[Show abstract][Hide abstract] ABSTRACT: Mounting evidence indicates that the gut microbiota are an important modifier of obesity and diabetes. However, so far there is no information on gut microbiota and "live gut bacteria" in the systemic circulation of Japanese patients with type 2 diabetes.RESEARCH DESIGN AND METHODS: Using a sensitive reverse transcription-quantitative PCR (RT-qPCR) method, we determined the composition of fecal gut microbiota in 50 Japanese patients with type 2 diabetes and 50 control subjects, and its association with various clinical parameters, including inflammatory markers. We also analyzed the presence of gut bacteria in blood samples.RESULTS: The counts of the Clostridium coccoides group, Atopobium cluster, and Prevotella (obligate anaerobes) were significantly lower (P < 0.05), while the counts of total Lactobacillus (facultative anaerobes) were significantly higher (P < 0.05) in fecal samples of diabetic patients than in those of control subjects. Especially, the counts of Lactobacillus reuteri and Lactobacillus plantarum subgroups were significantly higher (P < 0.05). Gut bacteria were detected in blood at a significantly higher rate in diabetic patients than in control subjects (28% vs. 4%, P < 0.01), and most of these bacteria were Gram-positive.CONCLUSIONS: This is the first report of gut dysbiosis in Japanese patients with type 2 diabetes as assessed by RT-qPCR. The high rate of gut bacteria in the circulation suggests translocation of bacteria from the gut to the bloodstream.
[Show abstract][Hide abstract] ABSTRACT: Overall adiposity is associated with insulin resistance. Decline in insulin sensitivity induces a compensatory increase in insulin secretion from beta cells. The impact of adipose tissue distribution, i.e., visceral versus subcutaneous fat, on beta cell function remains to be elucidated. The aim of this study was to retrospectively investigate the relation between the areas of subcutaneous and visceral fat and the increment in C-peptide levels (CPR) during glucagon load (ΔCPR) in Japanese patients with type 2 diabetes. In 195 Japanese patients with type 2 diabetes, beta cell function was evaluated by ΔCPR, CPR index (100 × fasting CPR divided by fasting glucose), and 24-h urinary C-peptide excretion (U-CPR) during the 1-week hospitalization for diabetes education. Then, we investigated the relationships between markers of beta cell function and the areas of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) determined by abdominal computed tomography. Stepwise multiple regression analyses identified SAT, but not VAT, as an independent variable of both ΔCPR and U-CPR [standard regression coefficient (Stdβ) = 0.332, P < 0.01 for ΔCPR, and Stdβ = 0.181, P < 0.05 for U-CPR], and both SAT and VAT were identified as independent variables for CPR index (Stdβ = 0.253, P < 0.01 for SAT, and Stdβ = 0.193, P < 0.01 for VAT). Our results indicated that SAT is independently correlated with beta cell function by glucagon test in Japanese patients with type 2 diabetes.
[Show abstract][Hide abstract] ABSTRACT: Previous studies reported that both cilnidipine and azelnidipine have a renoprotective effect compared with amlodipine. The aim of this study was to compare the effects of cilnidipine and azelnidipine on blood pressure, heart rate and albuminuria. An open-label prospective crossover trial was carried out. We recruited 19 type 2 diabetics treated with amlodipine (5 mg/day) at least for 12 weeks. At study entry, amlodipine was changed to cilnidipine (10 mg/day) or azelnidipine (16 mg/day) and each administered for 16 weeks. Then, the drugs were switched and the treatment was continued for another 16 weeks. Despite no differences in 24-h blood pressure and heart rate between cilnidipine and azelnidipine, treatment with cilnidipine resulted in a greater reduction in urinary albumin:creatinine ratio than azelnidipine. Our results suggested that cilnidipine is more efficient in reducing albuminuria than azelnidipine independent of its blood pressure lowering effect in type 2 diabetic patients with hypertension. This trial was registered with UMIN (no. 000007201).
Journal of diabetes investigation. 03/2013; 4(2):202-5.
