Glycemic risk factors of diabetic vascular complications: the role of glycemic variability

Efficacy of Different Modalities and Frequencies of Physical Exercise on Glucose Control in People with Prediabetes (GLYCEX Randomised Trial)

To assess the efficacy of different modalities and frequencies of physical exercise on glycaemic control in adults with prediabetes. A two-phase, parallel, randomised, controlled clinical trial will be carried out, in 210 participants. In phase 1, 120 participants will be randomized into four arms: (1) aerobic exercise, (2) aerobic exercise combined with resistance, (3) high-intensity intervallic exercise and (4) control group. In phase 2, 90 new participants will be randomized into three arms, using the exercise modality that showed the best glycaemic control in phase 1 in the following manner: (1) frequency of 5 days/week, (2) frequency of 3 days/week and (3) frequency of 2 days/week. The control group (n = 30) will be included in phase 1 to evaluate the effect of any type of intervention versus no intervention. Data collection will be performed at baseline and after 15 weeks of follow up. Sociodemographic data, medication, comorbidity, blood biochemical parameters, blood pressure, anthropometric measurements, body composition, physical activity, sedentary lifestyle, diet, smoking, alcohol consumption, quality of life and sleep questionnaires will be collected. Physical activity, sedentary behaviour and sleep will be further determined with an accelerometer, and continuous glycaemia will be determined with a glycaemic monitor, both during seven days, at two time points. The main dependent variable will be the reduction in the mean amplitude of glycaemic excursions. The impact of these interventions on health will also be evaluated through gene expression analysis in peripheral blood cells. The results of this study will contribute to a better understanding of the mechanisms behind the glucose response to physical exercise in a population with prediabetes as well as improve physical exercise prescriptions for diabetes prevention. Increasing glycaemic control in people with prediabetes through physical exercise offers an opportunity to prevent diabetes and reduce associated comorbidities and health costs.

Endothelial Dysfunction and Platelet Hyperactivation in Diabetic Complications Induced by Glycemic Variability

The development and progression of the complications of chronic diabetes mellitus are attributed not only to increased blood glucose levels but also to glycemic variability. Therefore, a deeper understanding of the role of glycemic variability in the development of diabetic complications may provide more insight into targeted clinical treatment strategies in the future. Previously, the mechanisms implicated in glycemic variability-induced diabetic complications have been comprehensively discussed. However, endothelial dysfunction and platelet hyperactivation, which are two newly recognized critical pathogenic factors, have not been fully elucidated yet. In this review, we first evaluate the assessment of glycemic variability and then summarise the roles of endothelial dysfunction and platelet hyperactivation in glycemic variability-induced complications of diabetes, highlighting the molecular mechanisms involved and their interconnections.

Retrospective Evaluation on the Use of a New Polysaccharide Complex in Managing Paediatric Type 1 Diabetes with Metabolic Syndrome (MetS)

Background: Children and adolescents affected by type 1 diabetes have an increased risk of being overweight or obese and of suffering from cardiometabolic symptoms. Aims: To retrospectively evaluate the effects of a new complex of polysaccharide macromolecules, Policaptil Gel Retard^® (PGR), on auxological and metabolic parameters, glycaemic variability and control parameters in paediatric patients with type 1 diabetes and metabolic syndrome (MetS). Patients and Methods: Data for 27 paediatric patients with a diagnosis of type 1 diabetes in conjunction with obesity and MetS of at least 5 years’ standing were collected and retrospectively studied. Of these, 16 (median age 12.9, range 9.5–15.8 years) had been adjunctively treated with PGR and 11 (median age 12.6, range 9.4–15.6 years) had not been treated with PGR. Auxological, metabolic and glycaemic control and variability parameters and insulin dosing were compared after 6 months in the two groups. Results: PGR significantly reduced BMI standard deviation score (SDS) (p < 0.005), waist SDS (p < 0.005), HbA1c (p < 0.05) and daily mean insulin dose requirement (p < 0.005). A significant improvement was also observed in the metabolic and glycaemic variability parameters of mean daily blood glucose (BG) levels (p < 0.005), SD of daily BG levels (p < 0.0001), mean coefficient of variation (p < 0.05), LBGI (p < 0.0001), HBGI (p < 0.0001), J-index (p < 0.005), total cholesterol (p < 0.005), HDL-cholesterol (p < 0.005) and LDL-cholesterol (p < 0.005) and triglycerides (p < 0.05). Conclusions: PGR produces a good auxological and metabolic response in obese patients with MetS who are affected by type 1 diabetes. It led to a significant reduction in BMI SDS, waist SDS and an improvement in glucose control and variability as well as in other MetS parameters. The use of polysaccharide compounds, especially if associated with appropriate dietary changes, may help achieve treatment targets in type 1 diabetes and reduce the risk that patients develop metabolic syndrome.

Efficacy of Ketogenic Diets on Type 2 Diabetes: a Systematic Review

To assess the pleiotropic effects of ketogenic diets (KD) on glucose control, changes in medication, and weight loss in individuals with type 2 diabetes, and to evaluate its practical feasibility RECENT FINDINGS: KD results in improved HbA1c already after 3 weeks, and the effect seems to persist for at least 1 year. This is associated with a reduction in glucose-lowering medications. The weight loss observed after a short time period seems to be maintained with a long-term diet. Adequate support (supportive psychological counseling, enhancing positive affectivity, reinforcing mindful eating) is necessary to achieve a benefit and to assure adherence. Despite the documented decrease in HbA1, a definitive causal effect of KD remains to be proven. KD should be performed under strict medical supervision. Future research should clarify how compliance can be maximized and how ketosis can be optimally monitored.

New Innovation: Use of Flash Glucose Monitoring for Evaluating Glycaemic Variability, Patient Satisfaction and Clinical Utility in Pregnant Women with Diabetes

Aim

Application of Flash glucose monitoring (FGM) system to evaluate glycaemic variability (GV), patient satisfaction and clinical utility in pregnant women with diabetes.

Methods

This prospective study was conducted in a tertiary care teaching hospital on 70 pregnant women with diabetes where blood sugar levels were monitored by FGM and self-monitoring of blood glucose (SMBG).

Results

FGM generated 19,950 readings versus 1470 readings by SMBG over 3 days. Glucose values measured by FGM and SMBG had significant positive correlation (r > 0.89; p < 0.001). Significant difference (p < 0.001) was present between minimum glucose values by FGM (52.49 ± 15.42 mg/dl) and SMBG (72.74 ± 18.30 mg/dl). FGM (20.9%) was able to pick exact duration of hypoglycaemia, while one-third of this duration was missed by conventional SMBG (14.7%; p < 0.05). Hypoglycaemic episodes were observed in 92.9% women by FGM as compared to 45.7% by SMBG (p < 0.001). No significant difference was observed in maximum glucose level or duration of hyperglycaemia by both methods. FGM identified hyperglycaemia in 74% women vs. 52% by SMBG (p < 0.001). GV calculated by using MODD by FGM was 118.4 ± 52.4 mg/dl and by SMBG was 83.2 ± 53.2 mg/dl (p < 0.001). 100% women preferred AGP vs. SMBG.

Conclusion

This is the first study to evaluate FGM for GV and patient satisfaction in women with GDM. Significant correlation was observed in glucose values by FGM and SMBG. FGM was more sensitive in detecting GV and hypoglycaemic excursions as compared to SMBG. All women preferred FGM over SMBG. Use of FGM gave new insights in clinical management of challenging cases.

