Randomized clinical trial of quick-release bromocriptine among patients with type 2 diabetes on overall safety and cardiovascular outcomes

Targeting orphan G protein-coupled receptors for the treatment of diabetes and its complications: C-peptide and GPR146

G protein-coupled receptors (GPCRs) are the most abundant receptor family encoded by the human genome and are the targets of a high percentage of drugs currently in use or in clinical trials for the treatment of diseases such as diabetes and its associated complications. Thus, orphan GPCRs, for which the ligand is unknown, represent an important untapped source of therapeutic potential for the treatment of many diseases. We have identified the previously orphan GPCR, GPR146, as the putative receptor of proinsulin C-peptide, which may prove to be an effective treatment for diabetes-associated complications. For example, we have found a potential role of C-peptide and GPR146 in regulating the function of the retinal pigment epithelium, a monolayer of cells in the retina that serves as part of the blood-retinal barrier and is disrupted in diabetic macular oedema. However, C-peptide signalling in this cell type appears to depend at least in part on extracellular glucose concentration and its interaction with insulin. In this review, we discuss the therapeutic potential of orphan GPCRs with a special focus on C-peptide and GPR146, including past and current strategies used to 'deorphanize' this diverse family of receptors, past successes and the inherent difficulties of this process.

The Landscape of Glucose-Lowering Therapy and Cardiovascular Outcomes: From Barren Land to Metropolis

The choice of glucose-lowering therapy (GLT) has expanded to include 11 different classes in addition to insulin. Since the 2008 Food and Drug Administration guidance for industry and mandate of demonstrating cardiovascular (CV) safety prior to any new drug approval, there were several trials primarily conducted to establish that goal. Some had neutral effects, while there were positively beneficial outcomes with more recent studies. Hospitalization for congestive heart failure has also been a heterogeneous finding among the different classes of GLT, with drug outcomes ranging from risky to beneficial. The current review selectively focuses on the evidence for CV outcomes for each class of GLT and summarizes the existing guidelines with regard to these drugs in heart disease. Moreover, it illustrates the dynamic status in the development of evidence. Finally, the review enables healthcare providers to formulate a plan for hypoglycemic therapy which will optimize CV health, in a patient-centered manner.

Practical combination therapy based on pathophysiology of type 2 diabetes

Type 2 diabetes is a complex, chronic, and progressive condition that often necessitates the use of multiple medications to achieve glycemic goals. Clinical guidelines generally recommend intensifying pharmacotherapy if glycemic goals are not achieved after 3 months of treatment. However, for many patients with type 2 diabetes, treatment intensification is delayed or does not occur. Initiating combination therapy early in the disease course has the potential to delay disease progression and improve patient outcomes. Guidelines generally provide a list of agents that may be used in combination regimens and emphasize individualization of treatment. The purpose of this review is to discuss the rationale for combination therapy, considering treatment effects on pathophysiologic aspects of type 2 diabetes and individual drug profiles. The combination of newer antidiabetes therapies with complementary mechanisms of action provides the opportunity to target multiple sites of tissue, organ, and cellular dysfunction.

Impact of bromocriptine-QR therapy on cardiovascular outcomes in type 2 diabetes mellitus subjects on metformin

OBJECTIVES

Type 2 diabetes mellitus (T2DM) is associated with a substantially increased risk of cardiovascular disease (CVD). Bromocriptine-QR (B-QR), a quick release sympatholytic dopamine D₂ receptor agonist, is a FDA-approved therapy for T2DM which may provide CVD risk reduction. Metformin is considered to be an agent with a potential cardioprotective benefit. This large placebo controlled clinical study assessed the impact of B-QR addition to existing metformin therapy on CVD outcomes in T2DM subjects.

METHODS

1791 subjects (1208 B-QR; 583 placebo) on metformin ± another anti-diabetes therapy at baseline derived from the Cycloset Safety Trial, a 12-month, randomized, multicenter, placebo-controlled, double-blind study in T2DM, were included in this study. The primary CVD endpoint evaluated was treatment impact on CVD event rate, prespecified as a composite of time to first myocardial infarction, stroke, coronary revascularization, or hospitalization for unstable angina/congestive heart failure. Impact on glycemic control was evaluated as a secondary analysis.

