Integrating glycaemic variability in the glycaemic disorders of type 2 diabetes: a move towards a unified glucose tetrad concept

Continuous glucose monitoring for the routine care of type 2 diabetes mellitus

Although continuous glucose monitoring (CGM) devices are now considered the standard of care for people with type 1 diabetes mellitus, the uptake among people with type 2 diabetes mellitus (T2DM) has been slower and is focused on those receiving intensive insulin therapy. However, increasing evidence now supports the inclusion of CGM in the routine care of people with T2DM who are on basal insulin-only regimens or are managed with other medications. Expanding CGM to these groups could minimize hypoglycaemia while allowing efficient adaptation and escalation of therapies. Increasing evidence from randomized controlled trials and observational studies indicates that CGM is of clinical value in people with T2DM on non-intensive treatment regimens. If further studies confirm this finding, CGM could soon become a part of routine care for T2DM. In this Perspective we explore the potential benefits of widening the application of CGM in T2DM, along with the challenges that must be overcome for the evidence-based benefits of this technology to be delivered for all people with T2DM.

Effects of Glycemic Variability on Regulatory T Cells in Patients with Type 2 Diabetes and Kidney Disease

Purpose

To investigate the pathogenesis of diabetic kidney disease (DKD) in type 2 diabetes mellitus (T2DM), we evaluated the effects of short-term glycemic variability (GV) on the profile of T cell subpopulations.

Methods

A total of 47 T2DM patients with normoalbuminuria, 47 microalbuminuria, and 49 macroalbuminuria were enrolled. The continuous glucose monitoring (CGM) determined the GV of enrolled patients. Flow cytometry was used to determine the proportion of T cell subpopulations.

Results

The frequency of T helper (Th) 17 and Th1 cells significantly increased while regulatory T cells (Tregs) significantly decreased in the macroalbuminuria group compared to normoalbuminuria and microalbuminuria groups (P < 0.01). The suppressive function of Tregs was significantly lower in the macroalbuminuria group than the normoalbuminuria group (P < 0.05). Compared with the normoalbuminuria group, the mean amplitude of glucose excursions (MAGE) of the macroalbuminuria group was significantly higher (P<0.05). Furthermore, there were negative associations between the proportion of Tregs and MAGE.

Conclusions

Increased GV could decrease the proportion of Tregs and may impair their function. This may lead to increases in Th1 and Th17 cells, and some inflammatory cytokines, which might contribute to the development and progression of DKD in T2DM.

Effects of Diet, Lifestyle, Chrononutrition and Alternative Dietary Interventions on Postprandial Glycemia and Insulin Resistance

As years progress, we are found more often in a postprandial than a postabsorptive state. Chrononutrition is an integral part of metabolism, pancreatic function, and hormone secretion. Eating most calories and carbohydrates at lunch time and early afternoon, avoiding late evening dinner, and keeping consistent number of daily meals and relative times of eating occasions seem to play a pivotal role for postprandial glycemia and insulin sensitivity. Sequence of meals and nutrients also play a significant role, as foods of low density such as vegetables, salads, or soups consumed first, followed by protein and then by starchy foods lead to ameliorated glycemic and insulin responses. There are several dietary schemes available, such as intermittent fasting regimes, which may improve glycemic and insulin responses. Weight loss is important for the treatment of insulin resistance, and it can be achieved by many approaches, such as low-fat, low-carbohydrate, Mediterranean-style diets, etc. Lifestyle interventions with small weight loss (7–10%), 150 min of weekly moderate intensity exercise and behavioral therapy approach can be highly effective in preventing and treating type 2 diabetes. Similarly, decreasing carbohydrates in meals also improves significantly glycemic and insulin responses, but the extent of this reduction should be individualized, patient-centered, and monitored. Alternative foods or ingredients, such as vinegar, yogurt, whey protein, peanuts and tree nuts should also be considered in ameliorating postprandial hyperglycemia and insulin resistance. This review aims to describe the available evidence about the effects of diet, chrononutrition, alternative dietary interventions and exercise on postprandial glycemia and insulin resistance.

Investigating the Postprandial Metabolome after Challenge Tests to Assess Metabolic Flexibility and Dysregulations Associated with Cardiometabolic Diseases

This review focuses on the added value provided by a research strategy applying metabolomics analyses to assess phenotypic flexibility in response to different nutritional challenge tests in the framework of metabolic clinical studies. We discuss findings related to the Oral Glucose Tolerance Test (OGTT) and to mixed meals with varying fat contents and food matrix complexities. Overall, the use of challenge tests combined with metabolomics revealed subtle metabolic dysregulations exacerbated during the postprandial period when comparing healthy and at cardiometabolic risk subjects. In healthy subjects, consistent postprandial metabolic shifts driven by insulin action were reported (e.g., a switch from lipid to glucose oxidation for energy fueling) with similarities between OGTT and mixed meals, especially during the first hours following meal ingestion while differences appeared in a wider timeframe. In populations with expected reduced phenotypic flexibility, often associated with increased cardiometabolic risk, a blunted response on most key postprandial pathways was reported. We also discuss the most suitable statistical tools to analyze the dynamic alterations of the postprandial metabolome while accounting for complexity in study designs and data structure. Overall, the in-depth characterization of the postprandial metabolism and associated phenotypic flexibility appears highly promising for a better understanding of the onset of cardiometabolic diseases.

Influence of dipeptidyl peptidase-4 inhibitors on glycemic variability in patients with type 2 diabetes: A meta-analysis of randomized controlled trials

OBJECTIVE

The influence of dipeptidyl peptidase-4 (DPP4) inhibitors on glycemic variability compared to other oral antidiabetic drugs (OADs), measured based on the mean amplitude of glycemic excursions (MAGE), has not been comprehensively analyzed. The aim of the study was to perform a meta-analysis to compare the effects of DPP4 inhibitors on MAGE with other OADs in type 2 diabetes mellitus (T2DM) patients without concurrent insulin treatments.

METHODS

The Medline (PubMed), Embase (Ovid), and CENTER (Cochrane Library) databases were searched for relevant randomized controlled trials (RCTs). Study characteristics and outcome data were independently extracted by two authors. A random-effect model was used to combine the results.

RESULTS

Fourteen studies with 855 patients were included. Compared to other OADs, DPP4 inhibitors significantly reduced MAGE (mean difference [MD]: -0.69 mmol/L, 95% confidence interval [CI]: -0.95 to -0.43, P<0.001) with mild heterogeneity (I^{2 =} 28%). Predefined subgroup analyses suggested that DPP4 inhibitors were more effective in reducing MAGE compared to insulin secretagogues (MD: -0.92 mmol/L, P<0.001) and non-secretagogues (MD: -0.43 mmol/L, P=0.02), as well as compared to sulfonylureas (MD: -0.91 mmol/L, P<0.001) and sodium glucose cotransporter 2 inhibitors (MD: -0.67 mmol/L, P=0.03).

CONCLUSIONS

DPP4 inhibitors may significantly reduce glycemic variability compared to other oral anti-diabetic drugs, as evidenced by MAGE in T2DM patients with no concurrent insulin treatment.

SYSTEMATIC REVIEW REGISTRATION

INPLASY, registration number: INPLASY2021120113.

Advantages of Studying the Metabolome in Response to Mixed-Macronutrient Challenges and Suggestions for Future Research Designs

Evaluating the postprandial response to a dietary challenge containing all macronutrients-carbohydrates, lipids, and protein-may provide stronger insights of metabolic health than a fasted measurement. Metabolomic profiling deepens the understanding of the homeostatic and adaptive response to a dietary challenge by classifying multiple metabolic pathways and biomarkers. A total of 26 articles were identified that measure the human blood metabolome or lipidome response to a mixed-macronutrient challenge. Most studies were cross-sectional, exploring the baseline and postprandial response to the dietary challenge. Large variations in study designs were reported, including the macronutrient and caloric composition of the challenge and the delivery of the challenge as a liquid shake or a solid meal. Most studies utilized a targeted metabolomics platform, assessing only a particular metabolic pathway, however, several studies utilized global metabolomics and lipidomics assays demonstrating the expansive postprandial response of the metabolome. The postprandial response of individual amino acids was largely dependent on the amino acid composition of the test meal, with the exception of alanine and proline, 2 nonessential amino acids. Long-chain fatty acids and unsaturated long-chain acylcarnitines rapidly decreased in response to the dietary challenges, representing the switch from fat to carbohydrate oxidation. Studies were reviewed that assessed the metabolome response in the context of obesity and metabolic diseases, providing insight on how weight status and disease influence the ability to cope with a nutrient load and return to homeostasis. Results demonstrate that the flexibility to respond to a substrate load is influenced by obesity and metabolic disease and flexibility alterations will be evident in downstream metabolites of fat, carbohydrate, and protein metabolism. In response, we propose suggestions for standardization between studies with the potential of creating a study exploring the postprandial response to a multitude of challenges with a variety of macronutrients.

