Relation of cardiac function to insulin resistance as evaluated by hyperinsulinemic-euglycemic clamp analysis in individuals with type 2 diabetes.

AIMS: Whereas homeostasis model assessment of insulin resistance (HOMA-IR), an easily measured but limited index of insulin resistance, has been shown to correlate with impairment of cardiac function in individuals without diabetes, the pathological relevance of insulin resistance to the development of cardiac dysfunction in individuals with type 2 diabetes has remained unclear. Here we investigated the relation between left ventricular (LV) function as assessed by echocardiography and insulin resistance as evaluated by hyperinsulinemic-euglycemic clamp analysis, the gold standard for measurement of this parameter, in individuals with type 2 diabetes. METHODS: This retrospective study included 34 individuals with type 2 diabetes who underwent both hyperinsulinemic-euglycemic clamp analysis and echocardiography. Both the insulin sensitivity index (ISI) as determined by glucose clamp analysis as well as HOMA-IR were determined as measures of insulin resistance. The ratio of the peak early- to late-diastolic mitral inflow velocities (E/A) and the LV ejection fraction (LVEF) were determined as measures of diastolic and systolic function, respectively. RESULTS: The ISI was significantly correlated with both the E/A ratio and LVEF (correlation coefficients of 0.480 and 0.360, respectively), whereas HOMA-IR was not correlated with either cardiac parameter. Multivariate analysis revealed that ISI was an independent predictor for both a high log [E/A] (P = 0.031) and a high LVEF (P = 0.045). CONCLUSIONS: Insulin resistance as evaluated by hyperinsulinemic-euglycemic clamp analysis may be causally related to LV diastolic and systolic dysfunction in individuals with type 2 diabetes.

Analysis of time-dependent alterations of parameters related to erythrocytes after ipragliflozin initiation.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors often increase the hematocrit. It remains unclear whether this increase would be observed in all patients administered SGLT2 inhibitors, however. We therefore used the data from the previous study and investigated time-dependent alterations of various outcomes related to erythrocytes, erythropoiesis, and clinical outcome in type 2 diabetes subjects (n = 89) treated with ipragliflozin for 16 weeks. Among a total of 89 participants, 71 subjects (80.0% of total participants) showed the elevation of the hematocrit and 18 subjects (20.0% of total participants) did not at 16 weeks. Although the hematocrit levels at baseline were significantly lower in hematocrit-elevated group than non-elevated group, they reached the same levels 4 weeks after the onset of treatment. Binomial logistic regression analysis demonstrated that a lower baseline hematocrit level was related to the elevation of hematocrit at 16 weeks. Optimal cutoff hematocrit levels at baseline to predict hematocrit elevation were 46.9% (male) and 41.7% (female) in ROC analysis. Random intercept model analysis revealed the serum erythropoietin level increased in both hematocrit-elevated and non-elevated groups, whereas only the former group showed an increase in the percentage of reticulocytes during the first 4 weeks. These results suggest that the ipragliflozin-induced increase in hematocrit which is affected by the baseline hematocrit level is attributable to the responsiveness to, but not to the production of, erythropoietin. Collectively, Ht elevation observed in administration of SGLT2 inhibitors can result from erythropoietin-induced erythropoiesis, which is determined by the pre-treatment Ht level. Trial registration: This trial has been registered with University Hospital Medical Information Network Clinical Trial Registry (UMIN-CTR no. 000015478).

Effects of insulin degludec and insulin glargine U300 on glycaemic stability in individuals with type 1 diabetes: A multicentre, randomized controlled crossover study.

