Insulin resistance, role of metformin and other non-insulin therapies in pediatric type 1 diabetes

Challenging directions in pediatric diabetes - the place of oxidative stress and antioxidants in systemic decline

Diabetes is a complex condition with a rising global incidence, and its impact is equally evident in pediatric practice. Regardless of whether we are dealing with type 1 or type 2 diabetes, the development of complications following the onset of the disease is inevitable. Consequently, contemporary medicine must concentrate on understanding the pathophysiological mechanisms driving systemic decline and on finding ways to address them. We are particularly interested in the effects of oxidative stress on target cells and organs, such as pancreatic islets, the retina, kidneys, and the neurological or cardiovascular systems. Our goal is to explore, using the latest data from international scientific databases, the relationship between oxidative stress and the development or persistence of systemic damage associated with diabetes in children. Additionally, we highlight the beneficial roles of antioxidants such as vitamins, minerals, polyphenols, and other bioactive molecules; in mitigating the pathogenic cascade, detailing how they intervene and their bioactive properties. As a result, our study provides a comprehensive exploration of the key aspects of the oxidative stress-antioxidants-pediatric diabetes triad, expanding understanding of their significance in various systemic diseases.

Muscle mitochondrial function is impaired in adults with type 1 diabetes

AIMS

Type 1 diabetes has been associated with mitochondrial dysfunction. However, the mechanism of this dysfunction in adults remains unclear.

METHODS

A secondary analysis was conducted using data from several clinical trials measuring in-vivo and ex-vivo mitochondrial function in adults with type 1 diabetes (n = 34, age 38.8 ± 14.6 years) and similarly aged controls (n = 59, age 44.6 ± 13.9 years). In-vivo mitochondrial function was assessed before, during, and after isometric exercise with 31phosphorous magnetic resonance spectroscopy. High resolution respirometry of vastus lateralis muscle tissue was used to assess ex-vivo measures.

RESULTS

In-vivo data showed higher rates of anaerobic glycolysis (p = 0.013), and a lower maximal mitochondrial oxidative capacity (p = 0.012) and mitochondrial efficiency (p = 0.024) in adults with type 1 diabetes. After adjustment for age and percent body fat maximal mitochondrial capacity (p = 0.014) continued to be lower and anaerobic glycolysis higher (p = 0.040) in adults with type 1 diabetes. Ex-vivo data did not demonstrate significant differences between the two groups.

CONCLUSIONS

The in-vivo analysis demonstrates that adults with type 1 diabetes have mitochondrial dysfunction. This builds on previous research showing in-vivo mitochondrial dysfunction in youths with type 1 diabetes and suggests that defects in substrate or oxygen delivery may play a role in in-vivo dysfunction.

Role of Dietary Macronutrient Composition and Fibre Intake in Development of Double Diabetes in Indian Youth

Introduction

Insulin resistance (IR) and obesity are common presentations of double diabetes (DD) in subjects with type-1 diabetes (T1D). There is evidence that dietary composition has an impact on developing IR. Objectives were to assess the impact of macronutrient and fibre intake on glycaemic control and the role of macronutrient composition of diet in the development of DD in subjects with T1D.

Methods

This cross-sectional study included 77 young adults (10-25 years) with T1D. Data related to demography, anthropometry, biochemistry and body composition were collected. Dietary data was collected by fourteen-day food diary. IR was calculated using eGDR, SEARCH and CACTI equations, and metabolic syndrome (MS) was diagnosed using the International Diabetes Federation Consensus Definition.

Results

Subjects at risk of DD had higher age, leptin levels, percentage carbohydrate consumption in diet and IR. A positive association of insulin sensitivity with fibre intake and %protein intake was noted. Poor glycaemic control, adiponectin/leptin ratio, fibre intake and insulin/carbohydrate ratio were significant negative predictors of IR. Addition of dietary factors to the regression model improved the R square and percentage of subjects identified correctly. Inclusion of dietary parameters significantly improves the prediction of the risk of development of DD in subjects with T1D.

Conclusion

Good glycaemic control and increased intake of dietary fibre may prevent the development of IR in subjects with T1D and reduce the burden of DD.

Effect and Safety of Adding Metformin to Insulin Therapy in Treating Adolescents With Type 1 Diabetes Mellitus: An Updated Meta-Analysis of 10 Randomized Controlled Trials

Background

The role of metformin in the treatment of adolescents with type 1 diabetes mellitus (T1DM) remains controversial. We conducted this updated meta-analysis to generate a comprehensive assessment regarding the effect and safety of metformin in treating adolescents with T1DM.

Methods

We systematically searched PubMed, Embase, and the Cochrane Central Registry of Controlled Trials (CENTRAL) from their inception to November 2021 to identify randomized controlled trials evaluating the efficacy of metformin in the treatment of adolescents with T1DM. The primary outcome was the HbA1c level, and secondary outcomes included the body mass index (BMI), total insulin daily dose (TIDD) (unit/kg/d), hypoglycemia events, diabetes ketoacidosis (DKA) events, and gastrointestinal adverse events (GIAEs). Statistical analysis was conducted using RevMan 5.4 and STATA 14.0.