Glucose Variability and Time in Range in Type 2 Diabetes Treated with U-500R by Pump or Injection: CGM Findings from the VIVID Study

Background: The EValuating U-500R Infusion Versus Injection in Type 2 Diabetes Mellitus (VIVID) study compared two methods of U-500R insulin delivery, continuous subcutaneous insulin infusion (CSII) and multiple daily injection (MDI), for 26 weeks in people with type 2 diabetes (T2D) requiring high doses of insulin. To assess glycemic variability (GV) and time in range (TIR), a subset of participants performed masked continuous glucose monitoring (CGM). Methods: VIVID participants were adults who had insulin requirements of >200 but ≤600 U/day and A1C 7.5% to 12%. Participants performed masked CGM for seven consecutive days on each of three occasions: before weeks 0 (baseline), 14, and 26. The primary objective was to compare GV between CSII and MDI groups, based on change from baseline of within-day standard deviation (SD_w) of CGM glucose. Results: Of 54 participants enrolled, 41 with evaluable data were analyzed (17 and 24 in CSII and MDI groups, respectively). The CSII group had a significantly greater reduction from baseline in mean SD_w of glucose (45.0 to 38.2 mg/dL [-8.1 mg/dL]) compared with the MDI group (47.0 to 45.8 [-0.4 mg/dL]; P = 0.047). TIR 70-180 mg/dL glucose increased significantly from baseline in the CSII group only, from 59.8% to 73.1% (change +12.9%, P < 0.05), but was not significantly different between groups. There were no significant between-group differences in the endpoint mean glucose or A1C. Conclusions: In the VIVID CGM substudy of U-500R in people with T2D requiring high doses of insulin, participants using CSII significantly reduced GV compared with MDI. CSII also significantly increased TIR with no difference between groups.

The relationship between glycaemic variability and cardiovascular autonomic dysfunction in patients with type 1 diabetes: A systematic review

Rigorous glycaemic control-reflected by low HbA1c goals-is of the utmost importance in the prevention and management of complications in patients with type 1 diabetes mellitus (T1DM). However, previous studies suggested that short-term glycaemic variability (GV) is also important to consider as excessive glucose fluctuations may have an additional impact on the development of diabetic complications. The potential relationship between GV and the risk of cardiovascular autonomic neuropathy (CAN), a clinical expression of cardiovascular autonomic dysfunction, is of increasing interest. This systematic review aimed to summarize existing evidence concerning the relationship between GV and cardiovascular autonomic dysfunction in T1DM. An electronic database search of Medline (PubMed), Web of Science and Embase was performed up to October 2019. There were no limits concerning year of publication. Methodological quality was evaluated using the Newcastle Ottawa Scale for observational studies. Six studies (four cross-sectional and two prospective cohorts) were included. Methodological quality of the studies varied from level C to A2. Two studies examined the association between GV and heart rate variability (HRV), and both found significant negative correlations. Regarding cardiovascular autonomic reflex tests (CARTs), two studies did not, while two other studies did find significant associations between GV parameters and CART scores. However, associations were attenuated after adjusting for covariates such as HbA1c, age and disease duration. In conclusion, this systematic review found some preliminary evidence supporting an association between GV and cardiovascular autonomic dysfunction in T1DM. Hence, uncertainty remains whether high GV can independently contribute to the onset or progression of CAN. The heterogeneity in the methodological approach made it difficult to compare different studies. Future studies should therefore use uniformly evaluated continuous glucose monitoring-derived parameters of GV, while standardized assessment of HRV, CARTs and other potential cardiac autonomic function parameters is needed for an unambiguous definition of CAN.

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.

Exhaled volatile substances in children suffering from type 1 diabetes mellitus: results from a cross-sectional study

Monitoring metabolic adaptation to type 1 diabetes mellitus in children is challenging. Analysis of volatile organic compounds (VOCs) in exhaled breath is non-invasive and appears as a promising tool. However, data on breath VOC profiles in pediatric patients are limited. We conducted a cross-sectional study and applied quantitative analysis of exhaled VOCs in children suffering from type 1 diabetes mellitus (T1DM) (n = 53) and healthy controls (n = 60). Both groups were matched for sex and age. For breath gas analysis, a very sensitive direct mass spectrometric technique (PTR-TOF) was applied. The duration of disease, the mode of insulin application (continuous subcutaneous insulin infusion vs. multiple daily insulin injection) and long-term metabolic control were considered as classifiers in patients. The concentration of exhaled VOCs differed between T1DM patients and healthy children. In particular, T1DM patients exhaled significantly higher amounts of ethanol, isopropanol, dimethylsulfid, isoprene and pentanal compared to healthy controls (171, 1223, 19.6, 112 and 13.5 ppbV vs. 82.4, 784, 11.3, 49.6, and 5.30 ppbV). The most remarkable differences in concentrations were found in patients with poor metabolic control, i.e. those with a mean HbA1c above 8%. In conclusion, non-invasive breath testing may support the discovery of basic metabolic mechanisms and adaptation early in the progress of T1DM.

Non-Invasive Assessment of Metabolic Adaptation in Paediatric Patients Suffering from Type 1 Diabetes Mellitus

An analysis of exhaled volatile organic compounds (VOC) may deliver systemic information quicker than available invasive techniques. Metabolic aberrations in pediatric type 1 diabetes (T1DM) are of high clinical importance and could be addressed via breathomics. Real-time breath analysis was combined with continuous glucose monitoring (CGM) and blood tests in children suffering from T1DM and age-matched healthy controls in a highly standardized setting. CGM and breath-resolved VOC analysis were performed every 5 minutes for 9 hours and blood was sampled at pre-defined time points. Per participant (n = 44) food intake and physical activity were identical and a total of 22 blood samples and 93 minutes of breath samples were investigated. The inter-individual variability of glucose, insulin, glucagon, leptin, and soluble leptin receptor relative to food intake differed distinctly between patients and controls. In T1DM patients, the exhaled amounts of acetone, 2-propanol, and pentanal correlated to glucose concentrations. Of note, the strength of these correlations strongly depended on the interval between food intake and breath sampling. Our data suggests that metabolic adaptation through postprandial hyperglycemia and related oxidative stress is immediately reflected in exhaled breath VOC concentrations. Clinical translations of our findings may enable point-of-care applicability of online breath analysis towards personalized medicine.

Effects of liraglutide addition to multiple diabetes regimens on weight and risk of hypoglycemia for a cohort with type 2 diabetes followed in primary care clinics in Saudi Arabia

Context:

Available therapies for type 2 diabetes mellitus (T2DM) do not adequately control glycemia in the long term as they do not address the issue of declining beta cell function and do not impact positively on weight or cardiovascular concerns associated with the disease.

Aims:

To measure changes in hemoglobin A1c, weight, and hypoglycemia after the addition of liraglutide to 3 therapeutic regimens of patients with T2DM.

Settings and Design:

An observational cohort study that was implemented in Al-Wazarat Health Center in Riyadh, Saudi Arabia.

Methods and Materials:

The study included 38 T2DM patients who were screened for initiation of liraglutide in combination with their treatment regimens; sulphonylurea, sulphonylurea with basal insulin (glargine), and multiple daily injections of insulin. The cohort was followed for 12 months, and the liraglutide was started with 0.6 mg dose that escalated to 1.2 and 1.8 mg. Glycemic level and weight were measured 3 times, whereas hypoglycemia was measured 2 times.

Statistical Analysis Used:

Quantitative continuous paired data were compared using a paired t-test and the nonparametric Wilcoxon signed rank test.

Results:

There was a statistically significant reduction of hemoglobin A1c with 1.2 mg dose (mean difference = 0.84%, P = 0.003). There were no statistically significant differences regarding the effect of liraglutide in addition to the 3 treatment regimens on patients’ weight (P = 0.08, 0.472, 0.08, respectively). Regarding hypoglycemia, liraglutide has showed minimal effect.

Conclusions:

Sustained effect of liraglutide on glycemic control in patients with T2DM without any major hypoglycemic episodes.

[The effect of biguanide derivatives on oxidative stress in rats with hyperglycemia]

The effect of the synthetic biguanide derivatives N-[imino(1-piperidinyl)methyl]guanidine (NIPMG) and 1,3-dimethyl-5-[(carbamimidamidomethanimidoil) amino]benzoyl-1,3dicarboxylate (DCB) on the degree of proteins oxidative modification (POM) and the DNA fragmentation, the content of the lipid peroxidation primary products - conjugated dienes (CD), and the activity of glutathione antioxidant system in the liver and heart of rats with experimental hyperglycemia was investigated. Administration of the biguanides (15.0 mg/kg) to hypoglycemic rats promoted reduction of the free radical processes intensity in the studied tissues. Data about CD and POM level changes in hyperglycemic rats treated by NIPMG and DKB correlate with the results of DNA fragmentation degree evaluation. At the same time, the activity of antioxidant enzymes (glutathione peroxidase and glutathione reductase), and the reduced glutathione content in the liver and heart of rats changed toward control values. For metformin, which was used as a comparison drug, changes in the studied parameters in the same direction were also found. These results indicate the ability of the tested biguanide derivatives to exhibit a positive regulatory effect on free radical homeostasis, reducing the degree of oxidative stress at this pathology.

