Inhibition of isoprenoid biosynthesis causes insulin resistance in 3T3-L1 adipocytes

Drug-induced mitochondrial toxicity: Risks of developing glucose handling impairments

Mitochondrial impairment has been associated with the development of insulin resistance, the hallmark of type 2 diabetes mellitus (T2DM). However, the relationship between mitochondrial impairment and insulin resistance is not fully elucidated due to insufficient evidence to support the hypothesis. Insulin resistance and insulin deficiency are both characterised by excessive production of reactive oxygen species and mitochondrial coupling. Compelling evidence states that improving the function of the mitochondria may provide a positive therapeutic tool for improving insulin sensitivity. There has been a rapid increase in reports of the toxic effects of drugs and pollutants on the mitochondria in recent decades, interestingly correlating with an increase in insulin resistance prevalence. A variety of drug classes have been reported to potentially induce toxicity in the mitochondria leading to skeletal muscle, liver, central nervous system, and kidney injury. With the increase in diabetes prevalence and mitochondrial toxicity, it is therefore imperative to understand how mitochondrial toxicological agents can potentially compromise insulin sensitivity. This review article aims to explore and summarise the correlation between potential mitochondrial dysfunction caused by selected pharmacological agents and its effect on insulin signalling and glucose handling. Additionally, this review highlights the necessity for further studies aimed to understand drug-induced mitochondrial toxicity and the development of insulin resistance.

Exenatide prevents statin-related LDL receptor increase and improves insulin secretion in pancreatic beta cells (1.1E7) in a protein kinase A-dependent manner

Statins are primary drugs in the treatment of hyperlipidemias. This group of drugs is known for its beneficial pleiotropic effects (e.g., reduction of inflammatory state). However, a growing body of evidence suggests its diabetogenic properties. The culpable mechanism is not completely understood and might be related to the damage to pancreatic beta cells. Therefore, we conceived an in vitro study to explore the impact of atorvastatin on pancreatic islet beta cells line (1.1.E7). We evaluated the influence on viability, insulin, low-density lipoprotein (LDL) receptor, and proprotein convertase subtilisin/kexin type 9 (PCSK9) expression. A significant drop in mRNA for proinsulin and insulin expression was noted. Concurrently, a rise in LDL receptor at the protein level in cells exposed to atorvastatin was noted. Further experiments have shown that exenatide - belonging to glucagon-like peptide 1 (GLP-1) analogs that are used in a treatment of diabetes and known for its weight reducing properties - can alleviate the observed alterations. In this case, the mechanism of action of exenatide was dependent on a protein kinase A pathway. In conclusion, our results support the hypothesis that statin may have diabetogenic properties, which according to our study is related to reduced insulin expression. The concomitant use of GLP-1 receptor agonist seemed to successfully revert insulin expression.

Choosing statins: a review to guide clinical practice

Statins are among the most widely prescribed medicines in the world and have proved their value in reducing cardiovascular events and mortality. Many patients report adverse effects that lead to interruption of treatment. This review aims to individualize statin treatment, considering efficacy for reducing cardiovascular risk and safety, in the setting of specific diseases, to minimize the side effects and improve compliance. We gathered evidence that may help clinicians to choose specific statins in different clinical situations, such as the risk of new diabetes, chronic kidney disease, liver disease, human immunodeficiency virus infection, organ transplant, heart failure and elderly people. Efficacy of statins is well established in a large number of clinical conditions. Therefore, main objective is to revise statin in specific clinical settings, based on pharmacokinetics, safety, drug metabolism and interactions to provide the best choice in different clinical scenarios.

Statins Are Associated With Increased Insulin Resistance and Secretion

Objective

Statin treatment reduces the risk of atherosclerotic cardiovascular disease but is associated with a modest increased risk of type 2 diabetes, especially in those with insulin resistance or prediabetes. Our objective was to determine the physiological mechanism for the increased type 2 diabetes risk.

Approach and Results

We conducted an open-label clinical trial of atorvastatin 40 mg daily in adults without known atherosclerotic cardiovascular disease or type 2 diabetes at baseline. The co-primary outcomes were changes at 10 weeks versus baseline in insulin resistance as assessed by steady-state plasma glucose during the insulin suppression test and insulin secretion as assessed by insulin secretion rate area under the curve (ISRAUC) during the graded-glucose infusion test. Secondary outcomes included glucose and insulin, both fasting and during oral glucose tolerance test. Of 75 participants who enrolled, 71 completed the study (median age 61 years, 37% women, 65% non-Hispanic White, median body mass index, 27.8 kg/m2). Atorvastatin reduced LDL (low-density lipoprotein)-cholesterol (median decrease 53%, P<0.001) but did not change body weight. Compared with baseline, atorvastatin increased insulin resistance (steady-state plasma glucose) by a median of 8% (P=0.01) and insulin secretion (ISRAUC) by a median of 9% (P<0.001). There were small increases in oral glucose tolerance test glucoseAUC (median increase, 0.05%; P=0.03) and fasting insulin (median increase, 7%; P=0.01).

Conclusions

In individuals without type 2 diabetes, high-intensity atorvastatin for 10 weeks increases insulin resistance and insulin secretion. Over time, the risk of new-onset diabetes with statin use may increase in individuals who become more insulin resistant but are unable to maintain compensatory increases in insulin secretion.

Predictive network modeling in human induced pluripotent stem cells identifies key driver genes for insulin responsiveness

Insulin resistance (IR) precedes the development of type 2 diabetes (T2D) and increases cardiovascular disease risk. Although genome wide association studies (GWAS) have uncovered new loci associated with T2D, their contribution to explain the mechanisms leading to decreased insulin sensitivity has been very limited. Thus, new approaches are necessary to explore the genetic architecture of insulin resistance. To that end, we generated an iPSC library across the spectrum of insulin sensitivity in humans. RNA-seq based analysis of 310 induced pluripotent stem cell (iPSC) clones derived from 100 individuals allowed us to identify differentially expressed genes between insulin resistant and sensitive iPSC lines. Analysis of the co-expression architecture uncovered several insulin sensitivity-relevant gene sub-networks, and predictive network modeling identified a set of key driver genes that regulate these co-expression modules. Functional validation in human adipocytes and skeletal muscle cells (SKMCs) confirmed the relevance of the key driver candidate genes for insulin responsiveness.

Insulin resistance is characterized by a defective response (“resistance”) to normal insulin concentrations to uptake the glucose present in the blood, and is the underlying condition that leads to type 2 diabetes (T2D) and increases the risk of cardiovascular disease. It is estimated that 25–33% of the US population are insulin resistant enough to be at risk of serious clinical consequences. For more than a decade, large population studies have tried to discover the genes that participate in the development of insulin resistance, but without much success. It is now increasingly clear that the complex genetic nature of insulin resistance requires novel approaches centered in patient specific cellular models. To fill this gap, we have generated an induced pluripotent stem cell (iPSC) library from individuals with accurate measurements of insulin sensitivity, and performed gene expression and key driver analyses. Our work demonstrates that iPSCs can be used as a revolutionary technology to model insulin resistance and to discover key genetic drivers. Moreover, they can develop our basic knowledge of the disease, and are ultimately expected to increase the therapeutic targets to treat insulin resistance and type 2 diabetes.

Statin Treatment-Induced Development of Type 2 Diabetes: From Clinical Evidence to Mechanistic Insights

Statins are the gold-standard treatment for the prevention of primary and secondary cardiovascular disease, which is the leading cause of mortality worldwide. Despite the safety and relative tolerability of statins, observational studies, clinical trials and meta-analyses indicate an increased risk of developing new-onset type 2 diabetes mellitus (T2DM) after long-term statin treatment. It has been shown that statins can impair insulin sensitivity and secretion by pancreatic β-cells and increase insulin resistance in peripheral tissues. The mechanisms involved in these processes include, among others, impaired Ca²⁺ signaling in pancreatic β-cells, down-regulation of GLUT-4 in adipocytes and compromised insulin signaling. In addition, it has also been described that statins’ impact on epigenetics may also contribute to statin-induced T2DM via differential expression of microRNAs. This review focuses on the evidence and mechanisms by which statin therapy is associated with the development of T2DM. This review describes the multifactorial combination of effects that most likely contributes to the diabetogenic effects of statins. Clinically, these findings should encourage clinicians to consider diabetes monitoring in patients receiving statin therapy in order to ensure early diagnosis and appropriate management.

