equivalent to those obtained with the reference method, assuring its clinical application when tested in both normolipidemic and dyslipidemic subjects.

Serum CETP status is independently associated with reduction rates in LDL-C in pitavastatin-treated diabetic patients and possible involvement of LXR in its association

BACKGROUND

Statins decrease cholesteryl ester transfer protein (CETP) levels, which have been positively associated with hepatic lipid content as well as serum low density lipoproteins-cholesterol (LDL-C) levels. However, the relationship between the CETP status and statin-induced reductions in LDL-C levels has not yet been elucidated in detail. We herein examined the influence of the CETP status on the lipid-reducing effects of pitavastatin in hypercholesterolemic patients with type 2 diabetes mellitus as well as the molecular mechanism underlying pitavastatin-induced modifications in CETP levels.

METHODS

Fifty-three patients were treated with 2 mg of pitavastatin for 3 months. Serum levels of LDL-C, small dense (sd) LDL-C, and CETP were measured before and after the pitavastatin treatment. The effects of pitavastatin, T0901317, a specific agonist for liver X receptor (LXR) that reflects hepatic cholesterol contents, and LXR silencing on CETP mRNA expression in HepG2 cells were also examined by a real-time PCR assay.

RESULTS

The pitavastatin treatment decreased LDL-C, sdLDL-C, and CETP levels by 39, 42, and 23%, respectively. Despite the absence of a significant association between CETP and LDL-C levels at baseline, baseline CETP levels and its percentage change were an independent positive determinant for the changes observed in LDL-C and sdLDL-C levels. The LXR activation with T0901317 (0.5 μM), an in vitro condition analogous to hepatic cholesterol accumulation, increased CETP mRNA levels in HepG2 cells by approximately 220%, while LXR silencing markedly diminished the increased expression of CETP. Pitavastatin (5 μM) decreased basal CETP mRNA levels by 21%, and this was completely reversed by T0901317.

CONCLUSION

Baseline CETP levels may predict the lipid-reducing effects of pitavastatin. Pitavastatin-induced CETP reductions may be partially attributed to decreased LXR activity, predictable by the ensuing decline in hepatic cholesterol synthesis.

TRIAL REGISTRATION

UMIN Clinical Trials Registry ID UMIN000019020.

Prevalence of plasma small dense LDL is increased in obesity in a Thai population

BACKGROUND

Plasma low density lipoprotein (LDL) particles vary in size, density, electrical charge and chemical composition. An increased presence of small dense LDL (sdLDL), along with raised triglyceride concentrations and decreased high density lipoprotein (HDL) cholesterol concentrations is commonly known as the atherogenic triad and has been observed in some cases of obesity, principally in Europe and America. This study examines the prevalence of sdLDL in the plasma of an obese (BMI≥25 kg/m2) Thai population.

METHODS

Plasma from fasted obese (n=48) and non-obese (n=16) Thai participants was subjected to density gradient ultracentrifugation in iodixanol to separate lipoproteins. Gradients were unloaded top-to-bottom into 20 fractions which were assayed for cholesterol, triglyceride, apo B and apo A-1 to identify lipoprotein types and subtypes.

RESULTS

LDL cholesterol was subfractionated into LDL I+II (fractions 3-6, ρ=1.021-1.033 g/ml) which was considered to represent large buoyant LDL (lbLDL), LDL III (fractions 7-9, ρ=1.036-1.039 g/ml) which was considered to represent sdLDL, and, LDL IV (fractions 10-12, ρ=1.044-1.051 g/ml) which was considered to represent very sdLDL. Concentrations of LDL III and IV were increased by 15-20% in obese participants whilst that of LDL I+II was concomitantly decreased by 10%. This was accompanied by a 50% increase in plasma triglyceride concentrations and 15% decrease in HDL cholesterol concentrations. Only 3/16 (19%) non-obese participants had a pattern B LDL cholesterol profile (peak density of >1.033 g/ml), whilst 28/48 (58%) obese participants were pattern B. When expressed as a fraction of the LDL concentration, total sdLDL (i.e. LDL III+IV) showed highly significant correlations to plasma triglyceride concentrations and the triglyceride/HDL cholesterol ratio.

CONCLUSIONS

The prevalence of sdLDL is increased in obesity in a Thai population such that they demonstrate a similar atherogenic triad to that previously observed in European and American populations.

