Correlations Between Glycemic Parameters Obtained from Continuous Glucose Monitoring and Hemoglobin A1c and Glycoalbumin Levels in Type 2 Diabetes Mellitus.

It is difficult to detect glycemic excursions using CGM in daily clinical practice. We retrospectively analyzed CGM data in type T2DM to define the correlations between HbA1c and GA levels at admission and the parameters representing glycemic excursions measured by CGM, including the mean amplitude of glycemic excursions (MAGE) and standard deviation (SD). The MAGE correlated significantly with GA and HbA1c, but not with the GA/HbA1c ratio. The SD correlated significantly with GA, HbA1c, and GA/HbA1c. Multivariate analysis identified the GA value to be the most reflective of MAGE. Patients were divided into 2 groups using a MAGE cutoff value of 75 mg/dl, which reflects stable diabetes. There was a significant difference in GA, but not HbA1c, between the groups with low and high mean amplitudes of glycemic excursions. Receiver operating characteristic curve analysis indicated that the cutoff for GA for identifying patients with MAGE of ≤75 mg/dl was 18.1%. Our study identified GA to be the most reflective of glycemic excursions in patients with T2DM. GA can be a useful index of glycemic excursions and treatment optimization to prevent arteriosclerosis.

A Study of the Vascular Endothelial Function in Patients with Type 2 Diabetes Mellitus and Rheumatoid Arthritis.

Objective Type 2 diabetes mellitus (T2DM) and rheumatoid arthritis (RA) are both complicated by arteriosclerosis, resulting in increased rates of cardiovascular events. No previous studies have compared the index between RA and T2DM. We assessed the vascular endothelial function in early-stage arteriosclerosis for each disease to determine the influential factors and compared the extent to which these two diseases cause vascular endothelial dysfunction. Methods This study is a retrospective study based on medical records. Differences in the reactive hyperemia index (RHI) among the groups and factors affecting the RHI in each group was analyzed. The vascular endothelial function was assessed by measuring the RHI using peripheral arterial tonometry. Patients The study subjects were 114 patients with non-functional thyroid tumors (healthy n=14), T2DM (T2DM n=64), and RA (RA n=36). Results The RHI was 2.29 in the control, 1.85 in the T2DM, and 1.83 in the RA group, with values lower in the T2DM and RA groups than in the control group (p=0.033) but not markedly different between the two disease groups. The RHI distribution (<1.68/1.68 to <2.10/≥2.1) was as follows: control group: 14.3%/28.6%/57.1%; T2DM group: 42.2%/39.1%/18.8%; and RA group: 36.1%/44.4%/19.4% (p=0.031), respectively. A multivariate analysis identified the triglyceride level and dyslipidemia in the control group and the Disease Activity Score in 28 joints with the erythrocyte sedimentation rate and fasting plasma glucose level in the RA group to influence the RHI. Conclusion The vascular endothelial function was impaired in approximately 80% of patients with T2DM and RA, with comparable degrees of impairment between the two diseases. No factors affecting the function were identified in the T2DM group, while the function was more impaired in patients with a higher disease activity in the RA group.

Glycemic Profiling in Patients with Drug-Naïve Type 2 Diabetes by Continuous Glucose Monitoring.

The purpose of this study was to determine the glycemic profiles of drug-naïve type 2 diabetes patients according to hemoglobin A1c (HbA1c) level using continuous glucose monitoring. We aimed to clarify factors associated with HbA1c and average blood glucose level. Patients were divided into three groups according to their HbA1c level (< 7.0% n=23, 7.0% ≤ HbA1c < 8.0% n=17 and ≥ 8.0% n=31), and the factors associated with HbA1c and average glucose of each group were evaluated. Pre-meal glucose levels were the highest before lunch, and the 2 hour postprandial blood glucose level was the lowest after lunch. The pre-meal and postprandial blood glucose levels increased after each meal with increases in HbA1c. Average glucose level was the most significant determinant of HbA1c, whereas pre-meal glucose level at dinner was the most significant determinant of average glucose level, and the range of increase in glucose from pre-meal at dinner was the most significant determinant of standard deviation (SD) of 24 hour glucose levels. HbA1c subgroup analysis indicated that pre-meal glucose level at lunch significantly correlated with average glucose level in the HbA1c < 8.0% group, while pre-meal glucose level at dinner significantly correlated with average glucose level in the HbA1c ≥ 8.0% group. The range of increase in glucose from pre-meal in the morning significantly correlated with SD of 24 hour glucose levels in the HbA1c < 8.0% group, and the postprandial peak glucose level at lunch significantly correlated with SD of 24 hour glucose levels in the HbA1c ≥ 8.0% group. The results suggest that improvement of the average glucose level is necessary to improve the HbA1c levels. For patients with HbA1c < 7.0%, it is important to improve blood glucose level after breakfast and before lunch to decrease the average glucose level. For patients with 7.0% ≤ HbA1c < 8.0%, it is important to improve blood glucose level before lunch and after dinner to decrease the average glucose level. For patients with HbA1c ≥ 8.0%, it is important to improve blood glucose levels after lunch and before dinner to decrease the average glucose level.