[Show abstract][Hide abstract] ABSTRACT: We investigated the clinical factors that affected routine laboratory tests of C-peptide levels (CPR) used for the evaluation of β-cell function in Japanese patients with type 2 diabetes. The study subjects were 215 Japanese patients with type 2 diabetes admitted to Juntendo University Hospital just for glycemic control. β-cell function was evaluated by ΔCPR (6-min postglucagon increment in CPR), CPR index (100 × fasting CPR divided by fasting glucose), and 24-h urinary CPR excretion (U-CPR). Stepwise multiple regression analyses of relationships between clinical parameters and these laboratory tests were carried out. The analysis identified BMI and treatment with insulin before admission, but not glycosylated hemoglobin at admission, as independent determinants of all β-cell function tests [BMI: Stdβ (standard regression coefficient) = 0.337, P < 0.01 for ΔCPR, Stdβ = 0.365, P < 0.01 for CPR index, and Stdβ = 0.207, P < 0.01 for U-CPR, and treatment with insulin before admission: Stdβ = −0.141, P = 0.023 for ΔCPR, Stdβ = −0.285, P < 0.01 for CPR index, and Stdβ = −0.258, P < 0.01 for U-CPR]. The estimated glomerular filtration rate (eGFR) was an independent determinant of U-CPR (Stdβ = 0.145, P = 0.023), but not ΔCPR. In conclusion, ΔCPR evaluates β-cell function without being affected by eGFR and glycemic control over the preceding 2–3 months.
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to investigate whether carotid intima-media thickness (IMT) and brachial-ankle pulse wave velocity (baPWV) add value to the Framingham risk score (FRS) in predicting the development of cardiovascular diseases (CVDs) in type 2 diabetic patients with a negative history of CVD.
Type 2 diabetic patients (n = 783) were retrospectively recruited and followed for CVD.
During a 5.4-year follow-up period, 85 incidences of CVD were recorded (10.9%). After adjustment for conventional arterial risk factors, multivariate analysis with the Cox proportional hazards model identified IMT, but not baPWV, as a significant determinant of CVD. In addition, the combination of FRS with IMT, but not with baPWV, improved the prediction of CVD.
Carotid IMT is a significant predictor of CVD in asymptomatic type 2 diabetic patients, and the combination of FRS and IMT improves the prediction of CVD in these patients.
Diabetes care 01/2012; 35(1):178-80. · 7.74 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to assess the relationship between masked hypertension (MHT) and vascular damage in patients with type 2 diabetes.
The study subjects were patients with type 2 diabetes who were normotensive based on blood pressure (BP) measurement in the clinic (n = 80) without antihypertensive drugs and free of retinopathy, macroalbuminuria, overt cardiovascular disease. Subjects underwent 24-h ambulatory blood pressure monitoring (ABPM), measurement of flow-mediated dilatation (FMD), and brachial-ankle pulse wave velocity (baPWV). Based on the results of ABPM, subjects with mean daytime systolic BP ≥135 and/or 85 mm Hg were defined as MHT and their clinical data were compared with those of normotensive patients (NT). The data were also compared with those of type 2 diabetic patients with hypertension (HT) as measured in the clinic (n = 32).
MHT was detected in 47.5% of the study subjects with normotension at clinic (n = 38). Impaired FMD (5.65 ± 2.00% for NT, 4.26 ± 1.88% for MHT, 3.90 ± 1.71% for HT, P < 0.001) and higher baPWV (1,514.2 ± 212.7 cm/s for NT, 1,749.9 ± 339.7 cm/s for MHT, and 1,768.6 ± 302.8 cm/s for HT, P < 0.001) were similarly noted in patients with MHT and HT compared with NT. Multivariate regression analysis indicated that daytime systolic BP measured by ABPM, the estimated duration of diabetes and serum triglycerides were significantly associated with FMD and daytime systolic BP measured by ABPM, not systolic BP at clinic, age, and HbA(1c) were significantly associated with baPWV.