Atorvastatin active metabolite inhibits oxidative modification of small dense low-density lipoprotein

We tested the hypothesis that atorvastatin active metabolite (ATM), on the basis of its distinct structural features and potent antioxidant activity, preferentially inhibits lipid oxidation in human small dense low-density lipoprotein (sdLDL) and other small lipid vesicles. LDL, sdLDL, and various subfractions were isolated from human plasma by sequential ultracentrifugation, treated with ATM, atorvastatin, pravastatin, rosuvastatin, or simvastatin and were subjected to copper-induced oxidation. Lipid oxidation was measured spectrophotometrically as a function of thiobarbituric acid reactive substances formation. Similar analyses were performed in reconstituted lipid vesicles enriched in polyunsaturated fatty acids and prepared at various sizes. ATM was found to inhibit sdLDL oxidation in a dose-dependent manner. The antioxidant effects of ATM in sdLDL were 1.5 and 4.7 times greater (P < 0.001) than those observed in large buoyant LDL and very low-density lipoprotein subfractions, respectively. ATM had similar dose- and size-dependent effects in reconstituted lipid vesicles. None of these effects were reproduced by atorvastatin (parent) or any of the other statins examined in this study. These data suggest that ATM interacts with sdLDL in a specific manner that also confers preferential resistance to oxidative stress. Such interactions may reduce sdLDL atherogenicity and improve clinical outcomes in patients with cardiovascular disease.

The association of very-low-density lipoprotein with ankle-brachial index in peritoneal dialysis patients with controlled serum low-density lipoprotein cholesterol level

Background

Peripheral artery disease (PAD) represents atherosclerotic disease and is a risk factor for death in peritoneal dialysis (PD) patients, who tend to show an atherogenic lipid profile. In this study, we investigated the relationship between lipid profile and ankle-brachial index (ABI) as an index of atherosclerosis in PD patients with controlled serum low-density lipoprotein (LDL) cholesterol level.

Methods

Thirty-five PD patients, whose serum LDL cholesterol level was controlled at less than 120mg/dl, were enrolled in this cross-sectional study in Japan. The proportions of cholesterol level to total cholesterol level (cholesterol proportion) in 20 lipoprotein fractions and the mean size of lipoprotein particles were measured using an improved method, namely, high-performance gel permeation chromatography. Multivariate linear regression analysis was adjusted for diabetes mellitus and cardiovascular and/or cerebrovascular diseases.

Results

The mean (standard deviation) age was 61.6 (10.5) years; PD vintage, 38.5 (28.1) months; ABI, 1.07 (0.22). A low ABI (0.9 or lower) was observed in 7 patients (low-ABI group). The low-ABI group showed significantly higher cholesterol proportions in the chylomicron fraction and large very-low-density lipoproteins (VLDLs) (Fractions 3–5) than the high-ABI group (ABI>0.9). Adjusted multivariate linear regression analysis showed that ABI was negatively associated with serum VLDL cholesterol level (parameter estimate=-0.00566, p=0.0074); the cholesterol proportions in large VLDLs (Fraction 4, parameter estimate=-3.82, p=0.038; Fraction 5, parameter estimate=-3.62, p=0.0039) and medium VLDL (Fraction 6, parameter estimate=-3.25, p=0.014); and the size of VLDL particles (parameter estimate=-0.0352, p=0.032).

Conclusions

This study showed that the characteristics of VLDL particles were associated with ABI among PD patients. Lowering serum VLDL level may be an effective therapy against atherosclerosis in PD patients after the control of serum LDL cholesterol level.

Role of the apical and basolateral domains of the enterocyte in the regulation of cholesterol transport by a high glucose concentration