Platelet indices and glucose control in type 1 and type 2 diabetes mellitus: A case-control study

BACKGROUND AND AIMS

The relationship between platelet indices and glucose control may differ in type 1 (T1DM) and type 2 (T2DM) diabetes. We aimed to investigate differences in mean platelet volume (MPV), platelet count, and platelet mass between patients with T1DM, T2DM, and healthy controls and to explore associations between these platelet indices and glucose control.

METHODS AND RESULTS

A total of 691 T1DM and 459 T2DM patients and 943 control subjects (blood donors) were included. HbA1c was measured in all subjects with diabetes and 36 T1DM patients further underwent 24 h-continuous glucose monitoring to estimate short-term glucose control (glucose mean and standard deviation). Adjusting for age and sex, platelet count was higher and MPV lower in both T1DM and T2DM patients vs control subjects, while platelet mass (MPV × platelet count) resulted higher only in T2DM. Upon further adjustment for HbA1c, differences in platelet count and mass were respectively 19.5 × 10⁹/L (95%CI: 9.8-29.3; p < 0.001) and 101 fL/nL (12-191; p = 0.027) comparing T2DM vs T1DM patients. MPV and platelet count were significantly and differently related in T2DM patients vs both T1DM and control subjects; this difference was maintained also accounting for HbA1c, age, and sex. Platelet mass and the volume-count relationship were significantly related to HbA1c only in T1DM patients. No associations were found between platelet indices and short-term glucose control.

CONCLUSION

By accounting for confounders and glucose control, our data evidenced higher platelet mass and different volume-count kinetics in subjects with T2DM vs T1DM. Long-term glucose control seemed to influence platelet mass and the volume-count relationship only in T1DM subjects. These findings suggest different mechanisms behind platelet formation in T1DM and T2DM patients with long-term glycaemic control being more relevant in T1DM than T2DM.

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.

Chaotic time series prediction for glucose dynamics in type 1 diabetes mellitus using regime-switching models

In patients with type 1 diabetes mellitus (T1DM), glucose dynamics are influenced by insulin reactions, diet, lifestyle, etc., and characterized by instability and nonlinearity. With the objective of a dependable decision support system for T1DM self-management, we aim to model glucose dynamics using their nonlinear chaotic properties. A group of patients was monitored via continuous glucose monitoring (CGM) sensors for several days under free-living conditions. We assessed the glycemic variability (GV) and chaotic properties of each time series. Time series were subsequently transformed into the phase-space and individual autoregressive (AR) models were applied to predict glucose values over 30-minute and 60-minute prediction horizons (PH). The logistic smooth transition AR (LSTAR) model provided the best prediction accuracy for patients with high GV. For a PH of 30 minutes, the average values of root mean squared error (RMSE) and mean absolute error (MAE) for the LSTAR model in the case of patients in the hypoglycemia range were 5.83 ( ± 1.95) mg/dL and 5.18 ( ± 1.64) mg/dL, respectively. For a PH of 60 minutes, the average values of RMSE and MAE were 7.43 ( ± 1.87) mg/dL and 6.54 ( ± 1.6) mg/dL, respectively. Without the burden of measuring exogenous information, nonlinear regime-switching AR models provided fast and accurate results for glucose prediction.

Efficacy and safety of glucagon-like peptide-1 receptor agonists in type 2 diabetes: A systematic review and mixed-treatment comparison analysis

AIMS

To compare efficacy and safety of glucagon-like peptide-1 receptor agonists (GLP-1RAs) in people with type 2 diabetes.

MATERIALS AND METHODS

We electronically searched, up to June 3, 2016, published randomized clinical trials lasting between 24 and 32 weeks that compared a GLP-1RA (albiglutide, dulaglutide, twice-daily exenatide and once-weekly exenatide, liraglutide, lixisenatide, semaglutide and taspoglutide) with placebo or another GLP-1RA. Data on cardiometabolic and safety outcomes were analysed using a mixed-treatment comparison meta-analysis.

RESULTS

A total of 34 trials (14 464 participants) met the inclusion criteria; no published data for semaglutide were available. Compared with placebo, all GLP-1RAs reduced glycated haemoglobin (HbA1c) and fasting plasma glucose (FPG) levels (reductions ranged from -0.55% and -0.73 mmol/L, respectively, for lixisenatide to -1.21% and -1.97 mmol/L, respectively, for dulaglutide). There were no differences within short-acting (twice-daily exenatide and lixisenatide) or long-acting (albiglutide, dulaglutide, once-weekly exenatide, liraglutide and taspoglutide) groups. Compared with twice-daily exenatide, dulaglutide treatment was associated with the greatest HbA1c and FPG reduction (0.51% and 1.04 mmol/L, respectively), followed by liraglutide (0.45% and 0.93 mmol/L, respectively) and once-weekly exenatide (0.38% and 0.85 mmol/L, respectively); similar reductions were found when these 3 agents were compared with lixisenatide. Compared with placebo, all GLP-1RAs except albiglutide reduced weight and increased the risk of hypoglycaemia and gastrointestinal side effects, and all agents except dulaglutide and taspoglutide reduced systolic blood pressure. When all GLP-1RAs were compared with each other, no clinically meaningful differences were observed in weight loss, blood pressure reduction or hypoglycaemia risk. Albiglutide had the lowest risk of nausea and diarrhoea and once-weekly exenatide the lowest risk of vomiting.

CONCLUSIONS

The RCTs in the present analysis show that all GLP-1RAs improve glycaemic control, reduce body weight and increase the risk of adverse gastrointestinal symptoms compared with placebo. Although there were no differences when short-acting agents were compared with each other or when long-acting agents were compared with each other, dulaglutide, liraglutide and once-weekly exenatide were superior to twice-daily exenatide and lixisenatide at lowering HbA1c and FPG levels. There were no differences in hypoglycaemia between these 3 agents, whilst once-weekly exenatide had the lowest risk of vomiting. These results, along with patient's preferences and individualized targets, should be considered when selecting a GLP-1RA.

Relationship between oxidative stress and blood glucose fluctuations evaluated with daily glucose monitoring in children with type 1 diabetes mellitus

BACKGROUND

The aim of this study is to determine the relationship between oxidative stress marker (8-iso-prostaglandine F2α) and glycemic indices computed from daily glucose monitoring data in children with type 1 diabetes mellitus (T1DM).

METHODS

Thirty-one children and adolescents with T1DM (median age 12.2 years) and healthy subjects (median age 11.7 years) were enrolled into the study. Anthropometric data were recorded for the entire group before the study. In addition, diabetes duration, insulin requirement, lipid values, microalbuminuria, HbA1c were recorded in T1DM subjects. T1DM subjects performed self-monitoring of blood glucose (SMBG) for a month (at least four times a day) for calculating glycemic indices. Twenty-four-hour urine 8-iso-prostoglandine F2α levels were studied at the end of the study period in the both groups.

RESULTS

Median diabetes duration was 5 years, hemoglobin A1c (HbA1c) was 7.3%. Standard deviation (SD) of the blood glucose (BG) was determined as 85 mg/dL. Median urinary 8-iso-prostoglandine F2α was found to be significantly higher than that of the healthy subjects (2808.9 and 298 pg/mg creatinine, p<0.001, respectively). There was no correlation between urinary 8-iso-prostoglandine F2α and age, anthropometric data, diabetes duration, insulin requirement, lipid values, microalbuminuria, HbA1c, or SD of BG in T1DM groups.

CONCLUSIONS

This study showed that, 8-iso-prostoglandine F2α that is an oxidative stress marker, is significantly higher in T1DM than that of healthy subjects while, no significant relation between glycemic indices and urinary 8-iso-prostoglandine F2α levels were demonstrated. Further studies are needed to assess other factors, and the relationship between glucose fluctuations and oxidative stress markers.