Impaired glucagon suppression and reduced insulin sensitivity in subjects with prediabetes undergoing atorvastatin therapy

OBJECTIVE

Statin therapy has been linked to an increased risk of type 2 diabetes in high-risk populations; however, the pathophysiology of this association remains to be clarified. We investigated glucagon suppression and its relationship with insulin resistance in prediabetic subjects undergoing atorvastatin therapy; in addition, we studied molecular insulin signaling in pancreatic α-cells exposed to atorvastatin in vitro.

DESIGN AND METHODS

Fifty subjects with prediabetes were divided into two groups based on atorvastatin therapy. All subjects underwent an oral glucose tolerance test. Early (0-30 min), late (30-120 min) and overall (0-120 min) glucagon suppression were evaluated. Insulin sensitivity was estimated by the insulin sensitivity index (ISI0-120). Insulin signaling pathway and insulin-mediated glucagon suppression were investigated in pancreatic αTC1-6 cells chronically exposed (24 or 48 h) to atorvastatin (100 ng/mL).

RESULTS

Individuals on statin therapy (n = 26) showed a significantly reduced early (0-30 min) (P = 0.003) and overall (0-120 min) (P = 0.01) glucagon suppression compared with controls (n = 24). In multivariate regression analysis, early glucagon suppression (0-30 min) exhibited a significant correlation with statin therapy. Regression analysis showed a significant association between ISI 0-120 and early0-30 (r = 0.33, P < 0.05) and overall0-120 (r = 0.38, P < 0.05) glucagon suppression. Moreover, in αTC1-6 cells atorvastatin treatment affected insulin-mediated glucagon suppression, insulin receptor phosphorylation and IRS-1-AKT pathway signaling.

CONCLUSIONS

Prediabetic patients undergoing statin therapy exhibit impaired glucagon suppression associated with lower insulin sensitivity. Our data revealed a new molecular aspect behind the deregulation of insulin sensitivity secondary to statin exposure.

Statin Short-term Inhibition of Insulin Sensitivity and Secretion During Acute Phase of ST-Elevation Myocardial Infarction

Hyperglycemia during myocardial infarction (MI) has a strong and direct association with mortality. In stable patients and experimental models, statins favor the elevation of glycaemia. The present study investigated whether short-course treatment with statins during MI can influence glucose homeostasis and thus the clinical outcome. In this prospective study, euglycemic hyperinsulinemic clamp (EHC) was performed at second (D2) and sixth (D6) day after MI in patients randomized to simvastatin (S)10 or 80 mg/day during hospitalization (n = 27). In addition, patients (n = 550) were treated without (WS) or with simvastatin (S) at 20, 40 or 80 mg/day had HOMA2S on admission (D1) and fifth (D5) day after MI. According to EHC, insulin sensitivity increased by 20 ± 60% in S10 and decreased by −6 ± 28% in S80 (p = 0.025). Consistently, the changes in HOMA2S between D1 and D5 were 40 ± 145% (WS), 22 ± 117% (S20), 16 ± 61% (S40) and −2% ± 88% (S80) (p = 0.001). In conclusion, statin during the acute phase of MI reduces insulin sensitivity in a dose-dependent manner.

Mechanisms of statin‐induced new‐onset diabetes

Statins, with their lipid‐lowering properties, are a first‐line therapy for the prevention of cardiovascular diseases. Recent evidence, however, suggests that statins can increase the risk of new‐onset diabetes (NOD). The molecular mechanisms of statin‐induced NOD are not precisely known, although some pathophysiologic mechanisms have been suggested. Specific to the beta cell, these mechanisms include alterations in insulin secretion, changes in ion channels, modulation of signaling pathways, and inflammation/oxidative stress. Outwith the beta cell, other suggested mechanisms involve adipocytes, including alterations in adipocyte differentiation and modulation of leptin and adiponectin, and genetic and epigenetic mechanisms, including alterations in microRNA. The evidence supporting these and other mechanisms will be discussed. Greater understanding of the underlying mechanisms linking the onset of diabetes to statin therapy is essential and clinically relevant, as it may enable novel preventative or therapeutic approaches to be instituted and guide the production of a new generation of statins lacking this side effect.

The effect of atorvastatin on cardiometabolic risk factors in women with non-classic congenital adrenal hyperplasia: A pilot study

BACKGROUND

Individuals with non-classic congenital adrenal hyperplasia (NC-CAH) often show evidence of hyperandrogenism, including premature pubarche, accelerated linear growth velocity, short final height, hirsutism, acne, alopecia, impaired ovulation, menstrual dysfunction and subfertility. Although statins were found to reduce elevated levels of androgens in subjects with this disorder, no previous study has investigated whether 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors affect cardiometabolic risk factors in patients with NC-CAH.

METHODS

We studied 12 women with NC-CAH, 6 of whom because of coexisting hypercholesterolemia received atorvastatin (20-40 mg daily). Circulating levels of lipids, glucose homeostasis markers, plasma levels of androgens, 17-hydroxyprogesterone, high-sensitivity C-reactive protein (hsCRP), uric acid, fibrinogen, homocysteine and 25-hydroxyvitamin D, as well as urinary albumin-to-creatinine ratio (UACR) were determined at the beginning of the study and 12 weeks later.

RESULTS

Beyond affecting plasma lipids, atorvastatin reduced circulating levels of testosterone, dehydroepiandrosterone sulphate, androstenedione and 17-hydroxyprogesterone, and decreased free androgen index. Moreover, atorvastatin caused a decrease in plasma levels/urinary loss of uric acid, hsCRP, homocysteine and UACR, and insignificantly increased circulating levels of 25-hydroxyvitamin D. The drug produced no effect on plasma fibrinogen. The effect of atorvastatin on hsCRP, uric acid, homocysteine, 25-hydroxyvitamin D and UACR correlated with the magnitude of reduction in 17-hydroxyprogesterone and androgens.

CONCLUSION

Our results suggest that statin therapy reduces cardiometabolic risk in women with NC-CAH.

Coenzyme Q10 does not improve peripheral insulin sensitivity in statin-treated men and women: the LIFESTAT study

Simvastatin is a cholesterol-lowering drug that is prescribed to lower the risk of cardiovascular disease following high levels of blood cholesterol. There is a possible risk of new-onset diabetes mellitus with statin treatment but the mechanisms behind are unknown. Coenzyme Q10 (CoQ10) supplementation has been found to improve glucose homeostasis in various patient populations and may increase muscle glucose transporter type 4 content. Our aim was to investigate if 8 weeks of CoQ10 supplementation can improve glucose homeostasis in simvastatin-treated subjects. Thirty-five men and women in treatment with a minimum of 40 mg of simvastatin daily were randomized to receive either 2 × 200 mg/day of CoQ10 supplementation or placebo for 8 weeks. Glucose homeostasis was investigated with fasting blood samples, oral glucose tolerance test (OGTT) and intravenous glucose tolerance test. Insulin sensitivity was assessed with the hyperinsulinemic-euglycemic clamp. Different indices were calculated from fasting samples and OGTT as secondary measures of insulin sensitivity. A muscle biopsy was obtained from the vastus lateralis muscle for muscle protein analyzes. There were no changes in body composition, fasting plasma insulin, fasting plasma glucose, or 3-h glucose with intervention, but glycated hemoglobin decreased with time. Glucose homeostasis measured as the area under the curve for glucose, insulin, and C-peptide during OGTT was unchanged after intervention. Insulin secretory capacity was also unaltered after CoQ10 supplementation. Insulin sensitivity was unchanged but hepatic insulin sensitivity increased. No changes in muscle GLUT4 content was observed after intervention. CoQ10 supplementation does not change muscle GLUT4 content, insulin sensitivity, or secretory capacity, but hepatic insulin sensitivity may improve.