RESULTS

The composite CVD end point occurred in 16/1208 B-QR treated (1.3%) and 18/583 placebo treated (3.1%) subjects resulting in a 55% CVD hazard risk reduction (intention-to-treat, Cox regression analysis; HR: 0.45 [0.23-0.88], p = 0.028). Kaplan-Meier curves demonstrated a significantly lower cumulative incidence rate of the CVD endpoint in the B-QR treatment group (Log-Rank p = 0.017). In subjects with poor glycemic control (HbA1c ≥ 7.5) at baseline, B-QR therapy relative to placebo resulted in a significant mean %HbA1c reduction of -0.59 at week 12 and -0.51 at week 52 respectively (p < 0.001 for both) and a 10 fold higher percent of subjects achieving HbA1c goal of ≤7% by week 52 (B-QR 30%, placebo 3%; p = 0.003).

CONCLUSION

These findings suggest that in T2DM subjects on metformin, BQR therapy may represent an effective strategy for reducing CVD risk. Cycloset Safety Trial registration: ClinicalTrials.gov Identifier: NCT00377676.

Pharmacology and therapeutic implications of current drugs for type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a global epidemic that poses a major challenge to health-care systems. Improving metabolic control to approach normal glycaemia (where practical) greatly benefits long-term prognoses and justifies early, effective, sustained and safety-conscious intervention. Improvements in the understanding of the complex pathogenesis of T2DM have underpinned the development of glucose-lowering therapies with complementary mechanisms of action, which have expanded treatment options and facilitated individualized management strategies. Over the past decade, several new classes of glucose-lowering agents have been licensed, including glucagon-like peptide 1 receptor (GLP-1R) agonists, dipeptidyl peptidase 4 (DPP-4) inhibitors and sodium/glucose cotransporter 2 (SGLT2) inhibitors. These agents can be used individually or in combination with well-established treatments such as biguanides, sulfonylureas and thiazolidinediones. Although novel agents have potential advantages including low risk of hypoglycaemia and help with weight control, long-term safety has yet to be established. In this Review, we assess the pharmacokinetics, pharmacodynamics and safety profiles, including cardiovascular safety, of currently available therapies for management of hyperglycaemia in patients with T2DM within the context of disease pathogenesis and natural history. In addition, we briefly describe treatment algorithms for patients with T2DM and lessons from present therapies to inform the development of future therapies.

Update on the treatment of type 2 diabetes mellitus

To achieve good metabolic control in diabetes and keep long term, a combination of changes in lifestyle and pharmacological treatment is necessary. Achieving near-normal glycated hemoglobin significantly, decreases risk of macrovascular and microvascular complications. At present there are different treatments, both oral and injectable, available for the treatment of type 2 diabetes mellitus (T2DM). Treatment algorithms designed to reduce the development or progression of the complications of diabetes emphasizes the need for good glycaemic control. The aim of this review is to perform an update on the benefits and limitations of different drugs, both current and future, for the treatment of T2DM. Initial intervention should focus on lifestyle changes. Moreover, changes in lifestyle have proven to be beneficial, but for many patients is a complication keep long term. Physicians should be familiar with the different types of existing drugs for the treatment of diabetes and select the most effective, safe and better tolerated by patients. Metformin remains the first choice of treatment for most patients. Other alternative or second-line treatment options should be individualized depending on the characteristics of each patient. This article reviews the treatments available for patients with T2DM, with an emphasis on agents introduced within the last decade.

New Pharmacologic Agents for Diabetes Treatment

Therapeutic options for diabetes management have expanded dramatically in the last five years. While there continues to be consensus that lifestyle modification aimed at 5-7% weight loss and metformin are the appropriate first line therapies for type 2 diabetes, there are many options for intensification of diabetes management. The American Diabetes Association (ADA) and the American Association of Clinical Endocrinologists (AACE) have released recent guidelines that prioritize use of the newer classes of medications.1,2 There are a number of considerations in selecting medications, including risk of hypoglycemia, effect on body weight, adverse event profile, renal function, and cost/insurance coverage. The objective of this article is to discuss mechanism, efficacy, and safety for each new class of medications. We conclude with a quick reference for the use of these medications in primary and specialty care, based on their various attributes and patient and provider preferences.

Evidence-based practice use of quick-release bromocriptine across the natural history of type 2 diabetes mellitus

OBJECTIVES

To provide an evidence-based practice overview on the clinical use of bromocriptine-quick release (QR) across the natural history of type 2 diabetes mellitus (T2DM).

