The addition of rosiglitazone to insulin in adolescents with type 1 diabetes and poor glycaemic control: a randomized-controlled trial

Fatty acid-mediated signaling as a target for developing type 1 diabetes therapies

INTRODUCTION

Type 1 diabetes (T1D) is an autoimmune disease in which pro-inflammatory and cytotoxic signaling drive the death of the insulin-producing β cells. This complex signaling is regulated in part by fatty acids and their bioproducts, making them excellent therapeutic targets.

AREAS COVERED

We provide an overview of the fatty acid actions on β cells by discussing how they can cause lipotoxicity or regulate inflammatory response during insulitis. We also discuss how diet can affect the availability of fatty acids and disease development. Finally, we discuss development avenues that need further exploration.

EXPERT OPINION

Fatty acids, such as hydroxyl fatty acids, ω-3 fatty acids, and their downstream products, are druggable candidates that promote protective signaling. Inhibitors and antagonists of enzymes and receptors of arachidonic acid and free fatty acids, along with their derived metabolites, which cause pro-inflammatory and cytotoxic responses, have the potential to be developed as therapeutic targets also. Further, because diet is the main source of fatty acid intake in humans, balancing protective and pro-inflammatory/cytotoxic fatty acid levels through dietary therapy may have beneficial effects, delaying T1D progression. Therefore, therapeutic interventions targeting fatty acid signaling hold potential as avenues to treat T1D.

Differences in insulin sensitivity in the partial remission phase of childhood type 1 diabetes; a longitudinal cohort study

AIMS

Studies suggest that type 1 diabetes (T1D) contributes to impaired insulin sensitivity (IS). Most children with T1D experience partial remission but the knowledge regarding the magnitude and implications of impaired IS in this phase is limited. Therefore, we investigate the impact of IS on the partial remission phase.

METHODS

In a longitudinal study of children and adolescents, participants were seen at three clinical visits during the first 14.5 months after diagnosis of T1D. Partial remission was defined as IDAA_1c (HbA_1c (%) + 4*daily insulin dose) ≤ 9. Beta-cell function was considered significant by a stimulated c-peptide > 300 pmol/L. Participants were characterized by (i) remission or non-remission and (ii) stimulated c-peptide levels above or below 300 pmol/L. IS, body mass index (BMI), total body fat, sex, age, pubertal status and ketoacidosis at onset were compared.

RESULTS

Seventy-eight children and adolescents aged 3.3-17.7 years were included. At 14.5 months post-diagnosis, 54.5% of the participants with stimulated c-peptide > 300 pmol/L were not in partial remission. Participants not in remission had significant lower IS 2.5 (p = 0.032), and 14.5 (p = 0.022) months after diagnosis compared to participants in partial remission with similar c-peptide levels. IS did not fluctuate during the remission phase.

CONCLUSIONS

A number of children and adolescents have impaired IS in the remission phase of paediatric T1D and are not in remission 14.5 months after diagnosis despite stimulated c-peptide > 300 pmol/L.

Non-insulin pharmacological therapies for treating type 1 diabetes

INTRODUCTION

Despite intensified insulin treatment, many persons with type 1 diabetes (T1D) do not achieve glycemic and metabolic targets. Consequently, non-insulin chemical therapies that improve glycemic control and metabolic parameters without increasing the risk of adverse events (including hypoglycemia) are of interest as adjunct therapies to insulin.

AREAS COVERED

In this review, the authors discuss the efficacy and safety of non-insulin therapies, including pramlintide, glucagon-like peptide-1 (GLP-1) receptor agonists, dipeptidyl peptidase-4 inhibitors (DPP-4), sodium-glucose cotransporter (SGLT1 and SGLT2) inhibitors, metformin, sulfonylureas, and thiazolidinediones as add-on therapies to insulin in T1D.

EXPERT OPINION

The current evidence shows that the efficacy of non-insulin therapies as add-on therapies to insulin is minimal or modest with an average HbA1c reduction of 0.2-0.5% (2-6 mmol/mol). Indeed, the current focus is on the development of SGLT inhibitors as adjuncts to insulin in type 1 diabetes. Studies of subgroups with obesity, residual beta-cell function (including newly diagnosed patients) and patients prone to hypoglycemia could be areas of future research.

