Functional characterization of multiple PAS domain-containing diguanylate cyclases in Synechocystis sp. PCC 6803.

Bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) is a second messenger known to control a variety of bacterial processes. The model cyanobacterium, Synechocystis sp. PCC 6803, has a score of genes encoding putative enzymes for c-di-GMP synthesis and degradation. However, most of them have not been functionally characterized. Here, we chose four genes in Synechocystis (dgcA-dgcD), which encode proteins with a GGDEF, diguanylate cyclase (DGC) catalytic domain and multiple Per-ARNT-Sim (PAS) conserved regulatory motifs, for detailed analysis. Purified DgcA, DgcB and DgcC were able to catalyze synthesis of c-di-GMP from two GTPs in vitro. DgcA had the highest activity, compared with DgcB and DgcC. DgcD did not show detectable activity. DgcA activity was specific for GTP and stimulated by the divalent cations, magnesium or manganese. Full activity of DgcA required the presence of the multiple PAS domains, probably because of their role in protein dimerization or stability. Synechocystis mutants carrying single deletions of dgcA-dgcD were not affected in their growth rate or biofilm production during salt stress, suggesting that there was functional redundancy in vivo. In contrast, overexpression of dgcA resulted in increased biofilm formation in the absence of salt stress. In this study, we characterize the enzymatic and physiological function of DgcA-DgcD, and propose that the PAS domains in DgcA function in maintaining the enzyme in its active form.

Comparing the effects of ipragliflozin versus metformin on visceral fat reduction and metabolic dysfunction in Japanese patients with type 2 diabetes treated with sitagliptin: A prospective, multicentre, open-label, blinded-endpoint, randomized controlled study (PRIME-V study).

A prospective, multicentre, open-label, blinded-endpoint, randomized controlled study was conducted to evaluate the efficacy of treatment with ipragliflozin (sodium-dependent glucose transporter-2 inhibitor) versus metformin for visceral fat reduction and glycaemic control among Japanese patients with type 2 diabetes treated with sitagliptin, HbA1c levels of 7%-10%, and body mass index (BMI) ≥ 22 kg/m2 . Patients were randomly assigned (1:1) to receive ipragliflozin 50 mg or metformin 1000-1500 mg daily. The primary outcome was change in visceral fat area as measured by computed tomography after 24 weeks of therapy. The secondary outcomes were effects on glucose metabolism and lipid metabolism. Mean percentage reduction in visceral fat area was significantly greater in the ipragliflozin group than in the metformin group (-12.06% vs. -3.65%, P = 0.040). Ipragliflozin also significantly reduced BMI, subcutaneous fat area, waist circumference, fasting insulin, and homeostatic model assessment (HOMA)-resistance, and increased HDL-cholesterol levels. Metformin significantly reduced HbA1c and LDL-cholesterol levels and increased HOMA-beta. There were no severe adverse events. The use of ipragliflozin or metformin in combination with dipeptidyl peptidase-4 inhibitors, widely used in Japan, may have beneficial effects in ameliorating multiple cardiovascular risk factors.

A case of pediatric Perthes' disease with unexplained hyperlactatemia at the time of initial surgery and anesthetic management with remimazolam for the subsequent surgery.

BACKGROUND: The causes of perioperative hyperlactatemia vary, but they are generally associated with hypoperfusion. Here, we report the case of a pediatric patient who developed unexplained hyperlactatemia during anesthesia with propofol and sevoflurane, which recurred during a second surgery under anesthesia with remimazolam. CASE PRESENTATION: An 8-year-old boy with Perthes disease and no remarkable past or family history was scheduled for an osteotomy. Anesthesia was induced with propofol and rocuronium and then maintained with sevoflurane and remifentanil. The patient developed lactic acidosis without hemodynamic instability during anesthesia, with a normal lactate/pyruvate ratio after surgery, suggesting a lack of hypoperfusion. We used remimazolam instead of propofol during the second surgery 6 months later, considering the possibility of drug-induced lactic acidosis, including malignant hyperthermia and propofol infusion syndrome, where the unexplained hyperlactatemia recurred. CONCLUSIONS: Distinguishing the causes of hyperlactatemia, particularly in the absence of other symptoms, is challenging. The lactate/pyruvate ratio during episodes of hyperlactatemia can provide insights into the underlying pathology.