Expert Group Recommendations on the Effective Use of Bolus Insulin in the Management of Type 2 Diabetes Mellitus

Evidence suggests a major contribution of postprandial glucose (PPG) excursions to the increased risk of micro- and macro-vascular complications in individuals with type 2 diabetes mellitus (T2DM). Administration of bolus insulin remains a very effective therapeutic option for PPG control. The aim of this expert group recommendation document was to provide practical and easy-to-execute guidelines for physicians on the appropriate use of bolus insulin in the management of T2DM. A panel of key opinion leaders from India reviewed and discussed the available clinical evidence and guideline recommendations on the following topics: (1) optimum control of PPG; (2) choice of bolus insulin; and (3) special situations and practical considerations. The expert panel critically analyzed the current literature and clinical practice guidelines and factored their rich clinical experience to develop a set of nine expert group recommendations for the effective use of bolus insulin. These recommendations will not only result in a more evidence-based application of bolus insulin in the clinical setting but also trigger further research and provide a valuable base for the development of future guidelines on the use of bolus insulin in the management of individuals with T2DM.

Glucose Variability is Independently Correlated with Serum Level of Pigment Epithelium-Derived Factor in Type 2 Diabetes

INTRODUCTION

Pigment epithelium-derived factor (PEDF) may play a role in cardiometabolic disorders. The aim of this study was to investigate which biochemical and clinical parameters are independently associated with serum PEDF levels in patients with type 2 diabetes mellitus (T2DM).

METHODS

We performed a cross-sectional analysis of 124 patients with T2DM who underwent continuous glucose monitoring (CGM) and blood chemistry analysis, including the diacron-reactive oxygen metabolites (d-ROMs) test and serum PEDF measurement (study 1). Then we investigated whether the changes in the studied biochemical and clinical parameters after 24 weeks of treatment (Δparameters) with anti-hyperglycemic agents, including sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide 1 receptor agonists, and/or insulin and anti-hypertensive drugs and statins, were independently correlated with change in PEDF (ΔPEDF) in 52 of the patients with T2DM for whom there was sufficient serum samples to perform the post-treatment analysis (study 2). Serum levels of PEDF were measured with an enzyme-linked immunosorbent assay. CGM metrics were calculated on days 2 and 3. Oxidative stress was evaluated using the d-ROMs test.

RESULTS

Body mass index (BMI), triglycerides, fasting C-peptide, mean amplitude of glycemic excursions (MAGE), urinary albumin-to-creatinine ratio (UACR), and d-ROMs were positively associated with serum PEDF level, and high-density lipoprotein cholesterol (HDL-C) and estimated glomerular filtration rate (eGFR) were inversely associated with serum PEDF level. Because these parameters were correlated with each other, multivariate stepwise analysis was performed: eGFR, HDL-C, BMI, MAGE, and UACR remained significant (R² = 0.452). Furthermore, ΔMAGE and Δd-ROMs were positively correlated with ΔPEDF in study 2.

CONCLUSIONS

The results of this study suggest that MAGE may be independently correlated with elevations in serum PEDF level in patients with T2DM.

Fasting Glucose of 6.1 mmol/L as a Possible Optimal Target for Type 2 Diabetic Patients with Insulin Glargine: A Randomized Clinical Trial

To observe whether different insulin glargine titration algorithms based on fasting blood glucose (FBG) levels lead to different glycaemic variations (GVs) in type 2 diabetes (T2D) patients, a prospective, randomized, single-centre, comparative, three-arm parallel-group, open-label, treat-to-target, 24-week study was performed. A total of 71 uncontrolled T2D patients were recruited and randomized 1 : 3 : 3 into Groups 1, 2, and 3 (insulin titration goals of FBG ≤ 5.6, ≤6.1, and ≤7.0) for this study. The initiated insulin glargine dose was recommended at 0.2 U/kg/day and was then titrated following the FBG target. Patients were subjected to two 3-day continuous glucose monitoring (CGM) at baseline and the endpoint, wherein the CGM data were analysed, and the study's primary endpoint was the difference in 24 hrs mean amplitude of glycaemic excursion (MAGE) among the three groups. We observed that patients in the three groups had similar MAGE levels at the endpoint; however, Group 2 achieved a significant decrease in the MAGE level from baseline to the endpoint as compared to Groups 1 and 3 (all p < 0.05). We also observed that these patients had significant glycated haemoglobin A1c (HbA1c) value improvements as compared to the other two groups (all p < 0.05). Therefore, choosing an FBG level of 6.1 mmol/L as an insulin titration target provided significant GVs and HbA1c value improvements in T2D patients. Moreover, our data indicated that an FBG of 6.1 mmol/L could possibly be an insulin glargine titration target in T2D patients.

Application of medium-term metrics for assessing glucose homoeostasis: Usefulness, strengths and weaknesses

This review aims to address the issue of whether or not the newer metrics, developed for continuous glucose monitoring [real-time CGM (rtCGM), intermittently scanned CGM (isCGM)], enhance assessment of the "glucose tetrad": Ambient hyperglycaemia, short-term glycaemic variability, postprandial glucose excursions and hypoglycaemia. The ever-increasing number of metrics offered with rtCGM and isCGM includes intermediate-term indicators referred to as "time in range" (TIR), the time spent in the range of 70-180mg/dL (TIR 70-180); time spent above the range of 180mg/dL (TAR>180); and time spent below the range of 70mg/dL or 54mg/dL (TBR<70 or TBR<54). The former two values are strongly correlated with HbA1c levels and can therefore serve as short- or medium-term markers of ambient hyperglycaemia, depending on whether glucose sensors are worn over periods of several days or weeks, respectively, whereas the latter indices (TBR<70 or<54) are more relevant for capturing hypoglycaemic events and quantifying their magnitude and duration, in contrast to random spot testing with self-monitoring of blood glucose. Nevertheless, although analyses of 24h glucose profiles by CGM provide a highly valuable method for quantifying postprandial glucose excursions and short-term glycaemic variability, neither of these factors can be fully represented by such TIR metrics. Thus, other metrics are clearly needed for more comprehensive assessment of glucose homoeostasis.

Relationships between Thigh and Waist Circumference, Hemoglobin Glycation Index, and Carotid Plaque in Patients with Type 2 Diabetes

BACKGROUND

This study investigated the relationships of thigh and waist circumference with the hemoglobin glycation index (HGI) and carotid atherosclerosis in patients with type 2 diabetes.

METHODS

This observational study included 3,075 Korean patients with type 2 diabetes, in whom anthropometric measurements and carotid ultrasonography were conducted. HGI was defined as the measured hemoglobin A1c (HbA1c) level minus the predicted HbA1c level, which was calculated using the linear relationship between HbA1c and fasting plasma glucose levels. Carotid atherosclerosis was defined as a clearly isolated focal plaque or focal wall thickening &gt;50% of the surrounding intima-media thickness.

RESULTS

The frequency of a positive HGI decreased with increasing thigh circumference in men and increased with increasing waist circumference in women after adjusting for potential confounding variables. Thigh and waist circumference had a combined augmentative effect on the likelihood of positive HGI, which was dramatically higher in patients in higher waist-to-thigh ratio quartiles (adjusted odds ratios for the highest compared to the lowest quartile: 1.595 in men and 1.570 in women). Additionally, the larger the thigh circumference, the lower the risk of carotid atherosclerosis, although in women, this relationship lacked significance after adjustment for potential confounders.

CONCLUSION

HGI was associated with thigh circumference in men and waist circumference in women. In addition, the combination of low thigh circumference and high waist circumference was strongly associated with a higher HGI in Korean patients with type 2 diabetes. In particular, thigh circumference was associated with carotid atherosclerosis in men. However, further longitudinal studies are warranted.

Influence of glucometric 'dynamical' variables on duodenal-jejunal bypass liner (DJBL) anthropometric and metabolic outcomes

BACKGROUND

The endoscopically implanted duodenal-jejunal bypass liner (DJBL) is an attractive alternative to bariatric surgery for obese diabetic patients. This article aims to study dynamical aspects of the glycaemic profile that may influence DJBL effects.