Adjuvant Pharmacotherapies to Insulin for the Treatment of Type 1 Diabetes

PURPOSE OF REVIEW

Insulin therapy alone fails to achieve target glycemic control in the majority of individuals with type 1 diabetes (T1D), motivating the investigation of additive medications. This review focuses on the recent findings on the use of adjunctive pharmacotherapy in T1D.

RECENT FINDINGS

Metformin and glucagon-like peptide-1 receptor agonists have been associated with weight reduction and decrease in daily insulin requirements without sustainable improvement in glycemic control. Sodium-glucose cotransporter (SGLT)-2 inhibitors, dual SGLT-1/2 inhibitors, and pramlintide have been shown to reduce hemoglobin A1c, induce weight loss, and lower insulin dose. The benefits of dipeptidyl peptidase-4 inhibitors, thiazolidinediones, and alpha glucosidase inhibitors appear to be more limited. Gastrointestinal symptoms and increased hypoglycemia are adverse effects of certain classes. Although not devoid of side effects, additive pharmacotherapies in T1D can improve glycemic control and lower body weight and insulin requirement. Longer studies are needed before consideration for widespread clinical care.

Role of sodium glucose cotransporter-2 inhibitors in type I diabetes mellitus

The burden of diabetes mellitus (DM) in general has been extensively increasing over the past few years. Selective sodium glucose cotransporter-2 (SGLT2) inhibitors were extensively studied in type 2 DM and found to have sustained urinary glucose loss, improvement of glycemic control, in addition to their proven metabolic effects on weight, blood pressure, and cardiovascular benefits. Type 1 DM (T1D) patients clearly depend on insulin therapy, which till today fails to achieve the optimal glycemic control and metabolic targets that are needed to prevent risk of complications. New therapies are obviously needed as an adjunct to insulin therapy in order to try to achieve optimal control in T1D. Many oral diabetic medications have been tried in T1D patients as an adjunct to insulin treatment and have shown conflicting results. Adjunctive use of SGLT2 inhibitors in addition to insulin therapies in T1D was found to have the potential to improve glycemic control along with decrease in the insulin doses, as has been shown in certain animal and short-term human studies. Furthermore, larger well-randomized studies are needed to better evaluate their efficacy and safety in patients with T1D. Euglycemic diabetic ketoacidosis incidences were found to be increased among users of SGLT2 inhibitors, although the incidence remains very low. Recent beneficial effects of ketone body production and this shift in fuel energetics have been suggested based on the findings of protective cardiovascular benefits associated with one of the SGLT2 inhibitors.

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

Type 1 diabetes mellitus (T1DM) in youth is a challenging chronic medical condition. Its management should address not only the glycemic control but also insulin resistance and cardiovascular disease risk factors which are increasingly recognized to be present in youth with TID. Current knowledge on the mechanisms of insulin resistance in T1DM is reviewed. The use of adjunctive therapies that are beneficial to achieve adequate glycemic control while mitigating the effects of insulin resistance are discussed with a focus on metformin therapy and an overview of other new pharmacologic agents.

Non-insulin drugs to treat hyperglycaemia in type 1 diabetes mellitus

Insulin treatment of individuals with type 1 diabetes has shortcomings and many patients do not achieve glycaemic and metabolic targets. Consequently, the focus is on novel non-insulin therapeutic approaches that reduce hyperglycaemia and improve metabolic variables without increasing the risk of hypoglycaemia or other adverse events. Several therapies given in conjunction with insulin have been investigated in clinical trials, including pramlintide, glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase-4 inhibitors, sodium-glucose co-transporter inhibitors, metformin, sulfonylureas, and thiazolidinediones. These drugs have pleiotropic effects on glucose metabolism and different actions complementary to those of insulin-this Review reports the effects of these drugs on glycaemic control, glucose variability, hypoglycaemia, insulin requirements, and bodyweight. Existing studies are of short duration with few participants; evidence for the efficacy of concomitant treatments is scarce and largely clinically insignificant. A subgroup of patients with type 1 diabetes for whom non-insulin antidiabetic drugs could significantly benefit glycaemic control cannot yet be defined, but we suggest that obese patients prone to hypoglycaemia and patients with residual β-cell function are populations of interest for future trials.