The Association of Statin Therapy with Incident Diabetes: Evidence, Mechanisms, and Recommendations

PURPOSE OF REVIEW

Recent studies have demonstrated a higher risk of incident diabetes associated with statin use, causing concern among patients and clinicians. In this review, we will assess the evidence and proposed mechanisms behind statin therapy and its association with incident diabetes. We will then review the current recommendations for statin use in light of this association and suggest next steps for clinicians managing these patients and researchers exploring this phenomenon.

RECENT FINDINGS

The annual risk of developing new-onset diabetes with statin treatment is approximately 0.1%. In comparison, the absolute risk reduction of major coronary events with statin use is approximately 0.42% annually. Statins are associated with the development of incident diabetes, particularly among those with predisposing risk factors for diabetes. However, the benefit of statin use among these patients in preventing major coronary events strongly favors statin use despite its risk of incident diabetes.

Drugs Involved in Dyslipidemia and Obesity Treatment: Focus on Adipose Tissue

Metabolic syndrome can be defined as a state of disturbed metabolic homeostasis characterized by visceral obesity, atherogenic dyslipidemia, arterial hypertension, and insulin resistance. The growing prevalence of metabolic syndrome will certainly contribute to the burden of cardiovascular disease. Obesity and dyslipidemia are main features of metabolic syndrome, and both can present with adipose tissue dysfunction, involved in the pathogenic mechanisms underlying this syndrome. We revised the effects, and underlying mechanisms, of the current approved drugs for dyslipidemia and obesity (fibrates, statins, niacin, resins, ezetimibe, and orlistat; sibutramine; and diethylpropion, phentermine/topiramate, bupropion and naltrexone, and liraglutide) on adipose tissue. Specifically, we explored how these drugs can modulate the complex pathways involved in metabolism, inflammation, atherogenesis, insulin sensitivity, and adipogenesis. The clinical outcomes of adipose tissue modulation by these drugs, as well as differences of major importance for clinical practice between drugs of the same class, were identified. Whether solutions to these issues will be found in further adjustments and combinations between drugs already in use or necessarily in new advances in pharmacology is not known. To better understand the effect of drugs used in dyslipidemia and obesity on adipose tissue not only is challenging for physicians but could also be the next step to tackle cardiovascular disease.

Functional Implications of HMG-CoA Reductase Inhibition on Glucose Metabolism

HMG-CoA reductase inhibitors, i.e. statins, are effective in reducing cardiovascular disease events but also in cardiac-related and overall mortality. Statins are in general well-tolerated, but currently the concerns are raised if statins may increase the risk of new-onset diabetes mellitus (NOD). In this review, the possible effects of statins on organs/tissues being involved in glucose metabolism, i.e. liver, pancreas, adipose tissue, and muscles, had been discussed. The net outcome seems to be inconsistent and often contradictory, which may be largely affected by in vitro experimental settings or/and in vivo animal conditions. The majority of studies point out statin-induced changes of regulations of isoprenoid metabolites and cell-associated cholesterol contents as predisposing factors related to the statin-induced NOD. On the other hand, it should be considered that dysfunctions of isoprenoid pathway and mitochondrial ATP production and the cholesterol homeostasis are already developed under (pre)diabetic and hypercholesterolemic conditions. In order to connect the basic findings with the clinical manifestation more clearly, further research efforts are needed.

Estrogen receptor 1 (ESR1) regulates VEGFA in adipose tissue

Vascular endothelial growth factor A (VEGFA) is a key factor in the regulation of angiogenesis in adipose tissue. Poor vascularization during adipose tissue proliferation causes fibrosis and local inflammation, and is associated with insulin resistance. It is known that 17-beta estradiol (E2) regulates adipose tissue function and VEGFA expression in other tissues; however, the ability of E2 to regulate VEGFA in adipose tissue is currently unknown. In this study, we showed that, in 3T3-L1 cells, E2 and the estrogen receptor 1 (ESR1) agonist PPT induced VEGFA expression, while ESR1 antagonist (MPP), and selective knockdown of ESR1 using siRNA decreased VEGFA and prevented the ability of E2 to modulate its expression. Additionally, we found that E2 and PPT induced the binding of hypoxia inducible factor 1 alpha subunit (HIF1A) in the VEGFA gene promoter. We further found that VEGFA expression was lower in inguinal and gonadal white adipose tissues of ESR1 total body knockout female mice compared to wild type mice. In conclusion, our data provide evidence of an important role for E2/ESR1 in modulating adipose tissue VEGFA, which is potentially important to enhance angiogenesis, reduce inflammation and improve adipose tissue function.

Pleiotropic effects of metformin to rescue statin-induced muscle injury and insulin resistance: A proposed mechanism and potential clinical implications

The 2013 American Heart Association Blood Cholesterol Guidelines increased the number of patients recommended for statin therapy in the United States to 56million. Two common statin side effects are muscle pain, referred to as "statin-associated muscle symptoms", and increased risk for new onset type-2-diabetes mellitus. Up to 25% of statin users report muscle symptoms resulting in many patients being switched to lower dose or lower potency statins, or refusing statins altogether. The most likely signaling mechanisms for statin-associated muscle symptoms overlaps with the proposed mechanism of statin-induced insulin resistance. Metformin has outstanding utility in reducing insulin resistance and preventing type-2-diabetes mellitus, but has not been studied for statin-associated muscle symptom rescue or prevention. The overlapping mechanisms of statin-associated muscle symptoms, statin-induced insulin resistance, and metformin intervention offers the potential to address two common and detrimental side effects of statins. As statins are the single best medication class for preventing cardiovascular events the potential for clinical benefit is large given metabolic syndrome's growing prevalence in the United States. Herein we hypothesize that metformin will rescue and prevent patients from statin-associated muscle symptoms. This hypothesis can benefit two patient groups: 1) patients at risk for diabetes who are taking a statin and experiencing muscle symptoms; and 2) patients with diabetes taking metformin who are to be started on a statin. Method to test Group 1) Symptom Rescue: randomized control trial of metformin versus placebo in patients with prediabetes who are already taking a statin, and are experiencing mild-to-moderate muscle symptoms. Method to test Group 2) Symptom Prevention: meta-analysis, of statin randomized control trials, with patient level data, comparing patients taking metformin at baseline to patients not taking metformin when a statin is started. An efficient method to simulate both symptom rescue and symptom prevention is a skeletal muscle cell culture model of statin-associated muscle symptom markers. These experiments would identify if metformin reverses (rescues) or prevents markers of statin-associated muscle symptoms. As metformin is recommended by the American Diabetes Association for type-2-diabetes mellitus prevention, yet not frequently used, validating this hypothesis will lead towards research and practice change including: a) decreases in the frequency of statin-associated muscle symptoms; leading to subsequent increases in statin therapy compliance; b) increases in metformin use in prediabetes with subsequent decrease in the incidence of type-2-diabetes mellitus; and c) decreases in complications of both cardiovascular disease and diabetes due to improved statin compliance and type-2-diabetes mellitus prevention.