To compare the effects of insulin degludec (IDeg) and insulin glargine U300 (IGlarU300) on glycaemic stability in subjects with type 1 diabetes. MATERIALS AND METHODS: In this multicentre, crossover trial, 46 individuals with type 1 diabetes and essentially undetectable circulating C-peptide were randomly assigned to either the IDeg-first/IGlarU300-second group or the IGlarU300-first/IDeg-second group, and were treated with the respective basal insulins for 4-week periods. Data were collected in the last week of each treatment period. The primary aim was to examine the potential non-inferiority of IDeg relative to IGlarU300 with regard to day-to-day variability, as evaluated by the standard deviation (SD) of fasting blood glucose (FBG) levels. Intra-day glycaemic variability and other variables were also determined by continuous glucose monitoring (CGM). RESULTS: The SD of FBG for IDeg was non-inferior to that for IGlarU300. The mean of FBG, coefficient of variation of FBG, and various glycaemic variability indexes determined by CGM did not differ between the two insulins. Whereas the administered doses of the insulins also did not differ, the mean glycaemic value was lower for IDeg than IGlarU300; the time above the target range (>180 mg/dL [10.0 mmol/L]) and the time below the target range (<70 mg/dL [3.9 mmol/L]) were shorter and longer, respectively, for IDeg than IGlarU300. CONCLUSIONS: Our data suggest that IDeg and IGlarU300 have comparable glucose-stabilizing effects in individuals with type 1 diabetes. However, the glucose-lowering effect of IDeg may be greater than that of IGlarU300 when titrated with a unit-based protocol.

Relation between HOMA-IR and insulin sensitivity index determined by hyperinsulinemic-euglycemic clamp analysis during treatment with a sodium-glucose cotransporter 2 inhibitor.

We had aimed to determine whether homeostasis model assessment-insulin resistance (HOMA-IR) reflects insulin resistance-sensitivity during treatment with a sodium-glucose cotransporter 2 inhibitor (SGLT2i). Hyperinsulinemic-euglycemic clamp analysis was performed in 22 patients with type 2 diabetic patients taking dapagliflozin (5 mg/day before or after breakfast). Propensity score matching of these individuals (SGLT2i group) for age, sex, body mass index, and clamp-derived tissue glucose uptake rate with 44 type 2 diabetic patients who had undergone clamp analysis without SGLT2i treatment (control group) identified 17 paired subjects in each group for further analysis of the relation between HOMA-IR and a clamp-derived insulin sensitivity index (ISI). Natural log-transformed HOMA-IR was negatively correlated with ISI in both SGLT2i (r = -0.527, p = 0.030) and control (r = -0.534, p = 0.027) groups. The simple regression lines for log-transformed HOMA-IR and ISI in the two groups showed similar slopes but differed in their intercepts. Multivariate analysis revealed that HOMA-IR for patients with the same ISI in the two groups was related by the formula: HOMA-IRcontrol = HOMA-IRSGLT2i × 2.45. In conclusion, HOMA-IR was well correlated with ISI during SGLT2i treatment, but values corresponding to the same ISI were lower in the SGLT2i group than in the control group.

Effects of ipragliflozin on glycemic control, appetite and its related hormones: A prospective, multicenter, open-label study (SOAR-KOBE Study).

AIMS/INTRODUCTION: Sodium-glucose cotransporter 2 (SGLT-2) inhibitors improve blood glucose control, as well as reducing bodyweight by promoting urinary glucose excretion. The weight loss is less than expected from urinary glucose loss, however, likely because of an increase in food intake. To investigate whether SGLT-2 inhibitors might increase appetite by affecting related hormones, we examined the effects of the SGLT-2 inhibitor, ipragliflozin, including those on appetite-regulating hormones, in individuals with suboptimally controlled type 2 diabetes. MATERIALS AND METHODS: The present prospective, multicenter, open-label study was carried out with 96 patients with a body mass index of ≥22 kg/m2 who were treated with ipragliflozin (50 mg/day) for 16 weeks. Parameters including glycated hemoglobin level, bodyweight, circulating leptin and active ghrelin concentrations, and appetite as assessed with a visual analog scale were measured before and during treatment. RESULTS: Both glycated hemoglobin level (from 7.9 ± 0.8 to 7.1 ± 0.7%) and bodyweight (from 75.2 ± 12.6 to 72.6 ± 12.4 kg) were significantly decreased after treatment for 16 weeks. The fasting serum leptin level was significantly decreased after 2 weeks (from 19.5 ± 13.1 to 18.1 ± 12.4 ng/mL) and remained decreased up to 16 weeks, even after adjustment for bodyweight, whereas the plasma active ghrelin level showed no significant change. The visual analog scale score for hunger was significantly increased at 2 and 8 weeks. CONCLUSIONS: The present results suggest that ipragliflozin improved glycemic control and reduced bodyweight, but also reduced serum leptin levels and might thereby have increased appetite.