Given that patients with impaired FMD and higher baPWV are known to be at higher risk of cardiovascular disease, our data suggest that type 2 diabetic patients with MHT could be also at increased risk of cardiovascular disease.
American Journal of Hypertension 11/2011; 25(2):165-70. · 3.67 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Severe hypoglycaemia associated with diabetes management is a potential risk for cardiovascular diseases. However, the effect and mechanism of hypoglycaemia on the progression of atherosclerosis remains largely unknown. As a first step towards elucidating the above, we investigated the effect of hypoglycaemia on monocyte-endothelial interaction.
Insulin was injected intraperitoneally once every 3 days for 5 weeks in Goto-Kakizaki rats, a non-obese rat model of type 2 diabetes. We counted the number of monocytes adherent to the endothelium of thoracic aorta as an index of early atherosclerogenesis. Cultured HUVEC were used to investigate the mechanism of action.
Insulin treatment increased the number of monocytes adherent to the vascular endothelium. This increase was abrogated by injection of glucose with insulin. Amosulalol, an α-1 and β-adrenoreceptor antagonist, suppressed monocyte adhesion to endothelium and levels of adhesion molecules (intercellular adhesion molecule-1 and vascular cell adhesion molecule-1) in the endothelial surface, which had been enhanced by insulin-induced hypoglycaemia. In HUVEC, adrenaline (epinephrine) significantly increased nuclear translocation of nuclear factor-κB (NF-κB) p65 and levels of adhesion molecules, effects that were abrogated following addition of SQ22536, a specific adenyl cyclase inhibitor.
Our data indicate that repetitive hypoglycaemia induced by insulin enhanced monocyte adhesion to endothelial cells in Goto-Kakizaki rat aorta through enhanced adrenaline activity and that the latter stimulated intracellular cAMP, leading to nuclear translocation of NF-κB with subsequent production of adhesion molecules in endothelial cells.
[Show abstract][Hide abstract] ABSTRACT: Aims/Introduction: Basal-bolus intensive insulin therapy has been believed to achieve best the glycemic control, but is also complicated as a result of the number of injections required and the type of insulin. This study compared the effect of thrice-daily lispro 50/50 (prandial premixed therapy [PPT]) with thrice daily lispro given in combination with sulfonylureas (prandial bolus therapy with sulfonylurea [PBTS]) as initial insulin therapy for type 2 diabetes. Materials and Methods: This 24-week, observational, parallel trial comprised a 12-week screening period and a 24-week intervention period for 31 diabetes patients who were poorly controlled with submaximal sulfonylurea. At the start of the intervention period, we commenced thrice-daily insulin injections and divided the 31 patients into either lispro 50/50 with discontinuation of sulfonylurea (PPT, n = 15) or lispro added to sulfonylurea (PBTS, n = 16). The same dose-adjustment algorithm was used for analyzing both groups; HbA1c, plasma glucose, insulin daily dose, bodyweight and number of hypoglycemic episodes were evaluated. Results: At the end of the study, HbA1c was significantly improved in both groups (P < 0.00001), but no difference was apparent between the groups. The daily doses of PPT were more than those of PBTS, albeit the difference was statistically insignificant (P = 0.051). There were significantly fewer hypoglycemic episodes encountered with PPT than with PBTS. Conclusions: Thrice-daily injections of lispro 50/50 provide an effective and safe regimen as initial insulin therapy for type 2 diabetes. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2010.00025.x, 2010).