Comparison of the Effects of Teneligliptin and Sitagliptin, Two Dipeptidyl Peptidase 4 Inhibitors with Different Half-Lives, on Glucose Fluctuation and Glucagon-Like Peptide-1 in Type 2 Diabetes Mellitus.

Our purpose was to determine the effects of teneligliptin and sitagliptin, two dipeptidyl peptidase 4 inhibitors (DPP4-Is) with different half-lives, on glycemic variability and glucagon-like peptide-1 (GLP-1) levels in Japanese patients with type 2 diabetes mellitus (T2DM). The study subjects were 14 drug-naïve patients with T2DM who were allocated to either a 20 mg/day teneligliptin group (n = 7) or a 50 mg/day sitagliptin group (n = 7) for 7 days, then switched to the other treatment for another 7 days. Meal tolerance tests were performed at the time of no treatment, and after treatment with each DPP4-Is at supper. We evaluated the effects of each drug on glucose fluctuation using continuous glucose monitoring (CGM). There was no significant difference between the two groups in the primary endpoint (maximum glucose level after supper), nor in the secondary endpoint: area under the curve (AUC) for plasma glucose (≥140 mg/dl) after supper (18:00 - 24:00). Teneligliptin significantly improved the AUC for plasma glucose (≥140 mg/dl) after supper (20:00-24:00) (P = 0.048), and also significantly increased the GLP-1 level at 30 minutes after the meal load (P = 0.030). No serious adverse effects were noted in either group, apart from a few episodes of asymptomatic hypoglycemia. A daily dose of teneligliptin improved the AUC for plasma glucose at 20:00 to 24:00 (≥140 mg/dl) after the meal tolerance test, and also significantly increased the levels of activated GLP-1 after the test meal.

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.

Twenty-four-hour variations in blood glucose level in Japanese type 2 diabetes patients based on continuous glucose monitoring.

AIMS/INTRODUCTION: High fluctuations in blood glucose are associated with various complications. The correlation between glycated hemoglobin (HbA1c) level and fluctuations in blood glucose level has not been studied in Japanese patients with type 2 diabetes. In the present study, blood glucose profile stratified by HbA1c level was evaluated by continuous glucose monitoring (CGM) in Japanese type 2 diabetes patients. MATERIALS AND METHODS: Our retrospective study included 294 patients with type 2 diabetes who were divided by HbA1c level into five groups (≥6.0 to <7.0%, ≥7.0 to <8.0%, ≥8.0 to <9.0%, ≥9.0 to <10.0% and ≥10%). The correlation between HbA1c level and CGM data was analyzed. The primary end-point was the difference in blood glucose fluctuations among the HbA1c groups. RESULTS: The mean blood glucose level increased significantly with increasing HbA1c (Ptrend  < 0.01). The standard deviation increased with increases in HbA1c (Ptrend  < 0.01). The mean amplitude of glycemic excursions did not vary significantly with HbA1c. The levels of maximum blood glucose, minimum blood glucose, each preprandial blood glucose, each postprandial maximum blood glucose, range of increase in postprandial glucose from pre-meal to after breakfast, the area under the blood concentration-time curve >180 mg/dL and percentage of the area under the blood concentration-time curve >180 mg/dL were higher with higher HbA1c. Mean glucose level and pre-breakfast blood glucose level were significant and independent determinants of HbA1c. CONCLUSIONS: In Japanese patients treated for type 2 diabetes, the mean amplitude of glycemic excursions did not correlate with HbA1c, making it difficult to assess blood glucose fluctuations using HbA1c. Parameters other than HbA1c are required to evaluate fluctuations in blood glucose level in patients receiving treatment for type 2 diabetes.

