Switching From Daily DPP-4 Inhibitor to Once-Weekly GLP-1 Receptor Activator Dulaglutide Significantly Ameliorates Glycemic Control in Subjects With Poorly Controlled Type 2 Diabetes Mellitus: A Retrospective Observational Study

AIM

At present, daily DPP-4 inhibitors are quite frequently prescribed in subjects with type 2 diabetes mellitus (T2DM). Recently, it has been drawing much attention that once-weekly incretin-based injection dulaglutide was developed. In this study, we aimed to examine the possible effects of once-weekly GLP-1 receptor activator (GLP-1RA) dulaglutide on glycemic control as well as various metabolic parameters.

METHODS

We made a direct comparison between the effect of daily DPP-4 inhibitor and once-weekly dulaglutide on glycemic control in "study 1 (pre-post comparison)" and set the control group using the propensity score matching method in "study 2".

RESULTS

In study 1, switching from daily DPP-4 inhibitor to dulaglutide significantly ameliorated glycemic control in subjects with T2DM. Such effects were more obvious in poorly controlled subjects. After 1:1 propensity score matching, the switching group improved glycemic control compared with the non-switching group in study 2.

CONCLUSION

We should bear in mind that switching from daily DPP-4 inhibitor to once-weekly GLP-1RA dulaglutide exerts more favorable effects on glycemic control regardless of age, body weight, and duration of diabetes in subjects with T2DM, especially when we fail to obtain good glycemic control with daily DPP-4 inhibitor.

Comparison of the effects of three kinds of glucose-lowering drugs on non-alcoholic fatty liver disease in patients with type 2 diabetes: A randomized, open-label, three-arm, active control study

Aims/Introduction

Non‐alcoholic fatty liver disease (NAFLD) is often observed in individuals with type 2 diabetes mellitus, and it is known that the presence of type 2 diabetes mellitus leads to the aggravation of NAFLD. The aim of this study was to compare the possible effects of three kinds of oral hypoglycemic agents on NAFLD in individuals with type 2 diabetes mellitus.

Materials and Methods

We carried out a prospective clinical trial (a randomized and open‐label study) in patients with type 2 diabetes mellitus and NAFLD. A total of 98 patients were randomly allocated either to the dapagliflozin (n = 32), pioglitazone (n = 33) or glimepiride (n = 33) group, and the patients took these drugs for 28 weeks. The primary end‐point was the change of the liver‐to‐spleen ratio on abdominal computed tomography.

Results

There was no difference in baseline clinical characteristics among the three groups. Dapagliflozin, pioglitazone and glimepiride ameliorated hyperglycemia similarly. Bodyweight and visceral fat area were significantly decreased only in the dapagliflozin group. Serum adiponectin levels were markedly increased in the pioglitazone group compared with the other two groups. Dapagliflozin and pioglitazone, but not glimepiride, significantly increased the liver‐to‐spleen ratio, and the effects of dapagliflozin and pioglitazone on the liver‐to‐spleen ratio were comparable.

Conclusions

The present study showed that the decrease of visceral fat area and the increase of adiponectin level contributed to the improvement of NAFLD in patients with type 2 diabetes mellitus. Furthermore, dapagliflozin and pioglitazone exerted equivalent beneficial effects on NAFLD in patients with type 2 diabetes mellitus, although it seemed that these two drugs had different mechanisms of action.

Impact of physical activity and sedentary time on glycated hemoglobin levels and body composition: Cross-sectional study using outpatient clinical data of Japanese patients with type 2 diabetes

AIMS/INTRODUCTION

This study examined the association among sedentary time (ST), physical activity (PA), glycated hemoglobin and body composition in Japanese type 2 diabetes patients.

MATERIALS AND METHODS

Patients with type 2 diabetes who visited the outpatient clinic at Kawasaki Medical School Hospital, Okayama, Japan, comprised the study's participants. Self-administered International Physical Activity Questionnaire short forms were obtained and analyzed for 1,053 patients, including 158 patients for whom waist circumference and visceral fat accumulation were measured. From the questionnaire, three categorical data (low, moderate, high) and continuous data (METs/h/week) regarding PA and ST (min/day), respectively, were obtained.

RESULTS

The patients categorized as having low PA had significantly higher body mass index than those categorized as having high levels, after adjustment was made for confounders. Continuous data of PA were negatively associated with waist circumference and visceral fat accumulation. ST was positively associated with body mass index. After dividing the participants into four groups according to medians of ST and PA, the following categories were established: long ST and low PA, long ST but high PA, short ST but low PA and short ST and high PA. In terms of body mass index, short ST and high PA measured significantly lower than long ST and low PA. For waist circumference and visceral fat accumulation, short ST but low PA and short ST and high PA measured significantly lower than long ST and low PA and long ST but high.

CONCLUSIONS

These results imply that the combination of avoiding sedentary behavior and increasing PA might be important in the prevention bodyweight gain and in the avoidance of central obesity, respectively, in Japanese type 2 diabetes patients.

Association Between Severity of Diabetic Neuropathy and Success in Weight Loss During Hospitalization Among Japanese Patients with Type 2 Diabetes: A Retrospective Observational Study

INTRODUCTION

This study aimed to examine the association between severity of diabetic neuropathy and weight loss during hospitalization in overweight participants with type 2 diabetes.

PATIENTS AND METHODS

Participants of this study comprised 193 patients who were hospitalized for type 2 diabetes treatment. The participants were divided into two groups in the study, based on whether or not reduction of bodyweight was at least 3% during hospitalization. Using Cox models, the association between severity of neuropathy and effectiveness of weight loss under a controlled diet was analyzed. Autonomic neuropathy was assessed on patient admission by R-R interval, as measured in an electrocardiogram (CVRR), and sensory neuropathy was assessed using both 128-Hz tuning-fork vibration and Achilles tendon reflex (ATR).

RESULTS

The adjusted hazard ratio for weight loss of at least 3% for CVRR was 1.17 (95% confidence interval 1.07-1.28, P=0.0006) and for vibration time 1.93 (1.01-3.68, P=0.045). After dividing CVRR and vibration time into tertiles based on participant number, the adjusted hazard ratio for the high tertile of CVRR was 2.17 (1.29-3.62, P=0.003), and for the long tertile of vibration time 1.84 (1.10-3.08, P=0.02), compared with the low and short tertiles, respectively. No association was detected between ATR category and weight loss.

CONCLUSION

Severity of diabetic neuropathy was found to be a determinant in weight loss under a caloric restriction regimen for patients with type 2 diabetes. The results of the study suggest that the peripheral nervous system is involved in responses to medical intervention for treatment for type 2 diabetes including bodyweight management.