METHODS

Articles for inclusion were selected after a comprehensive literature search of English-language PubMed articles and identification of other relevant references through other sources. Inclusion criteria were animal studies examining the mechanism of action and efficacy of bromocriptine, and clinical studies examining the safety and efficacy of bromocriptine-QR in patients with T2DM, without a time limitation.

RESULTS

The brain plays a key role in total body metabolism, in particular ensuring that sufficient levels of glucose are available for proper neural functioning. The hypothalamic suprachiasmatic nucleus (SCN), the body's biological clock, plays a key role in the regulation of seasonal and diurnal variations of insulin sensitivity. A daily surge of dopaminergic activity in the SCN upon waking enables insulin sensitivity throughout the day. When this is disrupted (e.g. by a high fat/sugar diet, stress, altered [diminished] exercise, altered sleep/wake cycle, diabetes), insulin resistance persists throughout the day and overnight. Improving the morning surge in dopaminergic activity with the short-acting dopamine D2 receptor agonist bromocriptine-QR can safely and effectively improve glycemic control, while improving cardiovascular disease risk factors and related adverse events, and reducing sympathetic tone, as demonstrated by 5 reports of the Cycloset Safety Trial and 3 additional clinical studies of bromocriptine-QR.

CONCLUSIONS

In patients with T2DM, the dopamine D2 receptor agonist bromocriptine-QR has been shown to be well tolerated, efficacious, and a logical treatment option.

Peripartum Cardiomyopathy

Peripartum cardiomyopathy is a potentially life-threatening pregnancy-associated disease that typically arises in the peripartum period and is marked by left ventricular dysfunction and heart failure. The disease is relatively uncommon, but its incidence is rising. Women often recover cardiac function, but long-lasting morbidity and mortality are not infrequent. Management of peripartum cardiomyopathy is largely limited to the same neurohormonal antagonists used in other forms of cardiomyopathy, and no proven disease-specific therapies exist yet. Research in the past decade has suggested that peripartum cardiomyopathy is caused by vascular dysfunction, triggered by late-gestational maternal hormones. Most recently, information has also indicated that many cases of peripartum cardiomyopathy have genetic underpinnings. We review here the known epidemiology, clinical presentation, and management of peripartum cardiomyopathy, as well as the current knowledge of the pathophysiology of the disease.

Combination therapy for the improvement of long-term macrovascular and microvascular outcomes in type 2 diabetes: Rationale and evidence for early initiation

Diabetes is a leading cause of macrovascular and microvascular complications that can increase the risk of mortality if not properly managed. Proper glucose control can reduce the incidence of these complications, in particular those of the microvasculature. Over the last~10years, the cardiovascular safety of glucose-lowering drugs has come to the forefront of diabetes management and clinical trial design. While early combination therapy improves glycemic control, its impact on long-term outcomes, is not as clearly understood. The objective of this review is to examine the evidence of early combination therapy for the treatment of type 2 diabetes mellitus as it relates to studies of long-term microvascular and macrovascular outcomes.

CONSENSUS STATEMENT BY THE AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY ON THE COMPREHENSIVE TYPE 2 DIABETES MANAGEMENT ALGORITHM--2015 EXECUTIVE SUMMARY

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.

Effects of bromocriptine mesylate on homocysteine and high-sensitivity C-reactive protein levels in patients with type-2 diabetes mellitus

Introduction: Quick release bromocriptine (BROM-QR), currently approved for glycemic control, reduces the risk of cardiovascular events in adults with type-2 diabetes mellitus (T2DM). This study evaluates the effect of BROM-QR on homocysteine (HOMC) and high sensitive C-reactive protein (hs-CRP), the biochemical markers of coronary atherosclerosis/inflammation, in patients with uncontrolled T2DM.

Methods: In this non-randomized, before-and-after clinical trial, patients with uncontrolled T2DM on stable doses of two oral hypoglycemic agents received BROM-QR for 6 months. The change in serum concentrations of HOMC was the primary endpoint. Anthropometric measurements such as body mass index (BMI) and waist circumference were measured at the baseline and at the completion of treatment along with fasting plasma glucose (FPG), HbA1c, total cholesterol, triglyceride, creatinine and hs-CRP. Multivariate regression analysis was performed to identify factors associated with changes in the levels of HOMC.

