Hepatic safety profile and glycemic control of pioglitazone in more than 20,000 patients with type 2 diabetes mellitus: postmarketing surveillance study in Japan

Efficacy of 3 months of additional pioglitazone treatment in type 2 diabetes patients with alcoholic fatty liver disease

Pioglitazone ameliorates liver dysfunction in type 2 diabetes (T2D) patients with non-alcoholic fatty liver disease (NAFLD); however, its efficacy in T2D patients with alcoholic fatty liver disease (AFLD) is unclear. Here, we conducted a retrospective single-center trial investigating whether pioglitazone ameliorates liver dysfunction in T2D patients with AFLD. T2D patients (n = 100) receiving 3 months of additional pioglitazone were divided into those with or without fatty liver (FL), and those with FL were further classified into AFLD (n = 21) and NAFLD (n = 57) groups. The effects of pioglitazone were compared across groups using medical record data on body weight changes; HbA1c, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyl transpeptidase (γ-GTP) levels; and fibrosis-4 (FIB-4) index. The pioglitazone dose (mean dose: 10.6 ± 4.6 mg/day) did not affect weight gain but significantly decreased the HbA1c level in patients with or without FL (P < 0.01 and P < 0.05, respectively). The decrease in HbA1c level was significantly more pronounced in patients with FL than in those without FL (P < 0.05). In patients with FL, the HbA1c, AST, ALT, and γ-GTP levels significantly decreased after pioglitazone treatment than before (P < 0.01). The AST and ALT levels, but not the γ-GTP level, and the FIB-4 index significantly decreased after pioglitazone addition in the AFLD group, similar to that in the NAFLD group (P < 0.05 and P < 0.01, respectively). Similar effects were observed following low-dose pioglitazone treatment (≤ 7.5 mg/day) (P < 0.05) in T2D patients with AFLD and NAFLD. These results suggest that pioglitazone may be also an effective treatment option for T2D patients with AFLD.

Diabetes and cirrhosis: Current concepts on diagnosis and management

Type 2 diabetes mellitus is often associated with cirrhosis as comorbidities, acute illness, medications, and other conditions profoundly alter glucose metabolism. Both conditions are closely related in NAFLD, the leading cause of chronic liver disease, and given its rising burden worldwide, management of type 2 diabetes mellitus in cirrhosis will be an increasingly common dilemma. Having diabetes increases cirrhosis-related complications, including HCC as well as overall mortality. In the absence of effective treatments for cirrhosis, patients with type 2 diabetes mellitus should be systematically screened as early as possible for NAFLD-related fibrosis/cirrhosis using noninvasive tools, starting with a FIB-4 index followed by transient elastography, if available. In people with cirrhosis, an early diagnosis of diabetes is critical for an optimal management strategy (ie, nutritional goals, and glycemic targets). Diagnosis of diabetes may be missed if based on A1C in patients with cirrhosis and impaired liver function (Child-Pugh B-C) as anemia may turn the test unreliable. Clinicians must also become aware of their high risk of hypoglycemia, especially in decompensated cirrhosis where insulin is the only therapy. Care should be within multidisciplinary teams (nutritionists, obesity management teams, endocrinologists, hepatologists, and others) and take advantage of novel glucose-monitoring devices. Clinicians should become familiar with the safety and efficacy of diabetes medications for patients with advanced fibrosis and compensated cirrhosis. Management is conditioned by whether the patient has either compensated or decompensated cirrhosis. This review gives an update on the complex relationship between cirrhosis and type 2 diabetes mellitus, with a focus on its diagnosis and treatment, and highlights knowledge gaps and future directions.

PPAR-Gamma Activation May Inhibit the In Vivo Degeneration of Bioprosthetic Aortic and Aortic Valve Grafts under Diabetic Conditions

BACKGROUND

We aimed to examine the anti-calcification and anti-inflammatory effects of pioglitazone as a PPAR-gamma agonist on bioprosthetic-valve-bearing aortic grafts in a rat model of diabetes mellitus (DM).

METHODS

DM was induced in male Wistar rats by high-fat diet with an intraperitoneal streptozotocin (STZ) injection. The experimental group received additional pioglitazone, and controls received normal chow without STZ (n = 20 each group). Cryopreserved aortic donor grafts including the aortic valve were analyzed after 4 weeks and 12 weeks in vivo for analysis of calcific bioprosthetic degeneration.

RESULTS

DM led to a significant media proliferation at 4 weeks. The additional administration of pioglitazone significantly increased circulating adiponectin levels and significantly reduced media thickness at 4 and 12 weeks, respectively (p = 0.0002 and p = 0.0107, respectively). Graft media calcification was highly significantly inhibited by pioglitazone after 12 weeks (p = 0.0079). Gene-expression analysis revealed a significant reduction in relevant chondro-osteogenic markers osteopontin and RUNX-2 by pioglitazone at 4 weeks.

CONCLUSIONS

Under diabetic conditions, pioglitazone leads to elevated circulating levels of adiponectin and to an inhibition of bioprosthetic graft degeneration, including lower expression of chondro-osteogenic genes, decreased media proliferation, and inhibited graft calcification in a small-animal model of DM.

Management of diabetes mellitus in patients with cirrhosis: An overview and joint statement

Type 2 diabetes mellitus (T2DM) is a frequent comorbidity in patients with cirrhosis that is projected to rise in prevalence due to the worldwide burden of obesity, insulin-resistance and non-alcoholic fatty liver disease. The management of T2DM in patients with cirrhosis is complex given the requirement for accurate adaptation according to the level of liver function impairment, with lack of summary of the little evidence available in the literature. Here, we summarise the data available with respect to the epidemiology and the impact of T2DM in patients with cirrhosis, as well as those on the management of T2DM in these patients. We provide guidance for the diagnosis of T2DM and the monitoring of glycaemic control in patients with cirrhosis, and for the management of nutrition and pharmacological treatments in relation to the level of liver dysfunction.

