Effects of pioglitazone on lipid and lipoprotein metabolism

Efficacy and Safety of Alogliptin-Pioglitazone Combination for Type 2 Diabetes Mellitus Poorly Controlled with Metformin: A Multicenter, Double-Blind Randomized Trial

BACKGRUOUND

Guidelines for switching to triple combination therapy directly after monotherapy failure are limited. This study investigated the efficacy, long-term sustainability, and safety of either mono or dual add-on therapy using alogliptin and pioglitazone for patients with type 2 diabetes mellitus (T2DM) who did not achieve their target glycemic range with metformin monotherapy.

METHODS

The Practical Evidence of Antidiabetic Combination Therapy in Korea (PEAK) was a multicenter, placebo-controlled, double-blind, randomized trial. A total of 214 participants were randomized to receive alogliptin+pioglitazone (Alo+Pio group, n=70), alogliptin (Alo group, n=75), or pioglitazone (Pio group, n=69). The primary outcome was the difference in glycosylated hemoglobin (HbA1c) levels between the three groups at baseline to 24 weeks. For durability, the achievement of HbA1c levels <7% and <6.5% was compared in each group. The number of adverse events was investigated for safety.

RESULTS

After 24 weeks of treatment, the change of HbA1c in the Alo+Pio, Alo, and Pio groups were -1.38%±0.08%, -1.03%±0.08%, and -0.84%±0.08%, respectively. The Alo+Pio group had significantly lower HbA1c levels than the other groups (P=0.0063, P<0.0001) and had a higher proportion of patients with target HbA1c achievement. In addition, insulin sensitivity and β-cell function, lipid profiles, and other metabolic indicators were also improved. There were no significant safety issues in patients treated with triple combination therapy.

CONCLUSION

Early combination triple therapy showed better efficacy and durability than the single add-on (dual) therapy. Therefore, combination therapy with metformin, alogliptin, and pioglitazone is a valuable early treatment option for T2DM poorly controlled with metformin monotherapy.

Management of Cardiovascular Risk in the Non-alcoholic Fatty Liver Disease Setting

Non-alcoholic fatty liver disease (NAFLD) is an overlooked and undetected pathology, which affects more than 32% of adults worldwide. NAFLD is becoming more common in Western industrialised countries, particularly in patients with central obesity, type 2 diabetes, dyslipidaemia and metabolic syndrome. Although NAFLD has traditionally been interpreted as a liver disease with a high risk of liver-related complications, NAFLD is an underappreciated and independent risk factor for atherosclerotic cardiovascular disease, which is the principal cause of death in patients with NAFLD. Treatment options to counteract both the progression and development of cardiovascular disease and NAFLD include lifestyle interventions, such as weight loss, increased physical activity and dietary modification, and optimal medical therapy of comorbid conditions; nevertheless, further studies are needed to define optimal treatment strategies for the prevention of both hepatic and cardiovascular complications of NAFLD.

Cure of Alzheimer's Dementia Requires Addressing All of the Affected Brain Cell Types

Multiple genetic, metabolic, and environmental abnormalities are known to contribute to the pathogenesis of Alzheimer's dementia (AD). If all of those abnormalities were addressed it should be possible to reverse the dementia; however, that would require a suffocating volume of drugs. Nevertheless, the problem may be simplified by using available data to address, instead, the brain cells whose functions become changed as a result of the abnormalities, because at least eleven drugs are available from which to formulate a rational therapy to correct those changes. The affected brain cell types are astrocytes, oligodendrocytes, neurons, endothelial cells/pericytes, and microglia. The available drugs include clemastine, dantrolene, erythropoietin, fingolimod, fluoxetine, lithium, memantine, minocycline, pioglitazone, piracetam, and riluzole. This article describes the ways by which the individual cell types contribute to AD's pathogenesis and how each of the drugs corrects the changes in the cell types. All five of the cell types may be involved in the pathogenesis of AD; of the 11 drugs, fingolimod, fluoxetine, lithium, memantine, and pioglitazone, each address all five of the cell types. Fingolimod only slightly addresses endothelial cells, and memantine is the weakest of the remaining four. Low doses of either two or three drugs are suggested in order to minimize the likelihood of toxicity and drug-drug interactions (including drugs used for co-morbidities). Suggested two-drug combinations are pioglitazone plus lithium and pioglitazone plus fluoxetine; a three-drug combination could add either clemastine or memantine. Clinical trials are required to validate that the suggest combinations may reverse AD.

Change in left ventricular diastolic function after pioglitazone treatment in patients with type 2 diabetes mellitus: A protocol for systematic review and meta-analysis

BACKGROUND

Pioglitazone is currently used as an anti-diabetic agent and can reduce cardiovascular events in in patients with type 2 diabetes mellitus (T2DM). Left ventricular diastolic dysfunction has been recognized as an early manifestation of myocardial dysfunction in T2DM patients. This systematic review and meta-analysis aimed to investigate changes in the left ventricular diastolic function after the treatment of pioglitazone.

METHODS

A systematic literature search of PubMed, Embase, and the Cochrane Library until May 2021 with keywords pioglitazone and left ventricular diastolic function was performed in accordance with the meta-analysis of observational studies in epidemiology guidelines and preferred reporting items for systematic reviews and meta-analyses statement. Three reviewers independently selected the studies and extracted data. Quality assessment of the included studies was undergone. A fixed effects model was used to calculate overall effect sizes. Subgroup analyses were subsequently performed. A fixed effects model was used to calculate the overall effect size. Subgroup analyses were then performed.

RESULTS

Seven studies with 233 patients were investigated. We found pioglitazone significantly improved hemoglobin A1c (%) in patients with T2DM and left ventricular diastolic function had an improvement tendency (weighted mean difference [WMD], 0.03; 95% confidence interval [CI], 0.01-0.05, P < .01) despite moderate heterogeneity (I2 = 66%). Subsequent subgroup analysis indicated that left ventricular diastolic function were significantly improved (WMD, 0.20; 95% CI, 0.12-0.29, P < .001) in T2DM patients whose average age < 55 after receiving pioglitazone treatment. However, in T2DM patients with mean age ≥ 55 years, there was no significant improvement of left ventricular diastolic function (WMD, 0.02; 95% CI, 0-0.04, P = .04).

CONCLUSION

Pioglitazone treatment significantly improved left ventricular diastolic function in type 2 diabetic patients with a mean age of < 55 years, but did not improve left ventricular diastolic function in patients with a mean age of ≥ 55 years.

Multi-organ Coordination of Lipoprotein Secretion by Hormones, Nutrients and Neural Networks

Plasma triglyceride-rich lipoproteins (TRL), particularly atherogenic remnant lipoproteins, contribute to atherosclerotic cardiovascular disease. Hypertriglyceridemia may arise in part from hypersecretion of TRLs by the liver and intestine. Here we focus on the complex network of hormonal, nutritional, and neuronal interorgan communication that regulates secretion of TRLs and provide our perspective on the relative importance of these factors. Hormones and peptides originating from the pancreas (insulin, glucagon), gut [glucagon-like peptide 1 (GLP-1) and 2 (GLP-2), ghrelin, cholecystokinin (CCK), peptide YY], adipose tissue (leptin, adiponectin) and brain (GLP-1) modulate TRL secretion by receptor-mediated responses and indirectly via neural networks. In addition, the gut microbiome and bile acids influence lipoprotein secretion in humans and animal models. Several nutritional factors modulate hepatic lipoprotein secretion through effects on the central nervous system. Vagal afferent signaling from the gut to the brain and efferent signals from the brain to the liver and gut are modulated by hormonal and nutritional factors to influence TRL secretion. Some of these factors have been extensively studied and shown to have robust regulatory effects whereas others are "emerging" regulators, whose significance remains to be determined. The quantitative importance of these factors relative to one another and relative to the key regulatory role of lipid availability remains largely unknown. Our understanding of the complex interorgan regulation of TRL secretion is rapidly evolving to appreciate the extensive hormonal, nutritional, and neural signals emanating not only from gut and liver but also from the brain, pancreas, and adipose tissue.