In Vivo Platelet Activation and Aspirin Responsiveness in Type 1 Diabetes

Platelet activation is persistently enhanced, and its inhibition by low-dose aspirin is impaired in type 2 diabetes mellitus. We investigated in vivo thromboxane (TX) and prostacyclin (PGI2) biosynthesis and their determinants, as well as aspirin responsiveness, in young adult subjects with type 1 diabetes mellitus (T1DM) without overt cardiovascular disease and stable glycemic control. The biosynthesis of TXA2 was persistently increased in subjects with T1DM versus matched healthy subjects, with females showing higher urinary TX metabolite (TXM) excretion than male subjects with T1DM. Microalbuminuria and urinary 8-iso-PGF2α, an index of in vivo oxidative stress, independently predicted TXM excretion in T1DM. No homeostatic increase in PGI2 biosynthesis was detected. Platelet COX-1 suppression by low-dose aspirin and the kinetics of its recovery after drug withdrawal were similar in patients and control subjects and were unaffected by glucose variability. We conclude that patients with T1DM and stable glycemic control display enhanced platelet activation correlating with female sex and microvascular and oxidative damages. Moreover, aspirin responsiveness is unimpaired in T1DM, suggesting that the metabolic disturbance per se is unrelated to altered pharmacodynamics. The efficacy and safety of low-dose aspirin in T1DM warrant further clinical investigation.

New Methods in Exploring Old Topics: Case Studying Brittle Diabetes in the Family Context

BACKGROUND

In questing for a more refined quantitative research approach, we revisited vector autoregressive (VAR) modeling for the analysis of time series data in the context of the so far poorly explored concept of family dynamics surrounding instable diabetes type 1 (or brittle diabetes).

METHOD

We adopted a new approach to VAR analysis from econometrics referred to as the optimized multivariate lag selection process and applied it to a set of raw data previously analyzed through standard approaches.

RESULTS

We illustrated recurring psychosomatic circles of cause and effect relationships between emotional and somatic parameters surrounding glycemic control of the child's diabetes and the affective states of all family members.

CONCLUSION

The optimized multivariate lag selection process allowed for more specific, dynamic, and statistically reliable results (increasing R(2) tenfold in explaining glycemic variability), which were derived from a larger window of past explanatory variables (lags). Such highly quantitative versus historic more qualitative approaches to case study analysis of psychosomatics surrounding diabetes in adolescents were reflected critically.

Improving the Quality of Outpatient Diabetes Care Using an Information Management System: Results From the Observational VISION Study

BACKGROUND

This study aimed to evaluate the effects of information management system (IMS) use with individuals with type 1 and type 2 diabetes who were treated in outpatient settings.

METHODS

In this 7-month, prospective, observational study, 965 adults with diabetes, mean (SD) baseline HbA1c 8.61(1.2)% (70.6[13.1] mmol/mol), were recruited from 132 outpatient care centers in Germany and Denmark. HbA1c was measured at baseline, month 4, and month 7. IMS reports were generated from uploaded self-monitored blood glucose data and therapy adjustments were documented at months 1 and 4. Hypoglycemic events were documented.

RESULTS

Mean (SD) HbA1c decreased from baseline in type 1 and type 2 diabetes patients at month 4 (-0.61[1.03]% (-6.7[11.3] mmol/mol), n = 213; -0.88[1.22]% (-9.6[13.3] mmol/mol), n = 589, respectively) and month 7 (-0.64[1.02]% (-7.0[11.1] mmol/mol), n = 219; -0.93[1.27]% (-10.2[13.9] mmol/mol), n = 594, respectively), all P < .0001, with no increase in hypoglycemic events. Therapy was adjusted in 106(42.7)% type 1 and 349(52.4)% type 2 diabetes patients at months 1 and 105(42.3)% type 1 and 282(42.3)% type 2 diabetes patients at month 4. Physicians used IMS reports to make therapy adjustments in 90% of patients at month 1 and 86% of patients at month 4.

CONCLUSIONS

Integration of the IMS into outpatient care facilitates significant improvements in glycemic control.

1,5-anhydroglucitol as a useful marker for assessing short-term glycemic excursions in type 1 diabetes

BACKGROUND

Type 1 diabetes is associated with more severe glycemic variability and more frequent hypoglycemia than type 2 diabetes. Glycemic variability is associated with poor glycemic control and diabetic complications. In this study, we demonstrate the clinical usefulness of serum 1,5-anhydroglucitol (1,5-AG) for assessing changes in glycemic excursion in type 1 diabetes.

METHODS

Seventeen patients with type 1 diabetes were enrolled in this study. A continuous glucose monitoring system (CGMS) was applied twice at a 2-week interval to evaluate changes in glycemic variability. The changes in serum glycemic assays, including 1,5-AG, glycated albumin and hemoglobin A1c (HbA1c), were also evaluated.

RESULTS

Most subjects showed severe glycemic excursions, including hypoglycemia and hyperglycemia. The change in 1,5-AG level was significantly correlated with changes in the glycemic excursion indices of the standard deviation (SD), mean amplitude of glucose excursion (MAGE), lability index, mean postmeal maximum glucose, and area under the curve for glucose above 180 mg/dL (r=-0.576, -0.613, -0.600, -0.630, and -0.500, respectively; all P<0.05). Changes in glycated albumin were correlated with changes in SD and MAGE (r=0.495 and 0.517, respectively; all P<0.05). However, changes in HbA1c were not correlated with any changes in the CGMS variables.

CONCLUSION

1,5-AG may be a useful marker for the assessment of short-term changes in glycemic variability. Furthermore, 1,5-AG may have clinical implications for the evaluation and treatment of glycemic excursions in type 1 diabetes.

Glycemic variability is associated with reduced cardiac autonomic modulation in women with type 2 diabetes

OBJECTIVE

To investigate the sex differences in cardiac autonomic modulation in patients with newly diagnosed type 2 diabetes and to determine whether cardiac autonomic modulation is associated with glycemic variability.

RESEARCH DESIGN AND METHODS

We investigated a cohort consisting of 48 men and 39 women with non-insulin-treated type 2 diabetes and a known duration of diabetes <5 years. All patients were equipped with a continuous glucose monitoring sensor for 3 days, and the mean amplitude of glycemic excursions (MAGE) was calculated to obtain individual glycemic variability. Cardiac autonomic modulation was quantified by analysis of heart rate variability (HRV) in time and frequency domains and during cardiovascular reflex tests (response to standing [RS], deep breathing [expiration-inspiration], and Valsalva maneuver).

RESULTS

Sex differences in age- and heart rate-adjusted HRV measures were observed in both active and passive tests. Low frequency (LF; P = 0.036), LF/high frequency (HF; P < 0.001), and RS (P = 0.006) were higher in men, whereas expiration-inspiration (P < 0.001), but not HF, was higher in women. In women, reduced cardiac autonomic modulation as assessed by the standard deviation of normal-to-normal intervals (P = 0.001), the root mean square of successive differences (P = 0.018), LF (P < 0.001), HF (P = 0.005), total power (P = 0.008), RS ratio (P = 0.027), and expiration-to-inspiration ratio (P = 0.006) was significantly associated with increased glycemic variability as assessed by MAGE. This was not the case in men. The association in women persisted in a multivariate regression analysis controlling for weight, mean heart rate, blood pressure (systolic), and triglycerides.

CONCLUSIONS

In patients with newly diagnosed and well-controlled type 2 diabetes, increased glycemic variability was associated with reduced cardiac autonomic modulation in women but not in men.

Combined use of basal insulin analog and acarbose reduces postprandial glucose in patients with uncontrolled type 2 diabetes

Aims/Introduction

Early initiation of basal insulin therapy is recommended for normalizing fasting blood glucose in type 2 diabetes mellitus. However, basal insulin treatment might not adequately control postprandial glucose levels. The present study evaluated whether the combination of the α-glucosidase inhibitor, acarbose, and basal insulin improved blood glucose control under daily-life treatment conditions in a large sample of Korean patients.

Materials and Methods

The present study was a multicenter, prospective, observational study under daily-life treatment conditions. A total of 539 patients with type 2 diabetes who were treated with basal insulin and additional acarbose were enrolled and followed up for 20 weeks. Changes in hemoglobin A1c, fasting and postprandial blood glucose were evaluated at baseline and at the end of the observation period. The physician and patient satisfaction of the combination treatment and safety were assessed.

