Exenatide Increases IL-1RA Concentration and Induces Nrf-2‒Keap-1‒Regulated Antioxidant Enzymes: Relevance to β-Cell Function

PURPOSE

We previously demonstrated the anti-inflammatory and antioxidant effects of exenatide. We now hypothesized that exenatide also increases the plasma concentration of interleukin-1 receptor antagonist (IL-1RA), an endogenous anti-inflammatory protein, and modulates the nuclear factor erythroid 2‒related factor‒Kelchlike ECH-associated protein 1‒antioxidant response element (Nrf-2‒Keap-1‒ARE) system to induce key antioxidant enzymes to suppress inflammatory and oxidative stress.

METHODS

Twenty-four patients with obesity and type 2 diabetes receiving combined oral and insulin therapy were randomly assigned to receive either exenatide 10 μg or placebo twice a day for 12 weeks.

RESULTS

Exenatide increased IL-1RA concentration by 61% (from 318 ± 53 to 456 ± 88 pg/mL; P < 0.05). Exenatide treatment also suppressed Keap-1 protein (P < 0.05) and increased messenger RNA expression of NQO-1, glutathione S-transferase PI, heme oxygenase-1, and p21 and increased NAD(P)H dehydrogenase [quinone] 1 protein (P < 0.05) in mononuclear cells.

CONCLUSIONS

Because IL-1RA protects, maintains, and stimulates β-cell function in humans and Nrf-2‒Keap-1‒ARE protects β cells in animals with experimental diabetes, these actions of exenatide may contribute to a potential protective effect on β cells in diabetes.

Diminished androgen and estrogen receptors and aromatase levels in hypogonadal diabetic men: reversal with testosterone

AIMS

One-third of males with type 2 diabetes (T2DM) have hypogonadism, characterized by low total and free testosterone concentrations. We hypothesized that this condition is associated with a compensatory increase in the expression of androgen receptors (AR) and that testosterone replacement reverses these changes. We also measured estrogen receptor and aromatase expression.

MATERIALS AND METHODS

This is a randomized double-blind placebo-controlled trial. Thirty-two hypogonadal and 32 eugonadal men with T2DM were recruited. Hypogonadal men were randomized to receive intramuscular testosterone or saline every 2 weeks for 22 weeks. We measured AR, ERα and aromatase expression in peripheral blood mononuclear cells (MNC), adipose tissue and skeletal muscle in hypogonadal and eugonadal males with T2DM at baseline and after 22 weeks of treatment in those with hypogonadism.

RESULTS

The mRNA expression of AR, ERα (ESR1) and aromatase in adipose tissue from hypogonadal men was significantly lower as compared to eugonadal men, and it increased significantly to levels comparable to those in eugonadal patients with T2DM following testosterone treatment. AR mRNA expression was also significantly lower in MNC from hypogonadal patients compared to eugonadal T2DM patients. Testosterone administration in hypogonadal patients also restored AR mRNA and nuclear extract protein levels from MNC to that in eugonadal patients. In the skeletal muscle, AR mRNA and protein expression are lower in men with hypogonadism. Testosterone treatment restored AR expression levels to that comparable to levels in eugonadal men.

CONCLUSIONS

We conclude that, contrary to our hypothesis, the expression of AR, ERα and aromatase is significantly diminished in hypogonadal men as compared to eugonadal men with type 2 diabetes. Following testosterone replacement, there is a reversal of these deficits.

Incretins: Beyond type 2 diabetes

While the use of incretins, including GLP-1 receptor agonists and PDD-IV inhibitors, is well established in the treatment of type 2 diabetes, many other aspects of these agents are yet to be discovered and utilized for their potential clinical benefit. These include the potential role of GLP-1 receptor agonists in the induction of weight loss, blood pressure reduction, anti-inflammatory and nephro- and cardio-protective actions. Their potential benefit in type 1 diabetes is also being investigated. This review will attempt to comprehensively describe novel discoveries in the field of incretin pathophysiology and pharmacology beyond their classical role in the treatment of type 2 diabetes.