We have recently shown that a high glucose (HG) concentration raised intestinal cholesterol (CHOL) transport and metabolism in intestinal epithelial cells. The objective of the present work is to determine whether the stimulus for increased CHOL absorption by glucose originates from the apical site (corresponding to the intestinal lumen) or from the basolateral site (related to blood circulation). We tackled this issue by using differentiated Caco-2/15 cells. Only basolateral medium, supplemented with 25 mmol/L glucose, stimulated [(14)C]-CHOL uptake via the up-regulation of the critical CHOL transporter NPC1L1 protein, as confirmed by its specific ezetimibe inhibitor that abolished the rise in glucose-mediated CHOL capture. No significant changes were noted in SR-BI and CD36. Elevated CHOL uptake was associated with an increase in the transcription factors SREBP-2, LXR-β, and ChREBP, along with a fall in RXR-α. Interestingly, although the HG concentration in the apical medium caused modest changes in CHOL processing, its impact was synergetic with that of the basolateral medium. Our results suggest that HG concentration influences positively intestinal CHOL uptake when present in the basolateral medium. In addition, excessive consumption of diets containing high levels of carbohydrates may strengthen intestinal CHOL uptake in metabolic syndrome, thereby contributing to elevated levels of circulating CHOL and, consequently, the risk of developing type 2 diabetes and cardiovascular disease.

Fatty liver in men is associated with high serum levels of small, dense low-density lipoprotein cholesterol

AIMS

Our study addressed potential associations between fatty liver and small, dense low-density lipoprotein cholesterol (sd-LDL-C) levels using a cross-sectional analysis.

METHODS

We enrolled 476 male subjects. Serum sd-LDL-C concentrations were determined using precipitation assays.

RESULTS

Subjects were divided into four groups based on triglyceride (TG) and LDL-C levels: A, TG < 150 mg/dl and LDL-C < 140 mg/dl; B, TG < 150 mg/dl and LDL-C ≥ 140 mg/dl; C, TG ≥ 150 mg/dl and LDL-C < 140 mg/dl; and D, TG ≥ 150 mg/dl and LDL-C ≥ 140 mg/dl. sd-LDL-C levels and the prevalence of fatty liver were significantly higher in groups B, C, and D than in group A. Subjects were also categorized into four groups based on serum sd-LDL-C levels; the prevalence of fatty liver significantly increased with increasing sd-LDL-C levels. Additionally, logistic regression analysis revealed an independent association between sd-LDL-C concentrations and fatty liver using such potential confounders as obesity and hyperglycemia as variables independent of elevated TG or LDL-C levels.

CONCLUSIONS

Fatty liver is a significant determinant of serum sd-LDL-C levels independent of the presence of obesity or hyperglycemia. Fatty liver may alter hepatic metabolism of TG and LDL-C, resulting in increased sd-LDL-C levels.

Pleiotropic effects of pitavastatin

3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) are established first line treatments for hypercholesterolaemia. In addition to the direct effects of statins in reducing concentrations of atherogenic low density lipoprotein cholesterol (LDL-C), several studies have indicated that the beneficial effects of statins may be due to some of their cholesterol-independent, multiple (pleiotropic) effects which may differ between different members of the class. Pitavastatin is a novel synthetic lipophilic statin that has a number of pharmacodynamic and pharmacokinetic properties distinct from those of other statins, which may underlie its potential pleiotropic benefits in reducing cardiovascular risk factors. This review examines the principal pleiotropic effects of pitavastatin on endothelial function, vascular inflammation, oxidative stress and thrombosis. The article is based on a systematic literature search carried out in December 2010, together with more recent relevant publications where appropriate. The available data from clinical trials and in vitro and animal studies suggest that pitavastatin is not only effective in reducing LDL-C and triglycerides, but also has a range of other effects. These include increasing high density lipoprotein cholesterol, decreasing markers of platelet activation, improving cardiac, renal and endothelial function, and reducing endothelial stress, lipoprotein oxidation and, ultimately, improving the signs and symptoms of atherosclerosis. It is concluded that the diverse pleiotropic actions of pitavastatin may contribute to reducing cardiovascular morbidity and mortality beyond that achieved through LDL-C reduction.