Results

Hemoglobin A1c decreased by 0.55 ± 1.05% from baseline (P < 0.0001). Fasting and postprandial blood glucose levels were reduced by 0.89 ± 3.79 and 2.59 ± 4.77 mmol/L (both P < 0.0001). The most frequently reported adverse drug reactions were flatulence (0.37%) and abnormal gastrointestinal sounds (0.37%), and all were mild in intensity and transient. In the satisfaction evaluation, 79.0% of physicians and 77.3% of patients were ‘very satisfied’ or ‘satisfied’ with the combined basal insulin and acarbose therapy.

Conclusions

Combination therapy of basal insulin and acarbose in patients with type 2 diabetes improved glucose control, and had no drug-specific safety concerns, suggesting that the treatment might benefit individuals who cannot control blood glucose with basal insulin alone.

Glycemic variability in normal glucose tolerance women with the previous gestational diabetes mellitus

BACKGROUND

Women with previous gestational diabetes mellitus (pGDM) and postpartum normal glucose tolerance (NGT) may carry impaired islet β cell secretion, insulin resistance and subsequent altered glucose homeostasis. And certain normoglycemic groups at risks of diabetes were presented with elevated glycemic variability. The aim of study was to investigate the glycemic variability in NGT women with pGDM.

METHODS

Total 48 NGT women with pGDM (pGDM group) and 48 age- and BMI-matched NGT women without pGDM (control group) were recruited in the study. Integrated β cell function was assessed with the Insulin Secretion-Sensitivity Index-2 (ISSI-2) derived from oral glucose tolerance test. All subjects were monitored using the continuous glucose monitoring system for consecutive 72 h. The multiple parameters of glycemic variability included the mean blood glucose (MBG), standard deviation of blood glucose (SDBG), mean of daily differences (MODD), mean amplitude of glycemic excursions (MAGE) and the incremental areas above preprandial glucose values (AUCpp).

RESULTS

The pGDM group had a higher MBG (6.5 ± 0.9 vs. 5.9 ± 0.8 mmol/L, p < 0.05), SDBG (1.3 ± 0.3 vs. 0.9 ± 0.2 mmol/L, p < 0.05), MODD (1.4 ± 0.3 vs. 1.1 ± 0.2 mmol/L, p < 0.05), MAGE (2.7 ± 0.4 vs. 1.8 ± 0.5 mmol/L, p < 0.05), and AUCpp (26.8 ± 3.4 vs. 19.2 ± 3.2 mmol/L·h, p < 0.05), when compared to the control group, and the differences remained significant after adjusting for anthropometric indices and metabolic risk factors. Islet β cell function index ISSI-2 in the pGDM group was lower than in the control group (p < 0.05). MBG, SDBG, MODD, MAGE and AUCpp were all negatively associated with ISSI-2 in the pGDM group (r = -0.31, -0.30, -0.34, -0.48 and -0.54, respectively, p < 0.05), and the correlations remained significant after adjusting for anthropometric indices and metabolic risk factors.

CONCLUSIONS

Normal glucose tolerance women with pGDM were presented with elevated glycemic variability, which may be associated with impaired islet β cell function.

Glucose variability indices in type 1 diabetes: parsimonious set of indices revealed by sparse principal component analysis

BACKGROUND

Continuous glucose monitoring (CGM) time-series are often analyzed, retrospectively, to investigate glucose variability (GV), a risk factor for the development of complications in type 1 diabetes (T1D). In the literature, several tens of different indices for GV quantification have been proposed, but many of them carry very similar information. The aim of this article is to select a relatively small subset of GV indices from a wider pool of metrics, to obtain a parsimonious but still comprehensive description of GV in T1D datasets.

MATERIALS AND METHODS

A pool of 25 GV indices was evaluated on two CGM time-series datasets of 17 and 16 T1D subjects, respectively, collected during the European Union Seventh Framework Programme project "Diadvisor" (2008-2012) in two different clinical research centers using the Dexcom(®) (San Diego, CA) SEVEN(®) Plus. After the indices were centered and scaled, the Sparse Principal Component Analysis (SPCA) technique was used to determine a reduced set of metrics that allows preserving a high percentage of the variance of the whole original set. In order to assess whether or not the selected subset of GV indices is dataset-dependent, the analysis was applied to both datasets, as well as to the one obtained by merging them.

RESULTS

SPCA revealed that a subset of up to 10 different GV indices can be sufficient to preserve more than the 60% of the variance originally explained by all the 25 variables. It is remarkable that four of these GV indices (i.e., Index of Glycemic Control, percentage of Glycemic Risk Assessment Diabetes Equation score due to euglycemia, percentage Coefficient of Variation, and Low Blood Glucose Index) were selected for all the considered T1D datasets.

CONCLUSIONS

The SPCA methodology appears a suitable candidate to identify, among the large number of literature GV indices, subsets that allow obtaining a parsimonious, but still comprehensive, description of GV.

The effect of addition of liraglutide to high-dose intensive insulin therapy: a randomized prospective trial

AIMS

Patients with type 2 diabetes and insulin resistance may require high insulin doses to control hyperglycaemia. The addition of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) to basal insulin therapy has been shown to reduce insulin requirement while reducing insulin-associated weight gain [1,2]. The effect of GLP-1 RA therapy added to intensive (basal/bolus) insulin therapy has not been studied in a prospective trial. This trial evaluated the effect of the addition of liraglutide to high-dose intensive insulin therapy compared with standard insulin up-titration in obese insulin-resistant patients with type 2 diabetes requiring high-dose insulin therapy.

METHODS

Thirty-seven subjects with type 2 diabetes requiring >100 units of insulin daily administered either by continuous subcutaneous insulin infusion (CSII) or by multiple daily injections (MDIs) with or without metformin were randomized to receive either liraglutide plus insulin (LIRA) or intensive insulin only (controls). Liraglutide was initiated at 0.6 mg subcutaneously (sq) per day and increased to either 1.2 or 1.8 mg daily in combination with intensive insulin therapy. Controls received intensive insulin up-titration only.

RESULTS

At 6 months, subjects receiving liraglutide plus insulin experienced statistically significant reductions in HbA1c, weight, insulin dose and glycaemic variability (GV) by continuous glucose monitor (CGM) compared with the control group receiving insulin only.

CONCLUSIONS

Adding liraglutide to intensive high-dose (basal/bolus) insulin therapy results in greater improvement in glycaemic control than insulin therapy alone, with additional benefits of weight loss and reduced GV.

Glycemic variability in normal glucose regulation subjects with elevated 1-h postload plasma glucose levels

Subjects with normal glucose regulation (NGR), whose 1-h postload plasma glucose is ≥8.6 mmol/L (155 mg/dL, NGR 1 h ≥ 8.6) during 75-g oral glucose tolerance test (OGTT), have an increased risk of type 2 diabetes and subclinical organ damage. And, the deficiency in islet β cell function is responsible for glycemic disorders. The purpose of this study is to investigate glycemic variability in NGR subjects with elevated 1-h postload plasma glucose levels and its association with islet β cell function. The 29 NGR subjects with 1-h postload plasma glucose ≥8.6 mmol/L (NGR 1 h ≥ 8.6) and 29 age- and sex-matched NGR subjects with 1-h postload plasma glucose <8.6 mmol/L (NGR 1 h < 8.6) were recruited in the study. Insulin sensitivity (Matsuda index, ISI), insulin secretion (insulinogenic index ΔI30/ΔG30), and integrated β cell function measured by the oral disposition index (ΔI30/ΔG30 multiplied by the ISI) were derived from OGTT. All subjects were monitored using the continuous glucose monitoring system for consecutive 72 h. The multiple parameters of glycemic variability included the standard deviation of blood glucose (SDBG), mean blood glucose (MBG), mean of daily differences (MODD), and mean amplitude of glycemic excursions (MAGE). MAGE is considered as a gold standard of glycemic variability. Glycemic variability parameters SDBG, MBG, MODD, and MAGE in NGR 1 h ≥ 8.6 group were higher than those in NGR 1 h < 8.6 group (p < 0.05), and oral disposition index in NGR 1 h ≥ 8.6 group was lower than that in NGR 1 h < 8.6 group (p < 0.05). SDBG, MBG, MODD, MAGE, and 1-h postload plasma glucose all negatively associated with oral disposition index in the separate group (p < 0.05) and in the whole subjects (p < 0.05). After multivariate regression analysis, oral disposition index was the strongest independent contributor to MAGE and 1-h postload plasma glucose in the separate group (p < 0.05) and in the whole subjects (p < 0.05). It is concluded that NGR 1 h ≥ 8.6 group had higher glycemic variability and lower oral disposition index, compared with NGR 1 h < 8.6 group. Increased glycemic variability parameters and elevated 1-h postload plasma glucose consistently associated with declined oral disposition index in subjects from NGR 1 h < 8.6 to NGR 1 h ≥ 8.6 group.