METHODS

Thirty patients underwent DJBL implantation and were followed for 10 months. Continuous glucose monitoring (CGM) was performed before implantation and at month 10. Dynamical variables from CGM were measured: coefficient of variation of glycaemia, mean amplitude of glycaemic excursions (MAGE), detrended fluctuation analysis (DFA), % of time with glycaemia under 6.1 mmol/L (TU6.1), area over 7.8 mmol/L (AO7.8) and time in range. We analysed the correlation between changes in both anthropometric (body mass index, BMI and waist circumference) and metabolic (fasting blood glucose, FBG and HbA1c) variables and dynamical CGM-derived metrics and searched for variables in the basal CGM that could predict successful outcomes.

RESULTS

There was a poor correlation between anthropometric and metabolic outcomes. There was a strong correlation between anthropometric changes and changes in glycaemic tonic control (∆BMI-∆TU6.1: rho = - 0.67, P < .01) and between metabolic outcomes and glycaemic phasic control (∆FBG-∆AO7.8: r = .60, P < .01). Basal AO7.8 was a powerful predictor of successful metabolic outcome (0.85 in patients with AO7.8 above the median vs 0.31 in patients with AO7.8 below the median: Chi-squared = 5.67, P = .02).

CONCLUSIONS

In our population, anthropometric outcomes of DJBL correlate with improvement in tonic control of glycaemia, while metabolic outcomes correlate preferentially with improvement in phasic control. Assessment of basal phasic control may help in candidate profiling for DJBL implantation.

Treatment and prevention of severe hypoglycaemia in people with diabetes: Current and new formulations of glucagon

Some therapies for diabetes increase the risk of hypoglycaemia, in particular all insulins and insulin secretagogues, including the glinides and sulfonylureas. Hypoglycaemia remains a major limiting factor to successful glycaemic management, despite the availability of prevention options such as insulin analogues, continuous glucose monitoring, insulin pumps, and dogs that have been trained to detect hypoglycaemia. Non-severe (self-treated) and severe (requiring assistance for recovery) hypoglycaemia rates are higher in people with type 1 diabetes, but those with insulin-treated type 2 diabetes are also at risk. Education and regular review are essential between people with diabetes and their caregivers and healthcare professionals about symptoms, prevention and treatment. Awareness of the potential dangers of hypoglycaemia is fundamental to the optimal management of diabetes. When therapy is intensified to achieve glycaemic targets, it is important that people at risk of severe hypoglycaemia, and particularly their caregivers, have ready access to effective treatment for hypoglycaemia emergencies. The current and potential formulations of glucagon available for treatment of severe hypoglycaemia are reviewed.

Association between breakfast skipping and postprandial hyperglycaemia after lunch in healthy young individuals

Breakfast skipping has become an increasing trend in the modern lifestyle and may play a role in obesity and type 2 diabetes. In our previous studies in healthy young individuals, a single incident of breakfast skipping increased the overall 24-h blood glucose and elevated the postprandial glycaemic response after lunch; however, it was difficult to determine whether this response was due to breakfast omission or the extra energy (i.e. lunch plus breakfast contents). The present study aimed to assess the postprandial glycaemic response and to measure their hormone levels when healthy young individuals had identical lunch and dinner, and the 24-h average blood glucose as a secondary outcome. Nine healthy young men (19−24 years) participated in two-meal trials: with breakfast (three-meal condition) or without breakfast (breakfast skipping condition). During the meals, each individual’s blood glucose was continuously monitored. Skipping breakfast resulted in a significantly higher (P &lt; 0·001) glycaemic response after lunch as compared with the glycaemic response after an identical lunch when breakfast was consumed. Despite the difference in the total energy intake, the 24-h average blood glucose was similar between the two-meal conditions (P = 0·179). Plasma NEFA level was significantly higher (P &lt; 0·05) after lunch when breakfast was omitted, and NEFA level positively correlated with the postprandial glycaemic response (r 0·631, P &lt; 0·01). In conclusion, a single incident of breakfast skipping increases postprandial hyperglycaemia, and associated impaired insulin response, after lunch. The present study showed that skipping breakfast influences glucose regulation even in healthy young individuals.

Postprandial glucose response after the consumption of three mixed meals based on the carbohydrate counting method in adults with type 1 diabetes. A randomized crossover trial

BACKGROUND & AIMS

People on intensive insulin therapy usually calculate their premeal insulin dose based on the total amount of consumed carbohydrates. However, arguments have been expressed supporting that also the protein and fat content of the meals should be considered when estimating premeal insulin dose. We examined the effectiveness of the carbohydrate counting method after consumption of mixed meals, and we further explored the effects of added extra virgin olive oil in these mixed meals, in adults with type 1 diabetes.

METHODS

Twenty adults (35.0 ± 8.9 years, BMI 27 ± 5 kg/m²) with diabetes duration 17 ± 11 years, on intensive insulin therapy with multiple injections, consumed 3 mixed meals (pasticcio, chicken with vegetables and baked giant beans), with and without the addition of 11 ml extra virgin olive oil (total of 6 meals), in random order, with the insulin dose determined by using the carbohydrate counting method. Capillary blood glucose was measured at premeal (baseline) and 30, 60, 90, 120, 150 and 180 min after meal consumption. At every visit, participants were assessed for anthropometric parameters and subjective stress.

RESULTS

Participants had mean HbA1c 7.5 ± 1.2%, mean carbohydrate to insulin ratio 9:1 IU and stable body weight, waist circumference and subjective stress throughout the study. The mean glucose concentration, for all 6 meals, 120 min postprandially was within target (<180 mg/dl) in nearly 80% of the sample. Addition of olive oil produced sustained increased postprandial glucose concentrations only to pasticcio meal, although within target, and no significant differences were noticed for the grilled chicken with vegetables or the baked giant beans (legume) meals.

CONCLUSIONS

The carbohydrate-counting method was effective for achieving postprandial glucose levels within target threshold up to 3 h postprandially. Moreover, adding small amounts of dietary fat (extra virgin olive oil) to low fat meals does not significantly alter the postprandial response within the first 3 h, whereas caused a sustained increase in postprandial blood glucose concentrations to the high energy density meal (i.e. the pasticcio meal).

Association between postprandial hyperglycemia at clinic visits and all-cause and cancer mortality in patients with type 2 diabetes: A long-term historical cohort study in Japan

AIMS

To evaluate the effect of postprandial hyperglycemia at clinic visits on all-cause and cancer mortality independent of glycated hemoglobin (HbA1c) levels in a real-world setting in Japanese patients with type 2 diabetes. We also investigated age at death.

METHODS

This historical cohort study included 1582 patients with type 2 diabetes who first visited our clinic from 1995 to 1998 and continued visiting for at least 1 year. The patients were followed up through 2017. Blood glucose levels at 2 h ± 30 min post-breakfast (2h-PBBG) were measured in 926 patients during the first year. The first measurements of 2h-PBBG levels were used as a measure of postprandial hyperglycemia.

RESULTS

A total of 233 patients died. The average age at death (men/women) was 75.6/80.8 years. A total of 139 patients who had 2h-PBBG levels measured died, including 46 deaths from cancer. Multivariate Cox regression analysis showed that 2h-PBBG levels significantly predicted all-cause and cancer mortality independent of HbA1c levels.

CONCLUSIONS

Postprandial hyperglycemia at clinic visits may be associated with all-cause and cancer mortality in patients with type 2 diabetes independent of HbA1c levels. As this is a small observational study, further studies are warranted to confirm our findings.

Antioxidant properties of drugs used in Type 2 diabetes management: could they contribute to, confound or conceal effects of antioxidant therapy?

OBJECTIVES

This is a narrative review, investigating the antioxidant properties of drugs used in the management of diabetes, and discusses whether these antioxidant effects contribute to, confound, or conceal the effects of antioxidant therapy.

METHODS

A systematic search for articles reporting trials, or observational studies on the antioxidant effect of drugs used in the treatment of diabetes in humans or animals was performed using Web of Science, PubMed, and Ovid. Data were extracted, including data on a number of subjects, type of treatment (and duration) received, and primary and secondary outcomes. The primary outcomes were reporting on changes in biomarkers of antioxidants concentrations and secondary outcomes were reporting on changes in biomarkers of oxidative stress.