[Show abstract][Hide abstract] ABSTRACT: Insulin resistance is mainly present in skeletal muscle in non-obese patients with myotonic dystrophy. Thiazolidinediones are reported to reduce insulin resistance in these patients. However, the effects of pioglitazone in overweight patients with myotonic dystrophy and type 2 diabetes mellitus have not been established. Here, we evaluated the effect of pioglitazone in two poorly-controlled over-weight diabetic patients with myotonic dystrophy. Case 1 was a 41- year-old women (BMI 27.8 kg/m(2)) with myotonic dystrophy and type 2 diabetes had been treated with 3 mg/day glimepiride and 500 mg/day metformin, but the treatment failed to achieve good glycemic control (HbA(1C) 11.8 %). Following admission to the hospital, she was treated with low-dose insulin and 30 mg/day pioglitazone. At 10 days after initiation of therapy, glycemic control was improved, serum IL-6 and hs-CRP decreased, and adiponectin level increased rapidly. Case 2 was a 47-year-old women (BMI 29.2 kg/m(2)) with myotonic dystrophy and type 2 diabetes mellitus had been treated with insulin without successful glycemic control (HbA(1C) 10.3 %). After admission, she was treated with 15 mg/day pioglitazone. This improved glycemic control, reduced daily insulin requirement, decreased IL-6 and hs-CRP levels rapidly and increased adiponectin level at 10 days after initiation of therapy. In both cases, pioglitazone rapidly improved glycemic control, enhanced adiponectin production, and reduced inflammatory cytokines. These results suggest that pioglitazone may be suitable for these patients.
[Show abstract][Hide abstract] ABSTRACT: Intensive lipid-lowering therapy with statins reduces levels of low-density lipoprotein (LDL)-cholesterol (C) and improves plaque volume and composition in patients with cardiovascular disease. Furthermore, rosuvastatin ameliorated carotid stenosis in the ASTEROID study, and altered the composition of plaques in a predominantly Caucasian study population in the ORION study. However, it is not known whether statin therapy achieves similar quantitative improvement in carotid artery plaque in other ethnic groups.
Fifty patients with hypercholesterolemia (LDL-C >or=120 mg/dl) and a maximum carotid intima-media thickness >or=1.8 mm will be enrolled and treated with rosuvastatin at a dose of 5 mg/day for 96 weeks. The primary endpoints will be the percent change of carotid plaque volume and the change in plaque composition after 96 weeks of treatment, as evaluated by magnetic resonance imaging.
The CHALLENGER study will provide a noninvasive assessment of the changes in carotid plaque volume and composition achieved by reduction of LDL levels in Japanese patients with carotid stenosis on long-term rosuvastatin therapy.
[Show abstract][Hide abstract] ABSTRACT: The increased flux of polyol pathway induced by hyperglycemia is implicated in the pathogenesis of various complications associated with diabetic, which results in increased oxidative stress. Because oxidative stress causes tissue damage in patients with diabetes, searching for an effective strategy to reduce oxidative stress in clinical setting is important in order to prevent diabetic complications. The aim of this study was to evaluate the effects of aldose reductase inhibition on oxidative stress in patients with type 2 diabetes mellitus. The subjects of this study were 21 patients with type 2 diabetes. We compared the levels of various oxidative stress markers and antioxidants including plasma thiobarbituric acid-reactive substances, malondialdehyde-modified low-density lipoprotein, vitamin E, beta-carotene and lipid hydroperoxides in erythrocytes at baseline with those measured after a 3-month course of epalrestat (150 mg/day), an aldose reductase inhibitor. While administration of epalrestat did not result in significant changes in plasma thiobarbituric acid-reactive substances, malondialdehyde-modified low-density lipoprotein, vitamin E, or beta-carotene, it significantly reduced lipid hydroperoxides in erythrocytes. Given the importance of measuring lipid hydroperoxides in erythrocytes as an index of oxidative stress, these results highlight the potential usefulness of epalrestat in reducing oxidative stress in type 2 diabetes mellitus.
[Show abstract][Hide abstract] ABSTRACT: Ectopic activation of hedgehog (HH) signalling in pancreas induces various abnormal morphogenetic events in the pancreas. This study analysed the dose-dependent requirement of patched homologue 1 (PTCH1), a negative regulator of HH signalling on pancreatic development.