Comparison Between Effectiveness of 100 mg/day Sitagliptin and a Switch to Mitiglinide Calcium Hydrate/Voglibose from 50 mg/day Sitagliptin in Patients with Type 2 Diabetes.

We analyzed the effects of 100 mg/day sitagliptin and a switch to mitiglinide calcium hydrate/voglibose compound tablets (MIT/VOG) in patients with type 2 diabetes mellitus (T2DM) treated with 50 mg/day sitagliptin. Five patients with T2DM treated with 50 mg/day sitagliptin and hemoglobin A1c (HbA1c) of ≥6.5% were switched to MIT/VOG, or the dose of sitagliptin was increased to 100 mg/day. The effects of the changes in therapy were compared in a crossover fashion by continuous glucose monitoring. The primary endpoint was mean amplitude of glycemic excursions (MAGE), and the secondary end points were 24-hour mean blood glucose level and mean blood glucose level from 0:00 a.m. to 7:00 a.m. and from 7:00 a.m. to 0:00 a.m., percentage of time with blood glucose level of ≥200 mg/dl and <70 mg/dl, maximum and minimum blood glucose levels, and increases in postprandial blood glucose levels. MAGE was significantly lower with MIT/VOG (P = 0.016), whereas mean blood glucose levels were lower between 0:00 a.m. and 7:00 a.m. with 100 mg/day sitagliptin. The percentage of time with blood glucose level ≥200 mg/dl was significantly shorter with MIT/VOG (P = 0.041). The maximum blood glucose level was significantly lower with MIT/VOG (P = 0.043), and the minimum was significantly lower with 100 mg/day sitagliptin (P = 0.043). Blood glucose levels after dinner and mean increases in postprandial blood glucose levels were significantly lower with MIT/VOG (P = 0.090 and P = 0.045 respectively). In patients with T2DM, treatment with MIT/VOG improves MAGE and postprandial hyperglycemia and 100 mg/day sitagliptin lowers early morning glucose levels. This trial was registered with the University Hospital Medical Information Network (UMIN) (No. UMIN R000008274).

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).

Effects of exenatide on postprandial vascular endothelial dysfunction in type 2 diabetes mellitus.

BACKGROUND: Basic studies have shown that glucagon-like peptide-1 (GLP-1) analogs exert a direct protective effect on the vascular endothelium in addition to their indirect effects on postprandial glucose and lipid metabolism. GLP-1 analogs are also reported to inhibit postprandial vascular endothelial dysfunction. This study examined whether the GLP-1 analog exenatide inhibits postprandial vascular endothelial dysfunction in patients with type 2 diabetes mellitus (T2DM). METHODS: Seventeen patients with T2DM underwent a meal tolerance test to examine changes in postprandial vascular endothelial function and in glucose and lipid metabolism, both without exenatide (baseline) and after a single subcutaneous injection of 10 µg exenatide. Vascular endothelial function was determined using reactive hyperemia index (RHI) measured by peripheral arterial tonometry before and 120 min after the meal loading test. The primary endpoint was the difference in changes in postprandial vascular endothelial function between the baseline and exenatide tests. RESULTS: The natural logarithmically-scaled RHI (L_RHI) was significantly lower after the baseline meal test but not in the exenatide test. The use of exenatide resulted in a significant decrease in triglycerides (TG) area under the curve and coefficient of variation (CV). The change in L_RHI correlated with changes in CV of triglycerides and HDL-cholesterol. Multivariate analysis identified changes in triglyceride CV as the only determinant of changes in L_RHI, contributing to 41% of the observed change. CONCLUSIONS: Exenatide inhibited postprandial vascular endothelial dysfunction after the meal loading test, suggesting that exenatide has a multiphasic anti-atherogenic action involving not only glucose but also lipid metabolism. TRIAL REGISTRATION: ClinicalTrials.gov: UMIN000015699.