RESULTS

Diabetes Mellitus is a disease characterized by increased oxidative stress. It is often accompanied by a spectrum of other metabolic disturbances, including elevated plasma lipids, elevated uric acid, hypertension, endothelial dysfunction, and central obesity. This review shows evidence that some of the drugs in diabetes management have both in vivo and in vitro antioxidant properties through mechanisms such as scavenging free radicals and upregulating antioxidant gene expression.

CONCLUSION

Pharmaceutical agents used in the treatment of type 2 diabetes has been shown to exert an antioxidant effect..

Nerve conduction study of the association between glycemic variability and diabetes neuropathy

BACKGROUND

It remains unclear whether glycemic variability is related to diabetes microvascular disease, especially diabetes peripheral neuropathy (DPN). We investigated the association between glycemic variability and DPN with type 1 or 2 diabetes.

METHODS

Forty patients (23 males and 17 females; aged 34-79 years) underwent continuous glucose monitoring (CGM) and a nerve conduction study (NCS). Glycemic variability was estimated by mean amplitude of glycemic excursions (MAGE) in CGM. DPN was quantitatively evaluated by NCS in the median, tibial, sural and medial plantar nerves.

RESULTS

MAGE had a significantly positive correlation with disease duration and low-density lipoprotein cholesterol level (r = 0.462, p = 0.003; and r = 0.40, p = 0.011, respectively), and a significantly negative correlation with BMI and medial plantar compound nerve action potential amplitude (r = - 0.39, p = 0.012; and r = - 0.32, p = 0.042, respectively). Multivariate linear regression analysis with adjustment for clinical background showed that MAGE (β = - 0.49, p= 0.007) was independently associated with a higher risk of medial plantar neuropathy.

CONCLUSIONS

Glycemic variability may be an independent risk factor for DPN.

Associations of serum glucagon levels with glycemic variability in type 1 diabetes with different disease durations

PURPOSE

Glucagon has been recognized as a pivotal factor implicated in the pathophysiology ofdiabetes. The purpose of this study is to investigate the dynamic secretion levels of serum glucagon (GLA) in patients with type 1 diabetes mellitus (T1DM) with different courses of disease, and to analyze its correlation with blood glucose fluctuation.

METHODS

This observational study included 55 T1DM patients and divided into 3 groups according to the courses of disease. Group 1(the disease duration <1 year), Group 2(1≤the disease durations≤5), 3(the disease durations >5 years). All patients underwent a 100g standard steamed buns meal test,measuring the levels of serum glucose, glucagon, insulin, C-peptide in different points of time, and 48 of the total patients used continuous glucose monitoring system (CGMS) to monitor blood glucose.

RESULTS

The fasting glucagon level in Group 1 was significantly higher than it in Group 2. Furthermore, the GLA1h, the GLA3h and the AUCGLA0-3h in Group 1 were greatly larger than those in Group 3. Referring to glycemic variability, the LBGI, AUC of hypoglycemia, the percentage of hypoglycemia time andthe times of nocturnal hypoglycemia in Group 1 were significantly lower than those in Group 3. Moreover,the fasting glucagon level was the independent factors to SD and MAGE. The AUCGLA0-3h were negatively correlated with MODD, LBGI, GRADE-hypo and AUC of nocturnal hypoglycemia.

CONCLUSIONS

It is concluded that glucagon secretory function impairs with duration of type 1 diabetes extended and correlates to glycemic fluctuation, especially hypoglycemia.

High-normal serum thyrotropin levels and increased glycemic variability in type 2 diabetic patients

PURPOSE

High-normal thyrotropin (TSH) is related to reduced insulin sensitivity and may contribute to glycemic disorders in diabetes. We investigated the relationship between normal serum TSH levels and glycemic variability in euthyroid type 2 diabetic patients.

METHODS

A total of 432 newly diagnosed type 2 diabetic patients with euthyroid function and normal serum TSH levels were recruited between March 2013 and February 2017. Insulin sensitivity was evaluated by the Matsuda index (ISI_Matsuda) following a 75-g oral glucose tolerance test. Multiple glycemic variability indices, including the mean amplitude of glycemic excursions (MAGE), mean of daily differences (MODD), and standard deviation of glucose (SD), were calculated from glucose data obtained with a continuous glucose monitoring system. Average glucose accessed by 24-h mean glucose (24-h MG) was also calculated.

RESULTS

A normal serum TSH level was positively correlated with MAGE, MODD, SD, and 24-h MG (r = 0.206, 0.178, 0.186, and 0.132, respectively, p < 0.01). After adjusting for somatometric parameters, lipid profiles, ISI_Matsuda, and HbA1c via multiple linear regression analysis, mean differences [B(95% CI)] in MAGE, MODD, SD, and 24-h MG between the patients in the lowest and highest quartiles of TSH levels were 0.128(0.031, 0.226), 0.085(0.022, 0.148), 0.039(0.001, 0.078), and 0.002(-0.264, 0.267) mmol/L, respectively. High-normal TSH was independently associated with MAGE, MODD, and SD, but not 24-h MG.

CONCLUSIONS

High-normal serum TSH is a significant additional risk factor for increased glycemic variability in type 2 diabetic patients.

Association of glycaemic variability evaluated by continuous glucose monitoring with diabetic peripheral neuropathy in type 2 diabetic patients

PURPOSE

Diabetic peripheral neuropathy (DPN), a common microvascular complication of diabetes, is linked to glycaemic derangements. Glycaemic variability, as a pattern of glycaemic derangements, is a key risk factor for diabetic complications. We investigated the association of glycaemic variability with DPN in a large-scale sample of type 2 diabetic patients.

METHODS

In this cross-sectional study, we enrolled 982 type 2 diabetic patients who were screened for DPN and monitored by a continuous glucose monitoring (CGM) system between February 2011 and January 2017. Multiple glycaemic variability parameters, including the mean amplitude of glycaemic excursions (MAGE), mean of daily differences (MODD), standard deviation of glucose (SD), and 24-h mean glucose (24-h MG), were calculated from glucose profiles obtained from CGM. Other possible risks for DPN were also examined.

RESULTS

Of the recruited type 2 diabetic patients, 20.1% (n = 197) presented with DPN, and these patients also had a higher MAGE, MODD, SD, and 24-h MG than patients without DPN (p < 0.001). Using univariate and multiple logistic regression analyses, MAGE and conventional risks including diabetic duration, HOMA-IR, and hemoglobin A1c (HbA1c) were found to be independent contributors to DPN, and the corresponding odds ratios (95% confidence interval) were 4.57 (3.48-6.01), 1.10 (1.03-1.17), 1.24 (1.09-1.41), and 1.33 (1.15-1.53), respectively. Receiver operating characteristic analysis indicated that the optimal MAGE cutoff value for predicting DPN was 4.60 mmol/L; the corresponding sensitivity was 64.47%, and the specificity was 75.54%.

CONCLUSIONS

In addition to conventional risks including diabetic duration, HOMA-IR and HbA1c, increased glycaemic variability assessed by MAGE is a significant independent contributor to DPN in type 2 diabetic patients.

Effects of 6 vs 3 eucaloric meal patterns on glycaemic control and satiety in people with impaired glucose tolerance or overt type 2 diabetes: A randomized trial

BACKGROUND/OBJECTIVES

The study aimed to compare the effects of two eucaloric meal patterns (3 vs 6 meals/day) on glycaemic control and satiety in subjects with impaired glucose tolerance and plasma glucose (PG) levels 140-199mg/dL at 120min (IGT-A) or PG levels 140-199mg/dL at 120min and >200mg/dL at 30/60/90min post-oral glucose load on 75-g OGTT (IGT-B), or overt treatment-naïve type 2 diabetes (T2D).

SUBJECTS/METHODS

In this randomized crossover study, subjects with IGT-A (n=15, BMI: 32.4±5.2kg/m²), IGT-B (n=20, BMI: 32.5±5kg/m²) or T2D (n=12, BMI: 32.2±5.2kg/m²) followed a weight-maintenance diet (45% carbohydrates, 20% proteins, 35% fats) in 3 or 6 meals/day (each intervention lasting 12 weeks). Anthropometrics, diet compliance and subjective appetite were assessed every 2 weeks. OGTT and measurements of HbA1c and plasma lipids were performed at the beginning and end of each intervention period.