[Procedures of examination and diagnosis to differentiate hypertriglyceridemia].

Hypertriglyceridemia is a common disorder encountered in daily medical practice. Since the causes of hypertriglyceridemia are various, we need to totally assess clinical history, physical findings, and laboratory examinations. In this section, we aim to show procedures of examination and diagnosis of hypertriglyceridemia. First, it is necessary to confirm a detection opportunity and conditions of blood sampling. Next, we move on to differentiate secondary hyperlipidemia and assess other arteriosclerosis risks. Finally, we diagnose primary hyperlipidemia by examining apoproteins, lipoproteins, and some metabolic enzymes of lipoproteins. To diagnose hypertriglyceridemia correctly, proficient clinical skills, understandings of pathophysiology, and knowledge of methods for respective examinations are needed.

Metabolomic analysis of serum samples from a clinical study on ipragliflozin and metformin treatment in Japanese patients with type 2 diabetes: Exploring human metabolites associated with visceral fat reduction.

STUDY OBJECTIVE: The effects of the sodium-dependent glucose transporter-2 inhibitor ipragliflozin were compared with metformin in a previous study, which revealed that ipragliflozin reduced visceral fat content by 12%; however, the underlying mechanism was unclear. Therefore, this sub-analysis aimed to compare metabolomic changes associated with ipragliflozin and metformin that may contribute to their biological effects. DESIGN: A sub-analysis of a randomized controlled study. SETTING: Chiba University Hospital and ten hospitals in Japan. PATIENTS: Fifteen patients with type 2 diabetes in the ipragliflozin group and 15 patients with type 2 diabetes in the metformin group with matching characteristics, such as age, sex, baseline A1C, baseline visceral fat area, smoking status, and concomitant medication. INTERVENTIONS: Ipragliflozin 50 mg or metformin 1000 mg daily. MEASUREMENTS: The clinical data were reanalyzed, and metabolomic analysis of serum samples collected before and 24 weeks after drug administration was performed using capillary electrophoresis time-of-flight mass spectrometry. MAIN RESULTS: The reduction in the mean visceral fat area after 24 weeks of treatment was significantly larger (p = 0.002) in the ipragliflozin group (-19.8%) than in the metformin group (-2.5%), as were the subcutaneous fat area and body weight. The A1C and blood glucose levels decreased in both groups. Glutamic pyruvic oxaloacetic transaminase, γ-glutamyl transferase, uric acid, and triglyceride levels decreased in the ipragliflozin group. Low-density lipoprotein cholesterol levels decreased in the metformin group. After ipragliflozin administration, N2-phenylacetylglutamine, inosine, guanosine, and 1-methyladenosine levels increased, whereas galactosamine, glucosamine, 11-aminoundecanoic acid, morpholine, and choline levels decreased. After metformin administration, metformin, hypotaurine, methionine, methyl-2-oxovaleric acid, 3-nitrotyrosine, and cyclohexylamine levels increased, whereas citrulline, octanoic acid, indole-3-acetaldehyde, and hexanoic acid levels decreased. CONCLUSIONS: Metabolites that may affect visceral fat reduction were detected in the ipragliflozin group. Studies are required to further elucidate the underlying mechanisms.

[Remifentanil increases urine output in patients undergoing laparoscopic colectomy].

BACKGROUND: It has been reported that laparoscopic surgery increases stress response such as oliguria. We investigated whether anesthetic methods affect urine output during anesthesia in patients undergoing laparoscopic colectomy. METHODS: Urine output during anesthesia was compared retrospectively between general anesthesia with intravenous infusion of remifentanil, without epidural anesthesia and general anesthesia combined with epidural anesthesia, without remifentanil. Patients were excluded if they had renal failure and/or had received diuretics. 331 American Society of Anesthesiologists (ASA) physical status 1-3 patients who had undergone elective laparoscopic colectomy were enrolled in the study (remifentanil group; n = 214, epidural group; n = 117). In addition, remifentanil group was divided into two groups (higher dose group; n = 108, lower dose group; n = 106) with the median value of 0.3 g x kg(-1) x min(-1). RESULTS: Urine output during anesthesia in remifentanil group was significantly higher than epidural group, although the volume of fluid infusion was significantly less in remifentanil group. Furthermore, urine output in higher dose remifentanil group was significantly higher than the lower dose group, while there were no significant differences in the volume of fluid infusion between the two groups. CONCLUSIONS: Adequate remifentanil injection might increase urine output by preventing stress response to laparoscopic colectomy.