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)

ARTERIAL ENDOTHELIAL DYSFUNCTION AND MYOCARDIAL ISCHEMIA IN PATIENTS WITH CARBOHYDRATE METABOLISM DISTURBANCES

Aim.To assess the role of vasomotor dysfunction and impaired flowdependent vasodilatation as a risk factor of silent myocardial ischemia (SMI) in patients with Type 2 diabetes mellitus (DM-2).

Material and methods.The study included 128 patients (66 men and 62 women; mean age 59,3±4,7 years), who underwent Holter ECG monitoring, stress test (Bruce protocol), echocardiography, vascular ultrasound, and brachial artery endothelium-dependent vasodilatation (EDVD) assessment.

Results.Patients with coronary heart disease and DM-2 demonstrated reduced EDVD levels (3,7±1,1%) and highly prevalent SMI (93,3%). There was a correlation between EDVD and the number (r=–0,68; p<0,05) or duration of SMI episodes (r=–0,53; p<0,01).

Conclusion.Patients with DM-2 require the assessment of vasomotor endothelial function in order to predict cardiovascular complications. Coronary artery endothelial dysfunction, which manifests in inadequate vasodilatation in response to increased myocardial demand for oxygen, plays an important role in the ischemia development and progression.

Differential effects of vildagliptin and glimepiride on glucose fluctuations in patients with type 2 diabetes mellitus assessed using continuous glucose monitoring

AIM

To assess whether there is a difference in the effects of vildagliptin and glimepiride on glucose fluctuation in patients with type 2 diabetes mellitus (T2DM) using continuous glucose monitoring (CGM).

METHODS

This was an open-label, randomized cross-over study conducted in T2DM patients. A total of 24 patients (age: 58.3 ± 5.56 years, baseline HbA1c: 7.6 ± 0.50%) who were on stable metformin monotherapy (500-3000 mg) were enrolled, and all completed the study. Each patient received two 5-day treatments (vildagliptin 50 mg b.i.d. or glimepiride 2 mg q.d.) in a cross-over manner. Various biomarkers and blood glucose concentrations were measured following breakfast. The 24-h glucose profiles were also measured using the CGM device at baseline and after 5 days of treatment, and fluctuations in glucose levels were estimated from CGM data.

RESULTS

Both vildagliptin and glimepiride reduced postprandial glucose levels, based on both CGM data (15% vs. 16%) and measured plasma glucose (13% vs.17%). Vildagliptin showed lower glucose fluctuations than glimepiride as measured by mean amplitude of glycaemic excursions (MAGE, p = 0.1076), standard deviation (s.d., p = 0.1346) of blood glucose rate of change, but did not reach statistical significance attributed to the small sample size. MAGE was reduced by ∼20% with vildagliptin versus glimepiride. Vildagliptin led to statistically significant lowering of the rate of change in the median curve (RCMC) and interquartile range (IQR) of glucose. Treatment with vildagliptin significantly increased the levels of active glucagon-like peptide-1 by 2.36-fold (p ≤ 0.0001) and suppressed glucagon by 8% (p = 0.01), whereas glimepiride significantly increased the levels of insulin and C-peptide by 21% (p = 0.012) and 12% (p = 0.003), respectively.

CONCLUSIONS

Vildagliptin treatment was associated with less fluctuation of glucose levels than glimepiride treatment as assessed by 24-h CGM device, suggesting vildagliptin may have the potential to offer long-term beneficial effects for patients with T2DM in preventing the development of complications of diabetes.

Synthesis and α-glucosidase inhibitory activity evaluation of N-substituted aminomethyl-β-d-glucopyranosides

A series of N-substituted 1-aminomethyl-β-d-glucopyranoside derivatives was prepared. These novel synthetic compounds were assessed in vitro for inhibitory activity against yeast α-glucosidase and both rat intestinal α-glucosidases maltase and sucrase. Most of the compounds displayed α-glucosidase inhibitory activity, with IC50 values covering the wide range from 2.3μM to 2.0mM. Compounds 19a (IC50=2.3μM) and 19b (IC50=5.6μM) were identified as the most potent inhibitors for yeast α-glucosidase, while compounds 16 (IC50=7.7 and 15.6μM) and 19e (IC50=5.1 and 10.4μM) were the strongest inhibitors of rat intestinal maltase and sucrase. Analysis of the kinetics of enzyme inhibition indicated that 19e inhibited maltase and sucrase in a competitive manner. The results suggest that the aminomethyl-β-d-glucopyranoside moiety can mimic the substrates of α-glucosidase in the enzyme catalytic site, leading to competitive enzyme inhibition. Moreover, the nature of the N-substituent has considerable influence on inhibitory potency.

12S-hydroxyeicosatetraenoic acid levels link to coronary artery disease in Type 2 diabetic patients

BACKGROUND

12(S)-Hydroxyeicosatetraenoic acid (12(S)-HETE) is a metabolite of arachidonic acid. 12(S)-HETE is involved in the pathogenesis of atherosclerosis and diabetes. However, the correlation between 12(S)-HETE and coronary artery disease (CAD) in the diabetic patient is unclear.

AIMS

The study investigated the relationship between 12(S)-HETE and CAD in Type 2 diabetes (T2D).

METHODS

Plasma 12(S)- HETE levels were detected by enzyme-linked immunosorbent assay in 103 healthy controls (control), 109 diabetic patients without CAD (diabetic), and 152 diabetic patients with CAD (diabetic-CAD).

RESULTS

12(S)-HETE levels were higher in both diabetic and diabetic-CAD groups compared to control and in the diabetic-CAD group compared to the diabetic group. In the multiple linear stepwise regression analysis, 12(S)-HETE levels correlated independently with CAD, systolic blood pressure, and glycated hemoglobin.

CONCLUSIONS

These results indicate that 12(S)-HETE levels are increased in diabetic patients with CAD, suggesting a role for atherosclerosis in T2D.

Metformin improves endothelial function in type 1 diabetic subjects: a pilot, placebo-controlled randomized study

AIMS

Several studies have investigated the effects of metformin treatment in patients with type 1 diabetes mellitus (T1DM). No study has hitherto examined its effects on endothelial function in these patients. In this study we sought to evaluate the effect of metformin on endothelial function in type 1 diabetic patients.

METHODS

Forty-two uncomplicated T1DM patients were randomized in a placebo-controlled, double-blind, 6-month trial to treatment with either metformin or placebo. Glycometabolic and clinical parameters as well as flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) of the right brachial artery were measured at baseline and at the end of the study. Glycaemic variability (GV, calculated from continuous glucose monitoring data) and a biomarker of oxidative stress [urinary 8-iso-prostaglandin F2α (PGF2α)] were also assessed.

RESULTS

Baseline data were similar in the two groups. Compared with placebo, metformin significantly reduced body weight [-2.27 kg (95% confidence interval: -3.99; -0.54); p = 0.012] whilst improved FMD [1.32% (0.30; 2.43); p = 0.013] and increased PGF2α [149 pg/mg creatinine (50; 248); p = 0.004]. Notably, the improvement of FMD did not correlate with the decrease of body weight (r(2)  < 1%). NMD, haemoglobin A1c, GV, daily insulin dose and other parameters did not significantly change after the treatment comparing the two groups.