Are all statins the same? Focus on the efficacy and tolerability of pitavastatin

Pitavastatin is the newest member of the HMG-CoA reductase inhibitor family and is approved as adjunctive therapy to diet to reduce elevated levels of total cholesterol, low-density lipoprotein (LDL) cholesterol, apolipoprotein (Apo) B, and triglycerides and to increase levels of high-density lipoprotein (HDL) cholesterol in adult patients with primary hyperlipidemia or mixed dyslipidemia. Pitavastatin undergoes minimal metabolism by cytochrome P450 (CYP) enzymes and, therefore, has a low propensity for drug-drug interactions with drugs metabolized by CYP enzymes or the CYP3A4 substrate grapefruit juice. In clinical trials, pitavastatin potently and consistently reduced serum levels of total, LDL, and non-HDL cholesterol, and triglycerides in patients with primary hypercholesterolemia where diet and other non-pharmacological measures were inadequate. Mean reductions from baseline in serum total and LDL cholesterol and triglyceride levels were 21-32%, 30-45%, and 10-30%, respectively. Moreover, a consistent trend towards increased HDL cholesterol levels of 3-10% was seen. Long-term extension studies show that the beneficial effects of pitavastatin are maintained for up to 2 years. Pitavastatin produces reductions from baseline in serum total and LDL cholesterol levels to a similar extent to those seen with the potent agent atorvastatin and to a greater extent than those seen with simvastatin or pravastatin. In the majority of other studies comparing pitavastatin and atorvastatin, no significant differences in the favorable effects on lipid parameters were seen, although pitavastatin was consistently associated with trends towards increased HDL cholesterol levels. Pitavastatin also produces beneficial effects on lipids in patients with type 2 diabetes mellitus and metabolic syndrome without deleterious effects on markers of glucose metabolism, such as fasting blood glucose levels or proportion of glycosylated hemoglobin. Pitavastatin appears to exert a number of beneficial effects on patients at risk of cardiovascular events independent of lipid lowering. In the JAPAN-ACS (Japan Assessment of Pitavastatin and Atorvastatin in Acute Coronary Syndrome) study, pitavastatin was non-inferior to atorvastatin at reducing plaque volume in patients with ACS undergoing percutaneous coronary intervention. Further beneficial effects, including favorable effects on the size and composition of atherosclerotic plaques, improvements in cardiovascular function, and improvements in markers of inflammation, oxidative stress, and renal function, have been demonstrated in a number of small studies. Pitavastatin is generally well tolerated in hyperlipidemic patients with or without type 2 diabetes, with the most common treatment-related adverse events being musculoskeletal or gastrointestinal in nature. Increases in plasma creatine kinase levels were seen in <5% of pitavastatin recipients and the incidence of myopathy or rhabdomyolysis was extremely low. In summary, pitavastatin, the latest addition to the statin family, produces potent and consistent beneficial effects on lipids, is well tolerated, and has a favorable pharmacokinetic profile. The combination of a potent decrease in total and LDL cholesterol levels and increase in HDL cholesterol levels suggest that pitavastatin may produce substantial cardiovascular protection.

Additional Treatment with Fenofibrate for Patients Treated with Pitavastatin Under Ordinary Medical Practice for Hypertriglyceridemia in Japan (APPROACH-J Study)

Safety and efficacy of combination therapy of pitavastatin and fenofibrate were examined in consecutive case series with fasting serum triglycerides ≥ 150 mg/dL despite receiving pitavastatin 1 or 2 mg daily for over 2 months and additionally administered micronized fenofibrate 67 mg daily for another 4 to 16 weeks. Such low doses were selected in consideration of safety, and normal liver and renal functions were incorporated in inclusion criteria. In result, a total of 56 cases were examined. The addition of fenofibrate 67 mg to pitavastatin 1 mg/2 mg yielded a 36.8%/35.6% reduction in triglycerides and 6.4%/12.4% elevation in high-density lipoprotein cholesterol, respectively. Almost 70% of the patients achieved triglycerides <150 mg/dL. Statistically significant elevation and decrease were observed in high-density lipoprotein cholesterol level and low-density lipoprotein cholesterol, respectively. Laboratory tests for liver, renal and muscle function statistically significantly elevated after starting fenofibrate co-administration, which were considered comparable to the effect of fenofibrate alone. No myopathy or serious adverse events were reported. In conclusion, while the safety and tolerability need to be further examined over the longer term, and careful monitoring is still needed, this regimen could be considered as one of the treatment option for hypercholesterolemia associated with hypertriglyceridemia.

Susceptibility of LDL and its subfractions to glycation

PURPOSE OF REVIEW

To highlight the potential importance of glycation as an atherogenic modification of LDL, factors determining glycated apolipoprotein B in vivo and susceptibility of LDL to glycation in vitro. We also discuss the distribution of glycated apolipoprotein B across different LDL subfractions in healthy controls, patients with type 2 diabetes and metabolic syndrome.