RESULTS

Body weight and physical activity levels remained stable throughout the study. In T2D, HbA1c and PG at 120min post-OGTT decreased with 6 vs 3 meals (P<0.001 vs P=0.02, respectively). The 6-meal intervention also improved post-OGTT hyperinsulinaemia in IGT-A subjects and hyperglycaemia in IGT-B subjects. In all three groups, subjective hunger and desire to eat were reduced with 6 vs 3 meals/day (P<0.05). There were no differences in HOMA-IR or plasma lipids between interventions.

CONCLUSION

Although weight loss remains the key strategy in hyperglycaemia management, dietary measures such as more frequent and smaller meals may be helpful for those not sufficiently motivated to adhere to calorie-restricted diets. Our study shows that 6 vs 3 meals a day can increase glycaemic control in obese patients with early-stage T2D, and may perhaps improve and/or stabilize postprandial glucose regulation in prediabetes subjects.

Continuous glucose monitoring adds information beyond HbA1c in well-controlled diabetes patients with early cardiovascular autonomic neuropathy

AIMS

Hyperglycemia as evaluated by HbA1c is a risk factor for the development of cardiovascular autonomic neuropathy (CAN). The aim of the present study was to investigate whether continuous glucose monitoring (CGM) may add information beyond HbA1c in patients with type 2 diabetes and CAN.

METHODS

81 patients with type 2 diabetes (43 men, mean age 58±11year, HbA1c 6.6±0.5%). Patients were tested for CAN using cardiovascular reflex tests (response to standing, deep breathing and Valsalva maneuver) and underwent CGM for three days. CAN was defined as early (one test abnormal), or manifest (two or three tests abnormal).

RESULTS

Twenty patients had early CAN and two patients had manifest CAN. Blood pressure, HbA1c, cholesterol levels and smoking habits were comparable in patients with vs. without CAN. Post-breakfast glycemic peak was significantly higher in patients with CAN (peak 207 vs 176mg/dL, P=0.009). Furthermore, the nocturnal glucose drop and dawn glucose was significantly higher in patients with CAN compared with patients without CAN (mean 134 vs. 118mg/dL, P=0.017 and mean 143 vs. 130mg/dL, P=0.045, respectively). Removing the two patients with manifest CAN from the statistical analysis didn't change the results.

CONCLUSIONS

These findings emphasize the importance of monitoring glucose patterns over 24-h and not only rely on HbA1c as therapeutic target in patients with type 2 diabetes and CAN.

The association of long-term glycaemic variability versus sustained chronic hyperglycaemia with heart rate-corrected QT interval in patients with type 2 diabetes

Objectives

Prolonged heart rate-corrected QT(QTc) interval is related to ventricular arrhythmia and cardiovascular mortality, with considerably high prevalence of type 2 diabetes. Additionally, long-term glycaemic variability could be a significant risk factor for diabetic complications in addition to chronic hyperglycaemia. We compared the associations of long-term glycaemic variability versus sustained chronic hyperglycaemia with the QTc interval among type 2 diabetes patients.

Methods

In this cross-sectional study, 2904 type 2 diabetes patients were recruited who had undergone at least four fasting plasma glucose (FPG) and 2-hour postprandial plasma glucose (PPG) measurements (at least once for every 3 months, respectively) during the preceding year. Long-term glycaemic variabilities of FPG and 2-hour PPG were assessed by their standard deviations (SD-FPG and SD-PPG, respectively), and chronic fasting and postprandial hyperglycaemia were assessed by their means (M-FPG and M-PPG, respectively). HbA1c was also determined upon enrolment to assess current overall glycaemic control. QTc interval was estimated from resting 12-lead electrocardiograms, and more than 440 ms was considered abnormally prolonged.

Results

Patients with prolonged QTc interval (≥440 ms) had greater M-FPG, M-PPG, SD-PPG and HbA1c than those with normal QTc interval but comparable SD-FPG. QTc interval was correlated with M-FPG, M-PPG, SD-PPG and HbA1c (r = 0.133, 0.153, 0.245 and 0.207, respectively, p = 0.000) but not with SD-FPG (r = 0.024, p = 0.189). After adjusting for metabolic risk factors via multiple linear regression analysis, SD-PPG, M-PPG and HbA1c (t = 12.16, 2.69 and 10.16, respectively, p = 0.000) were the major independent contributors to the increased QTc interval. The proportion of prolonged QTc interval increased significantly from 10.9% to 14.2% to 26.6% for the first (T1) to second (T2) to third (T3) tertiles of SD-PPG. After adjusting via multiple logistic regression analysis, the odd ratios of prolonged QTc interval of the T2 and T3 versus the T1 of SD-PPG were 1.15 (95% CI, 0.82–1.60) and 2.62 (1.92–3.57), respectively.

Conclusions

Increased long-term variability of PPG is a strong independent risk factor for prolonged QTc interval in type 2 diabetes patients, in addition to long-term postprandial hyperglycaemia and current HbA1c.

Effect of Linagliptin Versus Metformin on Glycemic Variability in Patients with Impaired Glucose Tolerance

BACKGROUND

Impaired glucose tolerance (IGT) and glycemic variability may be associated with increased risk of micro- and macrovascular complications. The aim of this study was to assess the effect of linagliptin versus metformin on glycemic variability in patients with IGT.

MATERIAL AND METHODS

A randomized, double-blind clinical trial with parallel groups was carried out in 16 adult patients with IGT, overweight or obesity. All patients signed an informed consent. The therapies were randomly assigned: (a) metformin 500 mg bid (n = 8) or (b) linagliptin 5 mg a.m. and placebo p.m. (n = 8), both for 90 days. At the beginning of the trial and 3 months later, fasting glucose, glycated hemoglobin A1c, oral glucose tolerance test (OGTT), and glycemic variability [area under the curve (AUC) of glucose, mean amplitude of glycemic excursion (MAGE), standard deviation (SD) of glucose, coefficient of variation (CV) of glucose, and mean blood glucose (MBG)] were measured. Mann-Whitney U, Wilcoxon, and Fisher exact tests were used for statistical analyses.

RESULTS

Both groups were similar in basal characteristics. After linagliptin administration, a significant decrease in glucose levels at 120 min of OGTT (9.0 ± 0.9 vs. 6.9 ± 2.2 mmol/L, P = 0.012) was observed. Glycemic variability showed a similar behavior and there were no significant differences in the AUC, MAGE, SD of glucose, CV of glucose, and MBG between groups.

CONCLUSION

Linagliptin administration resulted in better glycemic control according to the decrease of glucose levels by the OGTT at 120 min in patients with IGT. Meanwhile, glycemic variability was not modified in any of the study groups.

Impact of postprandial hyperglycemia at clinic visits on the incidence of cardiovascular events and all-cause mortality in patients with type 2 diabetes

AIMS/INTRODUCTION

We evaluated the impact of postprandial hyperglycemia at clinic visits on the incidence of cardiovascular diseases (CVD) and all-cause mortality independently of mean glycosylated hemoglobin in type 2 diabetes patients in a real-world setting.

MATERIALS AND METHODS

The present retrospective observational cohort study included 646 type 2 diabetes patients. All of the participants had their initial consultations at the Institute for Diabetes Care and Research, Asahi Life Foundation affiliated Marunouchi Hospital, Tokyo, Japan, during the period from 1995 to 1996, visited the clinic ≥4 times, had their 2-h post-breakfast blood glucose (2h-PBBG) levels measured and were followed up for ≥1 year. The 646 patients were followed up for survival. Of the 646 patients, 618 had no history of CVD at the first visit and had measured 2h-PBBG until the first CVD onset or censorings. These two cohorts were followed up through June 2012, and subsequently questionnaires were mailed. Multivariate Cox proportional hazard models were used to evaluate the risk of CVD incidence and death.

RESULTS

CVD occurred in 78 patients, and 56 patients died. The median follow-up periods of the CVD cohort and the mortality cohort were 15.6 and 15.9 years, respectively. The mean 2h-PBBG is a significant predictor of the CVD incidence and all-cause mortality after adjusting for the mean glycosylated hemoglobin, the number of 2h-PBBG measurements, age, sex and classical risk factors.

CONCLUSIONS

Postprandial hyperglycemia represented by the mean level of 2h-PBBG at clinic visits is associated with CVD incidence and all-cause mortality independently of the mean glycosylated hemoglobin level in type 2 diabetes patients. Prospective interventional trials are warranted to confirm the present findings.