Efficacy and safety of novel sodium glucose cotransporter-2 inhibitor remogliflozin in the management of type 2 diabetes mellitus: A systematic review and meta-analysis

BACKGROUND AND AIMS

No meta-analysis has analysed efficacy and safety of remogliflozin. We undertook this meta-analysis to address this gap in knowledge METHODS: Electronic databases were searched for RCTs involving diabetes patients receiving remogliflozin as compared to controls. Primary outcome was to evaluate changes in HbA1c. Secondary outcomes were to evaluate alterations in glycaemia, lipids and adverse events.

RESULTS

Data from 3 RCTs involving 535 patients was analysed [2 having pioglitazone and 1 having dapagliflozin as active comparator]. Over 12-24 weeks use, Hba1c [mean difference (MD) -0.13% (95% CI: 0.35 - 0.09%); P = 0.24; I² = 99%] and fasting glucose [MD 3.67 mg/dl (95% CI: 0.53 - 7.88 mg/dl); P = 0.09; I² = 52%]. reduction with remogliflozin was not significantly different from controls. Remogliflozin was inferior to dapagliflozin with regards to reduction in post-prandial glucose [MD+12.17 mg/dl (95%CI:10.79-13.55 mg/dl); P < 0.001].Remogliflozin use was associated with a significantly greater decline in body weight [MD -2.79 kg (95% CI: 3.07 to -2.51 kg); P < 0.001; I² = 30%]. Total adverse events [Risk ratio (RR) 1.21 (95% CI: 0.62-2.64); P = 0.58; I² = 59%] were comparable among groups.

CONCLUSION

Remogliflozin had HbA1c and fasting glucose reduction comparable to pioglitazone and dapagliflozin. The paradox with regard to post-prandial glucose reduction needs further evaluation. The current analysis is limited by considerable data heterogeneity and low certainty of evidence for most primary and secondary outcomes. There remains urgent need for high quality RCTs evaluating long-term outcomes with remogliflozin.

Pioglitazone use associated with reduced risk of the first attack of ischemic stroke in patients with newly onset type 2 diabetes: a nationwide nested case-control study

Background

Pioglitazone use is known to be associated with a reduced risk of recurrent stroke in patients with diabetes mellitus (DM) who have a history of stroke. However, it is unclear whether this benefit extends to patients without a history of stroke. We aimed to evaluate the association between pioglitazone use and development of first attack of ischemic stroke in patients with newly diagnosed type 2 DM.

Methods

Using longitudinal nationwide data from the 2002–2017 Korean National Health Insurance Service DM cohort, we analyzed the association between pioglitazone use and incidence of primary ischemic stroke using a nested case–control study. Among 128,171 patients with newly onset type 2 DM who were stroke-free at the time of DM diagnosis, 4796 cases of ischemic stroke were identified and matched to 23,980 controls based on age, sex, and the onset and duration of DM. The mean (standard deviation) follow-up time was 6.08 (3.34) years for the cases and controls. Odds ratios (ORs) and 95% confidence intervals (CIs) for the association between ischemic stroke and pioglitazone use were analyzed by multivariable conditional logistic regression analyses adjusted for comorbidities, cardiometabolic risk profile, and other oral antidiabetic medications.

Results

Pioglitazone use was associated with a reduced risk of first attack of ischemic stroke (adjusted OR [AOR] 0.69, 95% CI 0.60–0.80) when compared with non-use. Notably, pioglitazone use was found to have a dose-dependent association with reduced rate of ischemic stroke emergence (first cumulative defined daily dose [cDDD] quartile AOR 0.99, 95% CI 0.74–1.32; second quartile, AOR 0.77, 95% CI 0.56–1.06; third quartile, AOR 0.51, 95% Cl 0.36–0.71; highest quartile, AOR 0.48, 95% CI 0.33–0.69). More pronounced risk reduction was found in patients who used pioglitazone for more than 2 years. A further stratified analysis revealed that pioglitazone use had greater protective effects in patients with risk factors for stroke, such as high blood pressure, obesity, and current smoking.

Conclusions

Pioglitazone use may have a preventive effect on primary ischemic stroke in patients with type 2 DM, particularly in those at high risk of stroke.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01339-x.

Umbelliferone ameliorates oxidative stress and testicular injury, improves steroidogenesis and upregulates peroxisome proliferator-activated receptor gamma in type 2 diabetic rats

OBJECTIVES

Diabetes mellitus (DM) is a chronic disease associated with serious complications, including male infertility. Umbelliferone (UMB) is a coumarin with promising antioxidant, anti-inflammatory and other beneficial effects. This study investigated the ameliorative effect of UMB against testicular injury, oxidative stress and altered steroidogenesis in rats with type 2 DM.

METHODS

Rats received a high fat diet for 4 weeks followed by a single injection of streptozotocin. Diabetic rats were treated with UMB or pioglitazone (PIO) for 6 weeks and samples were collected for analysis.

KEY FINDINGS

Diabetic rats exhibited hyperglycemia, insulin resistance and dyslipidemia associated with increased serum pro-inflammatory cytokines, and decreased gonadotropins and testosterone. UMB significantly ameliorated metabolic alterations, decreased pro-inflammatory cytokines, and increased gonadotropins and testosterone levels. UMB prevented testicular injury, suppressed lipid peroxidation and nitric oxide and increased antioxidants in diabetic rats. In addition, UMB upregulated testicular gonadotropins receptors, steroidogenesis markers (steroidogenic acute regulatory protein, cytochrome P450 family 17 subfamily A member 1 [CYP17A1], 3β-hydroxysteroid dehydrogenase [3ß-HSD] and 17ß-hydroxysteroid dehydrogenase [17ß-HSD]), and peroxisome proliferator-activated receptor gamma (PPARγ) expression.

CONCLUSIONS

UMB prevents testicular injury by preventing metabolic alterations, suppressing oxidative damage and inflammation, and boosting antioxidant defenses in diabetic rats. UMB enhanced pituitary-gonadal axis and steroidogenesis and upregulated testicular PPARγ in diabetic rats. Thus, UMB may represent a protective agent against testicular injury and sexual dysfunction associated with chronic hyperglycemia.

The Promising Ability of Humulus lupulus L. Iso-α-acids vs. Diabetes, Inflammation, and Metabolic Syndrome: A Systematic Review

For centuries, natural medicines have represented the only option for treating human diseases and, nowadays, plant phytochemicals are considered as promising compounds to treat or prevent chronic conditions. Among them, hop flowers (Humulus lupulus L.), typically used in brewing industries to give the typical aroma and flavor to beer, have attracted particular attention for their health promoting properties. Several in vivo/vitro studies and human interventional trials have demonstrated the beneficial effects of these molecules on weight gain, lipid metabolism, glucose homeostasis, insulin sensitivities, and inflammation by acting on different targets. All these activities suggest a possible role of bitter hop acid in preventing metabolic syndrome and its related diseases. A systematic quest on PubMed and Scopus databases was performed to identify pre-clinical and clinical studies focusing on this topic. This systematic review summarizes the results obtained by different cell lines, animal models, and human interventional trials to propose iso-α-acids as medical nutrition therapy to treat or prevent metabolic syndrome and its related disorders as diabetes, dislipidemia inflammation, etc.

Current treatment paradigms and emerging therapies for NAFLD/NASH

Non-alcoholic fatty liver disease (NAFLD) is one the fastest emerging manifestations of the metabolic syndrome worldwide. Non-alcoholic steatohepatitis (NASH), the progressive form of NAFLD, may culminate into cirrhosis and hepatocellular cancer (HCC) and is presently a leading cause of liver transplant. Although a steady progress is seen in understanding of the disease epidemiology, pathogenesis and identifying therapeutic targets, the slowest advancement is seen in the therapeutic field. Currently, there is no FDA approved therapy for this disease and appropriate therapeutic targets are urgently warranted. In this review we discuss the role of lifestyle intervention, pharmacological agents, surgical approaches, and gut microbiome, with regard to therapy for NASH. In particular, we focus the role of insulin sensitizers, thyroid hormone mimetics, antioxidants, cholesterol lowering drugs, incretins and cytokines as therapeutic targets for NASH. We highlight these targets aiming to optimize the future for NASH therapy.