Effects of Insulin Degludec and Insulin Glargine U300 on Day-to-Day Fasting Plasma Glucose Variability in Individuals with Type 1 Diabetes: A Multicenter, Randomized, Crossover Study (Kobe Best Basal Insulin Study 2).

INTRODUCTION: Administered basal insulin markedly influences the fasting plasma glucose (FPG) level of individuals with type 1 diabetes. Insulin degludec (IDeg) and insulin glargine U300 (IGlar U300) are now available as ultra-long-acting insulin formulations, but whether or how their glucose-stabilizing effects differ remains unclear. We will compare the effects of these basal insulins on parameters related to blood glucose control, with a focus on day-to-day glycemic variability, in individuals with type 1 diabetes treated with multiple daily injections. METHODS: A multicenter, randomized, open-label, crossover, comparative study (Kobe Best Basal Insulin Study 2) will be performed at 13 participating institutions in Japan. A total of 46 C-peptide-negative adult outpatients with type 1 diabetes will be randomly assigned 1:1 by a centralized allocation process to IGlar U300 (first period)/IDeg (second period) or IDeg (first period)/IGlar U300 (second period) groups, in which subjects will be treated with the corresponding basal insulin for consecutive 4-week periods. The basal insulin will be titrated to achieve an FPG of less than 130 mg/dL initially and then less than 110 mg/dL if feasible. In the last week of each period, plasma glucose will be determined seven times a day by self-monitoring of blood glucose (SMBG) and intraday and day-to-day glucose excursions will be determined by flash glucose monitoring (FGM). The primary end point is comparison of day-to-day glycemic variability as evaluated by the standard deviation (SD) of FPG during the last week of each treatment period. Secondary end points include the coefficient of variance of FPG, the frequency of severe hypoglycemia as evaluated by SMBG, the duration of hypoglycemia as evaluated by FGM, intraday glycemic variability calculated from both SMBG and FGM data, and the administered insulin dose. PLANNED OUTCOMES: The results of the study will be submitted for publication in a peer-reviewed journal to report differences in the effects of two ultra-long-acting basal insulins, IDeg and IGlar U300. CONCLUSION: This head-to-head comparison will be the first study to compare the effects of IDeg and IGlar U300 on day-to-day FPG variability in C-peptide-negative individuals with type 1 diabetes. TRIAL REGISTRATION: Registered in University Hospital Medical Information Network (UMIN) Clinical Trials Registry as 000029630 on 20 June 2017. FUNDING: Novo Nordisk Pharma Ltd.

Effect of switching from conventional continuous subcutaneous insulin infusion to sensor augmented pump therapy on glycemic profile in Japanese patients with type 1 diabetes.