Intranasal Insulin Administration Does Not Affect LH Concentrations in Men with Diabetes

A quarter of men with obesity or type 2 diabetes have hypogonadotropic hypogonadism. Animal studies and in vitro data have shown that insulin action and insulin responsiveness in the brain are necessary for the maintenance of the functional integrity of the hypothalamo-hypophyseal-gonadal axis. We conducted a randomized, placebo-controlled trial to evaluate the effect of one dose of intranasal insulin (40 IU of regular insulin) or saline on LH concentrations in 14 men (8 with type 2 diabetes and 6 healthy lean men). Insulin or saline was administered intranasally on two different occasions, at least one week apart. Blood samples were collected to measure LH concentrations every 15 minutes for 5 hours. Study drug was administered intranasally after a 2-hour baseline sampling period. Patients remained fasting throughout the procedure. The primary endpoint of the study was to compare the change in LH concentrations after intranasal insulin as compared to placebo (intranasal saline). Change was defined as the difference between baseline LH concentrations (average of the 9 samples collected in two hours prior to drug administration) and average LH concentrations following drug administration (average of the 12 samples collected in 3 hours). There was no change in LH concentrations following insulin administration as compared to placebo in men with diabetes or in lean men. We conclude that one dose of 40 IU of regular insulin administered intranasally does not change LH concentrations acutely in men.

Efficacy and safety of dapagliflozin in patients with inadequately controlled type 1 diabetes (DEPICT-1): 24 week results from a multicentre, double-blind, phase 3, randomised controlled trial

BACKGROUND

Dapagliflozin is a sodium-glucose cotransporter-2 inhibitor approved for the treatment of type 2 diabetes. We aimed to assess the efficacy and safety of dapagliflozin as an add-on to adjustable insulin in patients with inadequately controlled type 1 diabetes.

METHODS

DEPICT-1 was a double-blind, randomised, parallel-controlled, three-arm, phase 3, multicentre study done at 143 sites in 17 countries. Eligible patients were aged 18-75 years and had inadequately controlled type 1 diabetes (HbA_1c between ≥7·7% and ≤11·0% [≥61·0 mmol/mol and ≤97·0 mmol/mol]) and had been prescribed insulin for at least 12 months before enrolment. After an 8 week lead-in period to optimise diabetes management, patients were randomly assigned (1:1:1) using an interactive voice response system to dapagliflozin 5 mg or 10 mg once daily, given orally, or matched placebo. Randomisation was stratified by current use of continuous glucose monitoring, method of insulin administration, and baseline HbA_1c. The primary efficacy outcome was the change from baseline in HbA_1c after 24 weeks of treatment in the full analysis set, which consisted of all randomly assigned patients who received at least one dose of study drug. An additional 55 patients who were incorrectly and non-randomly allocated to only dapagliflozin treatment groups were included in the safety analysis set. This study was registered with ClinicalTrials.gov, number NCT02268214; data collection for the present analysis was completed on Jan 4, 2017, and a 28 week extension phase is ongoing.

FINDINGS

Between Nov 11, 2014, and April 16, 2016, 833 patients were assigned to treatment groups and included in safety analyses (dapagliflozin 5 mg [n=277] vs dapagliflozin 10 mg [n=296] vs placebo [n=260]; 778 of these patients were randomly assigned and included in the full analysis set for efficacy analyses (259 vs 259 vs 260; difference due to randomisation error affecting 55 patients). Mean baseline HbA_1c was 8·53% (70 mmol/mol; SD 0·67% [7·3 mmol/mol]). At week 24, both doses of dapagliflozin significantly reduced HbA_1c compared with placebo (mean difference from baseline to week 24 for dapagliflozin 5 mg vs placebo was -0·42% [95% CI -0·56 to -0·28; p<0·0001] and for dapagliflozin 10 mg vs placebo was -0·45% [-0·58 to -0·31; p<0·0001]). Among patients in the dapagliflozin 5 mg (n=277), dapagliflozin 10 mg (n=296), and placebo (n=260) groups, the most common adverse events were nasopharyngitis (38 [14%] vs 36 [12%] vs 39 [15%]), urinary tract infection (19 [7%] vs 11 [4%] vs 13 [5%]), upper respiratory tract infection (15 [5%] vs 15 [5%] vs 11 [4%]), and headache (12 [4%] vs 17 [6%] vs 11 [4%]). Hypoglycaemia occurred in 220 (79%), 235 (79%), and 207 (80%) patients in the dapagliflozin 5 mg, dapagliflozin 10 mg, and placebo groups, respectively; severe hypoglycaemia occurred in 21 (8%), 19 (6%), and 19 (7%) patients, respectively. Adjudicated definite diabetic ketoacidosis occurred in four (1%) patients in the dapagliflozin 5 mg group, five (2%) in the dapagliflozin 10 mg group, and three (1%) in the placebo group.