Cerebral ischemic damage in diabetes: an inflammatory perspective

Stroke is one of the leading causes of death worldwide. A strong inflammatory response characterized by activation and release of cytokines, chemokines, adhesion molecules, and proteolytic enzymes contributes to brain damage following stroke. Stroke outcomes are worse among diabetics, resulting in increased mortality and disabilities. Diabetes involves chronic inflammation manifested by reactive oxygen species generation, expression of proinflammatory cytokines, and activation/expression of other inflammatory mediators. It appears that increased proinflammatory processes due to diabetes are further accelerated after cerebral ischemia, leading to increased ischemic damage. Hypoglycemia is an intrinsic side effect owing to glucose-lowering therapy in diabetics, and is known to induce proinflammatory changes as well as exacerbate cerebral damage in experimental stroke. Here, we present a review of available literature on the contribution of neuroinflammation to increased cerebral ischemic damage in diabetics. We also describe the role of hypoglycemia in neuroinflammation and cerebral ischemic damage in diabetics. Understanding the role of neuroinflammatory mechanisms in worsening stroke outcome in diabetics may help limit ischemic brain injury and improve clinical outcomes.

Initiation and Intensification Strategies in Type 2 Diabetes Management: A Comparison of Basal Plus and Premix Regimens

The progressive nature of type 2 diabetes (T2D) often results in the need for initiation and subsequent intensification of insulin treatment to achieve glycemic control. The aim of this review is to examine published clinical evidence that has directly compared two recommended treatment approaches in patients with T2D: (1) a 'basal plus' regimen, whereby 1-2 injections of prandial insulin are added to basal insulin; or (2) the use of once- or twice-daily premix insulin analogs, which contain both basal and prandial insulin in a single injection. Broadly, the available evidence suggests that both basal plus and premix regimens are comparable in terms of efficacy and safety when used for insulin initiation in insulin-naïve patients and intensification in patients who have failed on basal insulin; instances of greater glycemic control are observed with premix insulin; however, these are often accompanied by increases in hypoglycemia and/or weight relative to basal plus treatment, and results should be interpreted within the context of total insulin doses used. Relatively low numbers of patients achieved glycemic control when both regimens were used for insulin intensification following failure of basal insulin, suggesting that a full basal-bolus regimen and/or the use of different treatments is clinically indicated in certain patients. In summary, the current review argues that both basal plus and premix insulin regimens are relatively efficacious and safe options for patients with T2D during both insulin initiation in insulin-naïve patients and intensification in patients who have failed on basal insulin. This emphasizes the important role of patient-centered factors in clinical decision-making.

FUNDING

Novo Nordisk.

Evaluation of the Effect of Carbohydrate Intake on Postprandial Glucose in Patients With Type 1 Diabetes Treated With Insulin Pumps

BACKGROUND

It has been suggested that dietary freedom in functional insulin therapy may be detrimental to glycemic control in type 1 diabetes. This study evaluates the effect of carbohydrate intake on glycemic control and postprandial blood glucose concentrations.

METHODS

Insulin pump data from 148 adults with type 1 diabetes, trained in functional insulin therapy, using pumps for ≥6 months, with ≥2 weeks of consecutive downloaded data, ≥80% use of a bolus calculator, ≥3 capillary blood glucose tests/day, and a concurrent HbA1C, were analyzed. More detailed periprandial data (pre- and postmeal glucose, carbohydrate intake, insulin bolus) were collected from a subset of 105 downloads (3495 meals).

RESULTS

Mean (± SD) age of contributors was 43 ± 13 years, HbA1C 7.84% ± 0.93 (62.19 mmol/mol); daily carbohydrate intake 166 ± 71 g. HbA1C reduced with increased meals/day (r = -.370, P < .0005) and increased with mean carbohydrate content/meal (r = .198, P = .043). However, total daily carbohydrate intake had a weak but significant negative association with HbA1C (r = -.181, P = .027). There was no association between standard deviation of carbohydrate intake and HbA1C (r = .021, P = .802) or between meal carbohydrate content and postprandial change in blood glucose (r = -.004, P = .939) for meals with early postprandial (1-3 hours; n = 390) readings. There was a weak positive correlation (r = .184, P = .008) between meal carbohydrate content and late (4-7 hours; n = 390) postprandial readings.

DISCUSSION

With appropriate training, patients using insulin pumps can accommodate a flexible diet with variable carbohydrate intake, without detriment to glycemic control. However, large carbohydrate meals may contribute to poorer outcomes, through impact on late postprandial glycemia.

The impact of glycemic variability on diabetic peripheral neuropathy

Mean glucose values alone cannot explain the patterns of morbidity and mortality due to dysglycemia in diabetes. Development of continuous glucose monitoring systems has improved the analysis and interpretation of glycemic variability. The roles of glycemic components other than constant hyperglycemia in diabetic complications must be investigated because large clinical studies have indicated that risk factors besides the average glucose value of HbA1c are involved in chronic macrocomplications/microcomplications of diabetes. Among these complications, the pathogenesis of diabetic peripheral neuropathy is particularly complex, and several factors related to glucose and nonglucose pathways have been suggested as risk factors. There is little information regarding the effect of glycemic variability on diabetic peripheral neuropathy, unlike other microvascular complications of retinopathy and nephropathy, and whether glycemic variability causes harmful effects is still a matter of debate. In this review, we discuss the relationships between glycemic variability and diabetic peripheral neuropathy, focusing on somatosensory peripheral neuropathies rather than autonomic neuropathies.

Glycemic variability is an important risk factor for cardiovascular autonomic neuropathy in newly diagnosed type 2 diabetic patients

BACKGROUND

The relationship between glycemic variability, another component of glycemic disorders as well as chronic sustained hyperglycemia, and cardiovascular autonomic neuropathy (CAN) has not been clarified. Our aim is to investigate the association between glycemic variability and CAN in newly diagnosed type 2 diabetic patients.

METHODS

Ewing tests were performed in 90 newly diagnosed type 2 diabetic patients and 37 participants with normal glucose tolerance as control from May 1, 2009, through September 30, 2010. According to the scores from Ewing tests, diabetic patients were divided into two groups: without CAN (CAN-) and with CAN (CAN+). All participants underwent a 48-h to 72-h continuous glucose monitoring (CGM). Coefficient of variability of glycemia (%CV), mean amplitude of glycemic excursions (MAGE) and means of daily differences (MODD) were calculated with the CGM data.

RESULTS

The prevalence of CAN in patients with newly diagnosed type 2 diabetes was 22.2%. An increasing trend of glycemic variability was found from control group, CAN- group to CAN+ group. MAGE in CAN+ group was significantly higher than that in CAN- group (5.27±1.99mmol/L vs. 4.04±1.39mmol/L, P=0.001). In the Logistic regression analysis, a significant relationship was shown between MAGE and CAN [odds ratio (OR): 1.73, 95% confidence interval (CI): 1.01-2.73, P=0.018)]. The area under the receiver-operating characteristic curve for MAGE was superior to those for other dysglycemic indices in detecting CAN.

CONCLUSIONS

Glycemic variability is associated with CAN in patients with newly diagnosed type 2 diabetes. Among the glycemic variability indices, MAGE is a significant indicator for detecting CAN.

Pituitary Adenlylate Cyclase Activating Peptide Protects Adult Neural Stem Cells from a Hypoglycaemic milieu

Hypoglycaemia is a common side-effect of glucose-lowering therapies for type-2 diabetic patients, which may cause cognitive/neurological impairment. Although the effects of hypoglycaemia in the brain have been extensively studied in neurons, how hypoglycaemia impacts the viability of adult neural stem cells (NSCs) has been poorly investigated. In addition, the cellular and molecular mechanisms of how hypoglycaemia regulates NSCs survival have not been characterized. Recent work others and us have shown that the pituitary adenylate cyclase-activating polypeptide (PACAP) and the glucagon-like peptide-1 receptor (GLP-1R) agonist Exendin-4 stimulate NSCs survival against glucolipoapoptosis. The aim of this study was to establish an in vitro system where to study the effects of hypoglycaemia on NSC survival. Furthermore, we determine the potential role of PACAP and Exendin-4 in counteracting the effect of hypoglycaemia. A hypoglycaemic in vitro milieu was mimicked by exposing subventricular zone-derived NSC to low levels of glucose. Moreover, we studied the potential involvement of apoptosis and endoplasmic reticulum stress by quantifying protein levels of Bcl-2, cleaved caspase-3 and mRNA levels of CHOP. We show that PACAP via PAC-1 receptor and PKA activation counteracts impaired NSC viability induced by hypoglycaemia. The protective effect induced by PACAP correlated with endoplasmic reticulum stress, Exendin-4 was ineffective. The results show that hypoglycaemia decreases NSC viability and that this effect can be substantially counteracted by PACAP via PAC-1 receptor activation. The data supports a potential therapeutic role of PAC-1 receptor agonists for the treatment of neurological complications, based on neurogenesis impairment by hypoglycaemia.

