Keiichi Torimoto

Relationship between fluctuations in glucose levels measured by continuous glucose monitoring and vascular endothelial dysfunction in type 2 diabetes mellitus.

BackgroundFluctuations in blood glucose level cause endothelial dysfunction and play a critical role in onset and/or progression of atherosclerosis. We hypothesized that fluctuation in blood glucose levels correlate with vascular endothelial dysfunction and that this relationship can be assessed using common bedside medical devices.MethodsFluctuations in blood glucose levels were measured over 24 hours by continuous glucose monitoring (CGM) on admission day 2 in 57 patients with type 2 diabetes mellitus. The reactive hyperemia index (RHI), an index of vascular endothelial function, was measured using peripheral arterial tonometry (EndoPAT) on admission day 3.ResultsThe natural logarithmic-scaled RHI (L_RHI) correlated with SD (r=−0.504; P<0.001), the mean amplitude of glycemic excursions (MAGE) (r=−0.571; P<0.001), mean postprandial glucose excursion (MPPGE) (r=−0.411; P=0.001) and percentage of time ≥200 mg/dl (r=−0.292; P=0.028). In 12 patients with hypoglycemia, L_RHI also correlated with the percentage of time at hypoglycemia (r=−0.589; P= 0.044). L_RHI did not correlate with HbA1c or fasting plasma glucose levels. Furthermore, L_RHI did not correlate with LDL cholesterol, HDL cholesterol, and triglyceride levels or with systolic and diastolic blood pressures. Finally, multivariate analysis identified MAGE as the only significant determinant of L_RHI.ConclusionsFluctuations in blood glucose levels play a significant role in vascular endothelial dysfunction in type 2 diabetes.Trial registrationUMIN000007581

Determinants of hemoglobin A1c level in patients with type 2 diabetes after in-hospital diabetes education: A study based on continuous glucose monitoring

We investigated the relationship between blood glucose profile at hospital discharge, evaluated by continuous glucose monitoring (CGM), and hemoglobin A1c (HbA1c) level at 12 weeks after discharge in patients with type 2 diabetes who received inpatient diabetes education.

Prednisolone Dosing Regimen for Treatment of Subacute Thyroiditis.

The rate of recurrence of subacute thyroiditis (SAT) during prednisolone (PSL) therapy is approximately 10 to 20%. However, there is little or no information on the time period to relapse following administration of a tapered dose of PSL and the factors associated with such relapse. The aim of this study was to determine the correlation between SAT recurrence and PSL tapering regimen used in the treatment of SAT. This study was a medical record-based retrospective study and involved 26 patients (3 men, 23 women) who received PSL therapy for SAT. The primary endpoint was the association between recurrence and number of days required to taper daily PSL dose to 5 mg. The secondary endpoint was the relationship between recurrence and several variables including age, clinical score, free thyroxine, inflammatory reaction, thyroglobulin, total treatment time, total dose of PSL and presence or absence of creeping thyroiditis. The SAT recurrence rate was 15.3%. There was no significant difference in the initial PSL dose between the non-recurrence and recurrence groups (27.5 mg vs 24.5 mg, P = 0.302). However, for the primary endpoint, significant differences were found between the two groups in time required for tapering PSL to 5 mg/day (non-recurrence: 44.3 ± 15.3 days, recurrence: 19.0 ± 11.9 days, P = 0.012). None of the clinical variables evaluated correlated significantly with SAT relapse. In conclusion, to prevent recurrence of SAT, consideration should be given to the period required for PSL tapering to 5 mg/day.

Low levels of 1,5-anhydro-D-glucitol are associated with vascular endothelial dysfunction in type 2 diabetes.

BackgroundVascular endothelial dysfunction is involved in macrovascular disease progression in type 2 diabetes mellitus (T2DM). We reported previously that blood glucose fluctuations, as evaluated by continuous glucose monitoring (CGM), correlate with vascular endothelial function, serving as a marker of vascular endothelial function. However, the use of CGM is limited, suggesting the need for another marker of vascular endothelial function. Here, we investigated the relationship between vascular endothelial dysfunction and blood levels of 1,5-anhydro-D-glucitol (1,5-AG), a marker of both postprandial hyperglycemia and fluctuations in blood glucose.MethodsIn 32 inpatients with T2DM and HbA1c less than 8.0%, the reactive hyperemia index (RHI), an index of vascular endothelial function, was determined by peripheral arterial tonometry. The relationships between RHI and 1,5-AG, blood glucose, lipid metabolism markers, and blood pressure, were examined.ResultsThere was a strong correlation between 1,5-AG and natural logarithmic-scaled RHI (L_RHI) (r = 0.55; P = 0.001). However, there was no correlation between L_RHI and HbA1c, fasting blood glucose, IRI, LDL-C, HDL-C, TG, systolic blood pressure, or diastolic blood pressure. Multivariate analysis identified blood 1,5-AG levels to be the only significant and independent determinant of L_RHI.ConclusionsIn T2DM with HbA1c <8.0%, low 1,5-AG levels were associated with vascular endothelial dysfunction, suggesting it is a potentially useful marker for vascular endothelial dysfunction.Trial registrationUMIN000015317