Results

Ten studies enrolling 539 T1DM adolescents were included. Results suggested that metformin significantly decreased the HbA1c level at 12 months (mean difference [MD])=-0.50, 95% confidence interval [CI]=-0.61 to -0.39, P < 0.01); BMI (kg/m2) at 3 months (MD=-1.05, 95%CI=-2.05 to -0.05, P=0.04); BMI z-score at 6 months (MD=-0.10, 95%CI=-0.14 to -0.06, P<0.01); and TIDD at 3 (MD=-0.13, 95%CI=-0.20 to -0.06, P<0.01), 6 (MD=-0.18, 95%CI=-0.25 to -0.11, P<0.01), and 12 (MD=-0.42, 95%CI=-0.49 to -0.35, P<0.01) months but significantly increased the risk of hypoglycemia events (risk ratio [RR]=3.13, 95%CI=1.05 to 9.32, P=0.04) and GIAEs (RR=1.64, 95%CI=1.28 to 2.10, P<0.01). For remaining outcomes at other time points, no statistical difference was identified. Sensitivity analysis confirmed the robustness of all pooled results.

Conclusions

The use of metformin might result in decreased BMI (kg/m2), BMI z-score, and TIDD and increased risk of hypoglycemia events and GIAEs in adolescents with T1DM. However, future studies are required to further confirm the optimal dose and duration of metformin therapy.

Effect of kolaviron on islet dynamics in diabetic rats

Kolaviron, a biflavonoid isolated from the edible seeds of Garcinia kola, lowers blood glucose in experimental models of diabetes; however, the underlying mechanisms are not yet fully elucidated. The objective of the current study was to assess the effects of kolaviron on islet dynamics in streptozotocin-induced diabetic rats. Using double immunolabeling of glucagon and insulin, we identified insulin-producing β- and glucagon-producing α-cells in the islets of diabetic and control rats and determined the fractional β-cell area, α-cell area and islet number. STZ challenged rats presented with islet hypoplasia and reduced β-cell area concomitant with an increase in α-cell area. Kolaviron restored some islet architecture in diabetic rats through the increased β-cell area. Overall, kolaviron-treated diabetic rats presented a significant (p < 0.05) increase in the number of large and very large islets compared to diabetic control but no difference in islet number and α-cell area. The β-cell replenishment potential of kolaviron and its overall positive effects on glycemic control suggest that it may be a viable target for diabetes treatment.

Changes in innate and adaptive immunity over the first year after the onset of type 1 diabetes

AIMS

The development of the immune phenotype in patients with type 1 diabetes (T1D) during the first year following disease onset remains poorly described, and studies analysing the longitudinal development of a complex set of immunological and metabolic parameters are missing. Thus, we aim to provide such complex view in a cohort of 38 children with new onset T1D who were prospectively followed for 1 year.

METHODS

All subjects were tested for a set of immunological parameters (complete blood count; serum immunoglobulins; and T, B and dendritic cells), HbA1c and daily insulin dose at baseline and at 6 and 12 months after T1D diagnosis. A mixed meal tolerance test was administered to each of the subjects 12 months after diagnosis, and the C-peptide area under the curve (AUC) was noted and was then tested for association with all immunological parameters.

RESULTS

A gradual decrease in leukocytes (adjusted p = 0.0012) was reflected in a significant decrease in neutrophils (adjusted p = 0.0061) over the post-onset period, whereas Tregs (adjusted p = 0.0205) and originally low pDCs (adjusted p < 0.0001) increased. The expression of the receptor for BAFF (BAFFR) on B lymphocytes (adjusted p = 0.0127) markedly increased after onset. No immunological parameters were associated with C-peptide AUC; however, we observed a linear increase in C-peptide AUC with the age of the patients (p < 0.0001).

CONCLUSIONS

Our study documents substantial changes in the innate and adaptive immune system over the first year after disease diagnosis but shows no association between immunological parameters and residual beta-cell activity. The age of patients remains the best predictor of C-peptide AUC, whereas the role of the immune system remains unresolved.

Effects of Metformin Added to Insulin in Adolescents with Type 1 Diabetes: An Exploratory Crossover Randomized Trial

BACKGROUND

To comprehensively assess the effects of metformin added to insulin on metabolic control, insulin sensitivity, and cardiovascular autonomic function in adolescents with type 1 diabetes.

MATERIALS AND METHODS

This was an exploratory, crossover, randomized trial conducted in adolescents with type 1 diabetes aged 12-18 years old. Participants were randomly received metformin (≤1000 mg/d) added to insulin for 24 weeks followed by insulin monotherapy for a subsequent 24 weeks or vice versa. Blood pressure, body mass index, insulin dose, estimated insulin sensitivity, glycated hemoglobin A1c (HbA1c), and lipid profiles were measured, with a 72-hour continuous glucose monitoring and 24-hour Holter monitoring performed at baseline, 24, and 50 weeks for the assessments of glucose variability and heart rate variability.

RESULTS

Seventeen patients with mean ± SD age 14.4 ± 2.3 years, body mass index 18.17 ± 1.81 kg/m², median (IQR) diabetes duration 4.50 (3.58, 6.92) years, and HbA1c 9.0% (8.5%, 9.4%) were enrolled. The between-group difference in HbA1c of 0.28% (95% CI -0.39 to 0.95%) was not significant (P = 0.40). Changes in body mass index, insulin dose, blood pressure, lipid profiles, and estimated insulin sensitivity were similar for metformin add-on vs. insulin monotherapy. Glucose variability also did not differ. Compared with insulin monotherapy, metformin add-on significantly increased multiple heart rate variability parameters.