Efficacy of linagliptin and teneligliptin for glycemic control in type 2 diabetic patients with chronic kidney disease: assessment by continuous glucose monitoring; a pilot study

Introduction

Type 2 diabetes patients complicated by chronic kidney disease (CKD) require restricted use and dose adjustment of orally administered hypoglycemic agents because of renal dysfunction, and treatment is likely to be difficult. Linagliptin and teneligliptin are dipeptidyl-peptidase (DPP)-4 inhibitors that do not require dose adjustment even in type 2 diabetes patients complicated by CKD. The aim of this pilot study was to determine the efficacy of these agents for glycemic control using continuous glucose monitoring (CGM).

Materials and methods

A randomized crossover study was conducted in 13 type 2 diabetes patients with CKD who maintained glycosylated hemoglobin (HbA_1c) levels at <9 % by diet and exercise and had estimated glomerular filtration rates (eGFRs) <60 ml/min 1.73 m². They were treated with teneligliptin at 20 mg/day or linagliptin at 5 mg/day for 6 days then switched to the other agent for another 6 days. CGM was performed before and during treatment. The primary outcome was changes in mean amplitude of glucose excursions (MAGE).

Results

Mean MAGE was 83.8 ± 34.0 and 82.6 ± 32.6 [±standard deviation (SD)] during treatment with linagliptin and teneligliptin, respectively, with no significant difference between agents. The two agents showed comparable beneficial effects on 24-h mean sensor glucose levels and area under the curve for sensor glucose levels ≥180 mg/dl (AUC ≥180), and their use was associated with comparable incidence of hypoglycemia.

Conclusions

Linagliptin and teneligliptin have comparable effects on MAGE in type 2 diabetes patients with CKD and are potentially useful and safe for treatment of such patients.

Glycemic excursions are positively associated with changes in duration of asymptomatic hypoglycemia after treatment intensification in patients with type 2 diabetes

AIM

The aim of this study was to examine the association between glycemic excursions and duration of hypoglycemia after treatment intensification in patients with type 2 diabetes (T2D).

METHODS

Patients with T2D on oral anti-diabetes drug (OAD) with glycated hemoglobin (HbA1c) of 7.0-11.0% were switched to metformin monotherapy (500 mg thrice daily) for 8 weeks, followed by randomization to either glibenclamide or acarbose as add-on treatment for 16 weeks. Glycemic excursions were assessed as mean amplitude of glycemic excursions (MAGE) with 72-h ambulatory continuous glucose monitoring (CGM) before randomization and at the end of study. Hypoglycemia was defined as sensor glucose level of less than 60 mg/dl in two or more consecutive readings from CGM.

RESULTS

A total of 50 patients (mean age 53.5 ± 8.2 years, male 48%, mean baseline HbA1c 8.4 ± 1.2%) were analyzed. Duration of hypoglycemia significantly increased after treatment with glibenclamide (from 5.5 ± 13.8 to 18.8 ± 35.8 min/day, p=0.041), but not with acarbose (from 2.9 ± 10.9 to 14.7 ± 41.9 min/day, p=0.114). Post treatment MAGE was positively associated with change from baseline in duration of hypoglycemia after treatment with either glibenclamide (β coefficient 0.345, p=0.036) or acarbose (β coefficient 0.674, p=0.046). The association remained significant after multivariate adjustment (p<0.05 for all models).

CONCLUSIONS

Post treatment glycemic excursions are associated with changes in duration of hypoglycemia after treatment intensification with OAD in patients with T2D. Glycemic excursions should be an important treatment target for T2D to reduce the risk of hypoglycemia.

Platelets and diabetes mellitus

Platelet activation plays a key role in atherothrombosis in type 2 diabetes mellitus (T2DM) and increased in vivo platelet activation with enhanced thromboxane (TX) biosynthesis has been reported in patients with impairment of glucose metabolism even in the earlier stages of disease and in the preclinical phases. In this regards, platelets appear as addresses and players carrying and transducing metabolic derangement into vascular injury. The present review critically addresses key pathophysiological aspects including (i) hyperglycemia, glycemic variability and insulin resistance as determinants and predictors of platelet activation, (ii) inflammatory mediators derived from platelets, such as soluble CD40 ligand, soluble CD36, Dickkopf-1 and probably soluble receptor for advanced glycation-end-products (sRAGE), which expand the functional repertoire of platelets from players of hemostasis and thrombosis to powerful amplifiers of inflammation by promoting the release of cytokines and chemokines, cell activation, and cell-cell interactions; (iii) molecular mechanisms underpinning the less-than-expected antithrombotic protection by aspirin (ASA), despite regular antiplatelet prophylaxis at the standard dosing regimen, and (iv) stratification of patients deserving different antiplatelet strategies, based on the metabolic phenotype. Taken together, these pathophysiological aspects may contribute to the development of promising mechanism-based therapeutic strategies to reduce the progression of atherothrombosis in diabetic subjects.

Psychological aspects of diabetes care: Effecting behavioral change in patients

Patients with diabetes mellitus (DM) need psychological support throughout their life span from the time of diagnosis. The psychological make-up of the patients with DM play a central role in self-management behaviors. Without patient’s adherence to the effective therapies, there would be persistent sub-optimal control of diseases, increase diabetes-related complications, causing deterioration in quality of life, resulting in increased healthcare utilization and burden on healthcare systems. However, provision of psychosocial support is generally inadequate due to its challenging nature of needs and demands on the healthcare systems. This review article examines patient’s psychological aspects in general, elaborates in particular about emotion effects on health, and emotion in relation to other psychological domains such as cognition, self-regulation, self-efficacy and behavior. Some descriptions are also provided on willpower, resilience, illness perception and proactive coping in relating execution of new behaviors, coping with future-oriented thinking and influences of illness perception on health-related behaviors. These psychological aspects are further discussed in relation to DM and interventions for patients with DM. Equipped with the understanding of the pertinent nature of psychology in patients with DM; and knowing the links between the psychological disorders, inflammation and cardiovascular outcomes would hopefully encourages healthcare professionals in giving due attention to the psychological needs of patients with DM.

28-week, randomized, multicenter, open-label, parallel-group phase III trial to investigate the efficacy and safety of biphasic insulin aspart 70 thrice-daily injections vs twice-daily injections of biphasic insulin aspart 30 in patients with type 2 diabetes

Aims/Introduction:  An insulin analogue formulation with a 7:3 ratio of rapid‐acting and intermediate‐acting fractions, biphasic insulin aspart 70 (BIAsp70) was developed to supplement basal insulin between meals and mimic the physiological pattern of postprandial insulin secretion.

Materials and Methods:  We carried out a randomized, open‐label study to compare the efficacy and safety profiles of BIAsp70 and an insulin analogue formulation with a 3:7 ratio of rapid‐acting and intermediate‐acting fractions (BIAsp30) in type 2 diabetes mellitus patients. Patients were randomized and received either thrice‐daily BIAsp70 (n = 145) or twice‐daily BIAsp30 (n = 144) for 28 weeks. The primary end‐point was glycated hemoglobin (HbA_1c) after 16 weeks of treatment.

Results:  Non‐inferiority of BIAsp70 vs BIAsp30 was confirmed and superiority was established with a between‐group difference (BIAsp70–BIAsp30) in HbA_1c after 16 weeks of treatment of −0.35% (95% CI: −0.51 to −0.19; P < 0.0001 for superiority). The mean postprandial glucose increment (19.96 vs 54.35 mg/dL; P < 0.0001) and M‐value (12.99 vs 17.94; P < 0.0001) at 16 weeks were smaller in the BIAsp70 group than in the BIAsp30 group, and were maintained at 28 weeks. Pre‐breakfast glucose (157.9 vs 140.7 mg/dL), total insulin dose (46.8 vs 38.1 U/day) and weight gain (+1.94 vs 1.23 kg) at week 28 were greater in the BIAsp70 group. Incidence of nocturnal hypoglycemia was significantly lower with BIAsp70 vs BIAsp30 (1.23 vs 3.21 events/subject year; P = 0.0002) at week 28.