INTERPRETATION

Our results suggest that dapagliflozin is a promising adjunct treatment to insulin to improve glycaemic control in patients with inadequately controlled type 1 diabetes.

FUNDING

AstraZeneca and Bristol-Myers Squibb.

Minimizing Glycemic Fluctuations in Patients with Type 2 Diabetes: Approaches and Importance

Glycemic fluctuations, characterized by short-term oscillations in plasma glucose, are important when managing type 2 diabetes (T2D) and may be considered a target of glucose-lowering therapies. Continuous glucose monitoring (CGM) has been used to evaluate the effects of different treatments on glycemic fluctuations. This review examines approaches to and the importance of minimizing glycemic fluctuations among patients with T2D. Measures of HbA_1c, fructosamine, and glycated albumin reflect a long-term average of plasma glucose, and are therefore unable to provide an accurate measure of short-term glycemic oscillations. CGM provides accurate monitoring of real-time glucose fluctuations and has been used to investigate the effects of lifestyle and treatment on daily glycemic control. Dipeptidyl peptidase-4 inhibitors, sodium-glucose cotransporter 2 inhibitors, and glucagon-like peptide-1 receptor agonists have demonstrated significant improvements in measures such as the mean amplitude of glucose excursions and standard deviation of CGM. Case studies of two patients with T2D utilizing CGM are also included in this review, which demonstrated that CGM was a useful tool for diagnosing unrecognized hypoglycemia and hyperglycemia in situations in which it was impractical to check fingerstick concentrations. Altogether, the evidence suggests that glycemic fluctuations are a potential target to consider when managing T2D. CGM allows for the real-time evaluation of glycemic fluctuations and may assist in the development of an individualized treatment plan to adequately control short-term oscillations in blood glucose levels.

Liraglutide acutely suppresses glucagon, lipolysis and ketogenesis in type 1 diabetes

In view of the occurrence of diabetic ketoacidosis associated with the use of sodium-glucose transport protein-2 inhibitors in patients with type 1 diabetes (T1DM) and the relative absence of this complication in patients treated with liraglutide in spite of reductions in insulin doses, we investigated the effect of liraglutide on ketogenesis. Twenty-six patients with inadequately controlled T1DM were randomly divided into 2 groups of 13 patients each. After an overnight fast, patients were injected, subcutaneously, with either liraglutide 1.8 mg or with placebo. They were maintained on their basal insulin infusion and were followed up in our clinical research unit for 5 hours. The patients injected with placebo maintained their glucose and glucagon concentrations without an increase, but there was a significant increase in free fatty acids (FFA), acetoacetate and β-hydoxybutyrate concentrations. In contrast, liraglutide significantly reduced the increase in FFA, and totally prevented the increase in acetoacetate and β-hydroxybutyrate concentrations while suppressing glucagon and ghrelin concentrations. Thus, a single dose of liraglutide is acutely inhibitory to ketogenesis.

Dapagliflozin in patients with type 1 diabetes: A post hoc analysis of the effect of insulin dose adjustments on 24-hour continuously monitored mean glucose and fasting β-hydroxybutyrate levels in a phase IIa pilot study

AIMS

To investigate the effects of total daily insulin dose (TDD) reductions on 24-hour continuously monitored mean glucose and fasting β-hydroxybutyrate (a marker for diabetic ketosis/ketoacidosis [DKA]) levels, using patient-level data from a 14-day, pilot study of dapagliflozin in type 1 diabetes (T1DM).

METHODS

A post hoc exploratory correlation analysis was performed to determine the relationship between change in TDD and (1) 24-hour mean glucose, assessed by continuous glucose monitoring, and (2) fasting β-hydroxybutyrate, in 70 patients with T1DM receiving insulin and dapagliflozin (1, 2.5, 5 or 10 mg) or placebo. The pharmacodynamic effect of dapagliflozin was estimated as a virtual "insulin dose" using 24-hour urinary glucose excretion values and a recognized insulin-to-carbohydrate counting technique.

RESULTS

Trends for correlations were observed between change in TDD and 24-hour glucose (day 7: r = -0.264, P = .056) and β-hydroxybutyrate (day 7: r = -0.187, P = .133; day 14: r = -0.274, P = .047). The pharmacodynamic effect of dapagliflozin 5 or 10 mg was estimated as equivalent to ~20% of baseline TDD. Higher mean and maximum β-hydroxybutyrate levels were observed on days 7 and 14 in patients with a TDD reduction >20% vs ≤20%.