We used a recessive spontaneous mutant mouse denoted as mes which carries a mutated Ptch1 resulting in deletion of the most carboxy-terminal cytoplasmic domain of the PTCH1 protein. In this study, we analysed pancreatic morphology in Ptch1 ( +/+ ), Ptch1 ( +/mes ), Ptch1 (+/-), Ptch1 ( mes/me ) (s) and Ptch1 (-/mes ) mouse embryos, as well as the islet mass in adult Ptch1 (+/+), Ptch1 (+/mes ) and Ptch1 (+/-) mice.
Until embryonic day (E) 12.5, no obvious abnormality of pancreas was observed in any of the Ptch1 mutants. The levels of PDX1 and glucagon were also not evidently different among the mice genotypes studied. Thereafter, morphological abnormalities appeared in the Ptch1 mutant mice. The beta, alpha and exocrine cell masses decreased at E18.5 in parallel with increased HH signalling, with beta cell mass showing the highest sensitivity to HH signalling with a significant decrease even in Ptch1 (+/mes ) mice. Adult Ptch1 (+/-) mice also showed a significant decrease in beta cell mass compared with wild-type mice.
Our findings indicate that the carboxy-terminal domain of Ptch1 is essential for pancreatic development. In addition, the loss of Ptch1 function decreases both the endocrine and exocrine cell mass in a dose-dependent manner, with beta cells particularly sensitive to changes in HH signalling.
[Show abstract][Hide abstract] ABSTRACT: Angiotensin II type-1 receptor blockers (ARBs) are regarded as first-line treatments for type-2 diabetes with hypertension. Despite the availability of various types of ARBs, there are no comparative studies of their effects on patients with diabetes. In this open-label prospective crossover study, we compared the effects of olmesartan (20 mg/day) and telmisartan (40 mg/day). Twenty Japanese early-stage type-2 diabetes patients with hypertension treated with valsartan (80 mg/day) for at least 8 weeks were recruited to this study. At study entry, valsartan was changed to olmesartan (20 mg/day) or telmisartan (40 mg/day) and administered for 8 weeks. The drugs were then switched and treatment was continued for another 8 weeks. We analyzed the blood pressure lowering effects of each drug by 24-h ambulatory blood pressure monitoring at 0, 8, and 16 weeks. Simultaneously, we measured metabolic parameters and inflammation markers. Olmesartan lowered mean systolic and diastolic blood pressure more significantly than did telmisartan. While there were no differences between the groups in metabolic parameters, including HbA1c and adiponectin, the decreases in serum interleukin-6 and highly sensitive C-reactive protein were more significant by olmesartan treatment. Our results indicate that olmesartan has more potent arterial blood pressure lowering and anti-inflammatory effects than telmisartan.
Hypertension Research 02/2008; 31(1):7-13. · 2.94 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Monocyte adhesion to arterial endothelial cells is the initial step in atherosclerosis. Whereas angiotensin II is known to elicit leukocyte adhesion, it is not clear whether blockade of the angiotensin II receptor signaling reduces monocyte adhesion to endothelial cells beyond its antihypertensive action. This study compared the effect of two different antihypertensive drugs on monocyte adhesion to thoracic aorta endothelium in spontaneously hypertensive rats (SHR): the angiotensin II receptor blocker, valsartan (20 mg . kg(-1) . day(-1)) and the vasodilator, hydralazine (0.75 mg . kg(-1) . day(-1)). The effects were quantitated in vivo using an enface method that optimizes the observation of endothelial surfaces after immunohistochemical staining for CD68. Both agents significantly and comparably reduced blood pressure over 4-week treatment course. Both valsartan and hydralazine profoundly reduced monocyte adhesion compared with nontreated controls, with valsartan having a modestly more reductive effect. Both agents also reduced the intima and medial thickening with valsartan reducing the mean thickness modestly more than hydralazine. Our data confirms that the reduction of blood pressure is effective method to reduce monocyte adhesion. Also, our date demonstrates that valsartan has a modest beneficial effect on monocyte adhesion to endothelial cells and arterial intima-medial vessel thickening beyond its action as an antihypertensive agent.