[Anesthetic management for laparoscopic sigmoidectomy in a patient with impaired ventricular function caused by cardiac sarcoidosis].

It has been demonstrated that laparoscopic surgery can reduce surgical trauma and postoperative pain, allowing earlier recovery and hospital discharge. However, because patients with severe cardiac depression may not tolerate the adverse respiratory and cardiovascular effects of pneumoperitoneum with a head-up or head-down tilt position, laparoscopic surgery has been avoided in these patients. The present case with low ventricular function (ejection fraction=23-27%) due to cardiac sarcoidosis could successfully undergo laparoscopic sigmoidectomy by using pulmonary artery catheterization. Therefore, laparoscopic surgery can be performed in patients with cardiac dysfunction if the cardiopulmonary responses caused by pneumoperitoneum with a head-up or head-down tilt are sufficiently considered and adverse hemodynamic responses appropriately detected and treated through invasive monitoring techniques such as pulmonary artery catheterization and/or transesophageal echocardiography.

First-in-human autologous implantation of genetically modified adipocytes expressing LCAT for the treatment of familial LCAT deficiency.

Background: Familial lecithin: cholesterol acyltransferase (LCAT) deficiency (FLD) is a severe inherited disease without effective treatment. Patients with FLD develop severe low HDL, corneal opacity, hemolytic anemia, and renal injury. Objective: We developed genetically modified adipocytes (GMAC) secreting LCAT (LCAT-GMAC) for ex vivo gene therapy. GMACs were prepared from the patient's adipocytes to express LCAT by retroviral gene transduction to secrete functional enzymes. This study aimed to evaluate the safety and efficacy of LCAT-GMAC implantation in an FLD patient. Methods: Proliferative preadipocytes were obtained from a patient using a ceiling culture and retrovirally transduced with LCAT. After obtaining enough cells by expansion culture of the transduced cells, the resulting LCAT-GMACs were implanted into a patient with FLD. To evaluate the safety and efficacy, we analyzed the outcome of the autologous implantation for 24 weeks of observation and subsequent 240 weeks of the follow-up periods. Results: This first-in-human autologous implantation of LCAT-GMACs was shown to be safe by evaluating adverse events. The LCAT-GMAC implantation increased serum LCAT activity by approximately 50% of the baseline and sustained over three years. Consistent with increased LCAT activity, intermediate-density lipoprotein (IDL) and free cholesterol levels of the small and very small HDL fractions decreased. We found the hemoglobin/haptoglobin complex in the hemolyzed pre-implantation sera of the patient. After one week of the implantation, the hemoglobin/haptoglobin complex almost disappeared. Immediately after the implantation, the patient's proteinuria decreased temporarily to mild levels and gradually increased to the baseline. At 48 weeks after implantation, the patient's proteinuria deteriorated with the development of mild hypertension. By the treatment with antihypertensives, the patient's blood pressure normalized. With the normalization of blood pressure, the proteinuria rapidly decreased to mild proteinuria levels. Conclusions: LCAT-GMAC implantation in a patient with FLD is shown to be safe and appears to be effective, in part, for treating anemia and proteinuria in FLD.

Central administration of sodium-glucose cotransporter-2 inhibitors increases food intake involving adenosine monophosphate-activated protein kinase phosphorylation in the lateral hypothalamus in healthy rats.