Conclusions:  Thrice‐daily BIAsp70 was superior to twice‐daily BIAsp30 in terms of HbA_1c change, with less variation in daytime plasma glucose profiles. BIAsp70 was well tolerated, with a lower incidence of nocturnal hypoglycemia vs BIAsp30. This trial was registered with ClinicalTrial.gov (no. NCT00318786). (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2010.00015.x, 2010)

The relationship between glycemic variability and diabetic peripheral neuropathy in type 2 diabetes with well-controlled HbA1c

BACKGROUND

Diabetic peripheral neuropathy (DPN) is one of the most common microvascular complications of diabetes. Glycemic variability could be an independent risk factor for diabetes complications in addition to average glucose. Type 2 diabetes with well-controlled glycosylated hemoglobin A1c (HbA1c) may have different terms of glycemic variability and vascular complication consequences. The aim of the study is to investigate the relationship between glycemic variability and DPN in type 2 diabetes with well-controlled HbA1c (HbA1c < 7.0%).

METHODS

45 type 2 diabetes with well-controlled HbA1c(HbA1c < 7.0%) and with DPN (DM/DPN group) were recruited in the study, and 45 type 2 diabetes with well-controlled HbA1c and without DPN (DM/-DPN group) were set as controls. The two groups were also matched for age and diabetic duration. Blood pressure, body mass index(BMI), insulin sensitivity index (Matsuda index, ISI), total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDLC), and low density lipoprotein cholesterol (LDLC) were tested in the two groups. And all patients were monitored using the continuous glucose monitoring (CGM) system for consecutive 72 hours. The multiple parameters of glycemic variability included the standard deviation of blood glucose (SDBG), mean of daily differences (MODD) and mean amplitude of glycemic excursions (MAGE).

RESULTS

The DM/DPN group had a greater SDBG, MODD and MAGE, when compared to the DM/-DPN group (p < 0.05). BMI, TC, and LDLC of DM/DPN group were lower than those of DM/-DPN group (p < 0.05). The patients with hypoglycemia were comparable between the two groups (p > 0.05). Univariate analysis showed DPN was closely associated with BMI (OR 0.82, CI 0.72-0.94, p = 0.005), TC (OR 0.63, CI 0.42-0.93, p = 0.02), LDLC (OR 0.4, CI 0.20-0.80, p = 0.009), SDBG (OR 2.95, CI 1.55-5.61, p = 0.001), MODD (OR 4.38, CI 1.48-12.93, p = 0.008), MAGE (OR 2.18, CI 1.47-3.24, p < 0.001). Multivariate logistic regression analysis showed that MAGE (OR 2.05, CI 1.36-3.09, p = 0.001) and BMI (OR 0.85, CI 0.73-0.99, p = 0.033) were significantly correlating with DPN. Glycemic variability, evaluated by MAGE, was the most significantly independent risk factor for DPN.

CONCLUSIONS

There was a close relationship between glycemic variability evaluated by MAGE and DPN in type 2 diabetes with well-controlled HbA1c.

How can we monitor glycaemic variability in the clinical setting?

No universal consensus exists on how to express glycaemic variability. Among other parameters, standard deviation of blood glucose values, mean amplitude of glycaemic excursions (MAGE), the Low Blood Glucose Index (LBGI) and the High Blood Glucose Index (HBGI), which were subsequently combined into the Average Daily Risk Range (ADRR), mean of daily differences (MODD) and glycaemic variability index (GVI) are highlighted. The continuous glucose monitoring in research and clinical settings has been a great help for a comprehensive approach to circadian blood glucose evaluation and identification of individual patterns, mainly in type 1 diabetes, but recently also in type 2 diabetes. In everyday clinical practice the judicious use of self-monitoring of blood glucose in an educational setting involving the patient and the care team is an unreplaceable tool to effectively and safely guide behavioural and drug therapy.

Longitudinal dynamics of body weight change in the development of type 2 diabetes

OBJECTIVE

The aim of this study was to test the obesity-type 2 diabetes mellitus (T2DM) link in the context of longitudinal changes in body weight during the progression to diabetes in mature adult nonhuman primates (NHP).

DESIGN AND METHODS

A colony of 245 adult rhesus monkeys aged 8-41 years with 179 males were used to define overweight in males as a body weight: ≥13.5 kg or body fat (BF) ≥18% and obesity as ≥16.5 kg or BF ≥27%, and overweight in nonpregnant females was identified as a body weight >8.5 kg or BF >21% and obesity as ≥10.5 kg or BF ≥30%. A subgroup of 48 males (24 T2DM and 24 age-matched non-T2DM) males were studied before and following the onset of overt T2DM for the effects of changes in body weight and obesity in inducing this conversion to overt T2DM.

RESULTS

Three years before overt T2DM, mean body weight was 18.4 ± 3.3 kg. The DM-destined group body weight was 3.2 ± 1.1 kg greater and had a longer duration and greater severity of obesity, with peak body weight reached at 3.2 ± 1.8 years before overt T2DM. At DM onset the two groups did not differ significantly in body weight or adiposity.

CONCLUSIONS

The natural progression from pre-DM to overt T2DM is caused neither by the amount of excess body weight at DM onset nor by the proximate increases in body weight/adiposity during the pre-DM period of impaired glucose tolerance. Obesity was, however, essential preceding all NHP cases that developed T2DM.

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

Background

Fluctuations 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.

Methods

Fluctuations 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.

Results

The 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.

Conclusions

Fluctuations in blood glucose levels play a significant role in vascular endothelial dysfunction in type 2 diabetes.

Trial registration

UMIN000007581

Assessment of postprandial glucose excursions throughout the day in newly diagnosed type 2 diabetes

BACKGROUND

A growing body of evidence suggests that postprandial glucose (PPG) is independently linked to multiple complications and that testing of PPG should be added to hemoglobin A1c (HbA1c) and fasting glucose measurements in the evaluation of glycemic control of type 2 diabetes patients. An ongoing debate is questioning how to assess PPG. This observational study looks further into this question in a cohort of newly diagnosed type 2 diabetes patients.

SUBJECTS AND METHODS

PPG characteristics and intra-/intersubject variations post-breakfast, -lunch, and -dinner, obtained from continuous glucose monitoring (CGM), were retrospectively analyzed in 86 newly diagnosed non-insulin-treated type 2 diabetes patients.

RESULTS

In total, 462 recorded meals were analyzed. The area under the curve 1-4 h postmeal was significantly larger after breakfast compared with both lunch and dinner (P<0.001). Time to peak was approximately 90 min and did not differ significantly between meals. However, the distribution of the blood glucose peaks was only normally distributed among breakfasts, and time to peak had a day-to-day correlation coefficient of 0.60, compared with a nonsignificant result for lunch and dinner. Breakfast PPG peaks were highly correlated to HbA1c (P<0.05, r=0.64) and had a day-to-day correlation coefficient of 0.86 compared with 0.44 for lunch and 0.74 for dinner.

CONCLUSIONS

Self-monitoring of blood PPG should be evaluated with care. From our data, monitoring of PPG patterns in newly diagnosed type 2 diabetes patients should preferably be obtained following breakfast for a more consistent assessment, reducing day-to-day variations.

Impact of glycemic variability on cardiovascular outcomes beyond glycated hemoglobin. Evidence and clinical perspectives

AIMS

The aim of this review is to focus on intra-day glucose variability (GV), specifically reviewing its correlation with HbA1c, the methods currently available to measure it, and finally the relationship between GV and cardiovascular outcomes, in type 1 and type 2 diabetic patients, and in the non-diabetic population.

DATA SYNTHESIS

The term GV has been used in the literature to express many different concepts; in the present review, we focus our attention on intra-day GV. In particular, we try to assess whether GV provides additional information on glycemic control beyond HbA1c, since GV seems to be incompletely expressed by HbA1c, particularly in patients with good metabolic control. Many different indexes have been proposed to measure GV, however at the moment no "gold standard" procedure is available. Evidence in vitro, in experimental settings and in animal studies, shows that fluctuating glucose levels display a more deleterious effect than constantly high glucose exposure. However, these findings are not completely reproducible in human settings. Moreover, the relationship between GV and cardiovascular events is still controversial.

CONCLUSIONS

The term GV should be reserved to indicate intra-day variability and different indexes of GV should be used, depending on the metabolic profile of the population studied and the specific issue to be investigated. Self glucose monitoring or continuous glucose monitoring should be used for assessing glucose variability.