The Importance of Rhodanine Scaffold in Medicinal Chemistry: A Comprehensive Overview

After the clinical use of epalrestat that contains a rhodanine ring, in type II diabetes mellitus and diabetic complications, rhodanin-based compounds have become an important class of heterocyclic in the field of medicinal chemistry. Various modifications to the rhodanine ring have led to a broad spectrum of biological activity of these compounds. Synthesis of rhodanine derivatives, depended on advenced throughput scanning hits, frequently causes potent and selective modulators of targeted enzymes or receptors, which apply their pharmacological activities through different mechanisms of action. Rhodanine-based compounds will likely stay a privileged scaffold in drug discovery because of different probability of chemical modifications of the rhodanine ring. We have, therefore reviewed their biological activities and structure activity relationship.

In vitro studies of potent aldose reductase inhibitors: Synthesis, characterization, biological evaluation and docking analysis of rhodanine-3-hippuric acid derivatives

Inhibitors of aldose reductase are rate-limiting enzymes and could play a key role to prevent the complications of diabetes. In our attempt to develop novel inhibitors of aldose reductase, the derivatives of rhodanine-3-hippuric acid-pyrazole hybrid were synthesized and characterised by spectral data. The biological studies reveal that all the compounds show an excellent activity against ALR2 with IC₅₀ values ranging from 0.04 to 1.36 µM. Among these the synthesised compounds 6a-m, 6g and 6e showed specific inhibitory activity with IC₅₀ values of 0.04 and 0.06 µM respectively against ALR2 and found to be more potent than epalrestat (IC₅₀ = 0.87 μM), the only aldose reductase inhibitor currently used in the therapy. Molecular docking analysis using the AR-NADP⁺ complex as a receptor was performed with all the synthesized compounds. All the compounds exhibit a well-defined binding mode within the AR active site, similarly to previous described AR inhibitors, with the anion head group bound to the catalytic center, blocking thus its activity. By forming hydrogen bonds with Tyr48 and His110 of the protein from ALR2 (PDB ID: 2FZD), the compounds 6g and 6e interrupt the proton donation mechanism, which is necessary for the catalytic activity of ALR2.

[Diabetes mellitus and chronic liver diseases. Literature review (part 2): treatment features]

Diabetes mellitus (DM) and chronic liver disease (CLD) are pathological conditions associated with each other and reaching epidemic proportions. There is a strong pathogenetic relationship of carbohydrate metabolism disorders and a number of CLD. Common mechanisms that provoke metabolic and autoimmune disorders in the development of various CLD, leading to steatosis, insulin resistance (IR), impaired glucose tolerance and the development of DM are described. Effective glycemic control can have a beneficial effect on the treatment of these patients, and, conversely, there is evidence of a positive effect of CLD therapy on carbohydrate metabolism. This review discusses the correction of carbohydrate metabolism in patients with CLD, the main groups of modern hypoglycemic drugs, mechanisms of their action, the impact on the physiology of the liver, the possibility of using each of these pharmacological groups in patients with impaired liver function. The modern approaches and possibilities of drug effects on the process of fibrogenesis in CLD, the effect of these drugs on carbohydrate metabolism are listed.

Antidiabetic agents in patients with hepatic impairment

Chronic liver disease (CLD) often coexists with type 2 diabetes mellitus, making diabetes management a challenge to the clinician. It is well known that liver is the major site of drug metabolism, and, therefore, its impairment affects hepatic metabolism of many antidiabetic agents. Furthermore, patients with CLD have serious comorbidities such as impaired renal function, hypoalbuminemia, lactic acidosis, hypoglycemia and malnutrition, making their treatment even more difficult. On the other hand, most of the antidiabetic agents, with the exception of insulin, need dosage titration due to alterations to their pharmacokinetics in patients with CLD. For well-established antidiabetic treatments, like metformin and sulfonylureas there are studies regarding their dosage chance in these patients. However, despite the growing problem of management of diabetes in patients with CLD the existing literature data, especially on newer antidiabetic agents, are limited and, furthermore, no direct guidelines exist. Therefore, in the present review article we try to summarize the existing literature data regarding management of diabetes in patients with CLD.

Investigation of a Dipeptidyl Peptidase-4 Inhibitor/Thiazolidinedione Combination Drug for Patients With Type 2 Diabetes and Poor Glycemic Control: Difficulty With Patient Enrollment

Background

One of the treatment options for type 2 diabetes mellitus (DM) is a combination drug (CD) that contains the dipeptidyl peptidase-4 inhibitor (DPP4I) alogliptin (AG) together with pioglitazone (PG). This CD can improve impaired insulin secretion and insulin resistance, which are the two major pathologic factors for type 2 DM, and is also expected to increase adherence to treatment. We conducted a multicenter open-label prospective study to examine the usefulness of this CD for routine management of type 2 DM.

Methods

In type 2 DM patients with poor glycemic control who had been taking a DPP4I for ≥ 1 month, PG (15 mg/day) was added (first point). When the safety of PG was confirmed after 1 - 3 months, the DPP4I and PG were switched to the CD containing AG (25 mg) and PG (15 mg) (second point). Three months after switching to the CD was defined as the final point. Evaluation of objective findings, laboratory test results, and medication adherence was performed at these three points.

Results

Nineteen subjects completed the study, but this was far short of the target (160 subjects). Compared to the first point, white blood cell count (WBC), aspartate aminotransferase (AST), alanine aminotransferase (ALT), γ-glutamyl transpeptidase (γ-GTP), and fasting blood glucose (FBG) all showed a significant decrease at both the second and final points. No change in medication adherence was observed throughout the study period. The most notable point about this study was the extremely small number of subjects enrolled. As a possible explanation, we considered whether the preferences of the study doctors for antidiabetic drugs differed between specialties. The study doctors were mainly gastroenterologists, followed by endocrinologists/diabetologists and cardiologists in equal numbers. As an additional investigation, we determined the percentages of specialist doctors prescribing DPP4Is, sodium-glucose cotransporter-2 inhibitors (SGLT2Is), PG, or biguanides (BGs) as the main treatment for DM in 1 month at our hospital. We found that a low percentage of endocrinologists/diabetologists prescribing PG compared to other drugs, while cardiologists prescribed PG frequently.

Conclusions

It was confirmed that the combination of DPP4I with PG was effective for the treatment of type 2 DM and improving metabolic function. Our data also showed that prescription of antidiabetic drugs differed between specialties, suggesting differences in their response to the results of various clinical studies and adverse reaction reports.