Comparative analysis of the effects of alogliptin and vildagliptin on glucose metabolism in type 2 diabetes mellitus

The aim of this 24-week, prospective randomized open-label study was to compare the effects of alogliptin and vildagliptin on glucose control, renal function, and lipid metabolism. In Study 1, DPP-4 inhibitor-naive type 2 diabetes (T2DM) were randomly assigned to alogliptin 25 mg/day or vildagliptin 50 mg twice daily. In Study 2, T2DM on treatment with 50 mg/day sitagliptin were switched to either 25 mg/day alogliptin or 50 mg twice daily vildagliptin. The primary endpoint was change in glycosylated hemoglobin (HbA1c) level at 24 weeks, while the secondary endpoints were changes in urinary albumin excretion and low-density lipoprotein cholesterol (LDL-C) levels at 24 weeks. In Study 1, HbA1c levels changed at 24-week by -0.5±0.7% in the alogliptin group (p=0.002, relative to baseline) and -0.7±0.9% in the vildagliptin group (p=0.001, relative to baseline), and the extent of these changes were comparable between the two groups (p=0.219). The decrease in log urinary albumin excretion was more significant in the vildagliptin group (p=0.008). In Study 2, HbA1c levels at 24-week changed by 0.2±0.7% in the switch-to-alogliptin group (p=0.007) and 0.0±0.6% in the switch-to-vildagliptin group (p=0.188), indicating a significant difference between the groups (p=0.003). In both studies, the changes in LDL-C levels were comparable between the two groups. The two drugs had comparable glucose-lowering effects in DPP-4 inhibitor-naive patients but the effect was more pronounced for vildagliptin in patients switched from sitagliptin. The results may point to subtle yet important differences between the two DPP-4 inhibitors. This trial was registered with UMIN (no. #000019022).

Type 2 Diabetes and Vascular Endothelial Dysfunction

Vascular endothelial function is important for maintaining the homeostasis of the living body. Especially, nitric oxide (NO) produced in vascular endothelial cells regulates blood vessel tone and has an antiatherosclerotic effect. Type 2 diabetes is a typical disease that causes impaired vascular endothelial function, resulting in various vascular complications and damage to organs. Cardiovascular disease associated with type 2 diabetes is a chronic inflammatory disease that starts with endothelial dysfunction (ED), and vascular ED is important as an initial change in arteriosclerotic lesions. Vascular ED in type 2 diabetes is thought to be caused by hyperglycemia, hyperinsulinemia associated with insulin resistance, and hypoglycemia, in which elevated oxidative stress accompanying postprandial hyperglycemia and blood glucose fluctuation are involved. Vascular ED is also caused by postprandial metabolic abnormalities, so correcting postprandial metabolic abnormalities is also important. Meanwhile, Glucagon-like peptide-1 (GLP-1) receptor agonist, thiazolidine, biguanide and Dipeptidyl peptidase-4 (DPP-4) inhibitor have an effect of protecting vascular endothelial function beyond glycemic control. In order to promote a healthy lifestyle for diabetes patients, it is important not only to lower HbA1c but also to avoid postprandial hyperglycemia, blood glucose fluctuation, and hypoglycemia. It is also important to conduct treatment with a view to suppressing vascular complications, such as the selection of antiarteriosclerosis medications.

The Effects of Mitiglinide and Repaglinide on Postprandial Hyperglycemia in Patients Undergoing Methylprednisolone Pulse Therapy

One adverse effect of methylprednisolone (MP) pulse therapy is an acute dose-dependent increase in the blood glucose level. Five patients with thyroid ophthalmopathy but normal glucose tolerance received MP pulse therapy (3 cycles, 3 days/week) and were assessed by continuous glucose monitoring. Steroid therapy increased the mean sensor glucose level, and all patients developed steroid-induced diabetes. The patients were treated alternately with mitiglinide (30 mg/day) and repaglinide (1.5 mg/day) during the second or third MP pulse therapy. The sensor glucose levels before lunch and dinner were more favorable during treatment with repaglinide than during treatment with mitiglinide. Repaglinide may be more clinically appropriate than mitiglinide.