Ophiocordyceps formosana improves hyperglycemia and depression-like behavior in an STZ-induced diabetic mouse model

Background

A newly defined Cordyceps species, Ophiocordyceps formosana (O. formosana) has been implicated in multitudinous bioactivities, including lowering glucose and cholesterol levels and modulating the immune system. However, few literatures demonstrate sufficient evidence to support these proposed functions. Although the use of Cordyceps spp. has been previously addressed to improve insulin insensitivity and improve the detrimental symptoms of depression; its mechanistic nature remains unsettled. Herein, we reveal the effects of O. formosana in ameliorating hyperglycemia accompanied with depression.

Methods

Diabetes was induced in mice by employing streptozotocin(STZ), a chemical that is toxic to insulin-producing β cells of the pancreas. These streptozotocin (STZ)-induced diabetic mice showed combined symptoms of hyperglycemia and depressive behaviors. Twenty-four STZ-induced mice were randomly divided into 3 groups subjected to oral gavage with 100 μL solution of either PBS or 25 mg/mL Ophiocordyceps formosana extract (OFE) or 2 mg/mL rosiglitazone (Rosi, positive control group). Treatments were administered once per day for 28 days. An additional 6 mice without STZ induction were treated with PBS to serve as the control group. Insulin sensitivity was measured by a glucose tolerance test and levels of adiponectin in plasma and adipose tissue were also quantified. Behavioral tests were conducted and levels of monoamines in various brain regions relating to depression were evaluated.

Results

HPLC analysis uncovered three major constituents, adenosine, D-mannitol and cordycepin, within O. formosana similar to other prestigious medicinal Cordyceps spp.. STZ-induced diabetic mice demonstrated decreased body weight and subcutaneous adipose tissue, while these symptoms were recovered in mice receiving OFE treatment. Moreover, the OFE group displayed improved insulin sensitivity and elevated adiponectin within the plasma and adipose tissue. The anti-depressive effect of OFE was observed in various depression-related behavior tests. Concurrently, neurotransmitters, like 5-HT and dopamine in the frontal cortex, striatum and hippocampus were found to be up-regulated in OFE-treated mice.

Conclusions

Our findings illustrated, for the first time, the medicinal merits of O. formosana on Type I diabetes and hyperglycemia-induced depression. OFE were found to promote the expression of adiponectin, which is an adipokine involved in insulin sensitivity and hold anti-depressive effects. In addition, OFE administration also displayed altered levels of neurotransmitters in certain brain regions that may have contributed to its anti-depressive effect. Collectively, this current study provided insights to the potential therapeutic effects of O. formosana extracts in regards to hyperglycemia and its depressive complications.

Management of Severe Insulin Resistance in Patients with Type 1 Diabetes

Managing severe insulin resistance (IR) in patients with type 1 diabetes (T1DM) can be challenging for both clinicians and patients. As average weight for patients with T1DM has increased in recent decades, IR in this population has become more widespread. Currently, almost 50 % of patients with T1DM are overweight or obese. While intensive insulin therapy is associated with reduction in complications, aggressive treatment can lead to weight gain. With increasing weight, insulin can become less effective to control glycemia, resulting in higher insulin doses and hence more weight gain. Novel strategies to break this vicious cycle are needed. This review will investigate current research on insulin formulations, lifestyle modification, adjunct therapies, and surgery that may help better manage patients with T1DM and IR.

Adiponectin-SOGA Dissociation in Type 1 Diabetes

CONTEXT

Circulating adiponectin is elevated in human type 1 diabetes (T1D) and nonobese diabetic (NOD) mice without the expected indications of adiponectin action, consistent with tissue resistance.

OBJECTIVE

Adiponectin stimulates hepatocyte production of the suppressor of glucose from autophagy (SOGA), a protein that inhibits glucose production. We postulated that due to tissue resistance, the elevation of adiponectin in T1D should fail to increase the levels of a surrogate marker for liver SOGA, the circulating C-terminal SOGA fragment.