Results: In 64 patients (46 completed 6 months of treatment), age was 55±7 years and the duration of T2DM was 8.0 ± 4.4 years. On enrollment, mean HbA1c, FPG, hs-CRP and HOMC levels were 9.0± 1.3 percent, 184 ± 42 mg/dL, 3.8± 3.4 mg/dl and 10.8 ± 6.2 micromole/L; respectively. Mean decrease of 0.7 ± 1.1 percent for HbA1c (P = 0.001) and 22 ± 44 mg/dL for FPG was observed (P = 0.002). HOMC levels decreased to 8.5 ± 5.2 micromole/L (P = 0.011) while hs-CRP levels remained unchanged at 3.7 ± 2.9 mg/dL (P = 0.835).

Conclusion: While HOMC and HbA1c levels decreased significantly after 6 months of treatment with BROM-QR in patients with T2DM, serum levels of hs-CRP, total cholesterol and triglyceride did not significantly change.

Bromocriptine-QR therapy for the management of type 2 diabetes mellitus: developmental basis and therapeutic profile summary

An extended series of studies indicate that endogenous phase shifts in circadian neuronal input signaling to the biological clock system centered within the hypothalamic suprachiasmatic nucleus (SCN) facilitates shifts in metabolic status. In particular, a diminution of the circadian peak in dopaminergic input to the peri-SCN facilitates the onset of fattening, insulin resistance and glucose intolerance while reversal of low circadian peak dopaminergic activity to the peri-SCN via direct timed dopamine administration to this area normalizes the obese, insulin resistant, glucose intolerant state in high fat fed animals. Systemic circadian-timed daily administration of a potent dopamine D2 receptor agonist, bromocriptine, to increase diminished circadian peak dopaminergic hypothalamic activity across a wide variety of animal models of metabolic syndrome and type 2 diabetes mellitus (T2DM) results in improvements in the obese, insulin resistant, glucose intolerant condition by improving hypothalamic fuel sensing and reducing insulin resistance, elevated sympathetic tone, and leptin resistance. A circadian-timed (within 2 hours of waking in the morning) once daily administration of a quick release formulation of bromocriptine (bromocriptine-QR) has been approved for the treatment of T2DM by the U.S. Food and Drug Administration. Clinical studies with such bromocriptine-QR therapy (1.6 to 4.8 mg/day) indicate that it improves glycemic control by reducing postprandial glucose levels without raising plasma insulin. Across studies of various T2DM populations, bromocriptine-QR has been demonstrated to reduce HbA1c by -0.5 to -1.7. The drug has a good safety profile with transient mild to moderate nausea, headache and dizziness as the most frequent adverse events noted with the medication. In a large randomized clinical study of T2DM subjects, bromocriptine-QR exposure was associated with a 42% hazard ratio reduction of a pre-specified adverse cardiovascular endpoint including myocardial infarction, stroke, hospitalization for congestive heart failure, revascularization surgery, or unstable angina. Bromocriptine-QR represents a novel method of treating T2DM that may have benefits for cardiovascular disease as well.

Efficacy of bromocriptine on glycemic and metabolic control of prediabetic patients

Background:

It is suggested that bromocriptine could be effective in treatment of prediabetic patients and, consequently, in preventing type 2 diabetes (T2DM). In this study, we investigated the effectiveness of bromocriptine on glycemic and metabolic control of prediabetic patients.

Materials and Methods:

In this double-blind, placebo controlled trial study, prediabetic patients diagnosed during Isfahan Diabetes Prevention Project (IDPP) were enrolled. They randomized in two bromocriptine (2.5 mg) and placebo-treated groups, for 12 weeks. After physical examination, fasting plasma glucose (FPG), HbA1c, Insulin, cholesterol, HDL-c, and triglyceride were measured and glucose tolerance test (OGTT) was performed. HOMA-IR and LDL-c were calculated. The mean of the data were compared in the bromocriptine and placebo treated groups, before and after intervention by intention to treat analysis using mixed effect model. P values < 0.05 were considered, statistically, significant.

Results:

In this study, 53 prediabetic patients (27 in the bromocriptine group and 26 in the placebo group) were treated. There were no differences between data of two groups at baseline (P > 0.05). The mean body mass index, systolic blood pressure, fasting plasma glucose and glucose of 30 min, 60 min, 120 min of post OGTT, HbA1c, insulin, HOMA-IR, lipid profile did not change, significantly, in both bromocriptine and placebo-treated groups after 12 weeks (P > 0.05). However, diastolic blood pressure (P = 0.02) and the area under the curve of glucose (P = 0.045) were decreased in the bromocriptine-treated group.

