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ABSTRACT: The remodelling of the adipose tissue by pioglitazone may be associated with the sustained therapeutic effects. We studied the effects of withdrawal of pioglitazone after 3-month treatment on glucose, lipid and high-molecular weight (HMW) adiponectin levels as well as liver function in patients with type 2 diabetes mellitus.
Forty-nine Japanese patients with type 2 diabetes mellitus were randomly assigned into the withdrawal group after 3-month treatment with pioglitazone (15 or 30 mg daily) and the non-withdrawal group.
Three-month treatment with pioglitazone improved glycaemic control, homeostasis model assessment for insulin resistance (HOMA), dyslipidaemia and liver function tests in association with a marked increase in serum HMW adiponectin level. Three months later after the withdrawal of pioglitazone, however, fasting plasma glucose and HOMA increased, whereas serum HMW adiponectin decreased to the pretreatment levels. Dyslipidaemia also returned to the pretreatment level. On the other hand, liver enzymes at 3 months after the withdrawal remained lower after a mild rebound. In addition, the bone formation marker, serum bone-specific alkaline phosphatase, was significantly reduced by pioglitazone treatment in post-menopausal women.
The present study suggests that 3-month treatment with pioglitazone has no sustained beneficial effects except in liver function tests in patients with type 2 diabetes mellitus.
Journal of Clinical Pharmacy and Therapeutics 08/2010; 35(4):401-8. · 1.57 Impact Factor
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ABSTRACT: Postprandial hyperglycemia and hyperlipidemia are frequently associated with type 2 diabetes mellitus. The aim of the present study is to investigate the clinical determinants of postprandial glycemia and lipemia, especially serum high-molecular weight adiponectin.
Twenty-seven diabetic patients treated with diet alone and 13 healthy volunteers took liquid test meal containing 53 g carbohydrate and 47 g lipid, dosed with nonradioactive isotope (13)C-acetate. Venous blood and breath samples were obtained for 180 min after the meal. Gastric emptying was evaluated by peak excretion time of (13)CO(2) in the breath samples. Delayed gastric emptying was defined as peak excretion time > 2.5 h (mean + 2 SD in the healthy volunteers).
Diabetic patients showed delayed insulin secretion, postprandial hyperglycemia and hyperlipidemia compared with control. Postprandial glycemic increases significantly correlated with enhanced gastric emptying. Serum high-molecular weight adiponectin correlated with postprandial glycemic increases at 30 and 60 min after meal (r = 0.42, p < 0.05; r = 0.37, p < 0.05, respectively). Serum high-molecular weight adiponectin also correlated with gastric emptying (versus peak excretion time r = - 0.58, p < 0.05). In addition, diabetic patients with delayed gastric emptying showed the suppressed postprandial glycemia with lower serum high-molecular weight adiponectin than those with normal gastric emptying. On the other hand, postprandial increases in serum triglyceride were not related to serum high-molecular weight adiponectin or gastric emptying, but significantly related to liver function test (serum transaminases) and body mass index.
Early postprandial glycemic increases were related to elevated serum high-molecular weight adiponectin, which might be associated with enhanced gastric emptying.
Diabetes/Metabolism Research and Reviews 04/2009; 25(4):344-50. · 3.37 Impact Factor
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ABSTRACT: We herein report a rare case of MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes) and diabetes mellitus with ketoacidosis. An 18-year-old female patient was diagnosed to have diabetes mellitus and insulin therapy was thereafter initiated. At 26 years of age, she was hospitalized for diabetic ketoacidosis, soon followed by a loss of consciousness, left-sided dysmetria, and ataxic speech. MELAS was diagnosed because of the presence of ragged red fibers in a muscle biopsy. At 33 years of age, she was admitted to our hospital because of ketoacidosis and partial status epilepticus. A blood gas examination revealed as follows; arterial pH, 6.88; bicarbonate, 2.1 mmol/l; base excess - 29.8 mmol/l. The serum level of glucose had also increased to 30 mmol/l. The serum levels of lactate and B-hydroxybutyrate were elevated to 11.4 mmol/l and 1,990 micromol/l, respectively. Ketoacidosis improved by fluid replacement and continuous intravenous insulin infusion. A brain MRI demonstrated hyperintensity areas on FLAIR images in the bilateral temporal lobes and the cerebellum. A proton MRS demonstrated the abnormal lactate accumulation in the bilateral temporal and occipital lobes. Since epileptic seizures are rare in patients with diabetic ketoacidosis, such seizures may indicate the existence of MELAS syndrome.