CONCLUSIONS

Metformin added to insulin did not improve metabolic control or glucose variability in lean/normal-weight adolescents with type 1 diabetes. However, metformin added to insulin significantly increased heart rate variability, suggesting that metformin might improve cardiovascular autonomic function in this population.

Suppressive effects of metformin on colorectal adenoma incidence and malignant progression

BACKGROUND

The linear progression from normal colonic epithelium to adenoma initiation, carcinoma transformation and metastasis is considered the classical model of colorectal cancer (CRC) development. Although metformin has been extensively reported to be negatively related to cancer incidence, the effect of metformin on CRC development remains unclear. We aimed to evaluate the role of metformin in the entire CRC linear progression.

METHODS

Systematic searches and data extraction were performed in the PubMed, Embase, and Cochrane Library databases on Jan 31, 2019. The combined relative ratios (RRs) of colorectal tumor incidence and the hazard ratios (HRs) of overall survival (OS) and cancer-specific survival (CSS) were evaluated by a random-effects model. Then, the effects of metformin were further assessed through stratified analyses by population, medication duration and dosage, dose-response analysis and comparison with other antidiabetic agents.

RESULTS

A total of 50 studies consisting of 238,540 cases of diabetes mellitus (DM) were included in this study. Metformin use was negatively associated with the incidence of colorectal adenoma (RR: 0.75, 95% CI: 0.65-0.86) and CRC (RR: 0.73, 95% CI: 0.58-0.90). Moreover, CRC patients benefited from metformin in terms of both OS (HR: 0.73, 95% Cl: 0.63-0.84) and CSS (HR: 0.60, 95% Cl: 0.50-0.73). Stratified analyses suggested that a long duration of high-dose metformin (RR: 0.52, 95% Cl: 0.36-0.83) was more effective than a short duration in Asian populations against colorectal adenoma (RR: 0.66, 95% Cl: 056-0.70) and CRC (RR: 0.45, 95% Cl: 0.29-0.70). Interestingly, metformin use decreased CRC risk in a dose-dependent manner (RR: 0.91, 95% CI: 0.87-0.95). In addition, the benefit of metformin on CRC was more significant than that of other antidiabetic agents, including insulin.

CONCLUSIONS

The use of metformin is associated with a lower incidence of adenoma and CRC and a better prognosis, especially in Asian populations.

Metformin Improves Peripheral Insulin Sensitivity in Youth With Type 1 Diabetes

CONTEXT

Type 1 diabetes in adolescence is characterized by insulin deficiency and insulin resistance (IR), both thought to increase cardiovascular disease risk. We previously demonstrated that adolescents with type 1 diabetes have adipose, hepatic, and muscle IR, and that metformin lowers daily insulin dose, suggesting improved IR. However, whether metformin improves IR in muscle, hepatic, or adipose tissues in type 1 diabetes was unknown.

OBJECTIVE

Measure peripheral, hepatic, and adipose insulin sensitivity before and after metformin or placebo therapy in youth with obesity with type 1 diabetes.

DESIGN

Double-blind, placebo-controlled clinical trial.

SETTING

Multi-center at eight sites of the T1D Exchange Clinic Network.

PARTICIPANTS

A subset of 12- to 19-year-olds with type 1 diabetes (inclusion criteria: body mass index ≥85th percentile, HbA1c 7.5% to 9.9%, insulin dosing ≥0.8 U/kg/d) from a larger trial (NCT02045290) were enrolled.

INTERVENTION

Participants were randomized to 3 months of metformin (N = 19) or placebo (N = 18) and underwent a three-phase hyperinsulinemic euglycemic clamp with glucose and glycerol isotope tracers to assess tissue-specific IR before and after treatment.

MAIN OUTCOME MEASURES

Peripheral insulin sensitivity, endogenous glucose release, rate of lipolysis.

RESULTS

Between-group differences in change in insulin sensitivity favored metformin regarding whole-body IR [change in glucose infusion rate 1.3 (0.1, 2.4) mg/kg/min, P = 0.03] and peripheral IR [change in metabolic clearance rate 0.923 (-0.002, 1.867) dL/kg/min, P = 0.05]. Metformin did not impact insulin suppression of endogenous glucose release (P = 0.12). Adipose IR was not assessable with traditional methods in this highly IR population.

CONCLUSIONS

Metformin appears to improve whole-body and peripheral IR in youth who are overweight/obese with type 1 diabetes.