Effect of Combination Therapy of Canagliflozin Added to Teneligliptin Monotherapy in Japanese Subjects with Type 2 Diabetes Mellitus: A Retrospective Study

Recently, dipeptidyl peptidase-4 (DPP-4) inhibitors and sodium-glucose cotransporter 2 (SGLT2) inhibitors have been very often used in subjects with type 2 diabetes mellitus (T2DM). In addition, combination drugs of both inhibitors have attracted much attention in aspects of its cost-effectiveness and improvement of patients' adherence. However, it is still poorly understood which factors are related to the efficacy of SGLT2 inhibitors as add-on therapy to DPP-4 inhibitors. Therefore, we aimed to elucidate in which type of individuals and/or under which conditions canagliflozin as add-on therapy to teneligliptin could exert more beneficial effects on glycemic control and/or renal protection. We retrospectively analyzed 56 Japanese subjects with T2DM in the real-world clinical practice. Three months after starting the combination therapy, the change of HbA1c (ΔHbA1c) was strongly related to HbA1c levels at baseline. As expected, serum glucagon level was increased after starting the combination therapy. Interestingly, however, the change of glucagon levels (Δglucagon) was not related to HbA1c levels at baseline, ΔHbA1c, and other parameters, which indicated that the increase of glucagon did not clinically affect the effectiveness of combination therapy. In addition, the change of urinary albumin excretion (ΔUAE) was negatively correlated with systolic blood pressure and HbA1c levels at baseline and positively correlated with the change of systolic blood pressure (ΔsBP) in univariate analysis. Furthermore, in multivariate analysis, only ΔsBP was the independent factor associated with ΔUAE. Taken together, canagliflozin as add-on therapy to teneligliptin improves glycemic control in a Δglucagon-independent manner and reduces UAE in a ΔsBP-dependent manner in Japanese subjects with T2DM.

Correction to: Vascular endothelial PDPK1 plays a pivotal role in the maintenance of pancreatic beta cell mass and function in adult male mice

It has been brought to our attention that Fig. 5a showing the vasculature in islets of control flox mice is not in fact an endocrine cell but rather exocrine tissue.

Comparison of HbA1c levels and body mass index for prevention of diabetic kidney disease: A retrospective longitudinal study using outpatient clinical data in Japanese patients with type 2 diabetes mellitus

AIM

This study examined the association among the onset of diabetic kidney disease (DKD), blood glucose levels (HbA1_C), and body mass index (BMI) in Japanese patients with type 2 diabetes mellitus.

METHODS

Patients eligible for this study included those with type 2 diabetes who visited the outpatient clinic at Kawasaki Medical School Hospital between 2000 and 2018 and were followed up for more than two years. The Cox proportional hazards model was used in four categories of subjects: at the beginning of the follow-up period, "controlled" or "uncontrolled" glycemic control based on HbA1c and "overweight" or "non-overweight" based on BMI.

RESULTS

After dividing the participants into four categories according to HbA1c (lower than 7.0% (C) or higher (U)), and BMI (25 kg/m² or higher (O) or lower (N)), hazard ratios for groups CO, UN, and UO were 1.40 (95% CI 1.03-1.90, P = 0.030), 1.40 (1.04-1.88, P = 0.027), and 1.54 (1.12-2.11, P = 0.008), respectively, compared with the CN reference group, after adjustment was made for age, sex, duration of diabetes, and medication for hypertension or dyslipidemia.

CONCLUSION

Maintenance of both an HbA1c level lower than 7.0% and a BMI lower than 25 kg/m² was important for the prevention of DKD in Japanese patients with type 2 diabetes mellitus. Both factors had a similar effect on DKD in this study.

Vascular endothelial PDPK1 plays a pivotal role in the maintenance of pancreatic beta cell mass and function in adult male mice

AIMS/HYPOTHESIS

The aim of this study was to elucidate the impact of 3'-phosphoinositide-dependent protein kinase-1 (PDPK1) in vascular endothelial cells on the maintenance of pancreatic beta cell mass and function.

METHODS

Male vascular endothelial cell-specific Pdpk1-knockout mice (Tie2^+/-/Pdpk1^flox/flox mice) and their wild-type littermates (Tie2^-/-/Pdpk1^flox/flox mice; control) were used for this study. At 12 weeks of age, an IPGTT and OGTT were conducted. Pancreatic blood flow was measured under anaesthesia. Thereafter, islet blood flow was measured by the microsphere method. Mice were killed for islet isolation and further functional study and mRNA was extracted from islets. Pancreases were sampled for immunohistochemical analyses.

RESULTS

During the IPGTT, the blood glucose level was comparable between knockout mice and control flox mice, although serum insulin level was significantly lower in knockout mice. During the OGTT, glucose tolerance deteriorated slightly in knockout mice, accompanied by a decreased serum insulin level. During an IPGTT after pre-treatment with exendin-4 (Ex-4), glucose tolerance was significantly impaired in knockout mice. In fact, glucose-stimulated insulin secretion of isolated islets from knockout mice was significantly reduced compared with control flox mice, and addition of Ex-4 revealed impaired sensitivity to incretin hormones in islets of knockout mice. In immunohistochemical analyses, both alpha and beta cell masses were significantly reduced in knockout mice. In addition, the CD31-positive area was significantly decreased in islets of knockout mice. The proportion of pimonidazole-positive islets was significantly increased in knockout mice. mRNA expression levels related to insulin biosynthesis (Ins1, Ins2, Mafa, Pdx1 and Neurod [also known as Neurod1]) and beta cell function (such as Gck and Slc2a2) were significantly decreased in islets of knockout mice. Microsphere experiments revealed remarkably reduced islet blood flow. In addition, mRNA expression levels of Hif1α (also known as Hif1a) and its downstream factors such as Adm, Eno1, Tpi1 (also known as Ets1), Hmox1 and Vegfa, were significantly increased in islets of knockout mice, indicating that islets of knockout mice were in a more hypoxic state than those of control flox mice. As a result, mRNA expression levels related to adaptive unfolded protein response and endoplasmic reticulum stress-related apoptotic genes were significantly elevated in islets of knockout mice. In addition, inflammatory cytokine levels were increased in islets of knockout mice. Electron microscopy revealed reduced endothelial fenestration and thickening of basal membrane of vascular endothelium in islets of knockout mice.