Diabetes & Metabolism 12/2000; 26(5):407-10. · 2.41 Impact Factor
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ABSTRACT: Thiazolidinediones, synthetic ligands of peroxisome proliferator-activated receptor gamma (PPARgamma), are reported to have direct beneficial effects on diabetic nephropathy without lowering blood glucose levels in human and rat. We hypothesized these effects of thiazolidinediones might be derived from PPARgamma activation of kidney cells, and we examined the expression of PPARgamma and the effect of PPARgamma agonists, troglitazone and 15-deoxy-delta-prostaglandin J2 (15d-PGJ2), on the proliferation and differentiation in rat mesangial cells. A single band of mRNA of PPARgamma with a predicted size was detected in reverse transcription-polymerase chain reaction products (RT-PCR) using established PCR probes of PPARgamma. PPARgamma protein in rat mesangial cells was identified as PPARgamma1 by a Western blot. In a gel mobility shift assay to determine a binding activity of PPARgamma, the nuclear protein from rat mesangial cells bound to a (32)P-labeled oligonucleotide probe, including PPAR response elements. A synthetic and a natural ligand of PPARgamma, troglitazone and 15d-PGJ2, decreased thymidine incorporation in a dose dependent manner. After 7 days incubation with troglitazone and 15d-PGJ2, alpha-smooth muscle actin expression, a marker of mesangial cell de-differentiation, was decreased significantly compared to that of control. These results indicate that PPARgamma1 is expressing in rat mesangial cells, and PPARgamma1 activation with its agonists modulates the proliferation and differentiation of cultured rat mesangial cells.
Biochimica et Biophysica Acta 07/2000; 1497(1):148-54. · 4.66 Impact Factor
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ABSTRACT: To clarify the action of the new antidiabetic agent, troglitazone, on rat mesangial cells, we assessed its effect on the uptake and intracellular metabolism of glucose. Troglitazone increased the uptake of 2-deoxyglucose (2DOG) in a dose-dependent manner with an upregulation of glucose transporter 1 (GLUT1) mRNA, whereas it had no effect on the uptake of alpha-methyl glucoside (AMG). This troglitazone-induced glucose uptake was not suppressed by phlorizin. In 5 mmol/L glucose, 2 microg/mL (4.5 micromol/L) troglitazone increased glucose consumption 2.9-fold, similar to that in 20 mmol/L glucose. Troglitazone increased the production of pyruvate and lactate as a consequence of the increase in glycolysis, but did not increase the cellular ATP content. Troglitazone improved the high-glucose-induced accumulation of intracellular sorbitol and fructose and elevation of the cellular redox potential. These data suggest that troglitazone enhances glucose uptake through GLUT1 with an acceleration of glycolysis, and improves the abnormal intracellular glucose metabolism under high-glucose conditions in rat mesangial cells.
Metabolism 04/2000; 49(3):308-13. · 2.66 Impact Factor
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ABSTRACT: The effects of captopril on glucose uptake, as well as morphological and functional changes of retinal pericytes, in a high-glucose medium were examined. Retinal pericytes were incubated in medium with 5 and 30 mM glucose and 30 mM glucose with 10(-6) to 10(-3) M captopril. Captopril decreased the cellular uptakes of d-glucose and alpha-methyl glucoside in the presence, but not in the absence, of sodium. The cellular size and contents of glucose, sorbitol, and fructose were increased in 30 mM glucose concomitant with the decreased thymidine, cellular DNA content, and ratios in glucose to sorbitol and to fructose, compared with those in 5 mM glucose. These changes observed in 30 mM glucose were reversed by 10(-4) M captopril. These data suggest that the suppression of d-glucose uptake through a sodium-coupled glucose transporter by captopril may attenuate the swelling and loss of pericytes observed in the early stage of diabetic retinopathy.