CONCLUSIONS

Over 14 days, decreasing the insulin dose diminished the glucose-lowering effect of dapagliflozin-insulin combination therapy and increased levels of β-hydroxybutyrate. While insulin dose adjustments should always be individualized, these analyses suggest that, as a general rule, TDD reduction in dapagliflozin-treated patients with T1DM should not exceed 20%, to ensure glycaemic control does not deteriorate and to mitigate the potential for an increased risk of DKA.

Sodium-glucose co-transporter 2 inhibitors for type 2 diabetes mellitus: An overview for the primary care physician

AIMS

Sodium-glucose co-transporter type 2 (SGLT2) inhibitors are a new class of anti-hyperglycaemic agents in type 2 diabetes mellitus (T2DM). This review examines their mechanism of action and provides an overview of safety and efficacy from the main studies of SGLT2 inhibitors marketed in the United States and Europe, namely, canagliflozin, dapagliflozin and empagliflozin.

METHODS

We searched the PubMed database to identify relevant publications on the mechanism of action of SGLT2 inhibitors and clinical trial reports.

RESULTS

Clinical trials in patients with T2DM have shown significant improvements in glycaemic control vs placebo with canagliflozin, dapagliflozin and empagliflozin: patients were more likely to reach target glycated haemoglobin levels compared with patients receiving placebo. All SGLT2 inhibitors also led to modest reductions in body weight and blood pressure vs placebo. Generally, all agents were well tolerated, with the most common adverse events with this class being genital mycotic infections and urinary tract infections. Hypoglycaemia was reported at rates similar to those seen with placebo, except when SGLT2 inhibitors were given in combination with insulin or an insulin secretagogue. Long-term outcome data are available only for empagliflozin: in the EMPA-REG OUTCOME study, empagliflozin demonstrated reduced risk of the composite end-point of 3-point major adverse cardiovascular events (cardiovascular death, non-fatal myocardial infarction or non-fatal stroke), primarily because of a significant reduction in cardiovascular mortality.

CONCLUSIONS

SGLT2 inhibitors are an exciting addition to the list of available agents for T2DM, and may be suitable for various types of patients who need additional glycaemic control.

Exenatide induces an increase in vasodilatory and a decrease in vasoconstrictive mediators

In view of the known vasodilatory effects of glucagon-like peptide-1 and exenatide, we investigated the effects of exenatide on vasoactive factors. We analysed blood samples and mononuclear cells (MNCs) from a previous study, collected after a single dose and 12 weeks of exenatide or placebo treatment in a series of 24 patients with type 2 diabetes mellitus. After exenatide treatment, plasma concentrations of atrial natriuretic peptide, cyclic guanyl monophosphate (cGMP) and cyclic adenyl monophosphate increased significantly at 12 weeks. Plasma cGMP and adenylate cyclase expression in MNCs increased significantly after a single dose. Angiotensinogen concentration fell significantly 2 hours after a single dose and at 12 weeks, while renin and angiotensin II levels fell significantly only after a single dose and not after 12 weeks of treatment. Exenatide also suppressed the plasma concentration of transforming growth factor-β and the expression of P311 in MNCs at 12 weeks. Thus, exenatide induces an increase in a series of vasodilators, while suppressing the renin-angiotensin system. These changes may contribute to the overall vasodilatory effect of exenatide.

Antiinflammatory and ROS Suppressive Effects of the Addition of Fiber to a High-Fat High-Calorie Meal

BACKGROUND

Fiber intake is associated with a reduction in the occurrence of cardiovascular events and diabetes.

OBJECTIVE

To investigate whether the addition of fiber to a high-fat, high-calorie (HFHC) meal prevents proinflammatory changes induced by the HFHC meal.

DESIGN

Ten normal fasting subjects consumed an HFHC meal with or without an additional 30 g of insoluble dietary fiber on 2 separate visits. Blood samples were collected over 5 hours, and mononuclear cells (MNCs) were isolated.