Statin-Associated Side Effects

Hydroxy-methyl-glutaryl-coenzyme A (HMG-CoA) reductase inhibitors or statins are well tolerated, but associated with various statin-associated symptoms (SAS), including statin-associated muscle symptoms (SAMS), diabetes mellitus (DM), and central nervous system complaints. These are "statin-associated symptoms" because they are rare in clinical trials, making their causative relationship to statins unclear. SAS are, nevertheless, important because they prompt dose reduction or discontinuation of these life-saving mediations. SAMS is the most frequent SAS, and mild myalgia may affect 5% to 10% of statin users. Clinically important muscle symptoms, including rhabdomyolysis and statin-induced necrotizing autoimmune myopathy (SINAM), are rare. Antibodies against HMG-CoA reductase apparently provoke SINAM. Good evidence links statins to DM, but evidence linking statins to other SAS is largely anecdotal. Management of SAS requires making the possible diagnosis, altering or discontinuing the statin treatment, and using alternative lipid-lowering therapy.

Effect of Atorvastatin on Glycaemic Parameters in Normoglycaemic and Prediabetic Subjects: A Prospective, Panel Study

INTRODUCTION

Type 2 diabetes is associated with obesity and dyslipidemia, which are risk factor for cardiovascular disease. With recent FDA approved indications for statins being widened because of its lipid lowering and pleiotropic effects, statins are currently amongst the most widely used drugs in patients with or without diabetes. Although cardiovascular risk is reduced by statin therapy, its association with the development of diabetes is disputed.

AIM

This study was conducted to evaluate the effect of Atorvastatin on glycaemic status of normoglycaemic and prediabetic individuals.

MATERIALS AND METHODS

An observational, prospective panel study was conducted on 75 subjects who were on Atorvastatin therapy. After baseline data collection and investigations, subjects were recruited depending on their glycaemic status into three groups: normoglycaemic, Impaired Fasting Glucose (IFG) and Impaired Glucose Tolerance (IGT) group. Atorvastatin therapy was continued and the subjects were followed every 6 months up to 18 months. At every follow up all glycaemic parameters were evaluated and subjects were assessed for continuation of statin therapy, dosing schedule and possible adverse drug reactions.

RESULT

All three groups as a whole, irrespective of dose of Atrovastatin therapy, showed a statistically significant (p<0.0001) increase in all glycaemic parameters. In normoglycaemic group with low dose Atorvastatin, there was no significant change in 2-hour Post Prandial Blood Sugar (PPBS) but change in HbA1c% (p=0.0004) and FBS (p<0.0001) was significant, whereas, with high dose, changes in 2-hr PPBS and HbA1c % were significant from 6 months onwards. In IFG group, both with low and high dose of Atorvastatin, there was significant change in all glycaemic parameters from 12 months onwards. In case of IGT, especially with high dose Atorvastatin, significant changes were evident from 6 months onwards.

CONCLUSION

Atorvastatin therapy especially with higher dose was found to be associated with glucose intolerance in normoglycaemics and also caused progression towards diabetes in prediabetic individuals.

Association between familial hypobetalipoproteinemia and the risk of diabetes. Is this the other side of the cholesterol-diabetes connection? A systematic review of literature

Statin therapy is beneficial in reducing LDL cholesterol (LDL-C) levels and cardiovascular events, but it is associated with the risk of incident diabetes mellitus (DM). Familial hypercholesterolemia (FH) is characterized by genetically determined high levels of plasma LDL-C and a low prevalence of DM. LDL-C levels seem then inversely correlated with prevalence of DM. Familial hypobetalipoproteinemia (FHBL) represents the genetic mirror of FH in terms of LDL-C levels, very low in subjects carrying mutations of APOB, PCSK9 (FHBL1) or ANGPTL3 (FHBL2). This review explores the hypothesis that FHBL might represent also the genetic mirror of FH in terms of prevalence of DM and that it is expected to be increased in FHBL in comparison with the general population. A systematic review of published literature on FHBL was made by searching PubMed (1980-2016) for articles presenting clinical data on FHBL probands and relatives. The standardized prevalence rates of DM in FHBL1 were similar to those of the reference population, with a prevalence rate of 8.2 and 9.2%, respectively, while FHBL2 showed a 4.9% prevalence of DM. In conclusion, low LDL-C levels of FHBL do not seem connected to DM as it happens in subjects undergoing statin therapy and the diabetogenic effect of statins has to be explained by mechanisms that do not rely exclusively on the reduced levels of LDL-C. The review also summarizes the published data on the effects of FHBL on insulin sensitivity and the relationships between FH, statin therapy, FHBL1 and intracellular cholesterol metabolism, evaluating possible diabetogenic pathways.

Lessons from basic pancreatic beta cell research in type-2 diabetes and vascular complications

The changes in life-style with increased access of food and reduced physical activity have resulted in the global epidemic of obesity. Consequently, individuals with type 2 diabetes and cardiovascular disease have also escalated. A central organ in the development of diabetes is the pancreas, and more specifically the pancreatic beta cells within the islets of Langerhans. Beta cells have been assigned the important task of secreting insulin when blood glucose is increased to lower the glucose level. An early sign of diabetes pathogenesis is lack of first phase insulin response and reduced second phase secretion. In this review, which is based on the foreign investigator award lecture given at the JSDC meeting in Sendai in October 2016, we discuss a possible cellular explanation for the reduced first phase insulin response and how this can be influenced by lipids. Moreover, since patients with cardiovascular disease and high levels of cholesterol are often treated with statins, we summarize recent data regarding effects on statins on glucose homeostasis and insulin secretion. Finally, we suggest microRNAs (miRNAs) as central players in the adjustment of beta cell function during the development of diabetes. We specifically discuss miRNAs regarding their involvement in insulin secretion regulation, differential expression in type 2 diabetes, and potential as biomarkers for prediction of diabetes and cardiovascular complications.

Statin use and risk of developing diabetes: results from the Diabetes Prevention Program

OBJECTIVE

Several clinical trials of cardiovascular disease prevention with statins have reported increased risk of type 2 diabetes (T2DM) with statin therapy. However, participants in these studies were at relatively low risk for diabetes. Further, diabetes was often based on self-report and was not the primary outcome. It is unknown whether statins similarly modify diabetes risk in higher risk populations.

RESEARCH DESIGN AND METHODS

During the Diabetes Prevention Program Outcomes Study (n=3234), the long-term follow-up to a randomized clinical trial of interventions to prevent T2DM, incident diabetes was assessed by annual 75 g oral glucose tolerance testing and semiannual fasting glucose. Lipid profile was measured annually, with statin treatment determined by a participant's own physician outside of the protocol. Statin use was assessed at baseline and semiannual visits.

RESULTS

At 10 years, the cumulative incidence of statin initiation prior to diabetes diagnosis was 33%-37% among the randomized treatment groups (p=0.36). Statin use was associated with greater diabetes risk irrespective of treatment group, with pooled HR (95% CI) for incident diabetes of 1.36 (1.17 to 1.58). This risk was not materially altered by adjustment for baseline diabetes risk factors and potential confounders related to indications for statin therapy.

CONCLUSIONS

In this population at high risk for diabetes, we observed significantly higher rates of diabetes with statin therapy in all three treatment groups. Confounding by indication for statin use does not appear to explain this relationship. The effect of statins to increase diabetes risk appears to extend to populations at high risk for diabetes.

TRIAL REGISTRATION NUMBER

NCT00038727; Results.

Impact of statin therapy on plasma leptin concentrations: a systematic review and meta-analysis of randomized placebo-controlled trials

OBJECTIVES

The effects of statins on insulin sensitivity, metabolic homeostasis and adipokines in humans are controversial. Several studies have investigated the impact of statin therapy on plasma leptin concentrations but the results have been inconsistent. The aim of the present study was to conduct a systematic review and meta-analysis of available evidence to calculate the effect size of statin therapy in changing serum leptin concentrations.

METHODS

A systematic search in PubMed-Medline, SCOPUS, Web of Science and Google Scholar databases was performed to identify randomized placebo-controlled trials investigating the effect of statins on plasma leptin concentrations. A random-effects model and generic inverse variance method were used for meta-analysis. Sensitivity analysis, risk-of-bias evaluation and publication bias assessment were carried out using standard methods. Random-effects meta-regression was used to evaluate the impact of treatment duration on the estimated effect size.