Prescribed drugs containing nitrogen heterocycles: an overview

Heteroatoms as well as heterocyclic scaffolds are frequently present as the common cores in a plethora of active pharmaceuticals natural products. Statistically, more than 85% of all biologically active compounds are heterocycles or comprise a heterocycle and most frequently, nitrogen heterocycles as a backbone in their complex structures. These facts disclose and emphasize the vital role of heterocycles in modern drug design and drug discovery. In this review, we try to present a comprehensive overview of top prescribed drugs containing nitrogen heterocycles, describing their pharmacological properties, medical applications and their selected synthetic pathways. It is worth mentioning that the reported examples are actually limited to current top selling drugs, being or containing N-heterocycles and their synthetic information has been extracted from both scientific journals and the wider patent literature.

High-Throughput Algorithm for Discovering New Drug Indications by Utilizing Large-Scale Electronic Medical Record Data

Drug repositioning is an effective way to mitigate the production problem in the pharmaceutical industry. Electronic medical record (EMR) databases harbor a large amount of data on drug prescriptions and laboratory test results and may thus be useful for finding new indications for existing drugs. Here, we present a novel high-throughput data-driven algorithm that identifies and prioritizes drug candidates that show significant effects on specific clinical indicators by utilizing large-scale EMR data. We chose four laboratory tests as clinical indicators: hemoglobin A1c (HbA1c), low-density lipoprotein (LDL) cholesterol, triglycerides (TGs), and high-density lipoprotein (HDL) cholesterol. From a 5-year EMR database, we generated datasets consisting of paired data with averaged measurement values during on and off each drug in each patient, adjusted for co-administered drug effects at each timepoint, and applied one sample t-test with the Bonferroni correction for statistical analysis. Among 1,774 drugs, 45 were associated with increases in HDL cholesterol, and 41, 146, and 65 were associated with reductions in HbA1c, LDL cholesterol, and TGs, respectively. We compared the list of candidate drugs with that of drugs indicated for relevant clinical conditions and found that the algorithm had high values for both sensitivity (range 0.95-1.00) and negative predictive value (range 0.95-1.00). Our algorithm was able to rediscover well-known drugs that are used for diabetes and dyslipidemia while revealing potential candidates without current indications but have shown promising results in the literature. Our algorithm may facilitate the repositioning of drugs with proven safety profiles.

Effects of Basal Insulin on Lipid Profile Compared to Other Classes of Antihyperglycemic Agents in Type 2 Diabetic Patients

OBJECTIVE

The lipid profile represents a driver of cardiovascular risk in type 2 diabetes. The effect of chronic insulin therapy on cholesterol levels is unclear. We aim to evaluate the effect of basal insulin on lipid profile compared to other classes of antihyperglycemic agents in type 2 diabetic patients.

DESIGN

We performed a meta-analysis of randomized controlled trials reporting changes of lipid parameters in type 2 diabetic patients randomly assigned to basal insulin or other classes of anti-hyperglycemic agents.

RESULTS

The levels of total (TC) and low-density lipoprotein cholesterol (LDL-C) appeared to be significantly reduced by therapies with glucagon-like peptide-1 receptor agonists (GLP-1RA) in comparison to basal insulin (mean difference [MD] -3.80; 95% CI [-6.30 to -1.30] mg/dL, P < .001 and -4.17; 95% CI [-6.04 to -2.30] mg/dL, P < .0001), whereas no difference was detected between basal insulin and dipeptidyl peptidase-4 inhibitors (DPP4-I) or standard therapy (sulfonylurea ± metformin). Thiazolidinediones (TZD) produced a significant improvement in high-density lipoprotein cholesterol (HDL-C) (MD 3.55; 95% CI: 0.55 to 6.56 mg/dL, P = .02) but were associated with an increase in TC and LDL-C (MD 16.20; 95% CI: 9.09 to 23.31 mg/dL, P < .001 and 5.19: 95% CI: -3.00 to 13.39 mg/dL, P = .21). Basal insulin was superior to standard therapy in triglyceride reduction (MD 3.8; 95% CI: 0.99 to 6.63 mg/dL, P = .008).

CONCLUSIONS

GLP-1RA were superior to basal insulin in the control of TC and LDL-C. Basal insulin effectively reduced serum triglycerides. TZD led to improvement in HDL-C. DPP4-I and standard therapy did not have any significant effect on lipid levels.

S. Ferreira KC, Neto JCR. Pharmacological Strategies for Insulin Sensitivity in Obesity and Cancer: Thiazolidinediones and Metformin

Background:

Chronic diseases, such as obesity and cancer, have high prevalence rates. Both diseases have hyperinsulinemia, hyperglycemia, high levels of IGF-1 and inflammatory cytokines in common. Therefore, these can be considered triggers for cancer development and growth. In addition, low-grade inflammation that modulates the activation of immune cells, cellular metabolism, and production of cytokines and chemokines are common in obesity, cancer, and insulin resistance. Pharmacological strategies are necessary when a change in lifestyle does not improve glycemic homeostasis. In this regard, thiazolidinediones (TZD) possess multiple molecular targets and regulate PPARγ in obesity and cancer related to insulin resistance, while metformin acts through the AMPK pathway.

Objective:

The aim of this study was to review TZD and metformin as pharmacological treatments for insulin resistance associated with obesity and cancer.

Conclusions:

Thiazolidinediones restored adiponectin secretion and leptin sensitivity, reduced lipid droplets in hepatocytes and orexigen peptides in the hypothalamus. In cancer cells, TZD reduced proliferation, production of reactive oxygen species, and inflammation by acting through the mTOR and NFκB pathways. Metformin has similar effects, though these are AMPK-dependent. In addition, both drugs can be efficient against certain side effects caused by chemotherapy.

The association between total serum isomers of per- and polyfluoroalkyl substances, lipid profiles, and the DNA oxidative/nitrative stress biomarkers in middle-aged Taiwanese adults

Per- and polyfluoroalkyl substances (PFAS) have been widely used in consumer products. In vitro and animal studies have demonstrated that exposure to perfluorooctanoic acid (PFOA) and/or perfluorooctane sulfonate (PFOS) increases oxidative/nitrative stress. Recent studies have also found that isomers of PFOA/PFOS may have unique biological effects on clinical parameters. However, the correlation between PFOA/PFOS isomers and markers of oxidative/nitrative stress has never been investigated in the general population. In the current study, 597 adult subjects (ages between 22 and 63 years old) were enrolled from a control group of a case-control study entitled "Work-related risk factors and coronary heart disease". We investigated the correlation between the serum isomers of PFOA/PFOS, lipid profiles, and the urine compounds 8-hydroxy-2-deoxyguanosine (8-OHdG) and 8-nitroguanine (8-NO2Gua) in these participants. There were 519 men and 78 women with a mean age of 45.8 years. Linear PFOA levels were positively correlated with serum low density lipoprotein cholesterol (LDL-C), small dense LDL, and triglyceride, and linear PFOS levels were positively correlated with LDL-C and HDL-C in multiple linear regression analyses. After controlling for potential confounders, the mean levels of 8-OHdG and 8-NO2Gua significantly increased across the quartiles of linear PFOS in multiple linear regression analyses. When both the 8-OHdG and 8-NO2Gua levels were above the 50th percentile, the odds ratio (OR) of higher levels of LDL-C (>75th percentile) with one unit increase in ln linear PFOS level was the highest (OR 3.15 (95% CI = 1.45-6.64), P = 0.003) in logistic regression models. In conclusion, serum linear PFOA/PFOS were correlated with lipid profiles, and linear PFOS was associated with urine oxidative/nitrative stress biomarkers. The positive correlation between linear PFOS and LDL-C was more marked when concentrations of urine oxidative/nitrative stress biomarkers were elevated. Further studies are needed to elucidate the causal relationships among PFAS isomers, lipid profiles, and oxidative/nitrative stress.