CONCLUSIONS/INTERPRETATION

Vascular endothelial PDPK1 plays an important role in the maintenance of pancreatic beta cell mass and function by maintaining vascularity of pancreas and islets and protecting them from hypoxia, hypoxia-related endoplasmic reticulum stress, inflammation and distortion of capillary structure.

Verification of Kumamoto Declaration 2013 and Glycemic Targets for Elderly Patients with Diabetes in Japan for prevention of diabetic complications: A retrospective longitudinal study using outpatient clinical data

AIMS/INTRODUCTION

The present study examined the association between the onset of micro- and macroangiopathy in type 2 diabetes mellitus patients and levels of glycated hemoglobin (HbA1c) described in the Evidence-based Practice Guideline for the Treatment for Diabetes in Japan 2013 or those indicated in the Japan Diabetes Society and the Japan Geriatrics Society Joint Committee on Improving Care for Elderly Patients with Diabetes.

MATERIALS AND METHODS

Patients with type 2 diabetes mellitus who visited the outpatient clinic at Kawasaki Medical School Hospital between 2000 and 2016 and received follow up for >2 years were eligible for the present study. Two datasets, comprising 2,424 or 3,316 patients without micro- or macroangiopathy at the start of follow up, were used, respectively. The Cox model was used in two categories of patients, younger and elderly, with the dividing line set at the age of 65 years.

RESULTS

For the prevention of microangiopathy, in all patients, there was found to be no advantage in controlling HbA1c at a level of <6.0% based on the categories in the Evidence-based Practice Guideline for the Treatment for Diabetes in Japan 2013, and there was found to be a disadvantage in maintaining HbA1c ≥8.5% based on the categories in the Japan Diabetes Society and the Japan Geriatrics Society Joint Committee on Improving Care for Elderly Patients with Diabetes guideline. For the prevention of macroangiopathy in younger patients, there seemed to be an advantage in maintaining HbA1c within the range of 6.0-6.9% and <7.0% based on the Evidence-based Practice Guideline for the Treatment for Diabetes in Japan 2013 and the Japan Diabetes Society and the Japan Geriatrics Society Joint Committee on Improving Care for Elderly Patients with Diabetes, respectively.

CONCLUSIONS

In all type 2 diabetes mellitus patients, average HbA1c should be maintained <7.0% to prevent microangiopathy. However, in elderly patients, no optimal target for preventing macroangiopathy was found, in contrast to the younger patients in the present study.

Eicosapentaenoic acid/arachidonic acid ratio and weight loss during hospitalization for glycemic control among overweight Japanese patients with type 2 diabetes: a retrospective observational study

BACKGROUND

The study aimed to examine the relationship between levels of serum eicosapentaenoic acid (EPA), arachidonic acid (AA), as well as EPA/AA ratio and weight loss during hospitalization in participants considered to be overweight, with type 2 diabetes.

METHODS

The study participants included 142 patients who were hospitalized for treatment of type 2 diabetes. We divided the participants into two groups depending on the achievenemt in reduction of bodyweight 3% or more during hospitalization and examined the relationship between serum levels of EPA and AA, as well as ratio of EPA/AA on admission and effectiveness of weight loss under strict dietary therapy during hospitalization, using Cox proportional hazard models.

RESULTS

After adjustment was made for several confounders, the hazard ratio of effective weight loss for logarithmical serum EPA was 1.59 (95% CI 1.02-2.49, P = 0.04) and for logarithmical EPA/AA ratio 1.64 (1.03-2.61, P = 0.04), whereas the hazard ratio for effective weight loss for logarithmical serum AA was 1.11 (0.45-2.78, P = 0.82). In addition, after dividing EPA/AA ratio and serum EPA into quartiles based on participant number, the hazard ratio for the highest quartile of EPA/AA ratio was 2.33 (1.14-4.77, P = 0.02), and for the highest quartile of serum EPA 1.60 (0.80-3.19, P = 0.18) compared with the lowest quartile.

CONCLUSION

These results suggest the possibility that EPA is involved in bodyweight change under a caloric-restriction regimen. In addition, EPA/AA ratio was found to be a better predictor of medical intervention for weight loss among overweight patients with type 2 diabetes, compared with serum EPA level.

Suppression of free fatty acid receptor 1 expression in pancreatic β-cells in obese type 2 diabetic db/db mice: a potential role of pancreatic and duodenal homeobox factor 1

It is known that long-chain fatty acids bind to free fatty acid receptor 1 (Ffar1), also known as G protein-coupled receptor 40 (GPR40), and amplify glucose-stimulated insulin secretion (GSIS) from pancreatic β-cells and that Ffar1 agonists facilitates insulin secretion and ameliorates glycemic control. On the other hands, pancreatic and duodenal homeobox factor 1 (Pdx1) is an important transcription factor for various β-cell-related genes including insulin gene and thereby contributes to the maintenance of mature β-cell function. The aim of this study was to evaluate how Ffar1 expression in β-cells is altered under diabetic conditions. In this study, we used male obese type 2 diabetic mice and control mice. We evaluated Ffar1 and Pdx1 mRNA and protein expression levels in both mice. In addition, we examined whether Pdx1 is a possible regulator of Ffar1 expression using small interfering RNA for Pdx1 (siPdx1) in β-cell-derived cell line. As the results, Ffar1 mRNA and protein expression in β-cells were significantly lower in obese type 2 diabetic db/db mice compared to control mice which was accompanied by the decreased expression of Pdx1. In addition, down-regulation of Pdx1 expression using siPdx1 suppressed Ffar1 expression. Furthermore, adenoviral Pdx1 overexpression significantly increased Ffar1 expression. In conclusion, Ffar1 expression is markedly down-regulated under diabetic conditions which is accompanied by decreased expression of Pdx1. Furthermore, it is likely that Pdx1 is a regulator of Ffar1 expression in β-cells.

Association of the Glycemic Fluctuation as well as Glycemic Control with the Pancreatic β-cell Function in Japanese Subjects with Type 2 Diabetes Mellitus

Objective It is important to preserve the pancreatic β-cell function in order to maintain good glycemic control for a long period. The aim of this study was to examine which factors are associated with the β-cell function in subjects with type 2 diabetes mellitus. Methods A total of 372 subjects with type 2 diabetes who had been hospitalized for the amelioration of their glycemic control and/or education about diabetes in Kawasaki Medical School Hospital were included in this study. We evaluated the remnant β-cell function as the HOMA-%β using the computer software program HOMA2 and estimated the glycemic fluctuation with the glycoalbumin (GA)/hemoglobin A1c (HbA1c) ratio. In addition, we divided the subjects into a relatively young group (<65 years old) (n=210) and an elderly group (≥65 years old) (n=162) and performed several analyses in each group. Results The GA/HbA1c ratio, GA and HbA1c were independent determinant factors for the HOMA-%β regardless of age. We obtained almost the same results even after excluding those subjects using insulin secretagogues. These data suggest that the glycemic fluctuation and glycemic control are associated with the remnant β-cell function in Japanese subjects with type 2 diabetes. Conclusion It is very important to reduce glycemic fluctuation as well as to maintain good glycemic control in order to preserve β-cell function in subjects with type 2 diabetes.