RESULTS

Six trials, with a total of 425 subjects, met the eligibility criteria. Overall, statin therapy had no significant effect on leptin levels (weighted mean difference -0.32 ng ml^-1 , 95% confidence nterval: -2.94, 2.30, P = 0.813). This effect was robust in the sensitivity analysis and in subgroup analyses of trials with <12 or ≥12 weeks' duration. There was no association between the duration of statin therapy and changes in plasma leptin levels. Furthermore, there was no differential effect of hydrophilic and lipophilic statins on plasma leptin concentrations.

CONCLUSION

Unless more consistent evidence becomes available in the future, the hypothesis of a relationship between statin use and serum leptin concentrations seem to be unfounded.

Simvastatin inhibits glucose uptake activity and GLUT4 translocation through suppression of the IR/IRS-1/Akt signaling in C2C12 myotubes

Simvastatin,a 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitor, is clinically used in the prevention and treatment of cardiovascular diseases. Numerous studies demonstrate that statins increase the risk of new-onset diabetes in long-term therapy, but mechanisms underpinning this effect are still unclear. Here, we investigated whether simvastatin inhibited the glucose uptake activity and the underlying mechanisms in C2C12 myotubes. Our studies showed that simvastatin significantly inhibited glucose uptake activity and GLUT4 translocation, whereas the effect was reversible with mevalonolactone (ML), which acts as an intermediate of cholesterol synthesis pathway. Mechanistically, the inhibition of glucose uptake and GLUT4 translocation elicited by simvastatin were associated with the suppression of the insulin receptor (IR)/IR substrate (IRS)/Akt signaling cascade. Simvastatin suppressed the phosphorylation of IR, IRS-1 and Akt, and total expression of IR or IRS-1, but did not affect Akt. Furthermore, simvastatin decreased Rac1 GTP binding. In conclusion, our findings indicate that simvastatin suppresses glucose uptake activity and GLUT4 translocation via IR-dependent IRS-1/PI3K/Akt pathway. These results provide an important new insight into the mechanism of statins on insulin sensitivity which may be associated with new-onset diabetes.

Statin Use and the Risk for Incident Diabetes Mellitus in Patients with Acute Coronary Syndrome after Percutaneous Coronary Intervention: A Population-Based Retrospective Cohort Study in Taiwan

OBJECTIVES

The purpose of this study was to examine the association between statin use by individuals and the risk for incident diabetes mellitus in patients with acute coronary syndrome (ACS) following percutaneous coronary intervention (PCI).

METHODS

We conducted a retrospective cohort study of patients who were hospitalized for ACS between January 1, 2006, and December 31, 2010, and who had undergone PCI (n=30,665); the data were retrieved from the Taiwan National Health Insurance Research Database. A propensity score technique was used to establish a 1:1 matched cohort for statin users and non-statin users (n=9043 for each group). The risk for incident diabetes mellitus in statin users compared to non-statin users for patients with ACS after PCI was estimated by the multivariable Cox proportional hazards regression model.

RESULTS

Statin use was associated with a significant increase of 27% in the risk for new-onset diabetes mellitus (adjusted hazard ratio [HR] 1.27, 95% CI 1.14 to 1.41) compared to non-statin use in the matched cohort. The matched cohort analysis indicated that almost all individual statins were associated with a statistically significant increase in the risk for new-onset diabetes mellitus compared to those without statin use.

CONCLUSIONS

Our study indicated an association between increased risk for new-onset diabetes mellitus and statin use. Because the benefits of statins in prevention of morbidity and mortality in patients with ACS are well-established, clinical decision making should not be changed for patients with existing cardiovascular disease in whom statin therapy is recommended.

The diabetogenic action of statins - mechanisms and clinical implications

Treatment with statins has transformed primary and secondary prevention of cardiovascular disease (CVD), including thrombotic stroke. Evidence-based data demonstrate the benefits and safety of statin therapy and help to guide clinicians in the management of populations at high risk of CVD. Nevertheless, clinical trials, meta-analyses and observational studies highlight a 10-12% increase in new-onset diabetes mellitus (NODM) among patients receiving statins. The risk further increases with intensive therapy and among individuals with known risk factors for NODM. Mechanisms underpinning this effect are not yet fully understood; however, Mendelian randomization studies suggest that they are related to lowered activity of HMG-CoA reductase, the target of statin therapy. In vitro research indicates that statins potentially impair β-cell function and decrease insulin sensitivity but how these findings relate to patients is unknown. In the clinic, statins should be prescribed on the basis of CVD risk and individual patient characteristics. In addition, diet and lifestyle interventions should be emphasized to help mitigate the risk of NODM. Individuals who develop NODM while taking statins do not exhibit increased microvascular disease, which is reassuring. In diabetes mellitus of long duration, the effect of statins on glycaemic control is small and unlikely to be clinically important.

Trans, trans-farnesol as a mevalonate-derived inducer of murine 3T3-F442A pre-adipocyte differentiation

Based on our finding that depletion of mevalonate-derived metabolites inhibits adipocyte differentiation, we hypothesize that trans, trans-farnesol (farnesol), a mevalonate-derived sesquiterpene, induces adipocyte differentiation. Farnesol dose-dependently (25-75 μmol/L) increased intracellular triglyceride content of murine 3T3-F442A pre-adipocytes measured by AdipoRed™ Assay and Oil Red-O staining. Concomitantly, farnesol dose-dependently increased glucose uptake and glucose transport protein 4 (GLUT4) expression without affecting cell viability. Furthermore, quantitative real-time polymerase chain reaction and Western blot showed that farnesol increased the mRNA and protein levels of peroxisome proliferator-activated receptor γ (PPARγ), a key regulator of adipocyte differentiation, and the mRNA levels of PPARγ-regulated fatty acid-binding protein 4 and adiponectin; in contrast, farnesol downregulated Pref-1 gene, a marker of pre-adipocytes. GW9662 (10 µmol/L), an antagonist of PPARγ, reversed the effects of farnesol on cellular lipid content, suggesting that PPARγ signaling pathway may mediate the farnesol effect. Farnesol (25-75 μmol/L) did not affect the mRNA level of 3-hydroxy-3-methylglutaryl coenzyme A reductase, the rate-limiting enzyme in the mevalonate pathway. Farnesol may be the mevalonate-derived inducer of adipocyte differentiation and potentially an insulin sensitizer via activation of PPARγ and upregulation of glucose uptake.

Hypothyroidism is a Risk Factor for New-Onset Diabetes: A Cohort Study

OBJECTIVE

To identify risk factors for the development of statin-associated diabetes mellitus (DM).

RESEARCH DESIGN AND METHODS

The study was conducted in two phases. Phase one involved high-throughput in silico processing of a large amount of biomedical data to identify risk factors for the development of statin-associated DM. In phase two, the most prominent risk factor identified was confirmed in an observational cohort study at Clalit, the largest health care organization in Israel. Time-dependent Poisson regression multivariable models were performed to assess rate ratios (RRs) with 95% CIs for DM occurrence.

RESULTS

A total of 39,263 statin nonusers were matched by propensity score to 20,334 highly compliant statin initiators in 2004-2005 and followed until the end of 2010. Within 59,597 statin users and nonusers in a multivariable model, hypothyroidism and subclinical hypothyroidism carried an increased risk for DM (RR 1.53 [95% CI 1.31-1.79] and 1.75 [1.40-2.18], respectively). Hypothyroidism increased DM risk irrespective of statin treatment (RR 2.06 [1.42-2.99] and 1.66 [1.05-2.64] in statin users and nonusers, respectively). Subclinical hypothyroidism risk for DM was prominent only upon statin use (RR 1.94 [1.13-3.34] and 1.20 [0.52-2.75] in statin users and nonusers, respectively). Patients with hypothyroidism treated with thyroid hormone replacement therapy were not at increased risk for DM.