INTRODUCTION: Sodium glucose cotransporter-2 (SGLT2) inhibitors are widely used for diabetes treatment. Although SGLT2 inhibitors have been clinically observed to increase food intake, roles or even the presence of SGLT2 in the central nervous system (CNS) has not been established. We aimed to elucidate potential functions of SGLT2 in the CNS, and the effects of CNS-targeted SGLT2 inhibitors on food intake. RESEARCH DESIGN AND METHODS: We administered three kinds of SGLT2 inhibitors, tofogliflozin, dapagliflozin, and empagliflozin, into the lateral ventricle (LV) in rats and evaluated their effects on food intake. We also evaluated the effects of tofogliflozin administration in the third (3V) and fourth ventricle (4V). Intraperitoneal administration of liraglutide, a glucagon-like peptide-1 (GLP-1) receptor agonist known to suppress food intake, was combined with central tofogliflozin to elucidate whether GLP-1 signaling antagonizes the effect of central SGLT2 inhibitors on food intake. To elucidate potential molecular mechanisms mediating changes in feeding, hypothalamic areas associated with food intake regulation were harvested and analyzed after intracerebroventricular administration (ICV) of tofogliflozin. RESULTS: Bolus ICV injection of tofogliflozin induced a robust increase in food intake starting at 1.5 hours postinjection, and lasting for 5 days. No effect was observed when the same dose of tofogliflozin was administered intraperitoneally. ICV dapagliflozin and empagliflozin significantly enhanced food intake, although the strength of these effects varied among drugs. Food intake was most markedly enhanced when tofogliflozin was infused into the LV. Fewer or no effects were observed with infusion into the 3V or 4V, respectively. Systemic administration of liraglutide suppressed the effect of ICV tofogliflozin on food intake. ICV tofogliflozin increased phosphorylation of AMPK and c-fos expression in the lateral hypothalamus. CONCLUSIONS: SGLT2 inhibitors in the CNS increase food intake. SGLT2 activity in the CNS may regulate food intake through AMPK phosphorylation in the lateral hypothalamic area.

Comparison of Visceral Fat Reduction by Ipragliflozin and Metformin in Elderly Type 2 Diabetes Patients: Sub-Analysis of a Randomized-Controlled Study.

INTRODUCTION: To compare the effects of ipragliflozin, a sodium-glucose transporter 2 inhibitor, with those of metformin on visceral fat (as well as muscles and bones) in Japanese elderly patients with type 2 diabetes (T2D), we conducted a sub-analysis of a prospective, multicenter, blinded-endpoint randomized-controlled study. METHODS: In total, 103 patients with T2D (body mass index ≥ 22 kg/m2; glycated hemoglobin, 7-10%) and being treated with sitagliptin (a dipeptidyl peptidase-4 inhibitor) were included and randomized to receive ipragliflozin or metformin. The primary outcome was the change in visceral fat area measured using computed tomography 24 weeks following treatment. The secondary outcomes included changes in subcutaneous and total fat area, muscle volume, bone density measured using computed tomography, handgrip strength, bone markers, plasma glucose, insulin, homeostasis model assessment (HOMA)2-beta, HOMA2-R, glycated hemoglobin, lipid panel, uric acid, blood pressure, adiponectin, and high-sensitivity C-reactive protein. All patients aged 65-74 years were selected for sub-analysis. RESULTS: The sub-analysis included 15 and 14 patients in the ipragliflozin and metformin groups, respectively. The patients' backgrounds were well balanced. Visceral fat area reduction was greater in the ipragliflozin group than in the metformin group (- 10.58% vs. - 6.93%; P = 0.034). There were significant differences in the changes in bone absorption markers, uric acid, and total cholesterol levels between the groups. CONCLUSION: Ipragliflozin significantly reduced the visceral fat area compared with metformin when added to sitagliptin in elderly patients with T2D. Long-term and large-scale studies are required to elucidate whether ipragliflozin is suitable for elderly patients. TRIAL REGISTRATION: The study was registered at https://www.umin.ac.jp/ctr/ (UMIN-ID: UMIN 000015170).

Effects of ipragliflozin versus metformin in combination with sitagliptin on bone and muscle in Japanese patients with type 2 diabetes mellitus: Subanalysis of a prospective, randomized, controlled study (PRIME-V study).