RESULTS

Fiber addition to the HFHC meal significantly lowered glucose excursion in the first 90 minutes and increased insulin and C-peptide secretion throughout the 5-hour follow-up period compared with the meal alone. The HFHC meal induced increases in lipopolysaccharide (LPS) concentrations, MNC reactive oxygen species generation, and the expression of interleukin (IL)-1β, tumor necrosis factor α (TNF-α), Toll-like receptor (TLR)-4, and CD14. The addition of fiber prevented an increase in LPS and significantly reduced the increases in ROS generation and the expression of IL-1β, TNF-α, TLR-4, and CD14. In addition, the meal increased Suppressor of cytokine signaling (SOCS)-3 and protein tyrosine phosphatase 1B (PTP-1B) messenger RNA and protein levels, which were inhibited when fiber was added.

CONCLUSIONS

The addition of fiber to a proinflammatory HFHC meal had beneficial anti-inflammatory and metabolic effects. Thus, the fiber content of the American Heart Association meal may contribute to its noninflammatory nature. If these actions of dietary fiber are sustained following long-term intake, they may contribute to fiber's known benefits in the prevention of insulin resistance, type 2 diabetes, and atherosclerosis.

Use of Continuous Subcutaneous Insulin Infusion Pump in Patients With Type 2 Diabetes Mellitus

Purpose

In patients with type 2 diabetes, the control of hyperglycemia is often difficult despite full doses of oral hypoglycemic agents and extremely large doses of insulin. These patients pose a major management problem. The authors therefore investigated whether insulin given as a subcutaneous continuous infusion of insulin (CSII) would result in an improvement in glucose homeostasis.

Methods

Four patients with badly controlled type 2 diabetes, on treatment with extremely high doses of insulin and oral hypoglycemic agents, were started on CSII.

Results

All four patients had a marked improvement in plasma glucose concentrations with a corresponding fall in HbA1c levels. This improvement was associated with a marked fall in the insulin doses necessary to maintain adequate glucose homeostasis.

Conclusions

Since HbA1c levels fell from levels that would be associated with diabetic complications to those at which complications are markedly reduced, we recommend that patients with type 2 diabetes uncontrolled on extremely high doses of insulin be given a trial of treatment with CSII.

Effect of testosterone on hepcidin, ferroportin, ferritin and iron binding capacity in patients with hypogonadotropic hypogonadism and type 2 diabetes

CONTEXT

As the syndrome of hypogonadotropic hypogonadism (HH) is associated with anaemia and the administration of testosterone restores haematocrit to normal, we investigated the potential underlying mechanisms.

DESIGN

Randomized, double-blind, placebo-controlled trial.

METHODS

We measured basal serum concentrations of erythropoietin, iron, iron binding capacity, transferrin (saturated and unsaturated), ferritin and hepcidin and the expression of ferroportin and transferrin receptor (TR) in peripheral blood mononuclear cells (MNC) of 94 men with type 2 diabetes. Forty-four men had HH (defined as subnormal free testosterone along with low or normal LH concentrations) while 50 were eugonadal. Men with HH were randomized to testosterone or placebo treatment every 2 weeks for 15 weeks. Blood samples were collected at baseline, 3 and 15 weeks after starting treatment. Twenty men in testosterone group and 14 men in placebo group completed the study.

RESULTS

Haematocrit levels were lower in men with HH (41·1 ± 3·9% vs 43·8 ± 3·4%, P = 0·001). There were no differences in plasma concentrations of hepcidin, ferritin, erythropoietin, transferrin or iron, or in the expression of ferroportin or TR in MNC among HH and eugonadal men. Haematocrit increased to 45·3 ± 4·5%, hepcidin decreased by 28 ± 7% and erythropoietin increased by 21 ± 7% after testosterone therapy (P < 0·05). There was no significant change in ferritin concentrations, but transferrin concentration increased while transferrin saturation and iron concentrations decreased (P < 0·05). Ferroportin and TR mRNA expression in MNC increased by 70 ± 13% and 43 ± 10%, respectively (P < 0·01), after testosterone therapy.

CONCLUSIONS

The increase in haematocrit following testosterone therapy is associated with an increase in erythropoietin, the suppression of hepcidin, and an increase in the expression of ferroportin and TR.

Dapagliflozin as Additional Treatment to Liraglutide and Insulin in Patients With Type 1 Diabetes

CONTEXT

It is imperative that novel approaches to treatment of type 1 diabetes (T1D) are devised.

OBJECTIVE

The objective of the study was to investigate whether addition of dapagliflozin to insulin and liraglutide results in a significant reduction in glycemia and body weight.

DESIGN

This was a randomized clinical trial.