Hepatogenous Diabetes: An Underestimated Problem of Liver Cirrhosis

The prevalence of diabetes mellitus in cirrhotic patients is much higher than that in the general population. Two types of diabetes are usually seen in patients with cirrhosis: type 2 diabetes mellitus and hepatogenous diabetes (HD). The HD is an acquired condition which is believed to be caused by impaired insulin clearance and pancreatic β-cell dysfunction in cirrhotic patients. Increased levels of advanced glycation end products and hypoxia-inducible factors have been implicated in the pathogenesis of HD. Patients with HD typically present with normal fasting glucose, but abnormal response to an oral glucose tolerance test, which is required for the diagnosis. Because the level of glycated hemoglobin is often falsely low in patients with cirrhosis, it does not help in the early diagnosis of HD. HD is associated with an increased rate of complications of cirrhosis, decreased 5-year survival rate, and increased risk of hepatocellular carcinoma. The major complications of cirrhosis associated with HD include hepatic encephalopathy (HE), spontaneous bacterial peritonitis, sepsis, variceal hemorrhage, and renal dysfunction. Treatment of HD may be difficult as many antihyperglycemic therapies are associated with increased risk of complications in cirrhosis, particularly hypoglycemia. Biguanides, alpha-glucosidase inhibitors, and new medications such as dipeptidyl peptidase-4 inhibitors and sodium-glucose co-transporter 2 inhibitors appear to be safe in patients with cirrhosis. Though insulin therapy is currently advocated, requirement of insulin is variable and is difficult to predict. The liver transplantation usually results in reversal of HD. This review article provides an overview of magnitude, patients' characteristics, clinical implications, pathophysiological mechanisms, diagnosis, and management of HD.

Comparative Study on Adding Pioglitazone or Sitagliptin to Patients with Type 2 Diabetes Mellitus Insufficiently Controlled With Metformin

BACKGROUND

Diabetes mellitus is a progressive disorder that often requires combination therapy.

AIM

This study aimed to compare and study of add-on sitagliptin versus pioglitazone in patients with type 2 diabetes inadequately controlled with metformin.

METHODS

This 12-week, randomised, open-label and single centre study compared sitagliptin (100 mg daily, n = 80) and pioglitazone (30 mg daily, n = 80) in type 2 diabetic patients whose disease was not adequately controlled with metformin.

RESULTS

The mean change in HbA1c from baseline was -1.001 ± 0.83 with sitagliptin and -0.75 ± 1.20 with pioglitazone, and there were no significant difference between groups (P = 0.132). The mean change in fasting blood sugar (FBS) was -18.48 ± 33.32 mg/dl with sitagliptin and -20.53 ± 53.97 mg/dl with pioglitazone, and there were no significant difference between groups (P = 0.773). Sitagliptin caused 1.08 ± 2.39 kg decrease in weight, whereas pioglitazone caused 0.27 ± 2.42 kg increase in weight, with a between-group difference of 0.81 kg (P < 0.001). On the other hand, in sitagliptin group, there was greater improvement in lipid profile than pioglitazone group.

CONCLUSION

Sitagliptin and Pioglitazone demonstrated similar improvements in glycemic control in type 2 diabetes mellitus patients whose diabetes had been inadequately controlled with metformin. Nevertheless, sitagliptin was more effective than pioglitazone regarding lipid and body weight change.

Consensus Statement on Dose Modifications of Antidiabetic Agents in Patients with Hepatic Impairment

Liver disease is an important cause of mortality in type 2 diabetes mellitus (T2DM). It is estimated that diabetes is the most common cause of liver disease in the United States. Virtually, entire spectrum of liver disease is seen in T2DM including abnormal liver enzymes, nonalcoholic fatty liver disease, cirrhosis, hepatocellular carcinoma, and acute liver failure. The treatment of diabetes mellitus (DM) in cirrhotic patients has particular challenges as follows: (1) about half the patients have malnutrition; (2) patients already have advanced liver disease when clinical DM is diagnosed; (3) most of the oral antidiabetic agents (ADAs) are metabolized in the liver; (4) patients often have episodes of hypoglycemia. The aim of this consensus group convened during the National Insulin Summit 2015, Puducherry, was to focus on the challenges with glycemic management, with particular emphasis to safety of ADAs across stages of liver dysfunction. Published literature, product labels, and major clinical guidelines were reviewed and summarized. The drug classes included are biguanides (metformin), the second- or third-generation sulfonylureas, alpha-glucosidase inhibitors, thiazolidinediones, dipeptidyl peptidase-4 inhibitors, sodium-glucose co-transporter 2 inhibitors, glucagon-like peptide-1 receptor agonists, and currently available insulins. Consensus recommendations have been drafted for glycemic targets and dose modifications of all ADAs. These can aid clinicians in managing patients with diabetes and liver disease.

The Influences of Withdrawal and Daily Dose Reduction of Pioglitazone on Metabolic Parameters in Patients With Type 2 Diabetes: A Retrospective Longitudinal Observational Study

Background

The aim of the study was to understand the influences of withdrawal or dose reduction of pioglitazone in patients with type 2 diabetes.

Methods

We retrospectively picked up patients who had undergone withdrawal or daily dose reduction of pioglitazone after a continuous prescription for 3 months or longer between January 2010 and March 2014. We compared the data before the withdrawal or dose reduction of pioglitazone with the data at 3 or 6 months after those by a chart-based analysis.

Results

Among 713 patients taking pioglitazone at least once during the studied period, 20 patients had undergone withdrawal of pioglitazone (group A) and 51 patients had undergone daily dose reduction (group B). The mean pioglitazone dose at baseline was 23 mg in subjects of group A, and 30 mg in group B. The number of subjects who had taken high-dose metformin (≥ 1,000 mg) and dipeptidyl peptidase-4 (DPP-4) inhibitors increased after the withdrawal or dose reduction of pioglitazone in both groups. Although no significant change was observed in plasma glucose and HbA1c levels, body weight significantly decreased at 3 and 6 months after the dose reduction in group B. The same tendency was observed in group A. Serum high-density lipoprotein-cholesterol (HDL-C) levels significantly decreased at 3 and 6 months after the withdrawal in group A. The serum alanine aminotransferase levels significantly increased 3 months after the withdrawal in group A.