MicroRNA miR-222 mediates pioglitazone beneficial effects on skeletal muscle of diet-induced obese mice

Pioglitazone belongs to the class of drugs thiazolidinediones (TZDs) and is an oral hypoglycemic drug, used in the treatment of type 2 diabetes, which improves insulin sensitivity in target tissues. Adipose tissue is the main target of pioglitazone, a PPARg and PPARa agonist; however, studies also point to skeletal muscle as a target. Non-PPAR targets of TZDs have been described, thus we aimed to study the direct effects of pioglitazone on skeletal muscle and the possible role of microRNAs as targets of this drug. Pioglitazone treatment of obese mice increased insulin-mediated glucose transport as a result of increased fatty acid oxidation and mitochondrial activity. PPARg blockage by treatment with GW9662 nullified pioglitazone's effect on systemic and muscle insulin sensitivity and citrate synthase activity of obese mice. After eight weeks of high-fat diet, miR-221-3p expression in soleus muscle was similar among the groups and miR-23b-3p and miR-222-3p were up-regulated in obese mice compared to the control group, and treatment with pioglitazone was able to reverse this condition. In vitro studies in C2C12 cells suggest that inhibition of miR-222-3p protects C2C12 cells from insulin resistance and increased non-mitochondrial respiration induced by palmitate. Together, these data demonstrate a role of pioglitazone in the downregulation of microRNAs that is not dependent on PPARg. Moreover, miR-222 may be a novel PPARg-independent mechanism through which pioglitazone improves insulin sensitivity in skeletal muscle.

Consumption of Terpenoids-Rich Padina pavonia Extract Attenuates Hyperglycemia, Insulin Resistance and Oxidative Stress, and Upregulates PPARγ in a Rat Model of Type 2 Diabetes

Seaweeds are rich in structurally diverse bioactive compounds with promising therapeutic effects. This study aimed to isolate and identify terpenes from the brown alga Padina pavonia and to investigate its antidiabetic activity, pointing to the possible involvement of peroxisome proliferator-activated receptor (PPAR)γ. Type 2 diabetes was induced by feeding rats a high fat diet (HFD) for 4 weeks followed by injection of 35 mg/kg streptozotocin (STZ). The diabetic rats received P. pavonia extract (PPE; 50, 100 and 200 mg/kg) for 4 weeks and samples were collected for analyses. HFD/STZ-induced rats showed hyperglycemia, dyslipidemia, impaired glucose tolerance, decreased insulin, and increased HbA1c and HOMA-IR. PPE ameliorated hyperglycemia and dyslipidemia, and improved glucose tolerance and insulin sensitivity in diabetic rats. Treatment with PPE increased hepatic hexokinase activity and glycogen, suppressed glucose-6-phosphatase, fructose-1,6-biphosphatase, and glycogen phosphorylase, and attenuated oxidative stress, inflammation, and liver injury and lipid infiltration in HFD/STZ-induced rats. In addition, PPE boosted antioxidants and upregulated PPARγ gene and protein expression in the liver of diabetic rats. Phytochemical investigation resulted in the isolation of six terpenes from PPE and in silico analysis revealed their binding affinity toward PPARγ. In conclusion, P. pavonia-derived terpenes attenuated hyperglycemia, dyslipidemia, oxidative stress, and inflammation, and improved insulin sensitivity and carbohydrate metabolism in type 2 diabetic rats. These beneficial effects are mediated via PPARγ activation. However, further studies to explore the exact mechanisms underlying the antidiabetic effect of PPE are recommended.

Pioglitazone prevents cholesterol gallstone formation through the regulation of cholesterol homeostasis in guinea pigs with a lithogenic diet

Background

The cholesterol gallstones diseases (CGD) is highly correlated with metabolic syndrome and type 2 diabetes. The present study aimed to investigate preventive effects of pioglitazone (PIO), an antidiabetic drug, on the CGD in guinea pigs fed with a lithogenic diet (LD).

Methods

The guinea pigs were fed with the LD for 8 weeks. All guinea pigs were grouped as follows: low fat diet; LD; LD plus PIO (4 mg/kg); LD plus PIO (8 mg/kg); LD plus ezetimibe (EZE) (2 mg/kg). Gallbladder stones were observed using microscopy. The profile of biliary composition, and blood glucose, insulin and lipid were analyzed. The liver or ileum was harvested for determinations of hydroxyl-methyl-glutaryl-CoA reductase (HMGCR), sterol regulatory element-binding proteins 2 (SREBP2), 7α-hydroxylase (CYP7A1), adenosine triphosphate-binding cassette (ABC) sterol transporters G5 and G8 (ABCG5, ABCG8), bile salt export pump (BSEP), Niemann-Pick C1-Like 1 (NPC1L1) and acetyl-coenzyme A cholesterol acyltransferase (ACAT2) by Western blot. The gallbladders were used for histological examination.

Results

The LD successfully induced gallstone. Both pioglitazone and ezetimibe prevented gallstone formation, as well as hepatic and cholecystic damages. Pioglitazone significantly decreased HMGCR and SREBP2, but increased CYP7A1, ABCG5, ABCG8, and BSEP in the liver. Pioglitazone also remarkably decreased NPC1L1 and ACAT2, while increased ABCG5/8 in the intestine. The beneficial alterations of cholesterol and bile acids in the bile, as well as profile of glucose, insulin and lipid in the blood were found in the guinea pigs treated with pioglitazone.

Conclusion

Pioglitazone has a noticeable benefit towards the CGD, which is involved in changes of synthesis, transformation, absorption, and transportation of cholesterol.

Thiazolidinedione induces a therapeutic effect on hepatosteatosis by regulating stearoyl-CoA desaturase-1, lipase activity, leptin and resistin

Hepatosteatosis is a disease present worldwide, which presents a number of health problems. Recently, thiazolidinedione (TZD) has been used as a therapy for lipid disorders. The present study demonstrates the potential of TZD as a treatment for hepatosteatosis and its mechanism of action, particularly focusing on its role in lipid metabolism. A total of 60 (80-90 g) rats were divided into three groups: A normal group with a standard diet, a high-fat, high-carbohydrate diet (HFCD) group or a HFCD+TZD group (n=20/group). The HFCD induced hepatosteatosis over a period of 12 weeks and the HFCD+TZD group were administered TZD in weeks 13-16. Blood and tissue samples were collected to measure hepatic function, the lipid profile, metabolism and hormone biomarkers, including serum triglyceride (TG), lipoprotein lipase (LPL), stearoyl-CoA desaturase (SCD-1), leptin and resistin. The HFCD-fed rats exhibited a significant increase in serum TG, total cholesterol, low-density lipoproteins, alanine transaminase and bilirubin compared with the normal group as well as a significant decrease in high-density lipoprotein. In addition, serum leptin and resistin were significantly elevated in the HFCD group compared with the normal group. The administration of TZD significantly increased SCD-1 activity and significantly inhibited LPL activity. It also attenuated the changes in the lipid profiles and normalized serum leptin and resistin levels. The results of the present study indicated that HFCD induced lipid abnormalities associated with hypertriglyceridemia, hypercholesterolemia and hepatosteatosis. These changes resulted from disruption to leptin and resistin, which may be due to alterations in LPL and SCD-1 activity. TZD mitigated the effects of HFCD-induced hepatosteatosis, indicating a possible regulatory effect of TZD in the development of hepatosteatosis. The authors suggest that the manipulation of SCD-1 and lipase by TZD may be useful as a treatment for hepatosteatosis.