Effect of mild exercise on glycemic and bodyweight control in Japanese type 2 diabetes patients: A retrospective analysis

We retrospectively evaluated the effects of mild physical exercise (P) in a routine clinical setting on glycemic and bodyweight control in Japanese type 2 diabetes patients with and without individualized nutritional therapy (D). We analyzed 49 patients who participated in P that measured 2.5 metabolic equivalents and was held once every 2 weeks, compared with 83 non-participant controls, followed over a period of approximately 1.6 years. With a Cox model, the adjusted hazard ratio for improved glycated hemoglobin by numerical count of P was 1.03 (95% confidence interval [CI] 1.00-1.07; P = 0.025). Among four categories - with neither P nor D, only P, only D, and both P and D - the hazard ratios for reduced body mass index were 1.0, 0.87 (95% CI 0.46-1.67), 0.58 (95% CI 0.25-1.30) and 2.17 (95% CI 1.03-4.59), respectively. Even mild physical exercise contributed to glycemic control. The combination of P and D exerted beneficial effects on bodyweight control.

Protective effects of the SGLT2 inhibitor luseogliflozin on pancreatic β-cells in db/db mice: The earlier and longer, the better

AIMS

We compared the protective effects of sodium glucose co-transporter (SGLT) 2 inhibitor luseogliflozin on pancreatic β-cells between early and advanced stages of diabetes and between short- and long-term use.

MATERIALS AND METHODS

Diabetic db/db mice were treated with luseogliflozin for 2 weeks in an early stage of diabetes (7-9 weeks of age) and an advanced stage of diabetes (16-18 weeks) for a longer period of time (7-18 weeks). We performed various morphological analyses of pancreatic islets and examined gene expression profiles in islets after such treatment.

RESULTS

In diabetic db/db mice, insulin biosynthesis and secretion were markedly increased by luseogliflozin in an early stage of diabetes but not in an advanced stage. In addition, β-cell mass was preserved by luseogliflozin only in an early stage. Furthermore, when db/db mice were treated with luseogliflozin for a longer period of time, starting from an early stage, β-cell function and mass were markedly preserved even after a longer period of time compared to untreated db/db mice.

CONCLUSION

Luseogliflozin exerts more protective effects in an early stage of diabetes compared to an advanced stage, and longer-term use of luseogliflozin exerts more beneficial effects on pancreatic β-cells compared to short-term use.

Remission of hyperglycemia after withdrawal of oral antidiabetic drugs in Japanese patients with early-stage type 2 diabetes

AIMS/INTRODUCTION

To assess whether intervention with oral antidiabetic drug in Japanese patients with the early stage of type 2 diabetes could provide a significant remission of the disease process.

MATERIALS AND METHODS

Patients with diabetes duration <5 years were randomized to the lifestyle modification (LFS), pioglitazone (PIO) or sulfonylurea (SU) treatment group. In phase 1 as the on-treatment period and in phase 2 as the off-treatment period, the duration that glycated hemoglobin (HbA1c) was maintained at less than the target was compared among groups.

RESULTS

A total of 278 patients were assigned to LFS (n = 84), PIO (n = 101) and SU (n = 93), and 212 patients completed phase 1. The number of patients that dropped out because of HbA1c elevation was larger in the LFS group, and the duration of HbA1c being maintained at <7.9% was longer in the SU group than the other groups. The duration of HbA1c being maintained at <7.4% in phase 2 was significantly shorter in the SU group than in the other groups. The proportion of patients who achieved HbA1c <6.9% or 6.2% at the end of phase 1 was obviously less in the LFS group than other groups. The duration of HbA1c being maintained at <6.2% in phase 2 was longer in the PIO group than other groups, although not significant statistically. An increase in serum adiponectin and decreases in high-sensitivity C-reactive protein and homeostatic model assessment of insulin resistance were shown in patients treated with PIO, but not LFS and SU, in phase 1, but were canceled in the drug-off phase 2 period.

CONCLUSIONS

PIO treatment provided a prolonged remission of hyperglycemia after stopping the dosage in patients with the early stage of type 2 diabetes.

There is a Close Association Between the Recovery of Liver Injury and Glycemic Control after SGLT2 Inhibitor Treatment in Japanese Subjects with Type 2 Diabetes: A Retrospective Clinical Study

INTRODUCTION

Sodium-glucose co-transporter 2 (SGLT2) inhibitors function not only to reduce hyperglycemia but also to ameliorate liver injury and reduce body weight. The aim of this study was to examine in which subjects SGLT2 inhibitors are more effective for glycemic control, liver injury, and obesity in Japanese subjects with type 2 diabetes mellitus.

METHODS

We enrolled a total of 156 subjects with type 2 diabetes who initiated SGLT2 inhibitor treatment after September 1, 2014 in Kawasaki Medical School (Protocol No. 2375). We evaluated the alteration of glycemic control, liver injury, body mass composition, and various clinical parameters.

RESULTS

SGLT2 inhibitors significantly ameliorated glycemic control and improved liver injury in Japanese subjects with type 2 diabetes. SGLT2 inhibitors were more effective for liver injury when glycemic control was improved with SGLT2 inhibitors. In multivariate analyses, the amelioration of glycemic control was an independent determinant factor for the improvement of liver damage in Japanese subjects with type 2 diabetes. The reverse was also correct; the improvement of liver damage was an independent determinant factor for the amelioration of glycemic control.

CONCLUSION

Recovery of liver injury with SGLT2 inhibitor treatment was closely associated with their effects on glycemic control in Japanese subjects with type 2 diabetes.

Switching from low-dose thiazide diuretics to sodium-glucose cotransporter 2 inhibitor improves various metabolic parameters without affecting blood pressure in patients with type 2 diabetes and hypertension

AIMS/INTRODUCTION

Sodium-glucose cotransporter 2 (SGLT2) inhibitors function to increase urinary glucose excretion and improve glycemic control in individuals with type 2 diabetes mellitus. SGLT2 inhibitors, as well as diuretics, increase urinary volume, which leads to the reduction of blood pressure. The aim of the present study was to compare the effects of SGLT2 inhibitor and thiazide diuretic on blood pressure, metabolic parameters and body mass composition.