Effect of metformin on clinical and biochemical hyperandrogenism in adolescent girls with type 1 diabetes

Background Hyperandrogenism with or without polycystic ovarian syndrome is seen in adolescents with type 1 diabetes (T1D), especially those with suboptimal control. Objective To assess the effect of metformin on hyperandrogenism and ovarian function in adolescents with T1D. Methods This prospective study included 28 T1D females showing signs of hyperandrogenism. History taking (detailed diabetes history and menstrual history) and anthropometric measurements (weight, height, body mass index [BMI], waist and hip circumference) were initially performed, and then the patients were assessed for the manifestations of hyperandrogenism (acne, hirsutism as well as pelvic ultrasound [U/S] for ovarian morphology). Biochemical evaluation for ovulation (progesterone assessment during the luteal phase), sex steroids (estradiol, testosterone, dehydroepiandrosterone sulfate [DHEAS] and androstenedione), prolactin, glycemic control (hemoglobin A1c [HbA1c]) and gonadotropin levels (follicle stimulating hormone [FSH] and luteinizing hormone [LH]) was done. Patients were subjected to 500 mg metformin twice daily orally for 1 year, and then the patients were re-evaluated for clinical and biochemical parameters. Results Metformin therapy resulted in a significant reduction in weight (p = 0.001), BMI (p = 0.002), acne (p = 0.008), hirsutism score (0.007), LH (p = 0.008), testosterone (p < 0.001) and androstenedione levels (p = 0.028) in adolescent girls with T1D. Regarding menstrual irregularities, there was a significant reduction in the number of patients with oligomenorrhea (68%) with a p value of <0.001. However, there were no significant reduction in the daily insulin requirements (p = 0.782) or HbA1c (p = 0.068). Nausea and/or abdominal pain were the commonly reported side effects of metformin (64%). Conclusions Metformin as an insulin sensitizing agent improved the BMI and cycle regularity together with clinical and biochemical hyperandrogenism in T1D adolescent girls. However, it did not improve their glycemic control.

Insulin Glargine Dose and Weight Changes in Underweight, Normal Weight, and Overweight Children Newly Diagnosed with Type 1 Diabetes Mellitus

STUDY OBJECTIVE

Newly diagnosed pediatric patients with type 1 diabetes mellitus (T1D) can be underweight, overweight, or normal weight at presentation. Study objectives were to determine if, across weight categories, admission body weight (ABW)-based initial insulin glargine dosing resulted in similar fasting blood glucose responses on day of discharge, how initial ABW-based doses differed from doses at outpatient follow-up, and whether an ideal body weight (IBW) would provide a better estimate of body weight after discharge.

DESIGN

Retrospective chart review.

SETTING

Urban tertiary academic medical center.

PATIENTS

Eighty-one pediatric patients newly diagnosed with T1D who started therapy with subcutaneous insulin glargine between October 2014 and October 2016; patients were categorized by weight using body mass index (BMI) percentiles (underweight, normal weight, or overweight/obese).

MEASUREMENTS AND MAIN RESULTS

Data on patient parameters from hospitalization to outpatient physician follow-up were collected. The McLaren, Moore, and BMI IBW methods were used to calculate IBW for each patient; these IBWs were compared with weights at outpatient follow-up. Initial insulin glargine doses were similar among all weight groups: median (range) 0.299 (0.227-0.4), 0.297 (0.204-0.421), and 0.291 (0.194-0.394) units/kg/dose, respectively, for the underweight, normal weight, and overweight/obese groups. No significant differences in discharge fasting glucose level or insulin glargine dose change from admission to first outpatient follow-up visit were noted. Underweight patients gained significantly more weight within 60 days after discharge compared with normal and overweight/obese patients, (median 16.3% vs 7.7% and 5.7%, respectively; p=0.002), aligning closest with the McLaren IBW. ABW was the best estimate of weight at outpatient follow-up in the overweight/obese patient group.

CONCLUSION

For children who presented underweight, the McLaren IBW method was the best predictor of outpatient dose and body weight, whereas ABW was the best estimate in overweight and obese patients. Further investigation of the role of IBW- or ABW-based dosing methods in underweight pediatric patients with T1D may assist in optimal dosing.

Insulin resistance is a cardiovascular risk factor in humans

Diabetes is a common metabolic disorder associated to elevated cardiovascular morbidity and mortality that is not explained by hyperglycemia or traditional cardiovascular risk factors such as smoking or hypercholesterolemia. Intensive glycemic control with insulin that achieves near-normal glycemia does not reduce significantly macrovascular complications compared with conventional glycemic control. Cardiovascular disease continues to develop in patients with diabetes despite adequate glycemic control. In contrast, intensive control with metformin (leading to insulin resistance improvement) reduces diabetes complications, including cardiovascular events, suggesting that enhancement of insulin sensitivity rather than plasma glucose level has a major role improving diabetes outcomes. Accordingly, insulin resistance estimated by glucose tolerance tests is better predictor of future cardiovascular events than fasting glucose level in nondiabetic individuals. Insulin resistance precedes for decades the clinical onset of type 2 diabetes and deteriorates metabolic control of type 1 diabetes. Numerous investigations including cross-sectional and prospective studies, meta-analyses, and systematic reviews provide compelling evidence that insulin resistance by itself is a cardiovascular risk factor in a variety of population groups, including the general population and patients with diabetes. Several estimations of insulin resistance have been consistently associated with elevated rate of cardiovascular events independently of other cardiovascular risk factors and diabetes status. The clinical expression of insulin resistance (the metabolic syndrome or any of its components including obesity, hyperinsulinemia, hypertension, and dyslipemia) has been related to cardiovascular disease as well. An estimation conducted by the Archimedes model confirms that insulin resistance is the most important single cause of coronary artery disease.