AIMS: Evidence suggests that sensor augmented pump (SAP) therapy is superior to conventional continuous subcutaneous insulin infusion (CSII) for achieving glycemic control in patients with type 1 diabetes. However, the clinical benefit of SAP therapy in East Asians has not yet been demonstrated. METHODS: The effect of switching from conventional CSII to SAP therapy on glycemic profile was examined in 18 Japanese patients with type 1 diabetes. The glycemic profile of the patients was determined by retrospective continuous glucose monitoring (CGM) within 1 month before the treatment switch, whereas that at 6 and 12 months after the switch was evaluated with the CGM function of the SAP device. Hemoglobin A1c levels were also measured before and after the switch to SAP therapy. RESULTS: The duration of hypoglycemia was significantly decreased at both 6 and 12 months after the change in treatment (6.6 ± 4.5, 3.2 ± 4.1, and 3.0 ± 2.8 min/h for before and 6 and 12 months, respectively), as was the HbA1c level at 12 months (7.8 ± 1.0 and 7.4 ± 0.9%, respectively). The duration of hyperglycemia did not differ between before and after the treatment switch. The decline in HbA1c level at 12 months after the switch to SAP was negatively correlated with age. CONCLUSION: Switching from conventional CSII to SAP therapy was associated with a decrease in both the duration of hypoglycemia and the level of HbA1c in Japanese patients with type 1 diabetes.

Insulin Secretion and Insulin Sensitivity Before and After Surgical Treatment of Pheochromocytoma or Paraganglioma.

Context: Pheochromocytoma and paraganglioma are catecholamine-producing tumors that often impair glucose tolerance. The effects of these tumors on insulin sensitivity and insulin secretion in patients have remained unclear, however. Objective: To characterize the influence of pheochromocytoma or paraganglioma on glucose tolerance, we comprehensively analyzed various parameters related to insulin secretion or insulin sensitivity in patients with these tumors. Design: Hyperglycemic and hyperinsulinemic-euglycemic clamps, as well as an oral glucose tolerance test (OGTT), were performed in patients before and after tumor excision. Setting: Patients underwent metabolic analyses on admission to Kobe University Hospital. Patients: Eleven patients with pheochromocytoma and two with paraganglioma were examined. Intervention: None. Main Outcome Measures: We evaluated various parameters related to insulin secretion or insulin sensitivity as determined by an OGTT and by hyperglycemic and hyperinsulinemic-euglycemic clamp analyses. Results: Surgical treatment of the tumor reduced urinary catecholamine excretion and improved glucose tolerance. The insulinogenic index, but not total insulin secretion, measured during the OGTT as well as the first phase, but not the second phase, of insulin secretion during the hyperglycemic clamp were improved after surgery. The insulin sensitivity index determined during the hyperinsulinemic-euglycemic clamp remained unchanged after surgery. Conclusion: These results suggest pheochromocytoma and paraganglioma impair glucose tolerance primarily through impairment of insulin secretion-in particular, that of the early phase of the insulin secretory response. A prospective study with more patients is warranted to further confirm these results.

Characterization of gut microbiota profiles in coronary artery disease patients using data mining analysis of terminal restriction fragment length polymorphism: gut microbiota could be a diagnostic marker of coronary artery disease.

The association between atherosclerosis and gut microbiota has been attracting increased attention. We previously demonstrated a possible link between gut microbiota and coronary artery disease. Our aim of this study was to clarify the gut microbiota profiles in coronary artery disease patients using data mining analysis of terminal restriction fragment length polymorphism (T-RFLP). This study included 39 coronary artery disease (CAD) patients and 30 age- and sex- matched no-CAD controls (Ctrls) with coronary risk factors. Bacterial DNA was extracted from their fecal samples and analyzed by T-RFLP and data mining analysis using the classification and regression algorithm. Five additional CAD patients were newly recruited to confirm the reliability of this analysis. Data mining analysis could divide the composition of gut microbiota into 2 characteristic nodes. The CAD group was classified into 4 CAD pattern nodes (35/39 = 90 %), while the Ctrl group was classified into 3 Ctrl pattern nodes (28/30 = 93 %). Five additional CAD samples were applied to the same dividing model, which could validate the accuracy to predict the risk of CAD by data mining analysis. We could demonstrate that operational taxonomic unit 853 (OTU853), OTU657, and OTU990 were determined important both by the data mining method and by the usual statistical comparison. We classified the gut microbiota profiles in coronary artery disease patients using data mining analysis of T-RFLP data and demonstrated the possibility that gut microbiota is a diagnostic marker of suffering from CAD.