Clinical Features of Patients with Basedow's Disease and High Serum IgG4 Levels

Objective IgG4-related disease is a recently characterized condition presenting with high blood IgG4 levels, swelling of organs, and hypertrophic lesions. This disease is associated with thyroid disease, Hashimotos disease, and Riedels thyroiditis. However, there is little information on the association between IgG4-related disease and Basedows disease. We herein defined the clinical features of patients with Basedows disease and high IgG4 levels. Methods We compared two groups of patients with Basedows disease (n=72) who had either normal IgG4 levels (<135 mg/dL; n=67) or high IgG4 levels (≥135 mg/dL; n=5 [6.9%], mean IgG4: 206±116 mg/dL, IgG4/IgG ratio: 10.6%±3.3%). Patients Seventy-two newly diagnosed, untreated patients with Basedows disease. Results Compared to the normal IgG4 group, patients in the high IgG4 group were predominantly male and showed a significantly higher thyroid low-echo score (1.8±0.4 vs. 1.2±0.5) and eosinophil count (363±354/mm2 vs. 136±122/mm2). Five patients had high IgG4 levels: one had a pancreatic lesion, and four had thyroid lesions. Conclusion Patients with Basedows disease and high IgG4 levels may represent a new subtype of Basedows disease. Further studies with larger sample sizes are needed.

Pancreas-protective effect of rituximab for acute-onset type 1 diabetes in the honeymoon period: a case report

Summary A randomized controlled study of rituximab demonstrated that the drug protects pancreatic function in patients with acute-onset type 1 diabetes mellitus (AOT1DM). However, the mechanism of this protective effect is poorly understood. We examined the effects of rituximab in two patients with AOT1DM in the honeymoon period and the mechanism of these effects. Case 1 was a 40-year-old man and Case 2 was a 45-year-old man, both diagnosed with AOT1DM. Various tests indicated intact capacity for endogenous insulin secretion and that they were in the honeymoon phase of AOT1DM. Treatment with rituximab protected against pancreatic β-cell damage and maintained somewhat the endogenous insulin secretion. In Case 2, HbA1c level was maintained below 6.5% up to 24 months after treatment. However, in Case 1, the patient showed a gradual increase in HbA1c level starting around 9 months but fell at 12 months to >9.0% and required an insulin dose about twice greater than that of Case 2. High spleen tyrosine kinase (Syk) levels were recorded in the two patients before rituximab administration and after the treatment, the levels were further increased in Case 1, but decreased in Case 2. Both patients require continuous careful follow-up for glycemic control, insulin secretion capacity, and adverse reactions in the future. Although the clinical relevance of high Syk levels in AOT1DM patients remains unclear, the difference in the change in Syk level between the two patients may explain the different clinical courses. Learning points We described the pancreas-protective effect of rituximab in two patients with acute-onset type 1 diabetes mellitus in the honeymoon period and investigated the possible mechanism of action. The present study demonstrated that treatment with rituximab maintained endogenous insulin secretion capacity for 2 years in the two patients. The phosphorylated-spleen tyrosine kinase (p-Syk) data suggest that the differences in HbA1c level and the required insulin dose between the two patients could be due to reactivation or nonreactivation of β-cells.

Association Between Diabetic Microangiopathies and Glycemic Variability Assessed by Continuous Glucose Monitoring

The aim of this retrospective study was to elucidate the association between glucose profile using the continuous glucose monitoring system (CGMS) and microvascular complications in patients with type 2 diabetes mellitus (T2DM). The subjects were 160 inpatients with T2DM. The mean blood glucose (MBG) level, percentage of time in a 24-hour period spent with blood glucose level higher than 180 mg/dl (time at >180 mg/dl), standard deviation (SD), and mean amplitude of glycemic excursions (MAGE) were measured continuously over 48 hours using the CGMS. The primary outcome was the association between microvascular complications and glycemic variability. The secondary outcome was the association between microangiopathies and MBG. The SD and MAGE were not associated with presence of microangiopathies or number of complications. There were also no associations between abnormal vibratory sensation in the bilateral lower extremities, coefficient of variation of the R-R interval (CVRR), retinopathy stage, nephropathy stage, or microalbuminuria. MBG was associated, however, with retinopathy, retinopathy stage, and number of complications. Time at >180 mg/dl correlated with abnormal vibratory sensation in the bilateral lower extremities and presence or stage of retinopathy. MBG and time at >180 mg/dl were not associated with presence or stage of nephropathy. Our findings suggest that broad glycemic variability was not associated with microvascular complications, the number of which increased in patients with a high mean glucose level and long time spent with hyperglycemia. It is important, therefore, to reduce the mean glucose level and time spent with hyperglycemia to prevent future microangiopathies.