MATERIALS AND METHODS

A total of 31 participants were enrolled in the present study. We switched from thiazide diuretics to an SGLT2 inhibitor, ipragliflozin, in participants with type 2 diabetes and hypertension whose blood pressure was controlled with thiazide diuretics. Three months after the switch, we evaluated the effects of such switching on blood pressure, various metabolic parameters and body mass composition.

RESULTS

There was no significant difference in blood pressure from baseline to 3 months later. However, glycated hemoglobin, fasting plasma glucose and uric acid were significantly decreased after the switch. Body mass index and visceral fat area were also significantly reduced after the switch. Furthermore, urinary albumin excretion was also significantly decreased after the switch.

CONCLUSIONS

Switching from thiazide diuretic to an SGLT2 inhibitor, ipragliflozin, markedly improved various metabolic parameters and body mass composition without affecting blood pressure in participants with type 2 diabetes and hypertension.

Advanced breast cancer in a relatively young man with severe obesity and type 2 diabetes mellitus

It is known that male breast cancer is extremely rare and obesity is a strong risk factor of breast cancer in both male and female. In general, the prognosis in breast cancer in males is known to be very poor compared to that in females as it tends to be more advanced stage due to delayed initial diagnosis. Therefore, we should be aware of the possibility that breast cancer could be developed even in relatively young males without any specific risk factors especially when the subjects have severe obesity.

Administration of RAS Inhibitor before the Onset of Diabetic Nephropathy Counteracts the Adverse Effect of Chronic Hyperglycemia and Reduces the Augmentation of Urinary Albumin Excretion: A Retrospective Clinical Study

It is very important to explore how we can reduce urinary albumin excretion which is an independent risk factor for ischemic heart disease. In this study, we retrospectively evaluated the effects of RAS inhibitor therapy on diabetic nephropathy in Japanese subjects whose urinary albumin levels were within normal range. We enrolled 100 subjects with type 2 diabetes who did not take any renin-angiotensin system (RAS) inhibitor. We defined the subjects taking RAS inhibitor for more than 3 years as RAS inhibitor group. RAS inhibitor exerted protective effect on the progression of urinary albumin excretion in subjects with type 2 diabetes without diabetic nephropathy. In addition, RAS inhibitor exerted more protective effects on renal function especially in subjects with poor glycemic control. In conclusion, RAS inhibitor could protect renal function against the deleterious effect of chronic hyperglycemia in Japanese subjects with type 2 diabetes even before the onset of diabetic nephropathy.

Effect of Tofogliflozin on Body Composition and Glycemic Control in Japanese Subjects with Type 2 Diabetes Mellitus

Sodium-glucose cotransporter 2 inhibitor tofogliflozin is a new type of antidiabetic drug for individuals with type 2 diabetes mellitus (T2DM). The aim of this study was to examine in which type of individuals and/or under which conditions tofogliflozin could exert more beneficial effects on body composition and/or glycemic control in Japanese individuals with T2DM. We retrospectively evaluated the effects of tofogliflozin on body composition and/or glycemic control in individuals with T2DM who newly started taking tofogliflozin. After tofogliflozin treatment, body weight was significantly reduced and HbA1c levels were significantly decreased. Body fat mass, skeletal muscle mass, and skeletal muscle index, a marker for sarcopenia, were also reduced after the treatment. In univariate analyses, there was a statistically significant association between the decrease of HbA1c level after tofogliflozin treatment (Δ HbA1c) and the following parameters such as HbA1c levels at baseline, visceral fat area (VFA) at baseline, and reduction of VFA after the treatment (Δ VFA). Furthermore, in multivariate analyses, HbA1c levels at baseline and duration of diabetes were independently associated with Δ HbA1c. These results suggest that tofogliflozin would be more suitable for relatively obese individuals whose duration of diabetes is relatively short.

Efficacy and Safety of Switching from Insulin Glargine 100 U/mL to the Same Dose of Glargine 300 U/mL in Japanese Type 1 and 2 Diabetes Patients: A Retrospective Analysis

Objective Insulin glargine [300 U/mL (Gla-300)] achieved better glycemic control and reduced the risk of hypoglycemia in comparison to glargine [100 U/mL; (Gla-100)] in phase 3 trials. This is the first study to retrospectively evaluate the efficacy and safety of Gla-300 in Japanese type 1 and 2 diabetes patients in a routine clinical setting. Methods We analyzed 20 type 1 diabetes patients and 62 type 2 diabetes patients who switched from Gla-100 to the same dose of Gla-300. Sixty type 2 diabetes patients who continued the use of Gla-100 during the study were included as controls. Results At three months after switching, the HbA1c levels were decreased in the patients with type 1 diabetes, but not to a significant extent. In the type 2 diabetes patients, the HbA1c levels were significantly decreased after switching (p<0.01). In contrast, there was no change in the HbA1c levels of the type 2 diabetes patients who continued the use of Gla-100 over the same period. The BMI values of the type 1 diabetes patients tended to decrease (p=0.06) and there was a significant decrease in the BMI values of the type 2 diabetes patients (p<0.05). There was no change in the BMI values of the type 2 diabetes patients who continued the use of Gla-100. The rates of hypoglycemia and adverse events did not change during the follow-up period. Conclusion In the clinical setting, switching from Gla-100 to the same dose of Gla-300 had a favorable effect on glycemic control and body weight control in Japanese type 1 and type 2 diabetes patients, without any increase in adverse events; however, a prospective study should be performed to confirm these findings.

Decreased glucagon-like peptide 1 receptor expression in endothelial and smooth muscle cells in diabetic db/db mice: TCF7L2 is a possible regulator of the vascular glucagon-like peptide 1 receptor

AIMS

Incretin signalling is known to prevent the development of arteriosclerosis by relaxation response in endothelial cells via the glucagon-like peptide 1 receptor. It remains unclear, however, whether vascular glucagon-like peptide 1 receptor expression is altered under some conditions. The aim of this study is to examine whether vascular glucagon-like peptide 1 receptor expression is altered by diabetic state as reported in pancreatic β-cells.

METHODS

We used 18-week-old male diabetic db/db mice and control db/m mice. Excised thoracic artery was specifically collected, and vascular endothelial cells were cultured. We compared the glucagon-like peptide 1 receptor expression levels between the db/db and db/m mice.