Microvascular Research 12/1999; 58(3):215-23. · 2.83 Impact Factor
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ABSTRACT: We previously reported that sodium-dependent glucose uptake is present in bovine retinal pericytes and that phlorizin normalizes its glucose consumption under high glucose conditions. To clarify the effect of phlorizin on morphological and functional change of retinal pericytes under high glucose conditions, retinal pericytes were incubated in media with 5 mM glucose, 30 mM glucose, and 30 mM glucose plus 0.2 mM phlorizin for 7 days. The diameter of cells in the concentrations of glucose more than 10 mM were significantly larger than those in 5 mM glucose and 30 mM glucose plus phlorizin. Glucose, sorbitol and fructose contents of the cells in 30 mM glucose were significantly increased compared with those in 5 mM glucose, and were normalized by phlorizin. Thymidine uptake in the concentrations of glucose more than 20 mM was significantly decreased compared with that in 5 mM glucose. Myoinositol uptake, and DNA in 30 mM glucose were significantly reduced, and were normalized with phlorizin. Myoinositol content in 30 mM glucose was the same as that in 5 mM glucose, but was significantly decreased by phlorizin. The ratios of glucose to sorbitol or fructose in 30 mM glucose were significantly decreased, compared with those in 5 mM glucose and 30 mM glucose plus phlorizin. Therefore, the cellular enlargement and decreased DNA synthesis in cultured bovine retinal pericytes with abnormal glucose metabolism under high glucose conditions are attenuated by phlorizin, independent of the cellular myoinositol content.
Biochimica et Biophysica Acta 02/1999; 1453(1):83-91. · 4.66 Impact Factor
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ABSTRACT: Lipid-lowering fibrate drugs are known to affect the synthesis of fatty acids, which may alter the prostacyclin synthesis in diabetic patients. Therefore, the serum levels of precursor fatty acids and 6-keto-prostaglandin F1alpha (6-keto PGF1alpha) were determined in ten hyperlipidemic patients with Type 2 diabetes before and after administration of gemfibrozil (900 mg/day) for 3 months, in comparison with the results in seven non-diabetic hyperlipidemic patients. Gemfibrozil significantly reduced the serum concentration of dihomo-7-linolenic acid, total cholesterol and triglycerides, but did not affect the serum levels of arachidonic acid and 6-keto PGF1alpha in diabetic and non-diabetic patients. Thus, gemfibrozil did not affect the synthesis of prostacyclin in spite of the reduction of precursor fatty acids in diabetic and non-diabetic patients.
Diabetes Research and Clinical Practice 01/1999; 42(3):149-54. · 2.75 Impact Factor
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ABSTRACT: This study was performed to clarify the presence of sodium-dependent glucose uptake and its role in the synthesis of type IV and type VI collagen by cultured bovine retinal pericytes. The glucose uptake by retinal pericytes and retinal endothelial cells was measured using 3H-D-glucose in the presence or absence of sodium. Glucose uptake in the presence of sodium was twice as high as that observed in the presence of phlorizin and sodium or in the absence of sodium. Sodium-dependent glucose uptake was observed at different sodium concentrations, and its half-maximal stimulation occurred at 48 mM. These findings were not observed in retinal endothelial cells. Levels of type IV and type VI collagen produced by retinal pericytes were significantly increased at glucose concentrations higher than 20 mM. Phlorizin decreased both collagen synthesis and glucose consumption by retinal pericytes incubated with 30 mM of glucose to the levels observed with 5 mM of glucose. These data suggest that sodium-dependent glucose uptake is present in retinal pericytes and that excessive glucose entry into the cell is an important factor for overproduction of collagen. Phlorizin normalized the synthesis of type IV and type VI collagen with decreasing glucose consumption under high glucose conditions.
Biochimica et Biophysica Acta 12/1997; 1362(1):87-96. · 4.66 Impact Factor