CONCLUSIONS

Hypothyroidism is a risk factor for DM. Subclinical hypothyroidism-associated risk for DM is prominent only upon statin use. Identifying and treating hypothyroidism and subclinical hypothyroidism might reduce DM risk. Future clinical studies are needed to confirm the findings.

Pathogenesis and management of the diabetogenic effect of statins: a role for adiponectin and coenzyme Q10?

There is growing evidence to suggest that statin therapy is associated with an increased risk of incident diabetes. The risk for statin-related diabetes depends upon many factors including age, pre-existing diabetic risk, type and potency of statin. Several mechanisms have been suggested for the diabetogenic effects of statins involving processes that alter islet ß-cell function, resulting in impaired glucose metabolism. Recent evidence suggests that the association of statin therapy with the development of diabetes may be partly mediated by a statin-induced decrease in circulating adiponectin and coenzyme Q10. The available evidence suggests the benefit of statins in reducing cardiovascular events outweigh the risk of developing diabetes. Moreover, statin therapy does not impair glycemic control in diabetic patients. Expert recommendations for the use of statins in people at risk of developing diabetes have recently been published. However, further research is required to elucidate both the association between statin use and incident diabetes as well as underlying mechanisms.

Rosuvastatin Worsens Insulin Resistance in HIV-Infected Adults on Antiretroviral Therapy

BACKGROUND

Statins are associated with increased diabetes risk in large, human immunodeficiency virus (HIV)-uninfected cohorts; the impact of statins on insulin resistance or diabetes in HIV-infected persons has not been assessed within a randomized controlled study.

METHODS

HIV-infected participants on stable antiretroviral therapy with a low-density lipoprotein cholesterol level of ≤130 mg/dL and heightened immune activation or inflammation were randomized to rosuvastatin 10 mg daily or placebo for 96 weeks. Fasting serum glucose, insulin, and hemoglobin A1C (HgbA1C) were measured; insulin resistance was estimated by calculating the homeostatic model assessment of insulin resistance (HOMA-IR); and a 2-hour oral glucose tolerance test was administered.

RESULTS

Seventy-two participants were randomized to rosuvastatin therapy and 75 to placebo. Increases in fasting glucose were observed within both groups but were not different between study arms (P = .115); changes in glucose tolerance and HgbA1C did not differ between study arms (P = .920 and P = .650, respectively). Criteria for diabetes were met by 1 participant in the rosuvastatin and 3 in the placebo arm by week 96. Compared with placebo, rosuvastatin therapy was associated with significantly greater increases in insulin and HOMA-IR (P = .008 and P = .004, respectively).

CONCLUSIONS

We detected a significant worsening in insulin resistance and an increase in the proportion of participants with impaired fasting glucose but not a clinical diagnosis of diabetes in the rosuvastatin arm. Our findings suggest that prescription of statin therapy should be accompanied by a careful consideration of the risks and benefits, particularly in patients with lower cardiovascular disease risk.

CLINICAL TRIALS REGISTRATION

NCT01218802.

The Effect of Atorvastatin on Cardiometabolic Risk Factors in Bromocriptine-Treated Premenopausal Women with Isolated Hypercholesterolemia

AIMS

Hyperprolactinemia is often associated with hyperinsulinemia, insulin resistance, atherogenic dyslipidemia, and subclinical atherosclerosis. Dopamine agonists were found to reduce the prevalence of metabolic syndrome and cardiometabolic risk. The aim of this study was to compare the effect of statin therapy on cardiovascular risk factors between patients treated with a dopamine agonist and patients treated with metformin.

METHODS

The study included two age-, weight-, lipid-, and prolactin level-matched groups of premenopausal women with hypecholesterolemia and a history of hyperprolactinemia: patients treated with bromocriptine (5.0-7.5 mg daily, n = 14) and subjects receiving metformin (1.7-2.55 g daily, n = 17). Plasma prolactin, lipids, glucose homeostasis markers, and plasma levels of cardiometabolic risk factors were assessed before and after 12 weeks of atorvastatin treatment.

RESULTS

Baseline levels of the investigated variables were similar in women treated with bromocriptine and metformin. Apart from lowering total and LDL cholesterol, atorvastatin decreased plasma levels of uric acid, hsCRP, homocysteine, and fibrinogen, with no difference between treatment groups.

CONCLUSIONS

The obtained results suggest that the effect of atorvastatin on plasma lipids and circulating levels of cardiometabolic risk factors does not differ between patients receiving bromocriptine and metformin. Bromocriptine-statin combination therapy may be an alternative to metformin-statin combination therapy in hypercholesterolemic patients with glucose metabolism abnormalities in whom metformin administration is either contraindicated or results in adverse effects.

Statins can delay insulin use and reduce diabetes-related diseases in Asian patients with type 2 diabetes

We evaluated the role of statins in delaying insulin use and diabetes-related diseases in Asian patients with type 2 diabetes mellitus (T2DM) because statins can cause new-onset diabetes.We used data from the Longitudinal Health Insurance Database in this retrospective cohort study. The 12,470 T2DM patients were categorized into 2 cohorts: a statin cohort comprising 2545 patients who received statin therapy for at least 6 months (180 days) before the index date and a nonstatin cohort comprising 9925 patients who did not receive statin therapy. The control-to-case ratio was set at approximately 4:1. Univariable and multivariable Cox proportional hazards regression analyses were performed to evaluate the risk of diabetes-related events and insulin use on receiving statin treatment.Patients in the statin cohort had a 48% lower risk of diabetes-related coma than those in the nonstatin cohort (95% confidence interval = 0.29-0.92). Patients with >730 days of statin therapy had a significantly lower risk of insulin use, diabetes-related disorders of the eye and neurons, and peripheral circulatory disorders. Compared with patients in the nonstatin cohort, the risk of insulin use, diabetes-related coma, and diabetes-related disorders of the eye and neurons was lower in patients on a cumulative defined daily dose (cDDD) of statins for >475 days.These results suggest that longer duration of statin use and higher cDDD of statins can delay insulin use in Asian patients with T2DM.

An investigation into the therapeutic effects of statins with metformin on polycystic ovary syndrome: a meta-analysis of randomised controlled trials

OBJECTIVES

To investigate the therapeutic effects of statins with metformin on polycystic ovary syndrome (PCOS).

SETTINGS

Endocrinology department.

PARTICIPANTS

MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials were searched until October 2014. Studies comparing statins and placebo, as well as the combination of statins and metformin and metformin alone, were included in the analysis.

INTERVENTIONS

Data were independently extracted by two researchers; any convergence was resolved by a third reviewer.

PRIMARY AND SECONDARY OUTCOME MEASURES

The following properties were extracted from the qualified trials to identify the effects of statins: clinical variables, metabolic characteristics, hormone outcomes, sign of inflammation, glucose parameters and insulin outcomes.

RESULTS

Data from four trials comparing statin and metformin with metformin alone were analysed. The combination of statins and metformin decreases the levels of C reactive protein (standardised mean difference (SMD) -0.91; 95% CI -1.81 to -0.02; p=0.046), triglyceride (SMD -1.37; 95% CI -2.46 to -0.28; p=0.014), total cholesterol (SMD -1.28; 95% CI -1.59 to -0.97; p=0.000) and low-density lipoprotein (LDL) cholesterol (SMD -0.74; 95% CI -1.03 to -0.44; p=0.000). However, the combined therapy fails to reduce fasting insulin (SMD -0.92; 95% CI -2.07 to 0.24; p=0.120), homeostasis model assessment of insulin resistance (SMD -1.15; 95% CI -3.36 to 1.06; p=0.309) and total testosterone (SMD -1.12; 95% CI -2.29 to 0.05; p=0.061). Analysis of the five trials comparing statin with placebo shows that statin monotherapy reduces LDL-cholesterol, triglyceride and total cholesterol.