RESULTS

Metabolic parameters were significantly worse in db/db mice. The glucagon-like peptide 1 receptor and transcription factor 7-like 2 expression levels in endothelial and smooth muscle cells were significantly lower in db/db mice. Furthermore, siRNA to transcription factor 7-like 2 decreased the transcription factor 7-like 2 levels and such reduction of the transcription factor 7-like 2 resulted in the downregulation of the glucagon-like peptide 1 receptor expressions in cultured vascular endothelial cells.

CONCLUSION

The glucagon-like peptide 1 receptor expression level was significantly lower under diabetic condition which was accompanied by the reduction of the transcription factor 7-like 2 expression level. Furthermore, the transcription factor 7-like 2 is a possible regulator of the glucagon-like peptide 1 receptor expression in artery as reported in β-cells.

Promising Diabetes Therapy Based on the Molecular Mechanism for Glucose Toxicity: Usefulness of SGLT2 Inhibitors as well as Incretin-Related Drugs

Pancreatic β-cell dysfunction and insulin resistance are the main characteristics of type 2 diabetes. Chronic exposure of β-cells to hyperglycemia leads to the deterioration of β-cell function. Such phenomena are well known as pancreatic β-cell glucose toxicity. MafA, a strong transactivator of insulin gene, is particularly important for the maintenance of mature β-cell function, but its expression level is significantly reduced under diabetic conditions which is likely associated with β-cell failure. Reduction of incretin receptor expression level in β-cells in diabetes is also likely associated with β-cell failure. On the other hand, incretin-related drugs and sodium-glucose co-transporter 2 (SGLT2) inhibitors are promising diabetes therapy based on the mechanism for pancreatic β-cell glucose toxicity. Indeed, it was shown that incretin-related drugs exerted protective effects on β-cells through the augmentation of IRS-2 expression especially in the presence of pioglitazone. It was also shown that incretin-related drug and/or pioglitazone exerted more protective effects on β-cells at the early stage of diabetes compared to the advanced stage. SGLT2 inhibitors, new hypoglycemic agents, also exert beneficial effects for the protection of pancreatic β-cells as well as for the reduction of insulin resistance in various insulin target tissues. Taken together, it is important to select appropriate therapy based on the molecular mechanism for glucose toxicity.

Inadequate Triglyceride Management Worsens the Durability of Dipeptidyl Peptidase-4 Inhibitor in Subjects with Type 2 Diabetes Mellitus

Dipeptidyl peptidase-4 (DPP-4) inhibitors are often used all over the world and exert various beneficial effects including glucose-lowering effect in many subjects with type 2 diabetes. It is poorly understood, however, which factors are closely related with the durability of glucose-lowering effect by DPP-4 inhibitor. In this study, we examined retrospectively which factors could mainly influence the durability of DPP-4 inhibitor. We enrolled 212 participants with type 2 diabetes to whom DPP-4 inhibitor was administered for over 1 year without an addition or increase of other hypoglycemic agents. Age and baseline HbA1c level were significantly higher in the effective group than those in the ineffective group. The effective group had a tendency of smaller amounts of weight change, average total cholesterol, and average triglyceride compared with the ineffective group. Multiple logistic regression analysis showed that average triglyceride and baseline HbA1c were independent predictors associated with the durability of DPP-4 inhibitor. Moreover, an average triglyceride level contributed to the durability of DPP-4 inhibitor in the obese group (BMI ≥ 25 kg/m²) but not in the nonobese group (BMI < 25 kg/m²). These results suggest the importance of strict triglyceride management to maintain the durability of glucose-lowering effect by DPP-4 inhibitor, especially in obese subjects with type 2 diabetes.

Werner Syndrome and Diabetes Mellitus Accompanied by Adrenal Cortex Cancer

Werner syndrome is a rare genetic disease characterized by progeria, diabetes mellitus, cataracts and various types of malignancy. However, there are few reports showing adrenal cortex cancer in subjects with Werner syndrome. We herein report an extremely rare case of Werner syndrome accompanied by adrenal cortex cancer. Based on the data obtained from blood samples, computed tomography, magnetic resonance imaging and ¹³¹I adosterol scintigraphy, we diagnosed this subject with adrenal cortex cancer and Cushing's syndrome. Since the prognosis of adrenal cancer is very poor, we should be aware of the possibility of adrenal cancer occurring in subjects with Werner syndrome.

Association of GA/HbA1c ratio and cognitive impairment in subjects with type 2 diabetes mellitus

AIMS

The aim of this study was to search for factors influencing cognitive impairment and to clarify the association between the fluctuation of blood glucose levels and cognitive impairment in elderly Japanese subjects with type 2 diabetes.

METHODS

We recruited 88 relatively elderly subjects (≥65years old) with type 2 diabetes who were hospitalized in Kawasaki Medical School from January 2014 to December 2015. We evaluated the fluctuation of blood glucose levels with glycoalbumin (GA)/hemoglobin A1c (HbA1c) ratio, and estimated cognitive impairment with Hasegawa dementia scale-revised (HDS-R) score and mini mental state examination (MMSE) score.

RESULTS

Multivariate analyses showed that GA/HbA1c ratio and urinary albumin excretion, but not hypoglycemia, were independent determinant factors for cognitive impairment in elderly Japanese subjects with type 2 diabetes.

CONCLUSIONS

The fluctuation of blood glucose levels per se is closely associated with cognitive impairment in elderly subjects with type 2 diabetes even when hypoglycemia is not accompanied. Since it is very easy to calculate GA/HbA1c ratio, we should check this ratio so that we can reduce the fluctuation of blood glucose levels especially in elderly subjects with type 2 diabetes.

Strawberry milk-like blood in a subject with diabetic lipemia: dramatic change to transparent color after insulin therapy

Introduction

It is known that chylomicronemia is caused by several pathologies and is classified as primary and secondary chylomicronemia. Since hypertriglycemia is associated with an increased risk of cardiovascular disease and severe pancreatitis, it is very important to make a proper diagnosis of the cause of hypertriglycemia.

Case description

We herein present the case of a 40-year-old male who developed severe hypertriglycemia accompanied with acute exacerbation of type 2 diabetes mellitus. On admission, his blood glucose level was 306 mg/dl and HbA1c was 12.5 %. Moreover, serum triglyceride level was elevated up to 5661 mg/dl. When blood was drawn, it presented strawberry milk-like color. After receiving insulin treatment, he obtained good glycemic control and the serum became back to normal transparent color.

Discussion and Evaluation

Insulin resistance reduces triglyceride clearance and also increases triglyceride release from adipocyte. It is known that glucose toxicity and strong insulin resistance induce inactivation of LPL, which results in chylomicronemia.