Conclusion:

Bromocriptine did not have significant effect on glycemic control of prediabetic patients. Further studies, with bigger sample size are recommended.

A review of dopamine agonist therapy in type 2 diabetes and effects on cardio-metabolic parameters

Dopamine action appears to play a role in changes that are seen in obesity, metabolic syndrome and type 2 diabetes mellitus. Bromocriptine-QR (Quick Release), a dopamine agonist, is approved for use in treatment of type 2 diabetes. It has demonstrated modest improvement in glycemic parameters, cholesterol and weight in certain cohorts. Limited data using cabergoline, a long-acting dopamine agonist, also demonstrate glycemic efficacy. Additionally, bromocriptine-QR appears to have a favorable cardiovascular risk reduction. The direct mechanism by which bromocriptine-QR, or central dopamine agonism, achieves modest glycemic control and favorable cardio-metabolic profile is unclear. This relationship appears to be more complex than the historical explanation of "resetting" the circadian clock and may further be elucidated using data in individuals with hyperprolactinemia and prolactinoma.

One Small Step for Empagliflozin, One Giant Leap for Diabetology

This article discusses the recently published EMPA-REG OUTCOME trial, which assessed cardiovascular outcomes with empagliflozin therapy in persons with type 2 diabetes mellitus and coexisting cardiovascular disease. The article describes the background and challenges of modern cardiovascular outcome trials, points out the strengths of the EMPA-REG OUTCOME study, and places the results in perspective. It highlights the significant impact that these results will have on cardiovascular preventive pharmacotherapy, and on future drug development in diabetes. At the same time, it reminds readers of the limitations of the results, and lists the questions raised by, or left unanswered by, the trial.

Brain signaling systems in the Type 2 diabetes and metabolic syndrome: promising target to treat and prevent these diseases

The changes in the brain signaling systems play an important role in etiology and pathogenesis of Type 2 diabetes mellitus (T2DM) and metabolic syndrome (MS), being a possible cause of these diseases. Therefore, their restoration at the early stages of T2DM and MS can be regarded as a promising way to treat and prevent these diseases and their complications. The data on the functional state of the brain signaling systems regulated by insulin, IGF-1, leptin, dopamine, serotonin, melanocortins and glucagon-like peptide-1, in T2DM and MS, are analyzed. The pharmacological approaches to restoration of these systems and improvement of insulin sensitivity, energy expenditure, lipid metabolism, and to prevent diabetic complications are discussed.

The Effect of Atorvastatin on Cardiometabolic Risk Factors in Bromocriptine-Treated Premenopausal Women with Isolated Hypercholesterolemia

AIMS

Hyperprolactinemia is often associated with hyperinsulinemia, insulin resistance, atherogenic dyslipidemia, and subclinical atherosclerosis. Dopamine agonists were found to reduce the prevalence of metabolic syndrome and cardiometabolic risk. The aim of this study was to compare the effect of statin therapy on cardiovascular risk factors between patients treated with a dopamine agonist and patients treated with metformin.

METHODS

The study included two age-, weight-, lipid-, and prolactin level-matched groups of premenopausal women with hypecholesterolemia and a history of hyperprolactinemia: patients treated with bromocriptine (5.0-7.5 mg daily, n = 14) and subjects receiving metformin (1.7-2.55 g daily, n = 17). Plasma prolactin, lipids, glucose homeostasis markers, and plasma levels of cardiometabolic risk factors were assessed before and after 12 weeks of atorvastatin treatment.

RESULTS

Baseline levels of the investigated variables were similar in women treated with bromocriptine and metformin. Apart from lowering total and LDL cholesterol, atorvastatin decreased plasma levels of uric acid, hsCRP, homocysteine, and fibrinogen, with no difference between treatment groups.

CONCLUSIONS

The obtained results suggest that the effect of atorvastatin on plasma lipids and circulating levels of cardiometabolic risk factors does not differ between patients receiving bromocriptine and metformin. Bromocriptine-statin combination therapy may be an alternative to metformin-statin combination therapy in hypercholesterolemic patients with glucose metabolism abnormalities in whom metformin administration is either contraindicated or results in adverse effects.