AIMS/INTRODUCTION: Recent randomized clinical trials have suggested that sodium-glucose cotransporter 2 inhibitors might reduce cardiovascular events and heart failure, and have renal protective effects. Despite these remarkable benefits, the effects of sodium-glucose cotransporter 2 inhibitors on bone and muscle are unclear. MATERIALS AND METHODS: A subanalysis of a randomized controlled study was carried out to evaluate the effects of the sodium-glucose cotransporter 2 inhibitor, ipragliflozin, versus metformin on bone and muscle in Japanese patients with type 2 diabetes mellitus (baseline body mass index ≥22 kg/m2 and hemoglobin A1c 7-10%) who were already receiving sitagliptin. These patients were randomly administered ipragliflozin 50 mg or metformin 1,000-1,500 mg daily. The effects of these medications on the bone formation marker, bone alkali phosphatase; the bone resorption marker, tartrate-resistant acid phosphatase 5b (TRACP-5b); handgrip strength; abdominal cross-sectional muscle area; and bone density of the fourth lumbar vertebra were evaluated. RESULTS: After 24 weeks of treatment, the changes in bone density of the fourth lumbar vertebra, handgrip strength and abdominal cross-sectional muscle area were not significantly different between the two groups. However, TRACP-5b levels increased in patients treated with ipragliflozin compared with patients treated with metformin (median 11.94 vs -10.30%, P < 0.0001), showing that ipragliflozin can promote bone resorption. CONCLUSIONS: There were no adverse effects on bone or muscle when sitagliptin was used in combination with either ipragliflozin or metformin. However, ipragliflozin combination increased the levels of TRACP-5b. A long-term study is required to further understand the effects of this TRACP-5b increase caused by ipragliflozin.

Safety and Efficacy of Ranibizumab and Luseogliflozin Combination Therapy in Patients with Diabetic Macular Edema: Protocol for a Multicenter, Open-Label Randomized Controlled Trial.

INTRODUCTION: Diabetic macular edema (DME) threatens daily life activities such as reading and driving and reduces the patients' quality-of-life. Recently, anti-vascular endothelial growth factor (VEGF) agents have become a first-line therapy in DME. However, therapy with anti-VEGF agents has several problems: repeated invasive injections are required; medical costs are high; and a certain proportion of patients with DME are resistant to treatment with anti-VEGF agents. While sodium-glucose co-transporter 2 (SGLT2) inhibitors have been widely used for the treatment of type 2 diabetes mellitus (T2DM), the effects of a combination therapy with anti-VEGF agent and SGLT2 inhibitor on DME are not yet known. METHODS: This study enrolls subjects with T2DM and DME, randomizes them into either a study agent treatment group (treated with ranibizumab as anti-VEGF agent and luseogliflozin as SGLT2 inhibitor) or a control group (treated with ranibizumab and glimepiride), and observes the subjects for 52 weeks after initiation of treatment. Planned outcomes: The primary endpoint is intergroup difference in the number of intravitreal anti-VEGF injections to the study eye from baseline to week 48. Secondary and exploratory endpoints include safety and ophthalmologic and internal medical clinical parameters. REGISTRATION: This study is registered at the University Hospital Medical Information Network Clinical Trial Registry (UMIN000033961) and Japan Registry of Clinical Trials (jRCTs031180210).

Neuropathic pain is associated with increased nodal persistent Na(+) currents in human diabetic neuropathy.

Peripheral nerve injury alters function and expression of voltage gated Na(+) channels on the axolemma, leading to ectopic firing and neuropathic pain/paresthesia. Hyperglycemia also affects nodal Na(+) currents, presumably due to activation of polyol pathway and impaired Na(+)-K(+) pump. We investigated changes in nodal Na(+) currents in peripheral sensory axons and their relation with pain in human diabetic neuropathy. Latent addition using computerized threshold tracking was used to estimate nodal persistent Na(+) currents in radial sensory axons of 81 diabetic patients. Of these, 36 (44%) had chronic neuropathic pain and severe paresthesia. Compared to patients without pain, those with pain had greater nodal Na(+) currents (p = 0.001), smaller amplitudes of sensory nerve action potentials (SNAP) (p = 0.0003), and lower hemoglobin A1c levels (p = 0.006). Higher axonal Na(+) conductance was associated with smaller SNAP amplitudes (p = 0.03) and lower hemoglobin A1c levels (p = 0.008). These results suggest that development of neuropathic pain depends on axonal hyperexcitability due to increased nodal Na(+) currents associated with structural changes, but the currents could also be affected by the state of glycemic control. Our findings support the view that altered Na(+) channels could be responsible for neuropathic pain/paresthesia in diabetic neuropathy.