MAIN OUTCOME MEASURES

Liver and plasma SOGA were measured in NOD mice (n = 12) by Western blot. Serum adiponectin and SOGA were measured in T1D and control (Ctrl) participants undergoing a three-stage insulin clamp for the Coronary Artery Calcification in T1D study (n = 20). Glucose turnover was measured using 6,6[(2)H2]glucose (n = 12).

RESULTS

In diabetic NOD mice, the 13%-29% decrease of liver SOGA (P = .003) and the 30%-37% reduction of circulating SOGA (P < .001) were correlated (r = 0.826; P = .001). In T1D serum, adiponectin was 50%-60% higher than Ctrl, SOGA was 30%-50% lower and insulin was 3-fold higher (P < .05). At the low insulin infusion rate (4 mU/m(2)·min), the resulting glucose appearance correlated negatively with adiponectin in T1D (r = -0.985, P = .002) and SOGA in Ctrl and T1D (r = -0.837, P = .001). Glucose disappearance correlated with adiponectin in Ctrl (r = -0.757, P = .049) and SOGA in Ctrl and T1D (r = -0.709, P = .010). At 40 mU/m(2)·min, the lowered glucose appearance was similar in Ctrl and T1D. Glucose disappearance increased only in Ctrl (P = .005), requiring greater glucose infusion to maintain euglycemia (8.58 ± 1.29 vs 3.09 ± 0.87 mg/kg·min; P = .009).

CONCLUSIONS

The correlation between liver and plasma SOGA in NOD mice supports the use of the latter as surrogate marker for liver concentration. Reduced SOGA in diabetic NOD mice suggests resistance to adiponectin. The dissociation between adiponectin and SOGA in T1D raises the possibility that restoring adiponectin signaling and SOGA might improve the metabolic response to insulin therapy.

Effect of Rosiglitazone and Insulin Combination Therapy on Inflammation Parameters and Adipocytokine Levels in Patients with Type 1 DM

AIM

To investigate the efficacy of combined therapy of insulin and rosiglitazone on metabolic and inflammatory parameters, insulin sensitivity, and adipocytokine levels in patients with type 1 diabetes mellitus (type 1 DM).

MATERIAL AND METHODS

A total of 61 adults with type 1 DM were randomly and prospectively assigned in open-label fashion to take insulin and rosiglitazone 4 mg/day (n = 30) or insulin alone (n = 31) for a period of 18 weeks while undergoing insulin therapy without acute metabolic complications.

RESULTS

Combination therapy did not significantly improve metabolic and inflammatory parameters, insulin sensitivity, and adiponectin levels. While leptin and resistin levels decreased in both groups (group 1: resistin 6.96 ± 3.06 to 4.99 ± 2.64, P = 0.006; leptin 25.8 ± 17.6 to 20.1 ± 12.55, P = 0.006; group 2: resistin 7.16 ± 2.30 to 5.57 ± 2.48, P = 0.031; leptin 16.72 ± 16.1 to 14.0 ± 13.4, P = 0.007) Hgb and fibrinogen levels decreased only in group 1 (Hgb 13.72 ± 1.98 to 13.16 ± 1.98, P = 0.015, and fibrinogen 4.00 ± 1.08 to 3.46 ± 0.90, P = 0.002). Patients in both groups showed weight gain and the incidence of hypoglycemia was not lower.

DISCUSSION

The diverse favorable effects of TZDs were not fully experienced in patients with type 1 DM. These results are suggesting that insulin sensitizing and anti-inflammatory characteristics of TZDs were likely to be more pronounced in patients who were not totally devoid of endogenous insulin secretion.

Treatment effects on measures of body composition in the TODAY clinical trial

OBJECTIVE

The Treatment Options for type 2 Diabetes in Adolescents and Youth (TODAY) trial showed superiority of metformin plus rosiglitazone (M+R) over metformin alone (M), with metformin plus lifestyle (M+L) intermediate in maintaining glycemic control. We report here treatment effects on measures of body composition and their relationships to demographic and metabolic variables including glycemia.

RESEARCH DESIGN AND METHODS

Measures of adiposity (BMI, waist circumference, abdominal height, percent and absolute fat, and bone mineral content [BMC] and density [BMD]) were analyzed as change from baseline at 6 and 24 months.