Evolving Pharmacotherapeutic Strategies for Type 1 Diabetes Mellitus

Despite pharmacotherapeutic advancements in the management of type 1 diabetes mellitus during the past several decades, patients struggle to achieve glycemic goals. Additionally, hypoglycemia, especially in extremes of age, decreases quality of life. The lack of optimal glycemic control and risk for hypoglycemia are multifactorial. Nevertheless, endeavors aiming to develop pharmacotherapeutic options with enhanced pharmacokinetic, pharmacodynamic, and clinical profiles continue. This review article discusses recent ventures in 3 categories of insulin, non-insulin, and glucagon products.

Youth With Type 1 Diabetes Have Adipose, Hepatic, and Peripheral Insulin Resistance

CONTEXT

Adolescents with type 1 diabetes (T1D) have difficulty obtaining optimal glucose control, which may relate to insulin resistance (IR), especially during puberty. Moreover, IR increases the risk for cardiovascular disease, the leading cause of death in T1D. However, the tissue specificity of IR in adolescents with T1D has not been fully phenotyped.

OBJECTIVE

To assess adipose, hepatic, and peripheral insulin sensitivity in adolescents with and without T1D.

DESIGN AND SETTING

Thirty-five youth with T1D [median age, 16 (first and third quartiles, 14, 17) years; 53% female; median body mass index (BMI) percentile, 82nd (55th, 96th); late puberty; median hemoglobin A1c, 8.3% (7.3%, 9.4%)] and 22 nondiabetic youth of similar age, BMI, pubertal stage, and level of habitual physical activity were enrolled. Insulin action was measured with a four-phase hyperinsulinemic euglycemic clamp (basal and 10, 16, and 80 mU/m2/min) with glucose and glycerol isotope tracers.

RESULTS

Adolescents with T1D had a significantly higher rate of lipolysis (P < 0.0001) and endogenous glucose production (P < 0.001) and lower peripheral glucose uptake (glucose rate of disappearance, 6.9 ± 2.9 mg/kg/min for patients with T1D vs 11.3 ± 3.3 for controls; P < 0.0001) during hyperinsulinemia compared with controls. In youth with T1D, glucose rate of disappearance correlated with free fatty acid at the 80-mU/m2/min phase (P = 0.005), markers of inflammation (IL-6; P = 0.012), high-sensitivity C-reactive protein (P = 0.001), and leptin (P = 0.008)], but not hemoglobin A1c.

CONCLUSIONS

Adolescents with T1D have adipose, hepatic and peripheral IR. This IR occurs regardless of obesity and metabolic syndrome features. Youth with T1D may benefit from interventions directed at improving IR in these tissues, and this area requires further research.

Commentary on the Impact of Obesity on PediatricDiabetes

While conventionally most children diagnosed with diabetes are thought to have type 1 diabetes mellitus (T1DM), with the increased prevalence of obesity, more are being affected by type 2 (T2) DM. Obesity leads to increased insulin resistance, which over time can lead to progressive β-cell failure and ultimately T2DM. However, patients developing T1DM may also be obese, making both the proper classification and management of diabetes in children more challenging. In this commentary, the authors discuss the impact ofobesity on the presentation of pediatric diabetes, how to differentiate between T1DM and T2DM, and the proper management of both diseases.

Novel blood glucose lowering therapies for managing type 1 diabetes in paediatric patients

INTRODUCTION

Therapy for type 1 diabetes (T1D) is mainly restricted to insulin treatment. The management of paediatric patients with T1D should tackle not only glucose control, but also insulin resistance, beta-cell preservation, quality of life and cardiovascular disease risk factors, which are increasingly recognized to occur in adolescents with T1D.

AREAS COVERED

This review examines the recently published literature from PubMed on non-insulin agents for the management of T1D in paediatric patients.

EXPERT OPINION

Few paediatric patients with T1D are achieving their metabolic targets. Current data support the need for new strategies and the consideration of additional therapies that not only may help patients, their families and their physicians to meet HbA1c targets, but also may preserve residual islet mass and good quality of life and prevent microvascular and macrovascular complications, thereby, reducing hypoglycaemic episodes. Non-insulin adjunctive therapies may improve not only glucose control, but also insulin sensitivity, in addition to preserving beta-cell function in T1D patients. Thus, more studies are required to define the potential role of these therapies in the management of paediatric patients.

A Review of Insulin Resistance in Type 1 Diabetes: Is There a Place for Adjunctive Metformin?

There is a rising trend of overweight and obesity among individuals with type 1 diabetes. This is often associated with insulin resistance, increased insulin dose requirements and poor glycemic control. Insulin resistance is also seen during puberty and is strongly related to increased risk of cardiovascular disease. The role of metformin as an adjunct to ongoing intensive insulin therapy in type 1 diabetics has been evaluated in several randomized trials, including the recently concluded T1D Exchange Network trial in adolescents and the REMOVAL trial in adults. Metformin reduces the insulin dose requirement, insulin-induced weight gain, and total and LDL cholesterol, but results in an increased risk of gastrointestinal adverse effects and a minor increase in the risk of hypoglycemia. In addition, metformin has been shown to reduce maximal carotid intima media thickness and therefore may extend cardioprotective benefits in type 1 diabetes. The role of metformin as adjunctive therapy in type 1 diabetes needs to be explored further in outcome trials.