Conclusions

Present study demonstrated that the withdrawal of pioglitazone exacerbated serum HDL-C and liver function in patients with type 2 diabetes, although glycemic control could be maintained by using high-dose metformin or DPP-4 inhibitors.

Identification of novel pyrazole–rhodanine hybrid scaffolds as potent inhibitors of aldose reductase: design, synthesis, biological evaluation and molecular docking analysis

A series of novel pyrazole–rhodanine derivatives was designed, synthesized, and biologically evaluated for their potential inhibitory effect on both aldehyde reductase (ALR1) and aldose reductase (ALR2).

Fish oil prevents excessive accumulation of subcutaneous fat caused by an adverse effect of pioglitazone treatment and positively changes adipocytes in KK mice

Pioglitazone, a thiazolidinedione (TZD), is widely used as an insulin sensitizer in the treatment of type 2 diabetes. However, body weight gain is frequently observed in TZD-treated patients. Fish oil improves lipid metabolism dysfunction and obesity. In this study, we demonstrated suppression of body weight gain in response to pioglitazone administration by combination therapy of pioglitazone and fish oil in type 2 diabetic KK mice. Male KK mice were fed experimental diets for 8 weeks. In safflower oil (SO), safflower oil/low-dose pioglitazone (S/PL), and safflower oil/high-dose pioglitazone (S/PH) diets, 20% of calories were provided by safflower oil containing 0%, 0.006%, or 0.012% (wt/wt) pioglitazone, respectively. In fish oil (FO), fish oil/low-dose pioglitazone (F/PL), and fish oil/high-dose pioglitazone (F/PH) diets, 20% of calories were provided by a mixture of fish oil and safflower oil. Increased body weight and subcutaneous fat mass were observed in the S/PL and S/PH groups; however, diets containing fish oil were found to ameliorate these changes. Hepatic mRNA levels of lipogenic enzymes were significantly decreased in fish oil-fed groups. These findings demonstrate that the combination of pioglitazone and fish oil decreases subcutaneous fat accumulation, ameliorating pioglitazone-induced body weight gain, through fish oil-mediated inhibition of hepatic de novo lipogenesis.

Relationship between urinary sodium excretion and pioglitazone-induced edema

To investigate the factors contributing to pioglitazone-induced edema, we analyzed sodium excretion and several clinical parameters before and after administration of pioglitazone. We analyzed these parameters before and after 8 weeks of administration of pioglitazone to female subjects with type 2 diabetes. When we evaluated whether a significant correlation was found between salt excretion and blood pressure, six patients showed such correlation and 20 patients did not. After 8 weeks of pioglitazone administration, five patients had developed edema, and, surprisingly, such correlation was not found in all five subjects. Salt excretion after administration of pioglitazone was significantly lower in subjects who developed edema and those who showed the correlation, and the hematocrit was significantly lower after administration in the subjects who showed the correlation, but not in the edema group. Pioglitazone-induced edema would be caused not only by fluid retention, but also by other factors, such as vascular permeability. (J Diabetes Invest, doi: 10.1111/ j.2040-1124.2010.00046.x, 2010).

Relationship between urinary sodium excretion and pioglitazone-induced edema

To investigate the factors contributing to pioglitazone-induced edema, we analyzed sodium excretion and several clinical parameters before and after administration of pioglitazone. We analyzed these parameters before and after 8 weeks of administration of pioglitazone to female subjects with type 2 diabetes. When we evaluated whether a significant correlation was found between salt excretion and blood pressure, six patients showed such correlation and 20 patients did not. After 8 weeks of pioglitazone administration, five patients had developed edema, and, surprisingly, such correlation was not found in all five subjects. Salt excretion after administration of pioglitazone was significantly lower in subjects who developed edema and those who showed the correlation, and the hematocrit was significantly lower after administration in the subjects who showed the correlation, but not in the edema group. Pioglitazone-induced edema would be caused not only by fluid retention, but also by other factors, such as vascular permeability. (J Diabetes Invest, doi: 10.1111/ j.2040-1124.2010.00046.x, 2010).

Randomized controlled trial of single-agent glimepiride and pioglitazone in Japanese patients with type 2 diabetes: A comparative study

Aims/Introduction:  To compare first‐line, single‐agent glimepiride and pioglitazone in Japanese patients with type 2 diabetes uncontrolled by diet and exercise with respect to glycemic control, safety and metabolic changes.

Materials and Methods:  Patients with previously untreated type 2 diabetes were enrolled in a multicenter, randomized, non‐blind, parallel‐group trial of glimepiride (0.5–6 mg/day) or pioglitazone (15–45 mg/day) for 6 months.

Results:  A total of 191 patients aged 30–75 years were randomized. Similar percentages of patients attained the primary end‐point, with glycated hemoglobin < 6.9% at month 6 with glimepiride and pioglitazone, respectively (61.2 vs 56.8%, P = 0.64). At month 6, the following significant (P < 0.05) intragroup changes in mean plasma lipid concentrations were noted as compared with baseline: total cholesterol decreased from 203.5 to 195.5 mg/dL and low‐density lipoprotein (LDL)‐cholesterol decreased from 124.5 to 116.3 mg/dL in the glimepiride group, whereas high‐density lipoprotein (HDL)‐cholesterol increased from 51.6 to 56.0 mg/dL and triglycerides decreased from 167.6 to 143.6 mg/dL in the pioglitazone group. The only symptomatic adverse events were mild‐to‐moderate in four patients receiving pioglitazone, and constipation in one patient receiving glimepiride. Similar numbers of patients experienced asymptomatic hypoglycemia (<60 mg/dL) in the glimepiride and pioglitazone groups (n = 7 and 5, respectively).