CONCLUSIONS

Combined statin and metformin therapy can improve lipid and inflammation parameters, but cannot effectively improve insulin sensitivity and reduce hyperandrogenism in women with PCOS. A large-scale randomised controlled study must be conducted to ascertain the long-term effects of the therapy.

Pharmacological treatment and therapeutic perspectives of metabolic syndrome

Metabolic syndrome is a disorder based on insulin resistance. Metabolic syndrome is diagnosed by a co-occurrence of three out of five of the following medical conditions: abdominal obesity, elevated blood pressures, elevated glucose, high triglycerides, and low high-density lipoprotein-cholesterol (HDL-C) levels. Clinical implication of metabolic syndrome is that it increases the risk of developing type 2 diabetes and cardiovascular diseases. Prevalence of the metabolic syndrome has increased globally, particularly in the last decade, to the point of being regarded as an epidemic. The prevalence of metabolic syndrome in the USA is estimated to be 34% of adult population. Moreover, increasing rate of metabolic syndrome in developing countries is dramatic. One can speculate that metabolic syndrome is going to induce huge impact on our lives. The metabolic syndrome cannot be treated with a single agent, since it is a multifaceted health problem. A healthy lifestyle including weight reduction is likely most effective in controlling metabolic syndrome. However, it is difficult to initiate and maintain healthy lifestyles, and in particular, with the recidivism of obesity in most patients who lose weight. Next, pharmacological agents that deal with obesity, diabetes, hypertension, and dyslipidemia can be used singly or in combination: anti-obesity drugs, thiazolidinediones, metformin, statins, fibrates, renin-angiotensin system blockers, glucagon like peptide-1 agonists, sodium glucose transporter-2 inhibitors, and some antiplatelet agents such as cilostazol. These drugs have not only their own pharmacologic targets on individual components of metabolic syndrome but some other properties may prove beneficial, i.e. anti-inflammatory and anti-oxidative. This review will describe pathophysiologic features of metabolic syndrome and pharmacologic agents for the treatment of metabolic syndrome, which are currently available.

Statin induced diabetes and its clinical implications

Statins are one of the most commonly used drugs in the world based on their potential to prevent adverse cardiovascular events. These cholesterol-lowering drugs received a US Food and Drug Administration warning, in February 2012, regarding increased risk of incident diabetes and impaired glycemic control in patients who already have diabetes. The possible association of diabetes with statin therapy has started a wave of discussion in the medical community. A number of meta-analyses conducted in recent years have demonstrated that the association is real although causality has not been proved yet. Individual statins differ with respect to their diabetogenic property; women and elderly persons appear to be at increased risk. Various aspects of statin's adverse effect on glycemic control remain to be explored. As further research in this area continues, physicians might still take some precautions to make risk benefit ratio more favorable for the patients.

Antioxidant effects of statins in the management of cardiometabolic disorders

Redox systems are key players in vascular health. A shift in redox homeostasis-that results in an imbalance between reactive oxygen species (ROS) generation and endogenous antioxidant defenses has the potential to create a state of oxidative stress that subsequently plays a role in the pathogenesis of a number of diseases, including those of the cardiovascular and metabolic system. Statins, which are primarily used to reduce the concentration of low-density lipoprotein cholesterol, have also been shown to reduce oxidative stress by modulating redox systems. Studies conducted both in vitro and in vivo support the role of oxidative stress in the development of atherosclerosis and cardiovascular diseases. Oxidative stress may also be responsible for various diabetic complications and the development of fatty liver. Statins reduce oxidative stress by blocking the generation of ROS and reducing the NAD+/NADH ratio. These drugs also have effects on nitric oxide synthase, lipid peroxidation and the adiponectin levels. It is possible that the antioxidant properties of statins contribute to their protective cardiovascular effects, independent of the lipid-lowering actions of these agents. However, possible adverse effects of statins on glucose homeostasis may be related to the redox system. Therefore, studies investigating the modulation of redox signaling by statins are warranted.

Use of antidepressants and statins and short-term risk of new-onset diabetes among high risk adults

AIMS

We evaluated the association of combined use of antidepressants and statins and the risk of new-onset diabetes among high-risk adults.

METHODS

We used a retrospective, observational, longitudinal design among adults (age ≥ 22 years) who were diabetes free at baseline and had reported hypertension or hyperlipidemia or heart disease. We used data were from 2004 to 2009 Medical Expenditure Panel Survey and identified from self-reported diabetes or insulin use. We categorized antidepressants and statins use into four groups: antidepressants only, statins only, combined use of antidepressants and statins (antidepressants-statins), and neither antidepressant nor statins. We conducted chi-square and multivariable logistic regressions to examine the association between use of antidepressants-statins and new-onset diabetes after controlling for demographic and economic characteristics, health-status, access to care, presence of depression, and lifestyle risk factors.

RESULTS

In our study sample, 9.3% used antidepressants only, 10.7% used statins only and 2.4% adults reported use of antidepressants-statins. Nearly 2% of the study sample reported new-onset diabetes. In unadjusted analyses, significantly higher proportion of adults using antidepressants-statins (3.2%) reported new-onset diabetes compared to those using neither antidepressants nor statins (1.1%). However, after controlling for all other variables in multivariable regression we did not observe a statistically significant association between use of antidepressants-statins and new-onset diabetes.

CONCLUSIONS

Our study results do not suggest that use of antidepressants-statins may increase the risk of new-onset diabetes. Future research needs to examine this relationship with specific combinations of these drug classes and using longer follow up periods.

Non-cardiovascular effects associated with statins

Statins form the pharmacologic cornerstone of the primary and secondary prevention of atherosclerotic cardiovascular disease. In addition to beneficial cardiovascular effects, statins seem to have multiple non-cardiovascular effects. Although early concerns about statin induced hepatotoxicity and cancer have subsided owing to reassuring evidence, two of the most common concerns that clinicians have are myopathy and diabetes. Randomized controlled trials suggest that statins are associated with a modest increase in the risk of myositis but not the risk of myalgia. Severe myopathy (rhabdomyolysis) is rare and often linked to a statin regimen that is no longer recommended (simvastatin 80 mg). Randomized controlled trials and meta-analyses suggest an increase in the risk of diabetes with statins, particularly with higher intensity regimens in people with two or more components of the metabolic syndrome. Other non-cardiovascular effects covered in this review are contrast induced nephropathy, cognition, cataracts, erectile dysfunction, and venous thromboembolism. Currently, systematic reviews and clinical practice guidelines indicate that the cardiovascular benefits of statins generally outweigh non-cardiovascular harms in patients above a certain threshold of cardiovascular risk. Literature is also accumulating on the potential non-cardiovascular benefits of statins, which could lead to novel applications of this class of drug in the future.

Effects of pitavastatin versus atorvastatin on the peripheral endothelial progenitor cells and vascular endothelial growth factor in high-risk patients: a pilot prospective, double-blind, randomized study

BACKGROUND

Circulating endothelial progenitor cells (EPCs) reflect endothelial repair capacity and may be a significant marker for the clinical outcomes of cardiovascular disease. While some high-dose statin treatments may improve endothelial function, it is not known whether different statins may have similar effects on EPCs.This study aimed to investigate the potential class effects of different statin treatment including pitavastatin and atorvastatin on circulating EPCs in clinical setting.

METHODS

A pilot prospective, double-blind, randomized study was conducted to evaluate the ordinary dose of pitavastatin (2 mg daily) or atorvastatin (10 mg daily) treatment for 12 weeks on circulating EPCs in patients with cardiovascular risk such as hypercholesterolemia and type 2 diabetes mellitus (T2DM). Additional in vitro study was conducted to clarify the direct effects of both statins on EPCs from the patients.