Conclusion

This case report suggests that when serum triglyceride level is markedly elevated due to diabetic lipemia, it is extremely important to obtain good glycemic control.

Clinical effects of liraglutide are possibly influenced by hypertriglyceridemia and remaining pancreatic β-cell function in subjects with type 2 diabetes mellitus

We searched for factors influencing the clinical effects of GLP-1 analogue liraglutide in subjects with type 2 diabetes. Multivariate analyses showed that hypertriglyceridemia and baseline HbA1c levels were independent predictors for the efficacy of liraglutide and that CPR index was an independent predictor for the durability of liraglutide.

Case of iliopsoas abscess that was markedly recovered after percutaneous and surgical drainage in a patient with poorly controlled type 2 diabetes

We experienced a case of iliopsoas abscess which was markedly recovered after percutaneous and surgical drainage in a subject with poorly controlled type 2 diabetes. When iliopsoas abscess is suspected, physicians should survey patients by CT scan or MRI and should consider invasive treatment including surgical drainage.

Six-Year Graft Survival After Partial Pancreas Heterotopic Auto-Transplantation: A Case Report

BACKGROUND

Long-term graft survival of partial pancreas auto-transplantation after total pancreatectomy has not been clarified. The clinical implications of repeat completion pancreatectomy for locally recurrent pancreatic carcinoma in the remnant pancreas after initial pancreatectomy also have not been clarified.

METHODS

We have previously reported a 61-year-old woman presenting with re-sectable carcinoma of the remnant pancreas at 3 years after undergoing a pylorus-preserving pancreaticoduodenectomy for invasive ductal carcinoma of the pancreas head. We also performed distal pancreas auto-transplantation with the use of a part of the resected pancreas to preserve endocrine function.

RESULTS

The patient was discharged at 20 days after surgery without any complications. She had been followed regularly in our outpatient clinic. She had been treated with S-1 as adjuvant chemotherapy; 72 months after the completion total pancreatectomy with distal partial pancreas auto-transplantation, the patient was alive without any evidence of the pancreatic carcinoma recurrence. The pancreas graft was still functioning with a blood glucose level of 112 mg/dL, HbA1C of 6.7%, and serum C-peptide of 1.2 ng/mL; and urinary C-peptide was 11.6 μg/d.

CONCLUSIONS

Our patient demonstrated that repeated pancreatectomies can provide a chance for survival after a locally recurrent pancreatic carcinoma if the disease is limited to the remnant pancreas. An additional partial pancreas auto-transplantation was successfully performed to preserve endocrine function. However, the indications for pancreas auto-transplantation should be decided carefully in the context of pancreatic carcinoma recurrence.

Combination of DPP-4 inhibitor and PPARγ agonist exerts protective effects on pancreatic β-cells in diabetic db/db mice through the augmentation of IRS-2 expression

We investigated the effects of long- and short-term treatment with pioglitazone (Pio) and/or alogliptin (Alo) on β-cells in diabetic db/db mice. Six-week-old male db/db mice received Pio (25 mg/kg, oral) and/or Alo (30 mg/kg, oral) for 4 weeks and for 2 days. Blood glucose levels were decreased after 4-week intervention, but not after 2-day intervention. Pio increased adiponectin levels, and Alo decreased glucagon levels and increased active GlP-1 levels. Insulin sensitivity was restored by Pio. After 4-week treatment, β-cell mass was increased (over 2-fold increase) and expression levels of various β-cell-related factors were restored. Expression levels of IRS-2 and various downstream factors were up-regulated by Pio and Alo after 2-day and 4-week intervention. In addition, mRNA and protein levels of IRS-2 and various downstream factors were up-regulated in MIN6 cells after 24-h exposure to Pio and exendin-4. These results suggest that Pio and Alo additively up-regulate IRS-2 expression independently of the alteration of glycemic control. Taken together, combination of Pio and Alo exerts protective effects on β-cells in diabetic db/db mice, at least in part, through the augmentation of IRS-2 expression.

Influence of atherosclerosis-related risk factors on serum high-sensitivity C-reactive protein levels in patients with type 2 diabetes: Comparison of their influence in obese and non-obese patients

Aims/Introduction

Increased levels of high‐sensitivity C‐reactive protein (hs‐CRP) likely leads to the development of atherosclerosis. Therefore, it is very important to know which factors largely influence hs‐CRP levels. In the present study, we examined the influence of various atherosclerosis‐related factors on hs‐CRP levels in patients with type 2 diabetes.

Materials and Methods

A total of 275 patients (176 men, 99 women) were enrolled in this study. We tested the relationship between the number of risk factors reaching a desired value and hs‐CRP levels. The Mann–Whitney U‐test was used to compare two groups. The Kruskal–Wallis test was used to carry out overall group comparisons, and the Steel–Dwass test was used to carry out between‐group comparisons. Spearman's rank correlation was carried out to study the correlation between hs‐CRP levels and clinical parameters. Multivariate regression method was used to analyze the factors independently contributing to hs‐CRP levels.

Results

Hs‐CRP levels were lower in patients with a larger number of risk factors reaching a desired value. In particular, triglyceride and body mass index (BMI) were independent risk factors determining hs‐CRP levels in a multivariate regression analysis. Furthermore, we compared the influence of various factors on hs‐CRP levels in both obese (BMI ≥25 kg/m²) and non‐obese patients with type 2 diabetes (BMI <25 kg/m²). In obese groups, BMI and urinary albumin were independent risk factors determining hs‐CRP levels, whereas triglyceride and statin were independent risk factors in non‐obese patients.

Conclusions

There is some difference in the factors responsible for hs‐CRP levels in obese and non‐obese patients with type 2 diabetes.

Protective effects of pioglitazone and/or liraglutide on pancreatic β-cells in db/db mice: Comparison of their effects between in an early and advanced stage of diabetes

The aim was to compare the protective effects of pioglitazone (PIO) and/or liraglutide (LIRA) on β-cells with the progression of diabetes. Male db/db mice were treated with PIO and/or LIRA for 2 weeks in an early and advanced stage. In an early stage insulin biosynthesis and secretion were markedly increased by PIO and LIRA which was not observed in an advanced stage. In concomitant with such phenomena, expression levels of various β-cell-related factors were up-regulated by PIO and LIRA only in an early stage. Furthermore, β-cell mass was also increased by the treatment only in an early stage. Although there was no difference in apoptosis ratio between the two stages, β-cell proliferation was augmented by the treatment only in an early stage. In conclusion, protective effects of pioglitazone and/or liraglutide on β-cells were more powerful in an early stage of diabetes compared to an advanced stage.