RECENT FINDINGS

Small, dense LDL, which is known to be most closely associated with atherogenesis, is more preferentially glycated in vivo and more susceptible to glycation in vitro than more buoyant LDL. Glycation and oxidation of LDL appear to be intimately linked. In patients with type 2 diabetes, plasma glycated apolipoprotein B correlated with small, dense LDL apolipoprotein B, but not with HbA1c. Glycated apolipoprotein B is significantly lower in statin-treated type 2 diabetes compared with those not on statins.

SUMMARY

Glycation of LDL occurs chiefly because of the nonenzymatic reaction of glucose and its metabolites with the free amino groups of lysine of which apolipoprotein B is rich. Higher concentrations of glycated LDL are present in diabetes than in nondiabetic individuals and metabolic syndrome. Even in nondiabetic individuals, however, there is generally more circulating glycated LDL than oxidatively modified LDL. Probably, oxidation and glycation of LDL are partially interdependent and indisputably coexist, and both prevent LDL receptor-mediated uptake and promote macrophage scavenger receptor-mediated LDL uptake. The recognition that LDL glycation is at least as important as oxidation in atherogenesis may lead to improvements in our understanding of its mechanism and how to prevent it.

Estimation of plasma small dense LDL cholesterol from classic lipid measures

Calculated low-density lipoprotein cholesterol (cLDL-C) may differ from direct measurement (dLDL-C), and this difference may depend on presence of small, dense LDL (sdLDL) particles in addition to variation in triglycerides (TG) and high-density lipoprotein cholesterol (HDL-C) concentrations. The presence of such dependence would offer a simple means to estimate sdLDL. We studied dependence of sdLDL on cLDL-C, dLDL-C, and other variables. We measured the levels of glucose, creatinine, total cholesterol, TG, HDL-C, and dLDL-C using standardized methods in 297 samples. For sdLDL cholesterol (sdLDL-C), a novel homogeneous assay was used. The cLDL-C was calculated using the Friedewald formula for 220 subjects after excluding for liver or renal disease. Using stepwise regression analysis identified non-HDL-C, cLDL-C, and dLDL-C as significant variables (P < .001; R(2) = 0.88). The regression equation was as follows: sdLDL-C (mg/dL) = 0.580 (non-HDL-C) + 0.407 (dLDL-C) - 0.719 (cLDL-C) - 12.05. The sdLDL-C concentration can be estimated from non-HDL-C, dLDL-C, and cLDL-C values. Identification of a simple, inexpensive marker for sdLDL particles provides a cost-effective method for screening cardiovascular disease risk.

Distinct effects of pitavastatin and atorvastatin on lipoprotein subclasses in patients with Type 2 diabetes mellitus

AIMS

Effects of pitavastatin and atorvastatin on the lipid profile and lipoprotein subclasses were compared in patients with Type 2 diabetes with dyslipidaemia.

METHODS

Patients with Type 2 diabetes with hypercholesterolaemia and/or hypertriglyceridaemia were randomized to receive pitavastatin 2 mg (n = 16) or atorvastatin 10 mg (n = 15) for 6 months, and blood lipid and lipoprotein profiles and cholesterol and triglyceride contents of 20 lipoprotein subclasses, determined by high-performance liquid chromatography, were compared.

RESULTS

At baseline, cholesterol in VLDL and LDL subclasses were increased equally in two groups of patients with diabetes as compared with normolipidaemic control subjects. As compared with baseline, serum levels of total cholesterol, LDL cholesterol, non-HDL cholesterol, LDL cholesterol:HDL cholesterol ratio and apolipoprotein B were decreased after 1, 3 and 6 months of treatment with atorvastatin and pitavastatin. Serum triglyceride levels were decreased after 1, 3 and 6 months of atorvastatin, but only at 3 months of pitavastatin. Serum HDL cholesterol was increased after 1, 3 and 6 months of pitavastatin, whereas HDL cholesterol was even decreased after 6 months of atorvastatin. Cholesterol levels of most VLDL and LDL subclasses were decreased equally in both groups. However, only pitavastatin increased cholesterol of medium HDL subclass. Serum triglyceride and triglyceride contents in VLDL and LDL subclasses were decreased only by atorvastatin.