Pathophysiology of Diabetic Dyslipidemia

Accumulating clinical evidence has suggested serum triglyceride (TG) is a leading predictor of atherosclerotic cardiovascular disease, comparable to low-density lipoprotein (LDL)-cholesterol (C) in populations with type 2 diabetes, which exceeds the predictive power of hemoglobinA1c. Atherogenic dyslipidemia in diabetes consists of elevated serum concentrations of TG-rich lipoproteins (TRLs), a high prevalence of small dense low-density lipoprotein (LDL), and low concentrations of cholesterol-rich high-density lipoprotein (HDL)2-C. A central lipoprotein abnormality is an increase in large TG-rich very-low-density lipoprotein (VLDL)1, and other lipoprotein abnormalities are metabolically linked to increased TRLs. Insulin critically regulates serum VLDL concentrations by suppressing hepatic VLDL production and stimulating VLDL removal by activation of lipoprotein lipase. It is still debated whether hyperinsulinemia compensatory for insulin resistance is causally associated with the overproduction of VLDL. This review introduces experimental and clinical observations revealing that insulin resistance, but not hyperinsulinemia stimulates hepatic VLDL production. LDL and HDL consist of heterogeneous particles with different size and density. Cholesterol-depleted small dense LDL and cholesterol-rich HDL2 subspecies are particularly affected by insulin resistance and can be named “Metabolic LDL and HDL,” respectively. We established the direct assays for quantifying small dense LDL-C and small dense HDL(HDL3)-C, respectively. Subtracting HDL3-C from HDL-C gives HDL2-C. I will explain clinical relevance of measurements of LDL and HDL subspecies determined by our assays. Diabetic kidney disease (DKD) substantially worsens plasma lipid profile thereby potentiated atherogenic risk. Finally, I briefly overview pathophysiology of dyslipidemia associated with DKD, which has not been so much taken up by other review articles.

Pioglitazone Prevents Stroke in Patients With a Recent Transient Ischemic Attack or Ischemic Stroke: A Planned Secondary Analysis of the IRIS Trial (Insulin Resistance Intervention After Stroke)

BACKGROUND

The IRIS trial (Insulin Resistance Intervention after Stroke) demonstrated that pioglitazone reduced the risk for a composite outcome of stroke or myocardial infarction among nondiabetic patients with insulin resistance and a recent stroke or transient ischemic attack. The current planned secondary analysis uses updated 2013 consensus criteria for ischemic stroke to examine the effect of pioglitazone on stroke outcomes.

METHODS

Participants were randomly assigned to receive pioglitazone (45 mg/d target dose) or placebo within 180 days of a qualifying ischemic stroke or transient ischemic attack and were followed for a maximum of 5 years. An independent committee, blinded to treatment assignments, adjudicated all potential stroke outcomes. Time to first stroke event was compared by treatment group, overall and by type of event (ischemic or hemorrhagic), using survival analyses and Cox proportional hazards models.

RESULTS

Among 3876 IRIS participants (mean age, 63 years; 65% male), 377 stroke events were observed in 319 participants over a median follow-up of 4.8 years. Pioglitazone was associated with a reduced risk for any stroke at 5 years (8.0% in comparison with 10.7% for the placebo group; hazard ratio [HR], 0.75; 95% confidence interval [CI], 0.60-0.94; log-rank P=0.01). Pioglitazone reduced risk for ischemic strokes (HR, 0.72; 95% CI, 0.57-0.91; P=0.005) but had no effect on risk for hemorrhagic events (HR, 1.00; 95% CI, 0.50-2.00; P=1.00).

CONCLUSIONS

Pioglitazone was effective for secondary prevention of ischemic stroke in nondiabetic patients with insulin resistance.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00091949.

Comparative RNA-Seq transcriptome analyses reveal distinct metabolic pathways in diabetic nerve and kidney disease

Treating insulin resistance with pioglitazone normalizes renal function and improves small nerve fibre function and architecture; however, it does not affect large myelinated nerve fibre function in mouse models of type 2 diabetes (T2DM), indicating that pioglitazone affects the body in a tissue-specific manner. To identify distinct molecular pathways regulating diabetic peripheral neuropathy (DPN) and nephropathy (DN), as well those affected by pioglitazone, we assessed DPN and DN gene transcript expression in control and diabetic mice with or without pioglitazone treatment. Differential expression analysis and self-organizing maps were then used in parallel to analyse transcriptome data. Differential expression analysis showed that gene expression promoting cell death and the inflammatory response was reversed in the kidney glomeruli but unchanged or exacerbated in sciatic nerve by pioglitazone. Self-organizing map analysis revealed that mitochondrial dysfunction was normalized in kidney and nerve by treatment; however, conserved pathways were opposite in their directionality of regulation. Collectively, our data suggest inflammation may drive large fibre dysfunction, while mitochondrial dysfunction may drive small fibre dysfunction in T2DM. Moreover, targeting both of these pathways is likely to improve DN. This study supports growing evidence that systemic metabolic changes in T2DM are associated with distinct tissue-specific metabolic reprogramming in kidney and nerve and that these changes play a critical role in DN and small fibre DPN pathogenesis. These data also highlight the potential dangers of a 'one size fits all' approach to T2DM therapeutics, as the same drug may simultaneously alleviate one complication while exacerbating another.

Long-Term Effect of Alogliptin on Glycemic Control in Japanese Patients With Type 2 Diabetes: A 3.5-Year Observational Study

Background

The goal of the current study was to investigate the long-term effects (after 3 years or more) of alogliptin on glycemic control in Japanese patients with type 2 diabetes.

Methods

We retrospectively studied the effect of alogliptin on glycemic control in the patients with type 2 diabetes who had participated in our previous 3-month study and who continued to take alogliptin for at least 36 months.

Results

The mean duration of alogliptin treatment was 42.8 ± 2.2 months. In all 39 patients, a significant reduction in hemoglobin A1c (HbA1c) levels was noted between the baseline and final visit: 7.8±0.6% to 7.2±1.0% (P = 0.0001). A significant reduction in HbA1c levels was found in a subgroup of patients who did not change their anti-diabetic drugs or did decrease the dose of their sulfonylureas (SUs) or did change to a lower strength repaglinide (n = 32): 7.7±0.6% to 7.2±1.0% (P = 0.0005). A significant decrease in low-density lipoprotein cholesterol (LDL-C) levels was observed in all of the patients that had LDL-C levels determined (P = 0.0406) (n = 37), and in a subgroup of patients who had not taken either statins, fibrates, or pioglitazone, or who had taken one or more of these drugs but the doses were not changed during the observation period (P = 0.0250) (n = 27).

Conclusion

The current study found that alogliptin performed well for glycemic control when evaluated by HbA1c levels in a long-term observation period exceeding 3 years in Japanese patients with type 2 diabetes. Alogliptin may also decrease circulating LDL-C levels with long-term use.

Acute Effect of Metformin on Postprandial Hypertriglyceridemia through Delayed Gastric Emptying

Postprandial hypertriglyceridemia is a potential target for cardiovascular disease prevention in patients with diabetic dyslipidemia. Metformin has been reported to reduce plasma triglyceride concentrations in the postprandial states. However, little is known about the mechanisms underlying the triglyceride-lowering effect of metformin. Here, we examined the effects of metformin on lipid metabolism after olive oil-loading in 129S mice fed a high fat diet for three weeks. Metformin administration (250 mg/kg) for one week decreased postprandial plasma triglycerides. Pre-administration (250 mg/kg) of metformin resulted in a stronger triglyceride-lowering effect (approximately 45% lower area under the curve) than post-administration. A single administration (250 mg/kg) of metformin lowered plasma postprandial triglycerides comparably to administration for one week, suggesting an acute effect of metformin on postprandial hypertriglyceridemia. To explore whole body lipid metabolism after fat-loading, stomach size, fat absorption in the intestine, and fat oxidation (¹³C/¹²C ratio in expired CO₂ after administration of glyceryl-1-¹³C tripalmitate) were measured with and without metformin (250 mg/kg) pre-treatment. In metformin-treated mice, larger stomach size, lower fat oxidation, and no change in lipid absorption were observed. In conclusion, metformin administration before fat loading reduced postprandial hypertriglyceridemia, most likely by delaying gastric emptying.

Pharmacologic Treatment of Dyslipidemia in Diabetes: A Case for Therapies in Addition to Statins

PURPOSE OF REVIEW

The purpose of the study is to review the use of statins and the role of both non-statin lipid-lowering agents and diabetes-specific medications in the treatment of diabetic dyslipidemia.