Conclusions:  There was no statistically significant difference between glimepiride and pioglitazone with respect to glycemic control, and both agents were well tolerated. Glimepiride significantly lowered total cholesterol and LDL‐cholesterol, whereas pioglitazone increased HDL‐cholesterol. This trial was registered with University Hospital Medical Information Network (UMIN), Japan, UMIN000004582. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2011.00115.x, 2011)

Relationship between urinary sodium excretion and pioglitazone-induced edema

To investigate the factors contributing to pioglitazone‐induced edema, we analyzed sodium excretion and several clinical parameters before and after administration of pioglitazone. We analyzed these parameters before and after 8 weeks of administration of pioglitazone to female subjects with type 2 diabetes. When we evaluated whether a significant correlation was found between salt excretion and blood pressure, six patients showed such correlation and 20 patients did not. After 8 weeks of pioglitazone administration, five patients had developed edema, and, surprisingly, such correlation was not found in all five subjects. Salt excretion after administration of pioglitazone was significantly lower in subjects who developed edema and those who showed the correlation, and the hematocrit was significantly lower after administration in the subjects who showed the correlation, but not in the edema group. Pioglitazone‐induced edema would be caused not only by fluid retention, but also by other factors, such as vascular permeability. (J Diabetes Invest, doi: 10.1111/ j.2040‐1124.2010.00046.x, 2010)

Effects of replacing metformin with pioglitazone on glycemic control in japanese patients with poorly controlled type 2 diabetes mellitus: A 12-week, open-label, prospective study

BACKGROUND

Insulin resistance is a critical aspect of the pathophysiology of type 2 diabetes mellitus and is also associated with other risk factors for cardiovascular disease (eg, dyslipidemia and hypertension). Accordingly, insulin resistance is a possible target for lowering plasma glucose concentration and preventing diabetic macroangiopathy. Biguanides, such as metformin, and thiazolidinediones (TZDs), such as pioglitazone, improve insulin resistance.

OBJECTIVES

The aims of this study were to assess the effects of replacing a biguanide with a TZD on glycemic control in patients with poorly controlled type 2 diabetes mellitus, and also to identify the factors affecting interpatient variation in the effects of treatment change.

METHODS

This was a 12-week, open-label, prospective study in which previously prescribed metformin (500 or 750 mg/d) was replaced with pioglitazone (15 or 30 mg/d) in patients with poorly controlled type 2 diabetes mellitus. Patients with a glycosylated hemoglobin (HbA1c) concentration >7% despite treatment with diet, exercise, and hypoglycemic agents other than TZDs were eligible for the study. Patients who never received TZDs were also eligible for inclusion. Vital signs, metabolic parameters, and arterial stiffness were assessed at baseline and after 12 weeks of treatment with pioglitazone. The primary end point was change in HbA1c concentration after replacing metformin with pioglitazone. Tolerability was assessed by medical history, physical examination, and laboratory tests (aspartate aminotransferase, alanine aminotransferase, and γ-glutamyl transpeptidase).

RESULTS

Twenty-one Japanese patients (15 women, 6 men; mean [SD] age, 61.8 [8.4] years; body mass index, 25.5 [3.0] kg/m(2)) were included in the study. HbA1c concentration was not significantly changed from baseline after 12 weeks of pioglitazone treatment (8.0% [0.7%] vs 8.2% [0.7%]). Fasting plasma glucose (FPG) concentration also was not significantly changed after the replacement of treatment (156 [27] vs 144 [30] mg/dL). In addition, the resistin concentration did not change significantly from baseline after 12 weeks of pioglitazone treatment (6.6 [3.8] vs 6.4 [3.6] ng/mL). In contrast, significant improvement from baseline was observed in triglyceride (TG) concentrations (157 [109] vs 117 [68] mg/dL; P = 0.003), high-density lipoprotein cholesterol (HDL-C) (55 [12] vs 61 [16] mg/dL; P = 0.016), remnant-like particle cholesterol (6.6 [6.0] vs 5.3 [3.5] mg/dL; P = 0.048), and serum adiponectin (8.8 [4.3] vs 23.3 [11.7] μg/mL; P < 0.001). Pulse wave velocity was also significantly improved (1730 [361] vs 1622 [339] m/sec; P = 0.009). Changes in HbA1c were significantly correlated with serum fasting insulin concentration at baseline in the patients not receiving insulin preparations (r = -0.635, P = 0.013). The percentage change in serum adiponectin concentration was correlated with the percentage changes in HbA1c and FPG concentrations (HbA1c, r = -0.518, P = 0.019; FPG, r = -0.594, P = 0.006). Body weight was significantly increased after treatment (62.6 [11.9] vs 65.5 [12.2] kg; P < 0.001). Mild edema was reported in 5 patients. One patient discontinued treatment due to an increase in serum creatine kinase activity to ~6.6 times the upper limit of normal.

CONCLUSIONS

Replacement of metformin with pioglitazone did not produce significant differences in HbA1c and FPG concentrations from baseline after 12 weeks of treatment in these patients with poorly controlled type 2 diabetes mellitus. However, the replacement was effective in a subset of patients whose serum insulin concentrations were high or whose serum adiponectin concentrations were sensitive to TZDs. In addition, the replacement was associated with significant improvements in TG, HDL-C, serum adiponectin concentration, pulse wave velocity, and body weight increase from baseline.

Comparative study of sitagliptin with pioglitazone in Japanese type 2 diabetic patients: the COMPASS randomized controlled trial

AIMS

To compare the efficacy and safety of these two agents and the impact on surrogate markers related to diabetic complications in Japanese type 2 diabetic patients.

METHODS

In a multicenter, open-label trial, 130 patients whose diabetes had been inadequately controlled (HbA1c, 6.9-9.5%) with metformin and/or sulphonylurea were randomly assigned to a sitagliptin group (50 mg/day) or a pioglitazone group (15 mg/day) and were followed up for 24 weeks. At 16 weeks, if the patient's HbA1c level was ≥6.5%, the dose of sitagliptin or pioglitazone was increased up to 100 or 30 mg/day, respectively. Main outcome measure was the difference in the mean changes in the HbA1c level from baseline at 24 weeks between these two groups.

RESULTS

Of the 130 patients who were enrolled, 115 subjects (sitagliptin group: 58 patients, pioglitazone group: 57 patients) completed this trial. At 0 weeks, the mean HbA1c level was 7.47 ± 0.66% in the sitagliptin group and 7.40 ± 0.61% in the pioglitazone group. At 24 weeks, the mean changes in the HbA1c level from baseline were -0.86 ± 0.63% versus -0.58 ± 0.68% (p = 0.024). Hypoglycaemia (2 patients, 3.4% vs. 2 patients, 3.5%), gastrointestinal symptoms (3 patients, 5.2% vs. 1 patient, 1.8%) and pretibial oedema (0 patients, 0% vs. 39 patients, 68.4%, p < 0.001) were observed for 24 weeks.