CONCLUSIONS

The impact on lipoprotein subclass profiles was different between pitavastatin and atorvastatin. It may be beneficial to determine lipoprotein subclass profile and select the appropriate statin for each profile in patients with diabetes with an additional cardiovascular risk such as low HDL cholesterol or hypertriglyceridaemia.

Place of pitavastatin in the statin armamentarium: promising evidence for a role in diabetes mellitus

Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, known as statins, have revolutionized the treatment of hypercholesterolemia and coronary artery disease prevention. However, there are considerable issues regarding statin safety and further development of residual risk control, particularly for diabetic and metabolic syndrome patients. Pitavastatin is a potent statin with low-density lipoprotein (LDL) cholesterol-lowering effects comparable to those of atorvastatin or rosuvastatin. Pitavastatin has a high-density lipoprotein (HDL) cholesterol raising effect, may improve insulin resistance, and has little influence on glucose metabolism. Considering these factors along with its unique pharmacokinetic properties, which suggest minimal drug–drug interaction, pitavastatin could provide an alternative treatment choice, especially in patients with glucose intolerance or diabetes mellitus. Many clinical trials are now underway to test the clinical efficacy of pitavastatin in various settings and are expected to provide further information.

Protective effect of dietary tocotrienols against infection and inflammation-induced hyperlipidemia: an in vivo and in silico study

Currently used hypolipidemic drugs, Fluvastatin and Atorvastatin, act via inhibiting the rate-limiting enzyme 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase of the mevalonate pathway. The associated severe side-effects of these statins led us to explore the therapeutic potentials of naturally occurring Tocomin (mixture of dietary α-, β-, γ- and δ-tocotrienols). Tocomin (10 mg) was orally administered daily for 10 days before and 12 h after bacterial lipopolysaccharide (200 μg) or 24 h after zymosan (20 mg) or turpentine (0.5 mL) to Syrian hamsters. The data showed that Tocomin significantly reduced the levels of plasma and lipoprotein lipids, cholesterol, apoB, small dense (sd)-LDL as well as LDL in the hyperlipidemia-induced hamsters. Further, the mechanism of action of α-, β-, γ- and δ-tocotrienols was validated by docking studies with HMG-CoA reductase enzyme using the Molegro Virtual Docker. The inhibition of HMG-CoA reductase predicted in terms of MolDockScore and interaction energy suggest the comparative potential in the descending order: Atorvastatin > Fluvastatin ~ δ > γ > β > α. The results favor the daily intake of naturally occurring tocotrienols as dietary supplement in the prevention and treatment of infection/inflammation induced dyslipidemia compared with the hypolipidemic drugs.

Pitavastatin: a new 3-hydroxy-3-methylglutaryl coenzyme a reductase inhibitor for the treatment of hyperlipidemia

Statins have proven beneficial for reducing both primary and secondary events in patients with coronary heart disease. Tight control of serum lipid parameters in these patients is recommended by the most recent clinical guidelines. Although numerous lipid-lowering treatments are available, only a small percentage of eligible patients receive therapy and fewer achieve their lipid-lowering goals. Thus it is clear that new treatment strategies to manage patients with lipid abnormalities are warranted. Pitavastatin (Lival; Kowa Pharmaceuticals America, Montgomery, AL, USA) has been recently approved for the treatment of hypercholesterolemia and combined dyslipidemia. Pitavastatin 1-4 mg/day has shown similar low-density lipoprotein-reducing activity to other commercially available statins, including simvastatin and atorvastatin. Adverse events occurred at similar rates to other statins in clinical trials with favorable effects seen in patients with dyslipidemia and metabolic syndrome. Pharmacokinetic drug-drug interactions are minimized due to the lack of significant metabolism of pitavastatin by the cytochrome P450 enzyme system, although some drugs affect its uptake into hepatocytes and should be avoided. In addition to its higher acquisition cost, pitavastatin has not been shown to improve clinical outcomes in high-risk patient populations and thus may not be the agent of choice in many patients at this time in lieu of cheaper, clinically proven alternatives.

Anti-obesity effect of fish oil and fish oil-fenofibrate combination in female KK mice

AIM

The aim of our study is to elucidate the effects of EPA- or DHA-rich fish oil, and of the latter plus fenofibrate, on lipid metabolism in female KK mice.