RECENT FINDINGS

Statins have a primary role in the treatment of dyslipidemia in people with type 2 diabetes, defined as triglyceride levels >200 mg/dl and HDL cholesterol levels <40 mg/dL. A number of clinical trials suggest that treatment with a fibrate may reduce cardiovascular events. However, the results of these trials are inconsistent, probably because many of their participants did not have dyslipidemia. The choice of medications used to treat diabetes can have major implications regarding management of dyslipidemia; metformin, GLP-1 agonists, and pioglitazone all have favorable lipid effects. These agents, as well as the new SGLT2 inhibitors, may reduce cardiovascular events. Management of dyslipidemia in people with type 2 diabetes should start with statin therapy and optimal glycemic control with agents that have favorable lipid and cardiovascular effects. We believe that there is a role for adding fenofibrate to moderate-intensity statins in selected patients with true dyslipidemia. We propose an algorithm for selecting add-on medications for diabetes (after metformin) based on lipid status.

Comparative Effect of Insulin Sensitizers and Statin on Metabolic Profile and Ultrasonographical Score in Non Alcoholic Fatty Liver Disease

INTRODUCTION

Non Alcoholic Fatty Liver Disease (NAFLD) is a metabolic disorder involving fat accumulation in the liver. The initial management for patients with NAFLD includes lifestyle modification and weight loss in overweight or obese patients.

AIM

The present study was conducted to compare the efficacy of insulin sensitizers and statin in the patients of NAFLD.

MATERIALS AND METHODS

The study included 98 patients diagnosed with NAFLD on USG (Ultrasonography) abdomen, divided into three Groups randomly and administered Metformin (Group I), Rosuvastatin (Group II) or Pioglitazone (Group III) along with dietary intervention and lifestyle modification. Their Body Mass Index (BMI), liver function tests, fasting lipid profile, USG scores for fatty liver were done and followed up at 4 weeks, 12 weeks and 24 week for change in above parameters.

RESULTS

Out of the three Groups, Group II showed a maximum improvements in usg scores for NAFLD (p<0.001) and fasting lipid profile. Group II also showed maximum derangement of liver enzymes at 24 weeks though none of the subjects had more than three times elevation of liver enzymes.

CONCLUSION

Rosuvastatin may be an effective therapy as add on treatment to dietary and lifestyle intervention in patients of NAFLD. As an add-on treatment Rosuvastatin was superior to Pioglitazone or Metformin and acute decompensation is unlikely with this drug. Metformin was not effective as add on therapy for NAFLD, rather rapid weight loss in short period of time resulted in worsening of hepatic steatosis.

Unintended positive and negative effects of drugs on lipoproteins

PURPOSE OF REVIEW

Dyslipidaemia is an important cardiovascular disease risk factor. Many drugs affect lipid profile and lipoprotein metabolism. We reviewed unintended effects of nonlipid modifying, commonly used medications on lipid profile and lipoprotein metabolism.

RECENT FINDING

Several detrimental effects of many drug classes such as diuretics, antidepressant, anticonvulsant and antiretroviral drugs have been reported, whereas other drug classes such as antiobesity, alpha 1-blockers, oestrogens and thyroid replacement therapy were associated with positive effects.

SUMMARY

Dyslipidaemia is a common side-effect of many medications. This should be taken into consideration, especially in patients at high risk of cardiovascular disease. Other drugs demonstrated positive effects on circulating lipids and lipoproteins. The impact of these unintended effects on atherosclerotic disease risk and progression is unclear.

The effect of pioglitazone on aldosterone and cortisol production in HAC15 human adrenocortical carcinoma cells

Pioglitazone belongs to the class of drugs called thiazolidinediones (TZDs), which are widely used as insulin sensitizers in the treatment of diabetes. A major side effect of TZDs is fluid retention. The steroid hormone aldosterone also promotes sodium and fluid retention; however, the effect of pioglitazone on aldosterone production is controversial. We analyzed the effect of pioglitazone alone and in combination with angiotensin II (AngII) on the late rate-limiting step of adrenocortical steroidogenesis in human adrenocortical carcinoma HAC15 cells. Treatment with pioglitazone for 24 h significantly increased the expression of CYP11B2 and enhanced AngII-induced CYP11B2 expression. Despite the observed changes in mRNA levels, pioglitazone significantly inhibited AngII-induced aldosterone production and CYP11B2 protein levels. On the other hand, pioglitazone stimulated the expression of the unfolded protein response (UPR) marker DDIT3, with this effect occurring at early times and inhibitable by the PPARγ antagonist GW9962. The levels of DDIT3 (CHOP) and phospho-eIF2α (Ser51), a UPR-induced event that inhibits protein translation, were also increased. Thus, pioglitazone promotes CYP11B2 expression but nevertheless inhibits aldosterone production in AngII-treated HAC15 cells, likely by blocking global protein translation initiation through DDIT3 and phospho-eIF2α. In contrast, pioglitazone promoted AngII-induced CYP11B1 expression and cortisol production. Since cortisol enhances lipolysis, this result suggests the possibility that PPARs, activated by products of fatty acid oxidation, stimulate cortisol secretion to promote utilization of fatty acids during fasting. In turn, the ability of pioglitazone to stimulate cortisol production could potentially underlie the effects of this drug on fluid retention.

Intestinal nuclear receptors in HDL cholesterol metabolism

The intestine plays a pivotal role in cholesterol homeostasis by functioning as an absorptive and secretory organ in the reverse cholesterol transport pathway. Enterocytes control cholesterol absorption, apoAI synthesis, HDL biogenesis, and nonbiliary cholesterol fecal disposal. Thus, intestine-based therapeutic interventions may hold promise in the management of diseases driven by cholesterol overload. Lipid-sensing nuclear receptors (NRs) are highly expressed in the intestinal epithelium and regulate transcriptionally the handling of cholesterol by the enterocytes. Here, we discuss the NR regulation of cholesterol fluxes across the enterocytes with special emphasis on NR exploitation as a bona fide novel HDL-raising strategy.

Pharmacological agents for NASH

NASH is a common liver disease that increases liver-related mortality and reduces survival. The need for optimal management of NASH is therefore a priority for today's practicing hepatologist. The rationale for specific pharmacological therapy for NASH is based on the potential for disease progression and the difficulties that many patients have successfully implementing, in the long term, diet and lifestyle changes. Even in those that succeed, limited evidence exists that severe liver injury in patients with NASH can be reversed by diet and lifestyle measures alone. This Review provides a personal and critical assessment of the histological efficacy and safety of agents tested in randomized trials in patients with NASH.

The future of thiazolidinedione therapy in the management of type 2 diabetes mellitus

Since their approval, thiazolidinediones (TZDs) have been used extensively as insulin-sensitizers for the management of type 2 diabetes mellitus (T2DM). Activation of peroxisomal proliferator-activated receptor gamma (PPARγ) nuclear receptors by TZDs leads to a vast spectrum of metabolic and antiinflammatory effects. In the past decade, clinicians and scientists across the fields of metabolism, diabetes, liver disease (NAFLD), atherosclerosis, inflammation, infertility, and even cancer have had high hopes about the potential for TZDs to treat many of these diseases. However, an increasing awareness about undesirable "off-target" effects of TZDs have made us rethink their role and be more cautious about the long-term benefits and risks related to their use. This review examines the most relevant work on the benefits and risks associated with TZD treatment, with a focus on the only PPARγ agonist currently available (pioglitazone), aiming to offer the reader a balanced overview about the current and future role of TZDs in the management of insulin-resistant states and T2DM.