CONCLUSIONS

Sitagliptin was not only more tolerable, but also more effective than pioglitazone in Japanese type 2 diabetic patients who had been treated with metformin and/or sulphonylurea.

Dipeptidyl Peptidase IV Inhibitor Improves Insulin Resistance and Steatosis in a Refractory Nonalcoholic Fatty Liver Disease Patient: A Case Report

A 67-year-old Asian woman was referred to Kurume University Hospital due to abnormal liver function tests. She was diagnosed with nonalcoholic fatty liver disease (NAFLD). NAFLD was treated by diet therapy with medication of metformin and pioglitazone; however, NAFLD did not improve. Subsequently, the patient was administered sitagliptin. Although her energy intake and physical activity did not change, her hemoglobin A1c level was decreased from 7.8 to 6.4% 3 months after treatment. Moreover, her serum insulin level and homeostasis model assessment-insulin resistance value were also improved, as was the severity of hepatic steatosis. These findings indicate that sitagliptin may improve insulin resistance and steatosis in patients with refractory NAFLD.

Postprandial hyperglycemia and endothelial function in type 2 diabetes: focus on mitiglinide

The risk of cardiovascular complication in a diabetes patient is similar to that in a nondiabetic patient with a history of myocardial infarction. Although intensive control of glycemia achieved by conventional antidiabetic agents decreases microvascular complications such as retinopathy and nephropathy, no marked effect has been reported on macrovascular complications or all-cause mortality. Evidence from VADT, ACCORD, and ADVANCE would suggest that glycemic control has little effect on macrovascular outcomes. Moreover, in the case of ACCORD, intensive glycemic control may be associated with an increased risk of mortality. There is sufficient evidence that suggests that postprandial hyperglycemia may be an independent risk factor for cardiovascular disease in diabetes patients. However, there are no prospective clinical trials supporting the recommendation that lowering postprandial blood glucose leads to lower risk of cardiovascular outcomes. Mitiglinide is a short-acting insulinotropic agent used in type 2 diabetes treatment. It has a rapid stimulatory effect on insulin secretion and reduces postprandial plasma glucose level in patients with type 2 diabetes. Because of its short action time, it is unlikely to exert adverse effects related to hypoglycemia early in the morning and between meals. Mitiglinide reduces excess oxidative stress and inflammation, plays a cardioprotective role, and improves postprandial metabolic disorders. Moreover, mitiglinide add-on therapy with pioglitazone favorably affects the vascular endothelial function in type 2 diabetes patients. These data suggest that mitiglinide plays a potentially beneficial role in the improvement of postprandial hyperglycemia in type 2 diabetes patients and can be used to prevent cardiovascular diseases. Although the results of long-term, randomized, placebo-controlled trials for determining the cardiovascular effects of mitiglinide on clinical outcomes are awaited, this review is aimed at summarizing substantial insights into this topic.

A review of methods used in assessing non-serious adverse drug events in observational studies among type 2 diabetes mellitus patients

Clinical drug trials are often conducted in selective patient populations, with relatively small numbers of patients, and a short duration of follow-up. Observational studies are therefore important for collecting additional information on adverse drug events (ADEs). Currently, there is no guidance regarding the methodology for measuring ADEs in such studies. Our aim was to evaluate whether the methodology used to assess non-serious ADEs in observational studies is adequate for detecting these ADEs, and for addressing limitations from clinical trials in patients with type 2 diabetes mellitus. We systematically searched MEDLINE and EMBASE for observational studies reporting non-serious ADEs (1999-2008). Methods to assess ADEs were classified as: 1) medical record review; 2) surveillance by health care professionals (HCP); 3) patient survey; 4) administrative data; 5) laboratory/clinical values; 6) not specified. We compared the range of ADEs identified, number and selection of patients included, and duration of follow-up. Out of 10,125 publications, 68 studies met our inclusion criteria. The most common methods were based on laboratory/clinical values (n = 25) and medical record review (n = 18). Solicited surveillance by HCP (n = 17) revealed the largest diversity of ADEs. Patient surveys (n = 15) focused mostly on hypoglycaemia and gastrointestinal ADEs, laboratory values based studies on hepatic and metabolic ADEs, and administrative database studies (n = 5) on cardiovascular ADEs. Four studies presented ADEs that were identified with the use of more than one method. The patient population was restricted to a lower risk population in 19% of the studies. Less than one third of the studies exceeded pre-approval regulatory requirements for sample size and duration of follow-up. We conclude that the current assessment of ADEs is hampered by the choice of methods. Many observational studies rely on methods that are inadequate for identifying all possible ADEs. Patient-reported outcomes and combinations of methods are underutilized. Furthermore, while observational studies often include unselective patient populations, many do not adequately address other limitations of pre-approval trials. This implies that these studies will not provide sufficient information about ADEs to clinicians and patients. Better protocols are needed on how to assess adverse drug events not only in clinical trials but also in observational studies.

Determinants of an optimal response to pioglitazone in terms of HDL-cholesterol

OBJECTIVE

The effect of pioglitazone on high-density lipoprotein cholesterol (HDL-C) has been attracting attention. However, there are limited data on the characteristics of patients who are likely to respond to pioglitazone in terms of the improvement in HDL-C levels (lipid responders). In the present study, the characteristics of lipid responders were investigated.

METHODS

Five hundred and sixty-three patients with type 2 diabetes who started pioglitazone treatment were followed for six months. They were divided into two groups according to the response to pioglitazone. Subjects whose HDL-C levels increased by 10% or more from the baseline were defined as lipid responders. The odds ratios (OR) for becoming lipid responders were calculated using logistic regression.