CONCLUSIONS

Our pilot trial showed that, in uncomplicated type 1 diabetic subjects, metformin improved FMD and increased PGF2α, a marker of oxidative stress, irrespective of its effects on glycaemic control and body weight. Randomized, blinded clinical trials are needed to evaluate the benefits and risks of metformin added to insulin in type 1 diabetes.

A new series of N2-substituted-5-(p-toluenesulfonylamino)phthalimide analogues as α-glucosidase inhibitors

Several members of a new family of non-sugar-type α-glycosidase inhibitors, bearing a 5-(p-toluenesulfonylamino)phthalimide moiety and various substituent at the N2 position, were synthesized and their activities were investigated. The newly synthesized compounds displayed different inhibition profile towards yeast α-glycosidase and rat intestinal α-glycosidase. Almost all the compounds had strong inhibitory activities against yeast α-glycosidase. Regarding rat intestinal α-glycosidase, only analogs with N2-aromatic substituents displayed varying degrees of inhibitory activities on rat intestinal maltase and lactase and nearly all compounds showed no inhibition against rat intestinal α-amylase. Structure-activity relationship studies indicated that 5-(p-toluenesulfonylamino)phthalimide moiety is a favorable scaffold to exert the α-glucosidase inhibitory activity and substituents at the N2 position have considerable influence on the efficacy of the inhibition activities.

Glycemic variability in type 2 diabetes mellitus: oxidative stress and macrovascular complications

Diabetes mellitus is a world-wide health issue with potential for significant negative health outcomes, including microvascular and macrovascular complications. The relationship of hemoglobin HbA1c and other glycosylation end products (AGEs) to these complications, particularly microvascular disease, is well understood. More recent evidence suggests that glycemic variability may be associated with diabetes macrovascular complications. As HbA1c is better representative of average glucose levels and does not account as well for glycemic variability, hence new methods to assess and treat this variability is needed to reduce incidence of complications. In this chapter, the relationship of glycemic control to diabetes complications will be explored with focus on the mechanisms of tissue damage from this variability along with the oxidative stress. Additionally, treatment strategies to optimize HbA1c and glycemic variability with the goal of reducing risk of complications in persons with diabetes are reviewed.

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.

HbA1c variability is associated with microalbuminuria development in type 2 diabetes: a 7-year prospective cohort study

AIMS/HYPOTHESIS

HbA(1c) variability has been shown to be an independent risk factor for nephropathy in patients with type 1 diabetes. In this study, we aimed to explore the association between HbA(1c) variability and microalbuminuria development in patients with type 2 diabetes. We also intended to test the applicability of serially measured HbA(1c) over 2 years for this risk assessment.

METHODS

Between 2003 and 2005, we recruited 821 middle-aged normoalbuminuric individuals with type 2 diabetes and followed them through to the end of 2010. The average follow-up time was 6.2 years. We defined microalbuminuria as a urine albumin to creatinine ratio of 30 mg/g (3.4 mg/mmol) or higher. HbA(1c) variability was calculated by the SD of serially measured HbA(1c). The Cox proportional hazards model was used to evaluate the association between HbA(1c) SD quartile and development of microalbuminuria.

RESULTS

The incidence of microalbuminuria for the overall population was 58.4, 58.6, 60.8 and 91.9 per 1,000 person-years for Q1- to Q4-adjusted HbA(1c) SD, respectively (p for trend = 0.042). Compared with patients in Q1, those in Q4 were about 37% more likely to develop microalbuminuria. The HR derived from a series of 2 year HbA(1c) measurements was similar to that from data collection for longer than 4 years.

CONCLUSIONS/INTERPRETATION

In addition to mean HbA(1c) values, HbA(1c) variability, even measured as early as 2 years, is independently associated with the development of microalbuminuria in patients with type 2 diabetes.

Dynamic Stress Factor (DySF): A Significant Predictor of Severe Hypoglycemic Events in Children with Type 1 Diabetes

Hemoglobin A1c (HbA1c) is the current standard used in the clinical treatment of patients with diabetes. However, it has been shown that patients with similar HbA1c values may have widely different fluctuations in blood glucose values over the same period of time, including time spent in hyper- and/or hypo-glycemia. Hence, there exists a need for quantitative measures that can supplement HbA1c in managing patients with diabetes. We introduce and compare the Dynamic Stress Factor, DySF, a newly developed metric that quantifies glycemic volatility based on patient-specific glucose transition density profiles with HbA1c and with currently used glucose variability metrics in predicting severe hypoglycemia in children with type 1 diabetes. DySF, the daily weighted number of large monotonic glycemic transitions that occur within one hour, was calculated for 441 total subjects with type 1 diabetes (146 children, aged 8-14 yrs) to assess the magnitude and frequency of glucose transitions per day. Severe hypoglycemic episodes (HE) were quantified for all subjects and evaluated against HbA1c and existing measures of glucose variability, including SD, MAGE, MODD, and CONGA using logistic regression models. DySF was found to be a predictor of severe HE in children (p = 0.018) with the likelihood of a child, aged 8-14 yrs, experiencing severe hypoglycemia increasing by up to 20% with decreasing values of up to 60% of DySF. Patients of any age who had one or multiple severe hypoglycemic episodes had on average a lower DySF when compared to those with no HE. Additionally, when considering mean glucose levels, DySF/mean was a preliminary predictor of severe HE in patients with HbA1c ≤ 6.5% (p = 0.062). DySF is a dynamic, quantitative, measure of daily glucose "volatility" that separates patients, within the same strata of HbA1c, into visually distinct patient profiles. DySF can be used as a preliminary predictor of clinically severe hypoglycemia in children and "well-controlled" patients with HbA1c ≤ 6.5%.

Are neurocognitive speed and inconsistency similarly affected in type 2 diabetes?

Type 2 diabetes (T2D) is a disease of aging with indirect but detectable and cumulative neurological implications. We systematically tested whether neurocognitive speed (mean rate) or inconsistency (intraindividual variability) was the more sensitive clinical marker of T2D. Three of four research questions used a cross-sectional wave of the Victoria Longitudinal Study (VLS) divided into T2D (age 55-81 years) and control (age = 53-91 years) groups. The fourth question addressed relative two-wave longitudinal changes. Each of four speeded tasks produced intraindividual mean rate (IM) and intraindividual standard deviation (ISD) scores. First, the T2D group performed more slowly than the controls. Second, this deficit extended to inconsistency, but less uniformly. Third, based on logistic regression analyses, IM was the more effective predictor of T2D status. Fourth, we observed similar longitudinal change patterns for IM and ISD. Results are linked to the theoretical location of T2D on an adjusted neural vulnerability continuum.

Translating glucose variability metrics into the clinic via Continuous Glucose Monitoring: a Graphical User Interface for Diabetes Evaluation (CGM-GUIDE©)

BACKGROUND

Several metrics of glucose variability have been proposed to date, but an integrated approach that provides a complete and consistent assessment of glycemic variation is missing. As a consequence, and because of the tedious coding necessary during quantification, most investigators and clinicians have not yet adopted the use of multiple glucose variability metrics to evaluate glycemic variation.

METHODS

We compiled the most extensively used statistical techniques and glucose variability metrics, with adjustable hyper- and hypoglycemic limits and metric parameters, to create a user-friendly Continuous Glucose Monitoring Graphical User Interface for Diabetes Evaluation (CGM-GUIDE©). In addition, we introduce and demonstrate a novel transition density profile that emphasizes the dynamics of transitions between defined glucose states.

RESULTS

Our combined dashboard of numerical statistics and graphical plots support the task of providing an integrated approach to describing glycemic variability. We integrated existing metrics, such as SD, area under the curve, and mean amplitude of glycemic excursion, with novel metrics such as the slopes across critical transitions and the transition density profile to assess the severity and frequency of glucose transitions per day as they move between critical glycemic zones.

CONCLUSIONS

By presenting the above-mentioned metrics and graphics in a concise aggregate format, CGM-GUIDE provides an easy to use tool to compare quantitative measures of glucose variability. This tool can be used by researchers and clinicians to develop new algorithms of insulin delivery for patients with diabetes and to better explore the link between glucose variability and chronic diabetes complications.