METHODS

Female KK mice were fed purified experimental diets containing lard/safflower oil (4:6, Lard/SO), EPA-rich fish oil (EPA), DHA-rich fish oil (DHA), or DHA-rich fish oil plus 0.2% (w/w) fenofibrate (DHA+FF) for 8 weeks. At the end of the experiments, we measured levels of plasma lipids, hepatic triglycerides, and cholesterol, as well as the hepatic mRNA expression of lipogenic and lipidolytic genes.

RESULTS

The final body weight of EPA- and DHA-fed groups was significantly lower than that of the Lard/SO-fed group, and that of the DHA+FF-fed group was the lowest. All three fish oil treatments significantly reduced plasma insulin levels. Hepatic lipid levels significantly decreased in all three of these groups compared with the Lard/SO-fed group. Plasma adiponectin increased in both the EPA-and DHA-fed groups, but the increase was suppressed in the DHA+FF-fed group. Hepatocytes of Lard/SO-fed mice were filled with numerous fat droplets, but fat accumulation was inhibited in both EPA- and DHA-fed mice and was significantly prevented by fenofibrate treatment. SREBP-1c mRNA levels were decreased by about half in EPA- and DHA-fed mice compared with Lard/SO-fed mice. FAS, Insig-1, HMG-CoA reductase, and LDL-receptor mRNA levels also markedly decreased in both EPA- and DHA-fed mice, but there was no additional decrease in DHA+FF fed mice. Fenofibrate treatment significantly induced mRNA expression of AOX and UCP-2, but not of PPARalpha.

CONCLUSION

These data suggest that fish oil inhibited body weight gain and exhibited an anti-obesity effect through the inhibition of lipid synthesis in female KK mice. Furthermore, fenofibrate treatment markedly inhibited body weight gain by the induction of fatty acid oxidation. Plasma adiponectin levels did not increase in mice fed DHA-rich fish oil with fenofibrate, although white adipose tissue (WAT) weight significantly decreased. We considered that adiponectin sensitivity increased more in mice fed DHA-rich fish oil with fenofibrate than in mice fed DHA-rich fish oil alone.

Effects of different statin treatments on small dense low-density lipoprotein in patients with metabolic syndrome

AIM

To compare the effects of different low-density lipoprotein (LDL) cholesterol-lowering statin treatments on small dense LDL (sd-LDL) in hypercholesterolemic patients with metabolic syndrome (MetS).

METHODS

Forty hypercholesterolemic MetS patients ?30 years of age were randomized to rosuvas-tatin (n=17) or other statins (n=23) groups. In the other statins group, those taking atorvastatin (n=12) were also evaluated separately. Statin doses were 10 mg/day rosuvastatin, 20 mg/day atorvas-tatin, 40 mg/day simvastatin, and 40 mg/day pravastatin. Treatment duration was planned to be 8 weeks. Sd-LDL levels were assessed at baseline and at the completion of treatment.

RESULTS

After treatment, sd-LDL levels were significantly reduced in all 3 groups (from 29.6+/-24.8 mg/dL to 8.9+/-8.5 mg/dL in the rosuvastatin group, p=0.001; from 26.2+/-15 mg/dL to 14.8+/-9.6 mg/dL in the atorvastatin group, p=0.02; and from 29.1+/-16.5 mg/dL to 14.7+/-11.2 mg/dL in the other statins group, p=0.0001). There was no significant difference in the mean percent changes among groups.

CONCLUSION

Significant reduction in sd-LDL levels was observed after 8 weeks of statin treatment in hypercholesterolemic patients with MetS. This effect was similar for all statins and can be considered a class effect.

Interaction of fenofibrate and fish oil in relation to lipid metabolism in mice

AIM

The aim of our study is to elucidate the interactive effects on lipid metabolism of fenofibrate and two fish oils with EPA and DHA contents in mice.

METHODS

Female C57BL/6J mice were fed purified experimental diets containing safflower oil (SO), EPA-rich menhaden oil (MO) or DHA-rich tuna oil (TO) with or without 0.1% fenofibrate for 8 weeks. At the end of the experiments, we measured plasma lipids and hepatic triglycerides and cholesterol, and the hepatic mRNA expression of lipogenic and lipidolytic genes.