RESULTS

Significant patients' characteristics of lipid responders were age, HbA1c, HDL-C and low-density lipoprotein cholesterol (LDL-C), yielding adjusted ORs of 0.76 [95% confidence interval (CI)=0.61-0.93] for an increment of 10 years, 0.79 (95% CI=0.66-0.95) for an increment of 1%, 0.83 (95% CI=0.72-0.96) for an increment of 10 mg/dL and 0.93 (95% CI=0.87-1.00) for an increment of 10 mg/dL, respectively. Patients with sulfonylurea treatment and those with both sulfonylurea and metformin treatment were less likely to become lipid responders than diet-treated patients with ORs of 0.32 (95% CI=0.15-0.69) and 0.41 (95% CI=0.19-0.87), respectively.

CONCLUSION

Pioglitazone could be beneficial especially for patients with young age, low HbA1c, low HDL-C or low LDL-C levels at baseline in terms of the improvement in HDL-C levels. Use of sulfonylureas at baseline could attenuate the effect of pioglitazone on HDL-C.

Effects of telmisartan on insulin resistance in Japanese type 2 diabetic patients

OBJECTIVE

PPARgamma agonists are widely used in type 2 diabetic patients to reduce insulin resistance. Recently, telmisartan, an AT1 receptor antagonist, was reported to function as a partial agonist of PPARgamma based on in vitro experiments. The aim of the present study was to investigate whether the PPARgamma enhancing activity of telmisartan is exerted clinically in diabetic patients.

METHODS

We compared the effects of telmisartan with those of candesartan, on insulin sensitivity, the serum levels of various adipocytokines and oxidative stress.

PATIENTS

In total, 85 Japanese type 2 diabetic patients with hypertension, maintained on 8 mg per day of candesartan, were randomly assigned to the TM group (candesartan switched to 40 mg of telmisartan, n=38) or the CD group (no treatment change, n=47).

RESULTS

After 3 months, oxidized lipids were significantly decreased only in the TM group. Although the homeostasis assessment model of insulin resistance (HOMA-R) tended to be improved and serum concentrations of HDL-cholesterol and HMW adiponectin tended to be increased only in the TM group, these alterations were too small to be significant by unpaired t-test. Interestingly, in subgroup analysis, the alterations of HOMA-R, serum concentrations of oxidized lipids, and HMW adiponectin were more apparent in obese TM group subjects and the changes reached statistical significance.

CONCLUSION

Switching from candesartan to telmisartan in obese subjects increases serum adiponectin and improves both insulin resistance and oxidative stress, while these effects were not statistically apparent in the total patient population. These results support the idea that telmisartan exerts its PPARgamma enhancing activity clinically in obese type 2 diabetic patients.

Insulin-dependent actions of pioglitazone in newly diagnosed, drug naïve patients with type 2 diabetes

The aim of this study was to study the effects of pioglitazone on several diabetic parameters with subjects possessing distinct levels of insulin. Treatment naive patients with type 2 diabetes received 15-30 mg/day pioglitazone monotherapy. At 3 months, levels of insulin, C-peptide, HbA1c, HOMA-R, HOMA-B and BMI were compared with those at baseline between the low (below 5.9 microU/ml, n = 48), medium (11.9-6 microU/ml n = 39) and high (above 12 microU/ml, n = 33) insulin groups. At baseline, differences existed in the levels of HbA1c, insulin, C-peptide, HOMA-R, HOMA-B, and BMI between these groups. In the high-insulin group significant reductions of insulin/C-peptide levels were observed, while in the low-insulin group significant increases of insulin/C-peptide were observed. In the medium-insulin group, no significant changes were observed. In contrast, the HbA1c levels significantly and similarly decreased in all the groups. Significant correlations between the changes of insulin/C-peptide levels with pioglitazone and the baseline insulin/C-peptide levels were observed. HOMA-R showed greater reductions in the high-insulin group, while HOMA-B showed greater increases in the low-insulin group in comparison to other groups. Multiple regression analysis revealed that the baseline insulin level is the predominant determinant of the changes of insulin levels with pioglitazone. These results suggest that pioglitazone appears to have two effects: to reduce insulin resistance (and lower insulin) and to improve beta-cell function (and increase insulin). The predominance of these effects appears to be determined by the insulin levels. Based on these data, a novel physiological model showing that pioglitazone may shift the natural history of diabetes toward an earlier stage (rejuvenation of beta-cell function) will be presented.

A pilot study suggests that the G/G genotype of resistin single nucleotide polymorphism at -420 may be an independent predictor of a reduction in fasting plasma glucose and insulin resistance by pioglitazone in type 2 diabetes

The aim of this study was to determine the relation between the G/G genotype of a resistin gene promoter single nucleotide polymorphism (SNP) at -420 (rs1862513) and glycemic control by pioglitazone in type 2 diabetes. In Study 1, 121 type 2 diabetic patients were treated with pioglitazone (15 or 30 mg/day) for 12 weeks, in addition to previous medication. In Study 2, 63 patients who had been treated with pioglitazone for 12 weeks were examined retrospectively. In Study 1, multiple regression analysis revealed that the G/G but not C/G genotype was correlated with a reduction in fasting plasma glucose (FPG) and homeostasis model assessment of insulin resistance (HOMA-IR) compared to C/C. When adjusted for age, gender, and BMI, the G/G genotype was an independent factor for the reduction of FPG (P=0.020) and HOMA-IR (P =0.012). When studies 1 and 2 were combined by adjusting the studies, age, gender, and BMI, the reduction of HbA1c was correlated with the G/G genotype (beta=-0.511, P=0.044). Therefore, this pilot study suggests that the G/G genotype of resistin SNP -420 may be an independent predictor of the reduction of fasting plasma glucose and HOMA-IR by pioglitazone.