Glycaemic variability affects ischaemia-induced angiogenesis in diabetic mice

The aim of the present study was to investigate the role of GV (glycaemic variability) in diabetic vascular complications and to explore the molecular pathways modulated by glycaemic 'swings'. We developed a murine model. A total of 30 diabetic mice received once daily basal insulin administration plus two oral boluses of glucose solution (GV group, named 'V') and 30 diabetic mice received once daily basal insulin plus two oral boluses of saline solution (stable hyperglycaemia group, named 'S') for a period of 30 days. Glycaemia was measured eight times daily to detect GV. Finally, postischaemic vascularization, induced by hindlimb ischaemia 30 days after diabetes onset, was evaluated. We found that GV was significantly different between S and V groups, whereas no significant difference in the mean glycaemic values was detected. Laser Doppler perfusion imaging and histological analyses revealed that the ischaemia-induced angiogenesis was significantly impaired in V mice compared with S group, after ischaemic injury. In addition, immunostaining and Western blot analyses revealed that impaired angiogenic response in V mice occurred in association with reduced VEGF (vascular endothelial growth factor) production and decreased eNOS (endothelial nitric oxide synthase) and Akt (also called protein kinase B) phosphorylation. In conclusion, we describe a murine model of GV. GV causes an impairment of ischaemia-induced angiogenesis in diabetes, likely to be independent of changes in average blood glucose levels, and this impaired collateral vessel formation is associated with an alteration of the VEGF pathway.

Nateglinide and acarbose for postprandial glucose control after optimizing fasting glucose with insulin glargine in patients with type 2 diabetes

AIMS

Basal insulin treatment is frequently used in type 2 diabetes, but the successful control of postprandial glucose is challenging. We compared the effect of preferential postprandial glucose targeting drugs for postprandial glucose control after optimizing fasting glucose with basal insulin.

METHODS

This study was performed in 58, insulin naïve type 2 diabetes. After fasting glucose was optimized by insulin glargine, nateglinide or acarbose was initiated and then crossed over after second wash out period. 75 g oral glucose tolerance test and 7 point self monitoring blood glucose for 3 days at the end of each period was performed.

RESULTS

Both drugs effectively reduced postprandial glucose levels compared with the insulin glargine monotherapy. No significant differences were found between nateglinide and acarbose in terms of mean glucose level, standard deviation of glucose levels, mean average glucose excursion and average daily risk range. Homeostasis model analysis (HOMA)% β, corrected insulin response and insulin-to-glucose ratio were significantly higher in the responder group compared with the non-responder. There was no episode of severe hypoglycemia.

CONCLUSIONS

Nateglinide and acarbose are equally effective in type 2 diabetes for postprandial glucose excursions during basal insulin treatment. The markers of beta cell function might be used for predicting response. (Clinical trial reg. no. NCT 00437918, clinicaltrial.gov.).

Addressing glycaemic variation

It is increasingly evident that glycated haemoglobin, fasting plasma glucose and postprandial glucose — the classical static parameters of glycaemic control — insufficiently reflect glycaemic variability. Other parameters such as mean glucose value and glycaemic swing offer valuable insights but glycaemic variability is complex. Even frequent self-monitoring of blood glucose may not adequately reflect the presence of acute glucose fluctuations that are associated with oxidative stress and may contribute to the development of complications. To date there have been no prospective clinical studies to investigate the true risks associated with glycaemic variability, but it is clearly important to individualise treatment to maintain glycaemic control in diabetes. Based on current evidence, improved assessment of glycaemic variability may in future help to reduce the risk of harmful hypoglycaemia, improve glycaemic control and reduce the risk of complications.

A novel treatment strategy for type 2 diabetes: Targeting glucose variability and β-cell failure

Blood glucose control has been a main focus for the treatment of type 2 diabetes. However, poor control and side-effect still are urgent problems to be solved. According to common blood glucose variability and its extremely deleterious diabetic-related complications in clinical practice, it should be considered as a potential key target. And β-cell failure has been approved that it can be reversible for early type 2 diabetes, which suggests another promising target. In this hypothesis, we propose a novel treatment strategy against on the two targets. An intelligent double-target drug delivery system is presented and characterized by dual-responsive functional gates for glucose sensitivity used controlled-release hypoglycemic agents and a sustained-release osmotic pump loaded drugs to repair impaired β-cell into the repository, respectively. The proposition may provide a new early therapeutic strategy for type 2 diabetes in order to better hold blood glucose homeostasis.

Combining basal-bolus insulin infusion for tight postprandial glucose control: an in silico evaluation in adults, children, and adolescents

BACKGROUND

Achieving good postprandial glycemic control, without triggering hypoglycemia events, is a challenge of treatment strategies for type 1 diabetes subjects. Continuous subcutaneous insulin infusion, the gold standard of therapy, is based on heuristic adjustments of both basal and prandial insulin. Some tools, such as bolus calculators, are available to aid patients in selecting a meal-related insulin dose. However, they are still based on empiric parameters such as the insulin-to-carbohydrate ratio and on the physicians' and patients' ability to fit bolus mode to meal composition.

METHODS

In this article, a nonheuristic method for assessment of prandial insulin administration is presented and evaluated. An algorithm based on set inversion via interval analysis is used to coordinate basal and bolus insulin infusions to deal with postprandial glucose excursions. The evaluation is carried out through an in silico study using the 30 virtual patients available in the educational version of the Food and Drug Administration-accepted University of Virginia simulator. Results obtained using the standard bolus strategy and different coordinated basal-bolus solutions provided by the algorithm are compared.

RESULTS

Coordinated basal-bolus solutions improve postprandial glucose performance in most cases, mainly in terms of reducing hypoglycemia risk, but also increasing the percentage of time in normoglycemia. Moreover, glycemic variability is reduced considerably by using these innovative solutions.

CONCLUSIONS

The algorithm presented here is a robust nonheuristic alternative to deal with postprandial glycemic control. It is shown as a powerful tool that could be integrated in future smart insulin pumps.

Relationship of glucose regulation to changes in weight: a systematic review and guide to future research

Although weight gain and obesity are risk factors for poor glucose regulation, the relationship, if any, of glucose regulation to changes in weight is not well understood. The purpose of this study was to conduct a systematic review of research examining the relationship of glucose regulation to changes in weight in human-based studies and to provide guidelines for future research in this area. We searched electronic databases and reference sections of relevant articles, including both diabetic and non-diabetic populations, to locate all the literature published before February 2010, and then conducted a systematic review across studies to compare the research designs and findings. The 22 studies meeting our criteria for review generally supported the relationship of glucose regulation to changes in weight. Three studies reported that poor glucose regulation is associated with weight gain; 12 studies concluded that poor glucose regulation is associated with weight loss; 5 showed complex relationships depending on age, sex, or race/ethnicity; and 2 suggested no relationship. The diverse findings may imply that the direction (negative or positive) of the relationship may depend on specific conditions. More research focused on different subpopulations may provide more definitive information supplemental to the current preliminary findings. Recommendations regarding future research in this particular area are provided in the discussion.

Effect of carbohydrate counting and medical nutritional therapy on glycaemic control in Type 1 diabetic subjects: a pilot study

AIMS

The effect of a balanced, carbohydrate-counting diet on glycaemic control in Type 1 diabetic subjects is unclear. Our aim was to determine its effect in a small, pilot trial.

METHODS

We randomized 256 Type 1 diabetic subjects to a Nutritional Education Programme (group A) or not (group B). Weight, body mass index, glycated haemoglobin (HbA1c), lipid profile, urate, creatinine, microalbuminuria and daily insulin requirements were measured at baseline and at the end of the study (9 months). During the study, the number of hypoglycaemic events (blood glucose<3.9 mmol/l) was also measured.

RESULTS

Compared with group B, group A showed: (i) a reduction in HbA1c (group A: 7.8+/-1.3-7.4+/-0.9%; group B: 7.5+/-0.8-7.5+/-1.1%; P<0.01); (ii) less hypoglycaemic events (4% vs. 7%; P<0.05); (iii) a reduction in dose of rapid insulin analogues (23.5+/-10.9 vs. 27.7+/-17.1 IU/24 h; P=0.03). No other between-group changes were observed.

CONCLUSIONS

This study shows the importance of medical nutritional therapy on glycaemic control in Type 1 diabetic subjects.