SETTING

The study was conducted at a single academic medical center.

PARTICIPANTS

Participants included T1D patients on liraglutide therapy for at least last 6 months.

INTERVENTION

Thirty T1D patients were randomized (in 2:1 ratio) to receive either dapagliflozin 10 mg or placebo daily for 12 weeks.

MAIN OUTCOME MEASURE

Change in mean glycated hemoglobin after 12 weeks of dapagliflozin when compared with placebo was measured.

RESULTS

In the dapagliflozin group, glycated hemoglobin fell by 0.66% ± 0.08% from 7.8% ± 0.21% (P < .01 vs placebo), whereas it did not change significantly in the placebo group from 7.40% ± 0.20% to 7.30% ± 0.20%. The body weight fell by1.9 ± 0.54kg (P < .05 vs placebo). There was no additional hypoglycemia (blood glucose < 3.88 mmol/L; P = .52 vs placebo). In the dapagliflozin group, there were significant increases in the plasma concentrations of glucagon by 35% ± 13% (P < .05), hormone-sensitive lipase by 29% ± 11% (P < .05), free fatty acids by 74% ± 32% (P < .05), acetoacetate by 67% ± 34% (P < .05), and β-hydroxybutyrate by 254% ± 81% (P < .05). Urinary ketone levels also increased significantly (P < .05). None of these changes was observed in the placebo group. Two patients in the dapagliflozin group developed diabetic ketoacidosis.

CONCLUSIONS

Addition of dapagliflozin to insulin and liraglutide in patients with T1D results in a significant improvement in glycemia and weight loss while increasing ketosis. If it is decided to use this approach, then it must be used only by a knowledgeable patient along with an endocrinologist who is well versed with it.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY POSITION STATEMENT ON THE ASSOCIATION OF TESTOSTERONE AND CARDIOVASCULAR RISK

This document represents the official position of the American Association of Clinical Endocrinologists and the American College of Endocrinology. Where there were no randomized controlled trials or specific U.S. FDA labeling for issues in clinical practice, the participating clinical experts utilized their judgment and experience. Every effort was made to achieve consensus among the committee members. Position statements are meant to provide guidance, but they are not to be considered prescriptive for any individual patient and cannot replace the judgment of a clinician.

Addition of Liraglutide to Insulin in Patients With Type 1 Diabetes: A Randomized Placebo-Controlled Clinical Trial of 12 Weeks

OBJECTIVE

To investigate whether addition of three different doses of liraglutide to insulin in patients with type 1 diabetes (T1D) results in significant reduction in glycemia, body weight, and insulin dose.

RESEARCH DESIGN AND METHODS

We randomized 72 patients (placebo = 18, liraglutide = 54) with T1D to receive placebo and 0.6, 1.2, and 1.8 mg liraglutide daily for 12 weeks.

RESULTS

In the 1.2-mg and 1.8-mg groups, the mean weekly reduction in average blood glucose was -0.55 ± 0.11 mmol/L (10 ± 2 mg/dL) and -0.55 ± 0.05 mmol/L (10 ± 1 mg/dL), respectively (P < 0.0001), while it remained unchanged in the 0.6-mg and placebo groups. In the 1.2-mg group, HbA1c fell significantly (-0.78 ± 15%, -8.5 ± 1.6 mmol/mol, P < 0.01), while it did not in the 1.8-mg group (-0.42 ± 0.15%, -4.6 ± 1.6 mmol/mol, P = 0.39) and 0.6-mg group (-0.26 ± 0.17%, -2.8 ± 1.9 mmol/mol, P = 0.81) vs. the placebo group (-0.3 ± 0.15%, -3.3 ± 1.6 mmol/mol). Glycemic variability was reduced by 5 ± 1% (P < 0.01) in the 1.2-mg group only. Total daily insulin dose fell significantly only in the 1.2-mg and 1.8-mg groups (P < 0.05). There was a 5 ± 1 kg weight loss in the two higher-dose groups (P < 0.05) and by 2.7 ± 0.6 kg (P < 0.01) in the 0.6-mg group vs. none in the placebo group. In the 1.2- and 1.8-mg groups, postprandial plasma glucagon concentration fell by 72 ± 12% and 47 ± 12%, respectively (P < 0.05). Liraglutide led to higher gastrointestinal adverse events (P < 0.05) and ≤1% increases (not significant) in percent time spent in hypoglycemia (<55 mg/dL, 3.05 mmol/L).