RESULTS

Plasma TG levels fell in the group fed MO or TO alone and fell significantly in all fenofibrate-treated groups. Although plasma total cholesterol levels fell significantly in fish oil-fed groups, fenofibrate treatments increased significantly plasma total cholesterol levels in these fish oil groups, but not in the group fed SO alone; however, hepatic triglyceride and total cholesterol levels markedly decreased in MO-or TO-fed mice. In lipid synthesis, the hepatic mRNA level of SREBP-1c was not reduced in either fish oil group; however, Insig-1 mRNA decreased in MO and TO feeding groups by about half and FAS or SCD-1 mRNA decreased significantly in MO and TO feeding groups, compared with the SO feeding group. In both fish oil groups, SREBP-2 mRNA decreased significantly and HMG-CoA reductase mRNA also decreased with/without fenofibrate. On the other hand, fenofibrate supplementation significantly induced the mRNA expression of AOX and UCP-2, which play a role in lipid catabolism, in all diets. CYP7A1 mRNA increased markedly in mice fed MO diet with fenofibrate, compared with TO diet with fenofibrate.

CONCLUSION

These data suggest that differences in dietary contents of EPA and DHA do not influence the inhibition of lipogenesis, and that fenofibrate supplementation stimulates fatty acid oxidation, regardless of the oil type; however, cholesterol catabolism was induced by a combination of EPA-rich fish oil and fenofibrate, which suggests that EPA has a greater synergistic ability for cholesterol catabolism induction by fenofibrate than DHA.

Effects of statin on small dense low-density lipoprotein cholesterol and remnant-like particle cholesterol in heterozygous familial hypercholesterolemia

AIM

The effects of statin on small dense low-density lipoprotein cholesterol (sd-LDL-C) and remnant-like particle cholesterol (RLP-C) levels in heterozygous familial hypercholesterolemia (FH) have not been examined. This study aimed to clarify the effects of statin on sd-LDL-C and RLP-C levels in heterozygous FH.

METHODS

Seventeen patients with heterozygous FH were randomly assigned to 2 mg/day pitavastatin or 10 mg/day atorvastatin. At baseline and 12 weeks after treatment with statin, we measured sd-LDL-C and RLP-C levels.

RESULTS

Sd-LDL-C levels significantly decreased from 43 +/- 24 to 16 +/- 10 mg/dL (-63%, p=0.001) in the pitavastatin group, and from 44 +/- 17 to 19 +/- 10 mg/dL (-55%, p<0.001) in the atorvastatin group. RLP-C levels decreased from 8.4 +/- 2.8 to 6.6 +/- 2.7 mg/dL (-16%, p=0.156) in the pitava-statin group, and from 9.8 +/- 4.7 to 5.9 +/- 5.4 mg/dL (-45%, p=0.044) in the atorvastatin group. There were no significant differences in percent changes of sd-LDL-C (p=0.370) and RLP-C levels (p=0.097) between the two groups.

CONCLUSIONS

Sd-LDL-C measured by the heparin-magnesium precipitation method and RLP-C levels in heterozygous FH were decreased by 12 weeks of statin therapy. Statin might have additional anti-atherogenic effects by reducing not only LDL-C but also sd-LDL-C and RLP-C.

Is There a Role for Fibrates in the Management of Dyslipidemia in the Metabolic Syndrome?

The outcomes of fibrate trials have varied: positive with gemfibrozil in the primary prevention Helsinki Heart Study and the secondary prevention VA-HIT trial; positive with reservations in the primary prevention WHO trial (clofibrate); and mixed with bezafibrate in the secondary prevention BIP study and with fenofibrate in the combined primary and secondary prevention FIELD study. Overall, the mixed results, combined with potential for adverse effects when given in combination with statins, have limited the use of these fibrates as cardioprotective agents. However, post hoc analyses of several of the fibrate studies have shown that people with features of the metabolic syndrome, particularly overweight people with high plasma triglyceride levels and low levels of HDL cholesterol, derive a disproportionately large reduction in cardiovascular events when treated with these agents. Thus, there is a strong case for the use of a fibrate to reduce the cardiovascular risk in overweight people with high triglyceride and low HDL-C. However, it should be noted that such people also have their cardiovascular risk reduced by statin therapy. It remains to be determined whether the combination of a fibrate plus statin reduces the risk beyond that achieved with a statin alone.