Epigenetic regulation in B-cell maturation and its dysregulation in autoimmunity

B cells have a critical role in the initiation and acceleration of autoimmune diseases, especially those mediated by autoantibodies. In the peripheral lymphoid system, mature B cells are activated by self or/and foreign antigens and signals from helper T cells for differentiating into either memory B cells or antibody-producing plasma cells. Accumulating evidence has shown that epigenetic regulations modulate somatic hypermutation and class switch DNA recombination during B-cell activation and differentiation. Any abnormalities in these complex regulatory processes may contribute to aberrant antibody production, resulting in autoimmune pathogenesis such as systemic lupus erythematosus. Newly generated knowledge from advanced modern technologies such as next-generation sequencing, single-cell sequencing and DNA methylation sequencing has enabled us to better understand B-cell biology and its role in autoimmune development. Thus this review aims to summarize current research progress in epigenetic modifications contributing to B-cell activation and differentiation, especially under autoimmune conditions such as lupus, rheumatoid arthritis and type 1 diabetes.

Pharmacological Treatment in Diabetes Mellitus Type 1 - Insulin and What Else?

The basis of treatment in autoimmune diabetes is insulin therapy; however, many clinical cases have proven that this method does not solve all problems. Trials of causal treatment including blocking the autoimmune processes and insulin-producing cells transplants were carried out. Those methods require more research to be concerned as efficient and safe ways of treatment in type 1 diabetes. The use of non-insulin adjunct treatment is a new trend. It has been successfully used in laboratories as well as clinical trials. Metformin is the most widely used drug, together with sodium-glucose co-transporters 2 (SGLT2) inhibitors, amylin analogues, glucagon-like peptide 1 (GLP-1) receptor agonists, and dipeptidyl peptidase-4 (DPP-4) inhibitors. The results of administration of these medicaments give good outcomes in patients with diabetes mellitus type 1. Most likely, in the near future, they will progressively be used in both adult and adolescent patients with type 1 diabetes. Further multicenter, randomized studies are required to evaluate the efficacy of treatment and long term safety of these drugs.

Diabetes Modulates MicroRNAs 29b-3p, 29c-3p, 199a-5p and 532-3p Expression in Muscle: Possible Role in GLUT4 and HK2 Repression

The reduced expression of solute carrier family 2, facilitated glucose transporter member 4 (GLUT4) and hexokinase-2 (HK2) in skeletal muscle participates in insulin resistance of diabetes mellitus (DM). MicroRNAs (miRNAs) have emerged as important modulators of mRNA/protein expression, but their role in DM is unclear. We investigated miRNAs hypothetically involved in GLUT4/HK2 expression in soleus muscle of type 1 diabetes-like rats. In silico analysis revealed 651 miRNAs predicted to regulate solute carrier family 2 member 4 (Slc2a4) mRNA, several of them also predicted to regulate Hk2 mRNA, and 16 miRNAs were selected for quantification. Diabetes reduced Slc2a4/GLUT4 and Hk2/HK2 expression (50-77%), upregulated miR-29b-3p and miR-29c-3p (50-100%), and downregulated miR-93-5p, miR-150-5p, miR-199a-5p, miR-345-3p, and miR-532-3p (~30%) expression. Besides, GLUT4 and HK2 proteins correlated (P < 0.05) negatively with miR-29b-3p and miR-29c-3p and positively with miR-199a-5p and miR-532-3p, suggesting that these miRNAs could be markers of alterations in GLUT4 and HK2 expression. Additionally, diabetes increased the nuclear factor kappa B subunit 1 protein (p50) expression, a repressor of Slc2a4, which was also predicted as a target for miR-199a-5p and miR-532-3p. Correlations were also detected between these miRNAs and blood glucose, 24-h glycosuria and plasma fructosamine, and insulin therapy reversed most of the alterations. In sum, we report that diabetes altered miR-29b-3p, miR-29c-3p, miR-199a-5p and miR-532-3p expression in muscle of male rats, where their predicted targets Slc2a4/GLUT4 and Hk2/HK2 are repressed. These data shed light on these miRNAs as a markers of impaired skeletal muscle glucose disposal, and, consequently, glycemic control in diabetes.

Can Fetuin-A Be a Marker for Insulin Resistance and Poor Glycemic Control in Children with Type 1 Diabetes Mellitus?

OBJECTIVE

Metabolic impairment in type 1 diabetes mellitus (T1DM) with poor glycemic control causes insulin resistance, non-alcoholic fatty liver disease (NAFLD), atherosclerosis, and increased carotid intima-media thickness (CIMT). Fetuin-A has a protective effect in cardiovascular disorders and is increased in hepatosteatosis. We aimed to investigate the reliability of fetuin-A levels in early detection of diabetic complications in children with T1DM and to identify a cut-off value that may show poor metabolic control.

METHODS

The study included 80 patients who had T1DM for at least 5 years and who had no chronic complications or an auto-immune disorder. Blood samples were drawn to measure hemoglobin A1c (HbA1c), biochemical parameters, and fetuin-A levels. Anthropometric parameters were also measured. Percent body fat was calculated. Hepatosteatosis and CIMT were assessed by sonography.