The effects of pioglitazone on biochemical markers of bone turnover in the patients with type 2 diabetes

Aim. To investigate whether pioglitazone had detrimental effects on biochemical markers of bone turnover in patients with type 2 diabetes (T2DM). Methods. Seventy patients with T2DM were included in this study. The patients remained on their previous antihyperglycemic therapies during the trial. Pioglitazone was then added on their regimen for 3 months. Results. After 3 months of treatment with pioglitazone, the levels of fasting blood glucose and HbA1c were significantly decreased (7.9 ± 1.5 mmol/L versus 9.1 ± 1.6 mmol/L and 7.1 ± 1.0% versus 8.2 ± 1.4%, resp., P < 0.01), compared with baseline in the overall patients. Serum concentrations of P1NP and BAP were significantly decreased from baseline (45.0 ± 20.0  μ g/L versus 40.6 ± 17.9  μ g/L and 13.23 ± 4.7  μ g/L versus 12.3 ± 5.0  μ g/L, resp., P < 0.01) in female group, but not in male group. The serum levels of OC and CTX were unchanged in both female and male subgroups. In addition, the levels of serum BAP and P1NP were significantly decreased after pioglitazone treatment in postmenopausal subgroup, comparing with baseline. Conclusion. Pioglitazone inhibits bone formation and does not seem to affect bone resorption. Postmenopausal female patients rather than premenopausal or male patients are particularly vulnerable to this side effect of pioglitazone.

Pioglitazone prevents hyperglycemia induced decrease of AdipoR1 and AdipoR2 in coronary arteries and coronary VSMCs

BACKGROUND

Adiponectin receptors play an important role in inflammatory diseases like diabetes and atherosclerosis. Former studies revealed that the regulation of adiponectin receptors expression differs in the receptor responses to pioglitazone. However, expression of AdipoRs has not been investigated in the coronary arteries or the coronary vascular smooth muscle cells (VSMCs). In the present study we investigated the effect of pioglitazone on the adiponectin receptors both in vitro and in vivo.

METHODS

Male Sprague-Dawley rats were randomly divided in three groups. One of them fed with regular chow (the Control group) and two of them fed with high-fat diet and then received low-dose Streptozotocin once by intraperitoneal injection (the DM groups). Rats in one of the DM groups were further treated with pioglitazone (the PIO group). Blood pressure, serum adiponectin, fasting blood glucose, fasting serum insulin, cholesterol, triglyceride, AdipoR1 and AdipoR2 expression, and TNF-α expression in coronary arteries of these groups were investigated. For the in vitro study, the rat coronary VSMCs maintained under defined in vitro conditions were treated with either PIO or the PIO+ GW9662 (PPAR-γ antagonist), and then stimulated with high glucose. AdipoR1 and AdipoR2 expression, TNF-α expression and PPAR-γ expression were investigated.

RESULTS

Compared to the DM group, treatment with PIO in vivo significantly attenuated cholesterol level, triglyceride level, fasting serum insulin and TNF-α overexpression (p<0.05). PIO also increased AdipoR1 and AdipoR2 expression in coronary arteries, which were reduced notably in the DM group (p<0.05). Consistently, in the study with rat coronary VSMCs, PIO prominently downregulated TNF-α expression and induced PPAR-γ expression, as well as prevented hyperglycemia induced decrease of AdipoR1 and AdipoR2 expression (p<0.05). And pretreatment of PIO+GW9662 did not manifest the prevention effect.

CONCLUSION

In this study, we showed that treatment with PIO could ameliorate coronary insulin resistant and upregulate the expression of AdipoR1/R2. PIO showed an anti-atherogenic property via the activation of PPAR-γ, suppression of TNF-α overexpression in coronary and coronary VSMCs.

Outcomes and lessons from the PROactive study

Beyond improvement of glucose control, thiazolidinediones exert pleiotropic effects, which may contribute to some cardiovascular protection. PROactive ("PROspective pioglitAzone Clinical Trial In macroVascular Events") has provided valuable, although controversial, information on the impact of pioglitazone on cardiovascular outcomes in a high-risk population of patients with type 2 diabetes and established macrovascular disease. Since 2005, there has been much debate on the relative value of the statistically non-significant 10% reduction in the quite challenging primary composite endpoint (combining cardiovascular disease-driven and procedural events in all vascular beds) versus the statistically significant 16% decrease in the more robust and conventional main secondary endpoint (all-cause mortality, myocardial infarction, and stroke) observed with pioglitazone. Revisiting PROactive deserves much interest following the report of inconclusive results on cardiovascular efficacy and safety of rosiglitazone in RECORD, the withdrawal (limitation) of rosiglitazone because of cardiovascular safety concern, the recent publication of a statement positioning pioglitazone in type 2 diabetes and the near availability of cheaper generics of pioglitazone. Although subanalyses may have more limited value from a statistical viewpoint, they nonetheless can provide valuable information on the drug efficacy/safety profile and clinical insights into which patients might benefit most (in terms of cardiovascular outcomes) from pioglitazone therapy.

Evaluation and treatment of hypertriglyceridemia: an Endocrine Society clinical practice guideline

OBJECTIVE

The aim was to develop clinical practice guidelines on hypertriglyceridemia.

PARTICIPANTS

The Task Force included a chair selected by The Endocrine Society Clinical Guidelines Subcommittee (CGS), five additional experts in the field, and a methodologist. The authors received no corporate funding or remuneration.

CONSENSUS PROCESS

Consensus was guided by systematic reviews of evidence, e-mail discussion, conference calls, and one in-person meeting. The guidelines were reviewed and approved sequentially by The Endocrine Society's CGS and Clinical Affairs Core Committee, members responding to a web posting, and The Endocrine Society Council. At each stage, the Task Force incorporated changes in response to written comments.

CONCLUSIONS

The Task Force recommends that the diagnosis of hypertriglyceridemia be based on fasting levels, that mild and moderate hypertriglyceridemia (triglycerides of 150-999 mg/dl) be diagnosed to aid in the evaluation of cardiovascular risk, and that severe and very severe hypertriglyceridemia (triglycerides of > 1000 mg/dl) be considered a risk for pancreatitis. The Task Force also recommends that patients with hypertriglyceridemia be evaluated for secondary causes of hyperlipidemia and that subjects with primary hypertriglyceridemia be evaluated for family history of dyslipidemia and cardiovascular disease. The Task Force recommends that the treatment goal in patients with moderate hypertriglyceridemia be a non-high-density lipoprotein cholesterol level in agreement with National Cholesterol Education Program Adult Treatment Panel guidelines. The initial treatment should be lifestyle therapy; a combination of diet modification and drug therapy may also be considered. In patients with severe or very severe hypertriglyceridemia, a fibrate should be used as a first-line agent.

Hypertriglyceridemia secondary to obesity and diabetes

Hypertriglyceridemia is a common lipid abnormality in persons with visceral obesity, metabolic syndrome and type 2 diabetes. Hypertriglyceridemia typically occurs in conjunction with low HDL levels and atherogenic small dense LDL particles and is associated with increased cardiovascular risk. Insulin resistance is often an underlying feature and results in increased free fatty acid (FFA) delivery to the liver due to increased peripheral lipolysis. Increased hepatic VLDL production occurs due to increased substrate availability via FFAs, decreased apolipoprotein B100 degradation and increased lipogenesis. Postprandial hypertriglyceridemia also is a common feature of insulin resistance. Small dense LDL that coexist with decreased HDL particles in hypertriglyceridemic states are highly pro-atherogenic due to their enhanced endothelial permeability, proteoglycan binding abilities and susceptibility to oxidation. Hypertriglyceridemia also occurs in undertreated individuals with type 1 diabetes but intensive glucose control normalizes lipid abnormalities. However, development of visceral obesity in these patients unravels a similar metabolic profile as in patients with insulin resistance. Modest hypertriglyceridemia increases cardiovascular risk, while marked hypertriglyceridemia should be considered a risk for pancreatitis. Lifestyle modification is an important therapeutic strategy. Drug therapy is primarily focused on lowering LDL levels with statins, since efforts at triglyceride lowering and HDL raising with fibrates and/or niacin have not yet been shown to be beneficial in improving cardiovascular risk. Fibrates, however, are first-line agents when marked hypertriglyceridemia is present. This article is part of a Special Issue entitled Triglyceride Metabolism and Disease.

Glitazones for human nonalcoholic steatohepatitis

The rationale for specific pharmacologic therapy in nonalcoholic steatohepatitis (NASH) is determined by the potential for disease progression and the difficulties, in many patients, of successfully implementing diet and lifestyle changes over the long term. Owing to their ability to correct insulin resistance, insulin-sensitizing agents are attractive candidates for the treatment of NASH. In this review we provide an insight into the mechanism of action, therapeutic efficacy and safety issues regarding the use of glitazones in NASH.