Exploration of predictive metabolic factors for gestational diabetes mellitus in Japanese women using metabolomic analysis.

AIMS/INTRODUCTION: We aimed to explore novel predictive markers for gestational diabetes mellitus using metabolomic analysis in pregnant Japanese women. MATERIALS AND METHODS: We carried out a case-control study with a cohort of participants enrolled during the first or early second trimester in the Center of Chiba Unit of the Japan Environment and Children's Study. Participants were classified as either gestational diabetes mellitus cases or matched controls based on age, body mass index and parity. Metabolite levels of their serum and urine obtained randomly before the diagnosis of gestational diabetes mellitus were analyzed using hydrophilic interaction chromatography tandem mass spectrometry. Orthogonal projections to latent structures discriminant analysis was carried out to investigate metabolome profiles for the different groups. Metabolites with a variable importance in projection value of >1.5 were identified as potential markers. RESULTS: In total, 242 participants were enrolled in the study, of which 121 were cases. The R2X, R2Y and Q2 parameters for the discrimination ability of the resulting models were 0.388, 0.492 and 0.45 for serum, and 0.454, 0.674 and 0.483 for urine, respectively. We finally identified three metabolites in serum and 20 in urine as potential biomarkers. Glutamine in serum and ethanolamine and 1,3-diphosphoglycerate in urine showed >0.8 area under the receiver operating characteristic curves. CONCLUSIONS: The present study identified serum and urine metabolites that are possible predictive markers of subsequent gestational diabetes mellitus in Japanese women. Further studies are required to elucidate their efficacy.

CXCL12-CXCR4 pathway activates brown adipocytes and induces insulin resistance in CXCR4-deficient mice under high-fat diet.

Brown adipose tissue (BAT) plays a role in energy expenditure and is involved in nutrient metabolism. C-X-C chemokine ligand 12 (CXCL12)-CXCR4 pathway regulates the immune, nervous, and cardiovascular systems and affects the adipose tissue. Here, we investigated the role of this pathway as an activator of BAT. Uncoupling protein 1 mRNA and protein levels and oxygen consumption increased in the brown adipocytes treated with 100 nM CXCL12 peptide. CXCL12-mediated upregulation in P38 and extracellular signal-regulated kinase (ERK) levels was reduced by each inhibitor. Thus, the CXCL12-CXCR4 pathway activated the brown adipocytes through P38 and ERK that acted downstream of this pathway. Mice with CXCR4 defects only in the brown adipocytes were generated and fed with high-fat diet (HFD). Body weight and blood glucose after glucose injection increased in these mice. Long-term exposure to HFD deteriorated blood glucose level after glucose injection. Insulin sensitivity was exacerbated in the knockout mice fed with HFD. Serum lipid parameters and CXCL12 level in knockout mice were similar to those in control mice. These results suggest that the CXCL12-CXCR4 pathway induces brown adipocyte activity and affects nutrient metabolism under HFD load.

Postpartum risk of diabetes and predictive factors for glucose intolerance in East Asian women with gestational diabetes.

AIMS: Women with a history of gestational diabetes mellitus (GDM) are likely to develop postpartum diabetes mellitus (DM). We examined women in the early stages of pregnancy who were at high risk of postpartum DM progression to establish a follow-up method for early detection. METHODS: We performed the oral glucose tolerance test (OGTT) and identified predictive factors for postpartum impaired glucose tolerance (IGT) or DM in 77 women after GDM, for 2 years after delivery, retrospectively. Cutoff values for each factor were determined. We classified these women with GDM into four groups using these predictive factors and evaluated postpartum glucose intolerance (GI) in each group. RESULTS: In total, 44.1% of the women with a GDM history had developed postpartum GI within 2 years. We determined three risk factors for postpartum GI: elevated glucose level 120 min after a 75-g OGTT (Glu120), elevated glycated hemoglobin (HbA1c) level at diagnosis, and perinatal complications. The cutoff Glu120 and the HbA1c level were 155 mg/dl and 5.3% (34 mmol/mol), respectively. Type 2 DM developed in 53.8% of women, and IGT developed in 38.5% of women within 2 years in groups with high Glu120 and high HbA1c. CONCLUSIONS: High-risk groups require careful follow-up observation.