[Show abstract][Hide abstract] ABSTRACT: Recent studies have identified the involvement of inhibitor IkappaB kinase (IKK) in the pathogenesis of insulin resistance. To investigate the mechanism involved, we examined the role of nuclear factor kappaB (NF-kappaB), the distal target of IKK, in hepatic glucose metabolism.
To inhibit NF-kappaB activity, db/db mice were infected with adenovirus expressing the IkappaBalpha super-repressor.
The IkappaBalpha super-repressor adenovirus infection caused a moderate reduction of NF-kappaB activity in liver. The treatment was associated with improved glucose tolerance, reduction in the serum insulin level, and increased hepatic triacylglycerol and glycogen contents, but had no effect on insulin-stimulated phosphorylation of Akt. On the other hand, quantification of mRNA in the liver revealed marked reduction of expression of gluconeogenic genes, such as those encoding phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase, concurrent with reduced expression of gene encoding peroxisome proliferator-activated receptor gamma coactivator-1alpha (PPARGC1A, also known as PGC-1alpha). Furthermore, the production of super-repressor IkappaBalpha suppressed the increase in blood glucose level after pyruvate injection.
Our results indicate that moderate inhibition of NF-kappaB improved glucose tolerance through decreased gluconeogenesis associated with reduced PGC-1alpha gene expression in db/db mice, and suggest that inhibition of NF-kappaB activity in liver is a potentially suitable strategy for the normalisation of blood glucose concentration in type 2 diabetes.
[Show abstract][Hide abstract] ABSTRACT: Several epidemiological studies suggested that treatment with angiotensin II type 1 receptor blocker (ARB) provided a risk reduction of developing type 2 diabetes. In this study, we investigated whether and how ARB treatment can improve abnormalities of pancreatic islets in diabetes state. We randomized db/db mice, a model of type 2 diabetes with obesity, at the age of 8 weeks to receive candesartan, an ARB, for 6 weeks. We also studied age-matched db/misty mice as control. Glucose tolerance test revealed that candesartan treatment improved glucose tolerance with the modest increase in serum insulin level in db/db mice. Concurrently, candesartan increased beta-cell mass, increased staining intensity of insulin, and decreased staining intensity of components of NAD(P)H oxidase, p22phox and gp91phox, and those of oxidative stress markers in beta-cells. These changes were accompanied by reduction of mitochondrial volume. Treatment with candesartan also reduced fibrosis in and around the islets and prevented the loss of endothelial cells in islets. Our results showed that candesartan partially prevented deterioration of glucose tolerance by providing protection against progressive beta-cell damage in diabetes.
Biochemical and Biophysical Research Communications 07/2006; 344(4):1224-33. · 2.28 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Neurogenin3 (ngn3) is a transcription factor that is essential for the differentiation of pancreatic endocrine cells. To investigate the signaling pathway that regulates ngn3 expression, we used AR42J-B13 cells as a model of the differentiation of pancreatic islets. In these cells, treatment with activin A and hepatocyte growth factor (HGF) induced the expression of ngn3. Reporter gene analysis using human ngn3 gene (NEUROG3) promoter fragments of various lengths identified the region between -402 and -327 bp of NEUROG3 as an activin A- and HGF-responsive DNA sequence. This DNA sequence normally functions as a repressor in AR42J-B13 cells, but treatment with activin A and HGF negates the repressor activity. Interestingly, function of the activin A- and HGF-responsive sequence was not influenced by the overexpression of the Smad inhibitory factor, Smad7. Instead, activin A and HGF activation was inhibited by overexpression of a dominant-negative mutant of transforming growth factor-beta-activated kinase 1 (TAK1), or mitogen-activated protein kinase kinase 3 (MKK3), or by treatment with a p38 MAPK-specific inhibitor, SB203580. Activin A and HGF function through the TAK1-MKK3-p38 MAPK pathway to relieve transcription repressors located between -402 and -326 bp on the NEUROG3 promoter, and consequently activate ngn3 expression and endocrine differentiation of AR42J-B13 cells.
Journal of Biological Chemistry 07/2003; 278(24):21693-700. · 4.60 Impact Factor