RESULTS

Measures of fat accumulation were greatest in subjects treated with M+R and least in M+L. Although fat measures in M+L were less than those of M+R and M at 6 months, differences from M were no longer apparent at 24 months, whereas differences from M+R persisted at 24 months. The only body composition measure differing by race and/or ethnicity was waist circumference, greater in M+R than either M or M+L at both 6 and 24 months in whites. BMD and BMC increased in all groups, but increased less in M+R compared with the other two groups by 24 months. Measures of adiposity (increases in BMI, waist circumference, abdominal height, and fat) were associated with reduced insulin sensitivity and increased hemoglobin A1c (HbA1c), although effects of adiposity on HbA1c were less evident in those treated with M+R.

CONCLUSIONS

Despite differential effects on measures of adiposity (with M+R resulting in the most and M+L in the least fat accumulation), group differences generally were small and unrelated to treatment effects in sustaining glycemic control.

Noninsulin pharmacological management of type 1 diabetes mellitus

The injectable nature and other shortcomings of insulin have stimulated interest in studying the noninsulin pharmacological therapies to manage type 1 diabetes mellitus (T1DM). The purpose of this study is to conduct a systematic literature review of noninsulin pharmacological therapies for the management of T1DM. For this, the following PubMed search was conducted: Diabetes Mellitus, Type 1/therapy"[Mesh]

LIMITS

Review Sort by: Publication Date. After applying various inclusion and exclusion criteria, a total of 63 studies were reviewed. Based on this review, noninsulin pharmacological therapies can be divided into following classes: (1) Insulin-sensitizing agents (biguanides and thiazolidinediones), (2) gastrointestinal nutrient absorption modulators (α-Glucosidase inhibitors and amylin), (3) immunotherapeutic agents, (4) incretin-based therapies, (5) recombinant human insulin-like growth factors, and (6) other promising therapeutics. Some of these are already used either as monotherapy or adjuvant to insulin, whereas, to manage T1DM, the benefits and risks of the others are still under evaluation. Nonetheless, insulin still remains the cornerstone to manage the T1DM.

Childhood obesity and environmental chemicals

Childhood and adolescent rates of obesity and overweight are continuing to increase in much of the world. Risk factors such as diet composition, excess caloric intake, decreased exercise, genetics, and the built environment are active areas of etiologic research. The obesogen hypothesis, which postulates that prenatal and perinatal chemical exposure can contribute to risk of childhood and adolescent obesity, remains relatively underexamined. This review surveys numerous classes of chemicals for which this hypothesis has been explored. We focus on human data where they exist and also discuss the findings of rodent and cell culture studies. Organochlorine chemicals as well as several classes of chemicals that are peroxisome proliferator-activated receptor agonists are identified as possible risk factors for obesity. Recommendations for future epidemiologic and experimental research on the chemical origins of obesity are also given.

Approach to the obese adolescent with new-onset diabetes

The prevalence of both type 1 and type 2 diabetes among children and adolescents has been steadily increasing over the last few decades. However, as the general pediatric population becomes more obese and more ethnically diverse, reliance on phenotypic characteristics for distinguishing between these types of diabetes is becoming increasingly untenable. Yet, the recognition of differences in treatment strategies, associated disorders, and both short- and long-term diabetes and cardiovascular outcomes supports the importance of diagnostic efforts to make a distinction between diabetes types. An approach to determination of diabetes type is discussed, focused on the presence or absence of autoimmunity and assessment of β-cell function. At the time of diagnosis, it is generally not possible to be certain of diabetes type, and therefore, initial treatment decisions must be made based on aspects of the presenting physiology, with adjustments in treatment approach made as the individual's course proceeds and additional information becomes available. The apparent overlap between type 1 and type 2 diabetes that occurs in obese adolescents has resulted in some controversy regarding mixed forms of diabetes that are ultimately semantic, but this does raise interesting questions about the treatment of type 1 diabetes in the presence of an insulin-resistant phenotype. Finally, the lack of information about the efficacy of treatment of cardiovascular risk factors, such as dyslipidemia and hypertension, along with the well-documented challenges in adherence to chronic illness treatment in this population, creates substantial challenges.