RESULTS

A total of 26 patients (19 with T2DM) completed the study. While the lipid-lowering effects were similar in both treatments, the counts of circulating CD34+KDR+EPCs were significantly increased (from 0.021 ± 0.015 to 0.054 ± 0.044% of gated mononuclear cells, P < 0.05) only by pitavastatin treatment. Besides, plasma asymmetric dimethylarginine level was reduced (from 0.68 ± 0.10 to 0.53 ± 0.12 μmol/L, P < 0.05) by atorvastatin, and plasma vascular endothelial growth factor (VEGF) level was increased (from 74.33 ± 32.26 to 98.65 ± 46.64 pg/mL, P < 0.05) by pitavastatin. In the in vitro study, while both statins increased endothelial nitric oxide synthase (eNOS) expression, only pitavastatin increased the phosphorylation of eNOS in EPCs. Pitavastatin but not atorvastatin ameliorated the adhesion ability of early EPCs and the migration and tube formation capacities of late EPCs.

CONCLUSIONS

While both statins similarly reduced plasma lipids, only pitavastatin increased plasma VEGF level and circulating EPCs in high-risk patients, which is probably related to the differential pleiotropic effects of different statins.

TRIAL REGISTRATION

This trial is registered at ClinicalTrials.gov, NCT01386853.

How to balance cardiorenometabolic benefits and risks of statins

Statins, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, are important for preventing adverse cardiovascular events not only in patients with a high risk of vascular disease but also in those with a low risk, by reducing the levels of low-density lipoprotein cholesterol. Statin is associated with deteriorating glucose homeostasis and an increased risk of diabetes mellitus. Moreover, these off-target effects are dose-dependent; it has also been suggested that renal insult can be caused dose-dependently by statin treatment, in contrast to previous studies showing a renoprotective effect. The 2013 American College of Cardiology/American Heart Association guidelines recommend the use of high-intensity statin therapy, and extend its use to more people at risk of vascular diseases. However, a European committee has expressed concerns about the potential side effects of using statins in a large fraction of the population for extended periods. This is true of Asian people, for whom the disease burden from cardiovascular disorders is not as great as among Western ethnic groups. There are still many unanswered questions on how to balance the cardiovascular benefits with the potential renometabolic risks of statins. Therefore, genetic or pharmacogenetic approaches are needed to define who is more vulnerable to developing diabetes mellitus or acute kidney injury. In particular, more information is required regarding the metabolism of statins, and their off-target or unknown actions and overall impact. These different renometabolic effects of statins should help in formulating optimal therapeutic strategies for patients for reducing overall morbidity and mortality and not just those associated with cardiovascular diseases.

The effect of short-term simvastatin treatment on plasma adipokine levels in patients with isolated hypercholesterolemia: A preliminary report

BACKGROUND

Apart from reducing plasma lipids, statins produce numerous non-lipid-related pleiotropic effects. The aim of this study was to investigate whether short-term simvastatin treatment affects plasma adipokine levels in patients with isolated hypercholesterolemia.

METHODS

The study included 42 adult patients with untreated isolated hypercholesterolemia, complying throughout the study with lifestyle intervention, 23 of whom were treated with simvastatin (40 mg daily), as well as 18 healthy subjects with normal lipid profile. Plasma lipids, apolipoproteins, glucose metabolism markers, as well as plasma levels of C-reactive protein (CRP), free fatty acids (FFA), leptin, adiponectin, visfatin and tumor necrosis factor-α (TNF-α) were determined at baseline and after 30 days of treatment.

RESULTS

Compared with the control age-, sex-, and weight-matched healthy subjects, isolated hypercholesterolemic patients exhibited higher plasma levels of leptin, visfatin, TNF-α, FFA and CRP, as well as lower plasma levels of adiponectin. Apart from decreasing plasma total cholesterol, LDL cholesterol and apolipoprotein B-100 levels, simvastatin reduced plasma levels of FFA, leptin and TNF-α, as well as increased plasma levels of adiponectin, which was accompanied by a reduction in plasma CRP. There were no differences in simvastatin action on plasma adipokines and CRP between insulin-resistant and insulin-sensitive subjects.

CONCLUSIONS

Our results indicate that the presence of isolated hypercholesterolemia is associated with abnormal hormonal function of the adipose tissue. These changes are partially reversed by short-term simvastatin treatment, and this action may contribute to the clinical effectiveness of statins in the therapy of atherosclerosis-related disorders.

Effect of atorvastatin on pancreatic Beta-cell function and insulin resistance in type 2 diabetes mellitus patients: a randomized pilot study

OBJECTIVE

Statins are commonly used for the management of dyslipidemia in type 2 diabetes mellitus patients. We hypothesized that atorvastatin could modulate the beta-cell function by altering the levels of proapoptotic and antiapoptotic lipoproteins and could also have an effect on insulin resistance. The aim of the present pilot study was to assess the effect of atorvastatin 10 mg on pancreatic beta-cell function and insulin resistance in patients with hyperlipidemia and type 2 diabetes by using the homeostasis model assessment-2 (HOMA2) index.

METHODS

Fifty-one type 2 diabetes patients receiving oral antidiabetes drugs, not taking statins, with baseline low-density lipoprotein cholesterol between 2.6 mmol/L and 4.1 mmol/L were included. Forty-three patients (21 in placebo group and 22 in atorvastatin group) completed the study and were taken up for final analysis. Fasting blood samples were obtained at baseline and at 12 weeks to determine levels of blood glucose, lipid profile, insulin, C-peptide and glycosylated hemoglobin (A1C).

RESULTS

Atorvastatin nonsignificantly increased fasting serum insulin (+14.29%, p=0.18), accompanied by marginal nonsignificant increases in fasting plasma glucose and A1C. There was a decrease in HOMA2 percent beta-cell function (-2.9%, p=0.72) and increase in HOMA2 insulin resistance (+14%, p=0.16) in the atorvastatin group as compared with baseline, but the difference was not statistically significant.

CONCLUSIONS

Atorvastatin in the dose used failed to produce significant change in pancreatic beta-cell function and insulin resistance in type 2 diabetes patients as assessed by the HOMA2 index. The possible explanations include absence of lipotoxicity at prevailing levels of dyslipidemia at baseline or inadequacy of statin dose used in the study. (Clinical Trials Registry-India: CTRI/2008/091/000099).

Statin treatment and new-onset diabetes: a review of proposed mechanisms

New-onset diabetes has been observed in clinical trials and meta-analyses involving statin therapy. To explain this association, three major mechanisms have been proposed and discussed in the literature. First, certain statins affect insulin secretion through direct, indirect or combined effects on calcium channels in pancreatic β-cells. Second, reduced translocation of glucose transporter 4 in response to treatment results in hyperglycemia and hyperinsulinemia. Third, statin therapy decreases other important downstream products, such as coenzyme Q10, farnesyl pyrophosphate, geranylgeranyl pyrophosphate, and dolichol; their depletion leads to reduced intracellular signaling. Other possible mechanisms implicated in the effect of statins on new-onset diabetes are: statin interference with intracellular insulin signal transduction pathways via inhibition of necessary phosphorylation events and reduction of small GTPase action; inhibition of adipocyte differentiation leading to decreased peroxisome proliferator activated receptor gamma and CCAAT/enhancer-binding protein which are important pathways for glucose homeostasis; decreased leptin causing inhibition of β-cells proliferation and insulin secretion; and diminished adiponectin levels. Given that the magnitude of the risk of new-onset diabetes following statin use remains to be fully clarified and the well-established beneficial effect of statins in reducing cardiovascular risk, statins remain the first-choice treatment for prevention of CVD. Elucidation of the mechanisms underlying the development of diabetes in association with statin use may help identify novel preventative or therapeutic approaches to this problem and/or help design a new generation statin without such side-effects.