Dietary restriction preserves the mass and function of pancreatic β cells via cell kinetic regulation and suppression of oxidative/ER stress in diabetic mice

To assess the molecular mechanisms by which dietary restriction preserves the β-cell mass and function in diabetic db/db mice. Male db/db mice were divided into two groups with or without diet restriction. Daily food intake of db/db mice was adjusted to that of the control db/m mice, which was determined in advance. A dietary restriction was implemented for 6 weeks from 6 weeks of age. Islet morphology, β-cell function and gene expression profiles specific for pancreatic islet cells were compared. Food intake in db/m mice was 50% of that in db/db mice. Impaired glucose tolerance and insulin sensitivity were significantly ameliorated in db/db mice with dietary restriction. The pancreatic β-cell mass was greater in mice with dietary restriction than that in mice without intervention. The dietary restriction significantly increased cyclin D gene expression and down-regulated CAD gene expression at 12 weeks compared with untreated db/db mice. Antiapoptotic bcl-2 gene expression was significantly increased, whereas genes related to oxidative stress, ER stress and inflammatory processes, such as NADPH oxidase, CHOP10 and TNF, were markedly down-regulated in mice with dietary restriction. Dietary restriction preserved the pancreatic β-cell function and β-cell mass in diabetic db/db mice, suggesting that alimentary therapy prevented β-cell loss by suppressing cellular apoptosis and antioxidative stress in the pancreatic β cells.

Concomitant use of miglitol and mitiglinide as initial combination therapy in type 2 diabetes mellitus

AIM

To evaluate the efficacy of miglitol and mitiglinide alone or in combination on the metabolic profile and incretin secretion in Japanese type 2 diabetes patients.

METHODS

Patients on diet and exercise with or without metformin, were randomized to receive either miglitol, mitiglinide, or a combination, three times daily for 12 weeks.

RESULTS

At 12 weeks, HbA1c decreased significantly (p<0.001) and 1,5-AG increased significantly (p<0.001) in all three groups, with the greatest change seen with combination therapy. Effective improvement of postprandial hyperglycemia was demonstrated by a meal-loading test in all three interventions but serum insulin concentration was not increased by miglitol. In a subset of patients without prior metformin administration, faster and better glycemic control was achieved with the initial combination. After meal loading, serum total GLP-1 significantly increased only with miglitol monotherapy (p<0.05) and serum total GIP significantly decreased (p<0.01) in the arms employing miglitol after 12 weeks.

CONCLUSION

Miglitol/mitiglinide combination is more potent than monotherapy in improving glycemic control through the reduction of postprandial glucose excursion and the simultaneous sparing of additional insulin secretion. A marked difference in the effects of miglitol and mitiglinide on incretin secretion was also demonstrated.

Total pancreatectomy combined with partial pancreas autotransplantation for recurrent pancreatic cancer: a case report

We describe a patient presenting with a resectable carcinoma of the remnant pancreas at 3 years after undergoing a pylorus-preserving pancreaticoduodenectomy for invasive ductal carcinoma of the pancreatic head. We also performed a distal pancreas autotransplantation using a part of the resected pancreas to preserve endocrine function. Final histologic findings showed the second tumor to be an invasive ductal carcinoma consisting of a well-differentiated tubular adenocarcinoma with similar histopathologic findings as the first tumor. There were no microscopic lymph node metastases and no evidence of microvascular invasion (pStage IA [pT1, pN0, M0] and R0 according to the International Union Against Cancer TNM classification). The patient was discharged at 20 days after surgery without any trouble and followed by adjuvant chemotherapy with S-1. The carbohydrate antigen 19-9 value was again normalized after the second surgery. Twenty months after the second operation, the patient is alive without cancer recurrence. The pancreas graft is functioning with a blood glucose of 108 mg/dL, HbA1C of 6.2%, and serum C-peptide of 1.4 ng/mL.

Self-inducible secretion of glucagon-like peptide-1 (GLP-1) that allows MIN6 cells to maintain insulin secretion and insure cell survival

Based on the hypothesis that MIN6 cells could produce glucagon-like peptide-1 (GLP-1) to maintain cell survival, we analyzed the effects of GLP-1 receptor agonist, exendin-4 (Ex4), and antagonist, exendin-(9-39) (Ex9) on cell function and cell differentiation. MIN6 cells expressed proglucagon mRNAs and produced GLP-1, which was accelerated by Ex4 and suppressed by Ex9. Moreover, Ex4 further enhanced glucose-stimulated GLP-1 secretion, suggesting autocrine loop-contributed amplification of the GLP-1 signal. Ex4 up-regulated cell differentiation- and cell function-related CREBBP, Pdx-1, Pax6, proglucagon, and PC1/3 gene expressions. The confocal laser scanning images revealed that GLP-1 positive cells were dominant in the early stage of cells, but positive for insulin were more prominent in the mature stage of cells. Ex4 accelerated cell viability, while Ex9 and anti-GLP-1 receptor antibody enhanced cell apoptosis. MIN6 cells possess a mechanism of GLP-1 signal amplification in an autocrine fashion, by which the cells maintained insulin production and cell survival.

The effect of glaze on restorative glass-ionomer cements: evaluation of environmental durability in lactic acid solution

The surface texture changes of three kinds of glass-ionomer cements were compared with glazed and polished cement surfaces after thermal cycling in a storage media [lactic acid solution (pH 4.0)]. The changes were measured with regard to the surface roughness, colour-change, gloss, hardness, toothbrush wear, and SEM (scanning electron microscope) observation in the laboratory. The glazed cement surface was not affected after thermal cycling in the lactic acid solution.

The effect of glaze on restorative glass-ionomer cements

The surface texture changes of three kinds of glass-ionomer cements were compared with various glazed and polished cement surfaces after the initial finishing. Method 1--the glazing agent--was used, and method 2 consisted of four different Shofu Super Snap discs. In method 3 specimens were compressed with a glass plate. The glazed and polished surfaces were used for investigating various properties such as the surface roughness, colour change, gloss, hardness, toothbrush wear, and were also subject to SEM (scanning electron microscope) observation in the laboratory. The period of 48 h after mixing was chosen for the various testing data. The smoothest surface was formed after compression with a glass plate, however, the glazing agent gave the highest gloss surface for glass-ionomer cement. The lower roughness generally observed was for glazing compared to polishing. The glazed surface is effective as a glass-ionomer cement restoration.