Effect of mitiglinide on glycemic control over 52 weeks in Japanese type 2 diabetic patients insufficiently controlled with pioglitazone monotherapy

This study was performed to examine the efficacy and safety of the rapid- and short-acting insulinotropic SUR ligand mitiglinide given as add-on therapy for 52 weeks in type 2 diabetic patients whose blood glucose was insufficiently controlled by pioglitazone monotherapy. Type 2 diabetic patients aged > or = 20 years with postprandial plasma glucose (PPG1 or 2) > or = 200 mg/dL and glycated hemoglobin (HbA(1C)) 6.5-<9.0% despite receiving pioglitazone 15-45 mg/day were additionally treated with concomitant mitiglinide 10 mg tid p.o. for a total treatment period of 52 weeks. In 171 patients recruited, HbA(1C) was significantly reduced from 7.64 +/- 0.77% at baseline to 6.84 +/- 0.73%, 6.64 +/- 0.64%, 6.67 +/- 0.57% and 6.81 +/- 0.65% at weeks 16, 28, 40, and 52, respectively. Over half the patients achieved HbA(1C) target of <7.0%, and one third <6.5%. Significant reductions in fasting plasma glucose (FPG) and PPG 1 and 2 hours after a meal versus baseline were noted at all time-points evaluated. The most frequently noted adverse reactions were hypoglycemic symptoms, weight gain, and peripheral edema (all mild). In type 2 diabetic patients combination therapy with mitiglinide and pioglitazone exerted significant long-term improvements in HbA(1C), FPG, and PPG and was well tolerated. This drug combination therapy is a promising means of alleviating insufficient pancreatic insulin secretion and insulin resistance.

Addition of mitiglinide to pioglitazone monotherapy improves overall glycemic control in Japanese patients with type 2 diabetes: a randomized double blind trial

A 16-week, multicenter, randomized, double blind, parallel-group study was performed to examine whether additional administration of mitiglinide improves glycemic control in Japanese type 2 diabetic patients who are insufficiently controlled by pioglitazone monotherapy. Japanese adult type 2 diabetic patients were at first treated with diet plus pioglitazone 15-30 mg/day for 4 weeks then randomized to receive additional mitiglinide 5 or 10 mg or placebo tid for a further 16 weeks. In all, 381 patients were randomized. At final evaluation, glycated hemoglobin (HbA(1C)) was reduced by (mean +/- SD) -0.02 +/- 0.60% in the pioglitazone monotherapy group and by -0.45 +/- 0.77% and -0.67 +/- 0.59% in the mitiglinide 5 and 10 mg combination groups, respectively (both p<0.001 vs. pioglitazone monotherapy group). The percentage of patients who achieved HbA(1C) targets was significantly (p<0.001) higher in the mitiglinide combination groups than in the pioglitazone monotherapy group. Significant improvements in fasting plasma glucose and postprandial plasma glucose were noted in the mitiglinide combination groups versus the pioglitazone monotherapy group. No increase in adverse events was noted when mitiglinide was administered concomitantly with pioglitazone monotherapy. Hypoglycemic adverse events were infrequently and similarly observed in all three groups. Body weight gain and edema presented no clinical problem. HbA(1C) was significantly improved in the mitiglinide combination groups compared with the pioglitazone monotherapy group, and significantly more patients achieved HbA(1C) targets. Therefore mitiglinide effectively improves glycemic control in type 2 diabetic patients who are inadequately controlled by pioglitazone monotherapy.

Metformin, but not pioglitazone, decreases postchallenge plasma ghrelin levels in type 2 diabetic patients: a possible role in weight stability?

AIM

Effects of metformin and pioglitazone on body weight are clearly different. Recently, the role of ghrelin, an orexigenic peptide derived from stomach, has been appreciated. Plasma ghrelin levels display a preprandial peak and postprandial suppression, suggesting its physiological role. We hypothesized that metformin or pioglitazone may modulate circulating ghrelin levels and this modulation may be related to differential effects on body weight with these agents.

METHODS

Thirty-five Japanese type 2 diabetic patients [21 men and 14 women, age 62 +/- 2 years, body mass index (BMI) 26.6 +/- 0.5 kg/m(2) and haemoglobin A1c (HbA1c) 8.2 +/- 0.1%, mean +/- s.e.] were randomly assigned to groups for the addition of metformin or pioglitazone. At baseline and 4 months later, a 75-g oral glucose tolerance test (OGTT) was performed to measure plasma ghrelin levels.

RESULTS

In 33 subjects who completed the study, the overall decrease in HbA1c ( approximately 1%) was comparable between the two groups. As expected, BMI increased in the pioglitazone group but not in the metformin group. After the treatment, plasma ghrelin levels at each point of OGTT remained unchanged in the pioglitazone group. In the metformin group, fasting ghrelin levels were unaltered, whereas the absolute levels at 30, 60 and 120 min decreased significantly. The area under the curve for the 2-h ghrelin profile also decreased significantly.

CONCLUSIONS

Metformin, but not pioglitazone, decreased plasma ghrelin levels after the glucose load. This decrease may in part account for weight stability in type 2 diabetic patients treated with metformin.

Indicators for the efficacy of pioglitazone before and during treatment in Japanese patients with type 2 diabetes

BACKGROUND

The aim of this study is to explore appropriate indicators for the efficacy of pioglitazone (Pio) before and during treatment of Japanese patients with type 2 diabetes mellitus (T2DM).

METHODS

Forty-eight Japanese patients with T2DM (22 men, 26 women, 60 +/- 2 years old) were enrolled and treated with 15 mg/day of Pio for 12 weeks. Before and after the treatment, various parameters were evaluated regarding the efficacy of Pio. Patients who had a reduction in hemoglobin A1c (HbA1c) of >1% after 12 weeks of treatment were defined as responders.

RESULTS

Twenty-two patients were classified as responders. In the responder group, age, fasting plasma glucose (FPG), and percentage female were significantly (P < 0.05) higher compared with the non-responder group. In logistic regression analysis, female sex and higher FPG were selected as explanatory variables for the efficacy of Pio. Furthermore, the change of HbA1c (DeltaHbA1c) was positively correlated with that of fasting C-peptide level (DeltaCPR) and log-transformed high-sensitivity C-reactive protein (Deltalog HS-CRP), and negatively correlated with that of high-density lipoprotein cholesterol (DeltaHDL-C) and log-transformed adiponectin (Deltalog AP). In multiple stepwise regression analysis, DeltaCPR, Deltalog HS-CRP, and Deltalog AP (or DeltaFPG) were selected as explanatory variables for DeltaHbA1c.

CONCLUSIONS

We concluded that Pio is likely to show favorable effects on blood glucose control especially in female patients with higher FPG levels. Administration of Pio ameliorates blood glucose control accompanied by the increase of AP and the decrease of CPR or HS-CRP, suggesting that Pio exerts its beneficial effects through the enhancement of AP, which leads to suppression of inflammation and amelioration of insulin resistance.