Accelerated oligosaccharide absorption and altered serum metabolites during oral glucose tolerance test in young Japanese with impaired glucose tolerance.

AIMS/INTRODUCTION: Impaired glucose tolerance (IGT) is a subtype of prediabetes, a condition having high risk for development to diabetes mellitus, but its pathophysiology is not fully understood. In the present study, we examined metabolic changes in IGT by using two types (D-glucose [Glc] and partial hydrolysate of starch [PHS]) of oral glucose tolerance tests (OGTTs), with emphasis on serum incretins and metabolites. MATERIALS AND METHODS: We carried out the two types of OGTT (Glc/OGTT and PHS/OGTT) in 99 young Japanese individuals who had tested either positive (GU+ ; n = 48) or negative (GU- ; n = 51) for glycosuria. After OGTT, they were sub-grouped into five categories: normal glucose tolerance (NGT) in the GU- group (GU- /NGT; n = 49), NGT in the GU+ group (GU+ /NGT; n = 28), IGT (n = 12), diabetes mellitus (n = 1) and renal glycosuria (n = 9). Serum incretin and metabolites of GU- /NGT and IGT were then measured. RESULTS: When the serum insulin level at each time-point during PHS/OGTT was expressed as its ratio relative to Glc/OGTT, it was increased time-dependently in GU- /NGT, but not in IGT. Such an increase in the ratio was also detected of serum incretin levels in GU- /NGT, but not in IGT, suggesting a lack of deceleration of oligosaccharide absorption in IGT. Metabolome analysis showed a difference in the serum levels of two metabolites of unknown function in mammals, methylcysteine and sedoheptulose 1,7-bisphosphate, between GU- /NGT and IGT. CONCLUSIONS: Comparison of PHS/OGTT and Glc/OGTT showed that oligosaccharide absorption was accelerated in IGT. Methylcysteine and sedoheptulose 1,7-bisphosphate could be novel markers for dysregulated glucose metabolism.

Efficacy and safety of ipragliflozin and metformin for visceral fat reduction in patients with type 2 diabetes receiving treatment with dipeptidyl peptidase-4 inhibitors in Japan: a study protocol for a prospective, multicentre, blinded-endpoint phase IV randomised controlled trial (PRIME-V study).

INTRODUCTION: In Japan, dipeptidyl peptidase-4 (DPP-4) inhibitors are frequently used as the treatment of choice for patients with type 2 diabetes. In some cases, however, poor glycaemic and body weight control issues persist despite treatment with DPP-4 inhibitors. Previous researchers have revealed that sodium-dependent glucose transporter-2 (SGLT-2) inhibitors reduce both plasma glucose levels and body weight in patients with type 2 diabetes. However, further investigation regarding the effects of SGLT-2 inhibitors on body composition, especially in the Asian population who tends to have relatively low-to-moderate body mass indices, is required. Therefore, we aim to determine the effects of treatment with SGLT-2 inhibitors or metformin for reducing visceral fat in 106 Asian patients with type 2 diabetes who were undergoing treatment with the DPP-4 inhibitor sitagliptin (50 mg daily) for poor glycaemic control. METHODS AND ANALYSIS: A prospective, multicentre, blinded-endpoint phase IV randomised controlled study will be conducted to evaluate the safety and efficacy of a 24-week treatment with either an SGLT-2 inhibitor (ipragliflozin) or metformin for reducing visceral fat and plasma glucose levels in patients with type 2 diabetes. Patients who satisfy the eligibility criteria will be randomised (1:1) to receive ipragliflozin (50 mg daily) or metformin (1000 mg daily). The primary outcome is the rate of change in the total area of visceral fat for patients in both treatment groups, measured using CT, after 24 weeks of therapy. Two radiologists, blinded to the clinical information, will perform centralised analysis of the images in a unified measurement condition. ETHICS AND DISSEMINATION: The protocol was approved by the institutional review board of each hospital. This study is ongoing and due to finish in April 2017. The findings of this study will be disseminated via peer-reviewed publications and conference presentations, and will also be disseminated to participants. TRIAL REGISTRATION NUMBER: UMIN000015170, R000016861 (https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000016861); Pre-results.