CONCLUSIONS

Addition of 1.2 mg and 1.8 mg liraglutide to insulin over a 12-week period in overweight and obese patients with T1D results in modest reductions of weekly mean glucose levels with significant weight loss, small insulin dose reductions, and frequent gastrointestinal side effects. These findings do not justify the use of liraglutide in all patients with T1D.

Insulin Resistance and Inflammation in Hypogonadotropic Hypogonadism and Their Reduction After Testosterone Replacement in Men With Type 2 Diabetes

OBJECTIVE

One-third of men with type 2 diabetes have hypogonadotropic hypogonadism (HH). We conducted a randomized placebo-controlled trial to evaluate the effect of testosterone replacement on insulin resistance in men with type 2 diabetes and HH.

RESEARCH DESIGN AND METHODS

A total of 94 men with type 2 diabetes were recruited into the study; 50 men were eugonadal, while 44 men had HH. Insulin sensitivity was calculated from the glucose infusion rate (GIR) during hyperinsulinemic-euglycemic clamp. Lean body mass and fat mass were measured by DEXA and MRI. Subcutaneous fat samples were taken to assess insulin signaling genes. Men with HH were randomized to receive intramuscular testosterone (250 mg) or placebo (1 mL saline) every 2 weeks for 24 weeks.

RESULTS

Men with HH had higher subcutaneous and visceral fat mass than eugonadal men. GIR was 36% lower in men with HH. GIR increased by 32% after 24 weeks of testosterone therapy but did not change after placebo (P = 0.03 for comparison). There was a decrease in subcutaneous fat mass (-3.3 kg) and increase in lean mass (3.4 kg) after testosterone treatment (P < 0.01) compared with placebo. Visceral and hepatic fat did not change. The expression of insulin signaling genes (IR-β, IRS-1, AKT-2, and GLUT4) in adipose tissue was significantly lower in men with HH and was upregulated after testosterone treatment. Testosterone treatment also caused a significant fall in circulating concentrations of free fatty acids, C-reactive protein, interleukin-1β, tumor necrosis factor-α, and leptin (P < 0.05 for all).

CONCLUSIONS

Testosterone treatment in men with type 2 diabetes and HH increases insulin sensitivity, increases lean mass, and decreases subcutaneous fat.

Prevalence of subnormal testosterone concentrations in men with type 2 diabetes and chronic kidney disease

BACKGROUND

One-third of men with type 2 diabetes have subnormal testosterone concentrations along with inappropriately normal LH and FSH concentrations. It is not known if the presence of renal insufficiency affects free testosterone concentrations in men with type 2 diabetes.

HYPOTHESIS

We hypothesized that type 2 diabetic men with chronic renal disease (CKD; estimated glomerular filtration rate (eGFR) < 60 ml/min per 1.73 m(2)) have lower free testosterone concentrations than men with normal renal function (eGFR ≥ 60 ml/min per 1.73 m(2)).

STUDY DESIGN AND SETTING

This is a retrospective chart review of patients attending diabetes and nephrology clinics. Men with type 2 diabetes who had the following information available were included in the study: testosterone (total and free) done by LC/MS-MS followed by equilibrium dialysis, sex hormone binding globulin, LH, FSH and prolactin concentrations.

PARTICIPANTS

We present data on T and gonadotropin concentrations in 111 men with type 2 diabetes and CKD (stages 3-5) and 182 type 2 diabetic men without CKD.

RESULTS

The prevalence of subnormal free testosterone concentrations was higher in men with type 2 diabetes and CKD as compared to those without CKD (66% vs 37%, P < 0.001). Men with CKD had a higher prevalence of hypergonadotropic hypogonadism (26% vs 5%, P < 0.001) but not of hypogonadotropic hypogonadism (HH; 40% vs 32%, P = 0.22). There was an increase in the prevalence of hypergonadotropic hypogonadism with decreasing eGFR. Fifty-two percent of men with renal failure (CKD stage 5) had hypergonadotropic hypogonadism and 25% had HH. In men with CKD, the hemoglobin concentrations were lower in those with subnormal free T concentrations as compared to men with normal free T concentrations (119 ± 19 vs 128 ± 19 g/l, P = 0.04).

CONCLUSIONS

Two-thirds of men with type 2 diabetes and CKD have subnormal free T concentrations. The hypogonadism associated with CKD is predominantly hypergonadotropic.