RESULTS

Mean age of the patients was 13.5 years. Grade 1 hepatosteatosis was detected in 10%. Patients were stratified into 2 groups based on presence of NAFLD. Fetuin-A level was increased in patients with NAFLD. We identified a fetuin-A cut-off value (514.28 ng/mL; sensitivity: 47.34; specificity: 96.72) that may predict NAFLD. HbA1c and total cholesterol levels were found to be higher in patients with fetuin-A levels above higher the cut-off value.

CONCLUSION

Fetuin-A is a reliable parameter in the prediction of complications and poor glycemic control in patients with T1DM.

Type 1 Diabetes: Disease Stratification

Type 1 diabetes, a disorder characterized by immune-mediated loss of functional pancreatic beta cells, is a disease continuum with specific presymptomatic stages with defined risk of progression to symptomatic disease. Prognostic biomarkers have been developed for disease staging and for stratification of subjects that address the heterogeneity in rate of disease progression. Using biomarkers for stratification of subjects at different stages of type 1 diabetes will enable smaller and shorter intervention clinical trials with greater effect size. Addressing the heterogeneity of the disease will allow precision medicine-based approaches to prevention and interception of presymptomatic stages of disease and treatment and cure of symptomatic disease.

The effect of adding metformin to insulin therapy for type 1 diabetes mellitus children: A systematic review and meta-analysis

We aimed to assess the effectiveness of adding metformin to insulin in type 1 diabetes mellitus (T1DM) children for improving metabolic outcomes. We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) conducted on children age 6 to 19 years who are diagnosed with T1DM, and examined the effect of adding Metformin to standard insulin therapy. We performed literature searches on Ovid Midline, Ovid Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) from the date of inception of the database to February 15, 2016. Two reviewers screened titles and abstracts independently, assessed full text eligibility, and extracted information from eligible trials. The primary outcome is glycated hemoglobin (HbA1c), and the secondary outcomes are health-related quality of life, body mass index (BMI), lipid profile, total insulin daily dose, hypoglycaemia, and diabetes ketoacidosis. We screened 736 studies, and included 6 RCTs with 325 patients. All RCTs were of low risk of bias, and included adolescents (mean age 15 years). The meta-analysis showed that the addition of Metformin resulted in decreased total insulin daily dose (TIDD) (unit/kg/d) (mean difference [MD] = -0.15, 95%CI, -0.24, -0.06), and reduced BMI kg/m² (MD -1.46, 95%CI -2.54, 0.38), and BMI z-score (MD= - 0.11, 95%CI -0.21, -0.01), and similar HbA1c (%) (MD= - 0.05, 95%CI, -0.19, 0.29). The overall evidence quality was high to moderate. Current evidence does not support use of Metformin in T1DM adolescents to improve HbA1c. However, Metformin may provide modest reduction in TIDD and BMI.

Scopoletin Supplementation Ameliorates Steatosis and Inflammation in Diabetic Mice

Scopoletin is a bioactive component in many edible plants and fruits. This study investigated the effects of scopoletin on hepatic steatosis and inflammation in a high-fat diet fed type 1 diabetic mice by comparison with metformin. Scopoletin (0.01%, w/w) or metformin (0.5%, w/w) was provided with a high-fat diet to streptozotocin-induced diabetic mice for 11 weeks. Both scopoletin and metformin lowered blood glucose and HbA_1c , serum ALT, TNF-α and IL-6 levels, glucose intolerance, and hepatic lipid accumulation compared with the diabetic control group. Scopoletin or metformin down-regulated hepatic gene expression of triglyceride (Pparg, Plpp2, and Dgat2) and cholesterol (Hmgcr) synthesis as well as inflammation (Tlr4, Myd88, Nfkb1, Tnfa, and Il6), while it up-regulated Cyp7a1 gene. Hepatic PPARγ and DGAT2 protein levels were also down-regulated in scopoletin or metformin group compared with the control group. Scopoletin or metformin also inhibited hepatic fatty acid synthase and phosphatidate phosphohydrolase activities. These results suggest that scopoletin protects against diabetes-induced steatosis and inflammation by inhibiting lipid biosynthesis and TLR4-MyD88 pathways. Copyright © 2017 John Wiley & Sons, Ltd.

Epigenetics and type 1 diabetes: mechanisms and translational applications

Type 1 diabetes (T1D) is an irreversible degenerative disease with severe complications such as heart disease, nephropathy, neuropathy, and retinopathy. Although exogenous insulin administration is a life-saving therapy, it does not cure the disease. This review addresses the epigenetic mechanisms responsible for the development of T1D and discusses epigenetic-based strategies for prevention and treatment of the disease. We describe novel epigenetic biomarkers for the identification of susceptible individuals and the establishment of innovative therapies with epidrugs and cell therapy to regenerate the lost β-cells. Despite the wealth of promising data regarding the potential benefits of epigenetic tools to reduce the burden of T1D, clinical trials are still very few, and this issue needs to be resolved in the near future.

Comparison of adjunctive therapy with metformin and acarbose in patients with Type-1 diabetes mellitus

Objective:

All the aforementioned data have stimulated interest in studying other potential therapies for T1DM including noninsulin pharmacological therapies. The present study attempts to investigate the effect of adjunctive therapy with metformin and acarbose in patients with Type-1 diabetes mellitus.