The role of metformin and thiazolidinediones in the regulation of hepatic glucose metabolism and its clinical impact

Fasting hyperglycemia in type 2 diabetes mellitus (T2DM) results from elevated endogenous glucose production (EGP), which is mostly due to augmented hepatic gluconeogenesis. Insulin-resistant humans exhibit impaired insulin-dependent suppression of EGP and excessive hepatic lipid storage (steatosis), which relates to abnormal supply of free fatty acids (FFA) and energy metabolism. Only two glucose-lowering drug classes, the biguanide metformin and the thiazolidendiones (TZDs), exert insulin- and glucagon-independent hepatic effects. Preclinical studies suggest that metformin inhibits mitochondrial complex I. TZDs, as peroxisome proliferator-activated receptor (PPAR) γ-agonists, predominantly reduce the flux of FFA and cytokines from adipose tissue to the liver, but could also directly inhibit mitochondrial complex I. Although both metformin and TZDs improve fasting hyperglycemia and EGP in clinical trials, only TZDs decrease steatosis and peripheral insulin resistance. More studies are required to address their effects on hepatocellular energy metabolism with a view to identifying novel targets for the treatment of T2DM.

Pharmacological therapy for non-alcoholic steatohepatitis: How efficient are thiazolidinediones?

Although diet and lifestyle changes are the first-line therapy in patients with non-alcoholic steatohepatitis (NASH), few patients are able to successfully implement these measures over the long run while others have an advanced disease requiring specific pharmacological therapy. Because insulin resistance is the underlying condition favoring the occurrence of NASH, insulin sensitizers have been tested in this condition although available trials are heterogenous in terms of choice of the drug, dosage, length of therapy and patient profile. Overall, thiazolidinediones reduce aminotransferase levels and induce a strong anti-steatogenic response. Most studies have shown an improvement in inflammation and liver cell injury while none have convincingly demonstrated an effect on fibrosis regression. The optimal duration of therapy is unknown as prolonged therapy does not seem to induce additional histological benefit. Although some tolerance issues and safety concerns, in particular cardiovascular, have been raised, thiazolidinediones are the class of drugs with the largest body of evidence in the treatment of NASH so far and can be successfully used in some patients with this disease.

Fat redistribution preferentially reflects the anti-inflammatory benefits of pioglitazone treatment

Thiazoledinedione is known to have an anti-inflammatory effect besides a hypoglycemic effect. We investigated changes in high-sensitivity C-reactive protein (hsCRP), a proinflammatory marker, after pioglitazone treatment in association with the resulting changes in various metabolic and anthropometric parameters. A total of 93 type 2 diabetes mellitus patients (47 men and 46 women; mean age, 50.0 ± 10.8 years) who were being treated with a stable dose of sulfonylurea or metformin were enrolled in the study. Pioglitazone (15 mg/d) was added to their treatment regimen for 12 weeks, and metabolic and anthropometric measurements were taken before and after pioglitazone treatment. Pioglitazone treatment for 12 weeks decreased serum hsCRP levels (0.83 [1.14] to 0.52 [0.82] mg/L, P < .001) and improved glycemic control (fasting glucose, P < .001; glycosylated hemoglobin, P < .001) and lipid profiles (triglyceride, P = .016; high-density lipoprotein cholesterol, P < .001). Between responders and nonresponders to the hsCRP-lowering effect of pioglitazone, there were significant differences in baseline hsCRP levels and changes in the postprandial glucose and the ratio of visceral fat thickness (VFT) to subcutaneous fat thickness (SFT) (P = .004, .011, and .001, respectively). The percentage change in hsCRP levels after treatment was inversely correlated with baseline hsCRP levels (r = -0.497, P < .001) and directly correlated with the change in postprandial glucose (r = 0.251, P = .021), VFT (r = 0.246, P = .030), and VFT/SFT ratio (r = 0.276, P = .015). Logistic regression analysis revealed that the hsCRP-lowering effect of pioglitazone was affected by baseline hsCRP levels (odds ratio [OR] = 7.929, P = .007) as well as changes in postprandial 2-hour glucose (OR = 0.716, P = .025) and VFT/SFT ratio (OR = 0.055, P = .009). In conclusion, treatment with pioglitazone produced an anti-inflammatory effect, decreasing serum hsCRP levels; and a decrease in the VFT/SFT ratio was independently and most strongly associated with the hsCRP-decreasing effect. These results suggest that abdominal fat redistribution preferentially reflects the anti-inflammatory benefits of pioglitazone treatment.

Therapeutic trials in nonalcoholic steatohepatitis: insulin sensitizers and related methodological issues

Insulin sensitizers are attractive candidate therapies for nonalcoholic steatohepatitis mainly because of the strong association between this disease and insulin resistance. This review provides a critical overview of the mechanisms of action, clinical trial results, and safety issues of metformin and glitazones in nonalcoholic steatohepatitis. It also highlights methodological challenges for trial design and proposes endpoints for future proof of principle, registrational, and postmarketing trials.

The addition of pioglitazone in type 2 diabetics poorly controlled on insulin therapy: a meta-analysis

AIM

To quantify the effect of a pioglitazone on glycemic control and lipid parameters, as well as the risk of adverse events when incorporated into the treatment regimen of patients with type 2 diabetes inadequately controlled on insulin.

METHODS

The electronic databases PubMed, Embase and The Cochrane Library were searched systematically to identify randomized controlled trials (RCTs) of pioglitazone therapy in patients with type 2 diabetes mellitus (DM) inadequately controlled after treatment with insulin. Data on change of haemoglobin A1C (HbA1c), fasting plasma glucose (FPG), lipid parameters and risk of hypoglycemic, edema events were extracted from each study and pooled according to fixed effect model or random effect model in meta-analyses.

RESULTS

Four RCTs including 1767 patients were included. The pooled estimate of change in HbA1c from baseline was 1.22% (95% CI 1.01-1.44, p<0.001 vs. baseline) and of change in FPG from baseline was 1.63 mmol/l (95% CI 0.75-2.50, p<0.001 vs. baseline). Pioglitazone significantly increased high-density lipoprotein cholesterol (HDL-c) level (0.2 mmol/L, 95%CI: 0.13-0.28) and low-density lipoprotein cholesterol (LDL-c) level (0.10 mol/L, 95%CI: 0.09-0.17), and lowered triglyceride (TG) level (0.05 mmol/L, 95%CI: 0.01-0.09). The odds of experiencing a hypoglycemic event in pioglitazone-treated arms was significantly higher than comparator treatments (RR=1.57, 95% CI 1.12-2.20, p<0.001). The case was the same with edema (RR=2.42, 95% CI 1.67-3.50, p<0.001).

CONCLUSIONS

Our study implied that in patients with type 2 DM whose control is inadequate on insulin therapy, the additional pioglitazone could significantly improve glucose metabolism and might have a positive effect on important components of the lipid profile, which may have important implications in reducing the risk of cardiovascular disease, a major long-term complication in type 2 diabetes mellitus. Besides, the adverse events (AEs) were well tolerated.

Is the ADA/EASD algorithm for the management of type 2 diabetes (January 2009) based on evidence or opinion? A critical analysis

The ADA and the EASD recently published a consensus statement for the medical management of hyperglycaemia in patients with type 2 diabetes. The authors advocate initial treatment with metformin monotherapy and lifestyle modification, followed by addition of basal insulin or a sulfonylurea if glycaemic goals are not met (tier 1 recommendations). All other glucose-lowering therapies are relegated to a secondary (tier 2) status and only recommended for selected clinical settings. In our view, this algorithm does not offer physicians and patients the appropriate selection of options to individualise and optimise care with a view to sustained control of blood glucose and reduction both of diabetes complications and cardiovascular risk. This paper critically assesses the basis of the ADA/EASD algorithm and the resulting tiers of treatment options.