Analysis of Gut Microbiota in Coronary Artery Disease Patients: a Possible Link between Gut Microbiota and Coronary Artery Disease.

AIM: Recent studies have suggested that metabolic disorders such as obesity and type 2 diabetes are associated with gut microbiota. The association between atherosclerosis and gut microbiota has also been attracting increased attention. Our aim was to specify a characteristic trend of gut microbiota in coronary artery disease (CAD). METHODS: This study included 39 CAD patients, 30 age- and sex-matched no-CAD controls (Ctrls) with coronary risk factors and 50 healthy volunteers (HVs) without coronary risk factors. Bacterial DNA was extracted from their fecal samples and analyzed by terminal restriction fragment length polymorphism. RESULTS: A characteristic change of gut microbiota was observed in CAD patients, where the order Lactobacillales was increased (CAD, Ctrl vs. HV; 13.6%±12.0%, 6.2%±7.7% vs. 4.1%±5.9%; p＜0.001) and the phylum Bacteroidetes (Bacteroides＋Prevotella) was decreased (CAD, Ctrl vs. HV;35.5%±11.6%, 43.9%±11.2% vs. 47.4%±11.5%; p＜0.001). The CAD group was over-represented in enterotype "others" (III), compared with the Ctrl or HV group (p＜0.001, chi-squared test), although we could not deny the possibility that some drugs affect the gut flora types. CONCLUSIONS: Although this study had some limitations, we demonstrated that the incidence of CAD was linked with an alteration of gut microbiota. A prospective study is desired to clarify a causal relationship between CAD and gut microbiota.

Effects of insulin degludec and insulin glargine on day-to-day fasting plasma glucose variability in individuals with type 1 diabetes: a multicentre, randomised, crossover study.

AIMS/HYPOTHESIS: We compared the effects of insulin degludec (IDeg; Des(B30)LysB29(γ-Glu Nε-hexadecandioyl) human insulin) and insulin glargine (IGlar; A21Gly,B31Arg,B32Arg human insulin) on the day-to-day variability of fasting plasma glucose (FPG) levels in individuals with type 1 diabetes treated with basal-bolus insulin injections. METHODS: The effects of basal-bolus insulin therapy for 4 weeks with either IDeg or IGlar as the basal insulin in adult C-peptide-negative outpatients with type 1 diabetes were investigated in an open-label, multicentre, randomised, crossover trial. Randomisation was conducted using a centralised allocation process. The primary endpoints were the SD and CV of FPG during the final week of each treatment period. Secondary endpoints included serum glycoalbumin level, daily dose of insulin, intraday glycaemic variability and frequency of severe hypoglycaemia. RESULTS: Thirty-six randomised participants (17 in the IDeg/IGlar and 19 in the IGlar/IDeg groups) were recruited, and data for 32 participants who completed the trial were analysed. The mean (7.74 ± 1.76 vs 8.56 ± 2.06 mmol/l; p = 0.04) and SD (2.60 ± 0.97 vs 3.19 ± 1.36 mmol/l; p = 0.03) of FPG were lower during IDeg treatment than during IGlar treatment, whereas the CV did not differ between the two treatments. The dose of IDeg was smaller than that of IGlar (11.0 ± 5.2 vs 11.8 ± 5.6 U/day; p < 0.01), but other secondary endpoints did not differ between the treatments. CONCLUSIONS/INTERPRETATION: IDeg yielded a lower FPG level and smaller day-to-day variability of FPG at a lower daily dose compared with IGlar in participants with type 1 diabetes. IDeg serves as a good option for basal insulin in the treatment of type 1 diabetes. TRIAL REGISTRATION: University Hospital Medical Information Network 000009965. FUNDING: This research recieved no specific grant from any funding agency in the public, commercial or not-for-profit sectors.