Method:

In a single-center, placebo-controlled study (IRCT201102165844N1) we compared the results of two clinical trials conducted in two different time periods on 40 patients with Type-1 diabetes mellitus. In the first section, metformin was given to the subjects. After six months, metformin was replaced with acarbose in the therapeutic regimen. In both studies, subjects were checked for their BMI, FBS, HbA1C, TGs, Cholesterol, LDL, HDL, 2hpp, unit of NPH and regular insulin variations.

Results:

Placebo-controlled evaluation of selected factors has showna significant decrease in FBS and TG levels in the metformin group during follow up but acarbose group has shown substantial influence on two hour post prandial (2hpp) and regular insulin intake decline. Moreover, Comparison differences after intervention between two test groups has shown that metformin has had superior impact on FBS and HbA1C decline in patients. Nonetheless, acarbose treatment had noteworthy influence on 2hpp, TGs, Cholesterol, LDL, and regular insulin intake control.

Conclusion:

The results of this experiment demonstrate that the addition of acarbose or metformin to patients with Type-1 diabetes mellitus who are controlled with insulin is commonly well tolerated and help to improve metabolic control in patients.

Metformin; a review of its history and future: from lilac to longevity

Metformin is a widely prescribed medication that has been used to treat children with type 2 diabetes in the United States for the past 15 years. Metformin now has a variety of clinical applications in pediatrics, and its potential clinical uses continue to expand. In addition to reviewing the current understanding of its mechanisms of action including the newly discovered effects on the gastrointestinal tract, we will also discuss current clinical uses in pediatrics, including in type 1 diabetes. Finally, we examine the existing state of monitoring for metformin efficacy and side effects and discuss prospective future clinical uses.

The Effect of Metformin on Adolescents with Type 1 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background. The effect of metformin in combination with insulin in adolescents with type 1 diabetes (T1DM) is controversial. Methods and Results. The PubMed and EMBASE online databases were searched. Five double-blind randomized controlled trials (RCTs) that included 301 adolescents with T1DM were identified. Metformin plus insulin was associated with reduced hemoglobin A1C levels, total daily insulin dosage, body mass index (BMI), and body weight. However, the subgroup analysis demonstrated that HbA1c levels were not significantly changed in overweight/obese adolescents and were significantly reduced in the general patients. On the contrary, BMI and body weight were significantly reduced in overweight/obese adolescents but not in the general patients. Metformin was associated with higher incidence of adverse events. Conclusions. Among adolescents with T1DM, administering adjunctive metformin therapy in addition to insulin was associated with improved HbA1c levels, total daily insulin dosage, BMI, and body weight. However, there may be differences in the effects of this regimen between overweight/obese and nonobese adolescents. The risk of an adverse event may be increased with metformin treatment. These results provide strong evidence supporting future high-quality, large-sample trials.

Resveratrol improves glycemic control in insulin-treated diabetic rats: participation of the hepatic territory

BACKGROUND

Resveratrol is a natural polyphenol that has been proposed to improve glycemic control in diabetes, by mechanisms that involve improvement in insulin secretion and activity. In type 1 diabetes (T1D), in which insulin therapy is obligatory, resveratrol treatment has never been investigated. The present study aimed to evaluate resveratrol as an adjunctive agent to insulin therapy in a T1D-like experimental model.

METHODS

Rats were rendered diabetic by streptozotocin (STZ) treatment. Twenty days later, four groups of animals were studied: non-diabetic (ND); diabetic treated with placebo (DP); diabetic treated with insulin (DI) and diabetic treated with insulin plus resveratrol (DIR). After 30 days of treatment, 24-hour urine was collected; then, blood, soleus muscle, proximal small intestine, renal cortex and liver were sampled. Specific glucose transporter proteins were analyzed (Western blotting) in each territory of interest. Solute carrier family 2 member 2 (Slc2a2), phosphoenolpyruvate carboxykinase (Pck1) and glucose-6-phosphatase catalytic subunit (G6pc) mRNAs (qPCR), glycogen storage and sirtuin 1 (SIRT1) activity were analyzed in liver.

RESULTS

Diabetes induction increased blood glucose, plasma fructosamine concentrations, and glycosuria. Insulin therapy partially recovered the glycemic control; however, resveratrol as adjunctive therapy additionally improved glycemic control and restored plasma fructosamine concentration to values of non-diabetic rats. Resveratrol did not alter the expression of the glucose transporters GLUT2 and SGLT1 in the intestine, GLUT2 and SGLT2 in kidney and GLUT4 in soleus, suggesting that fluxes of glucose in these territories were unaltered. Differently, in liver, resveratrol promoted a reduction in Slc2a2, Pck1, and G6pc mRNAs, as well as in GLUT2 protein (P < 0.05, DIR vs. DI); besides, it increased (P < 0.01, DIR vs. DI) the hepatic glycogen content, and SIRT1 protein.

CONCLUSIONS

Resveratrol is able to improve glycemic control in insulin-treated T1D-like rats. This effect seems not to involve changes in glucose fluxes in the small intestine, renal proximal tubule, and soleus skeletal muscle; but to be related to several changes in the liver, where downregulation of Slc2a2/GLUT2, Pck1, and G6pc expression was observed, favoring reduction of glucose production and efflux. Besides, resveratrol increased SIRT1 nuclear protein content in liver, which may be related to the observed gene expression regulations.