Revisiting weight reduction and management in the diabetic patient: Novel therapies provide new strategies

Weight gain has been so synonymous with diabetes care that overweight/obesity is considered an intractable aspect of diabetes and its management. A healthy body mass index (BMI) is paramount, however, in preserving the cardiometabolic profile, slowing the course of the disease and extending the life expectancy of patients. It is also key to fostering a healthy and productive society at large. Two trends in care press us to challenge our assumptions about weight control in this population by reconsidering traditional approaches to the management of diabetes. First, new anti-diabetes drug classes have emerged that are more "weight-friendly" than previously available treatments and "gentler" on the faltering β cell. Second, novel anti-obesity agents are proving efficacious in patients with diabetes. This paper presents the composite of newer and older anti-obesity and anti-diabetic drugs. It makes recommendations for anti-diabetic regimens and processes of care that engender weight loss, or neutralize or minimize weight gain, while getting many patients to their glycated hemoglobin (HbA1c) goal. Anti-obesity agents that can be safely and effectively incorporated into these regimens for the patient needing supplemental support are reviewed in detail.

Pharmacologic treatment of type 2 diabetes: oral medications

OBJECTIVE

To review the oral and injectable pharmacologic treatment options for type 2 diabetes.

DATA SOURCES

A literature search was conducted using PubMed electronic database for studies published in English between 1993 and September 2014. Search terms included diabetes mellitus, type 2 diabetes, and the individual name for each antidiabetic medication reviewed. In addition, manual searches were performed for cross-references from publications. Package inserts, United States Food and Drug Administration (FDA) Web site, Institute for Safe Medication Practices Web site, American Diabetes Association Web site and scientific session poster presentations, and individual drug company Web pages were also reviewed.

STUDY SELECTION AND DATA EXTRACTION

This review focused on information elucidated over the past 10 years to assist prescribers in choosing optimal therapy based on individual patient characteristics. Studies leading to the approval of or raising safety concerns for the antidiabetic medications reviewed in this article were included.

DATA SYNTHESIS

In the past 10 years, there have been 4 novel oral antidiabetic medication classes and 9 new injectable agents and insulin products approved by the FDA for the treatment of type 2 diabetes as well as new information regarding the safety and use of several older antidiabetic medication classes. The distinctions were reviewed for each individual agent, and a comparison was completed if there was more than one agent in a particular therapeutic class. Using current information available, select investigational agents in phase III trials or those with a pending new drug application were highlighted.

CONCLUSION

There are now 9 distinct oral pharmacologic classes and a variety of insulin and noninsulin injectable medications available for the treatment of type 2 diabetes. Metformin remains the first-line treatment option for most patients. When considering options for alternative or additional treatment, prescribers must weigh the benefits and risks using individual patient characteristics.

Oral antihyperglycemic treatment options for type 2 diabetes mellitus

Table 3 provides an overview of the oral antihyperglycemic drugs reviewed in this article. A 2011 meta-analysis by Bennett and colleagues found low or insufficient quality of evidence favoring an initial choice of metformin, SUs, glinides, TZDs, or (table see text) DPP-4 inhibitors (alpha-glucosidase inhibitors, bromocriptine mesylate, and SGLT2 inhibitors were not included in this meta-analysis) with regard to the outcomes measures of all-cause mortality, cardiovascular events and mortality, and incidence of microvascular disease (retinopathy, nephropathy, and neuropathy) in previously healthy individuals with newly diagnosed T2DM. Likewise, the Bennett and colleagues meta-analysis judged these drugs to be of roughly equal efficacy with regard to reduction of HbA1c (1%–1.6%) from the pretreatment baseline. The ADOPT clinical trial of 3 different and, at the time, popular, oral monotherapies for T2DM provides support for the consensus recommendation of metformin as first-line therapy. The ADOPT trial showed slightly superior HbA1c reduction for rosiglitazone compared with metformin, which was in turn superior to glyburide. However, significant adverse events, including edema, weight gain, and fractures, were more common in the rosiglitazone-treated patients. The implication of this trial is that the combination of low cost, low risk, minimal adverse effects, and efficacy of metformin justifies use of this agent as the cornerstone of oral drug treatment of T2DM. Judicious use of metformin in groups formerly thought to be at high risk for lactic acidosis (ie, those with CHF, chronic kidney disease [eGFR >30 mL/min/1.73 m2], and the elderly) may be associated with mortality benefit rather than increased risk. Secondary and tertiary add-on drug therapy should be individualized based on cost, personal preferences, and overall treatment goals, taking into account the wishes and priorities of the patient.

Impact of Bromocriptine-QR Therapy on Glycemic Control and Daily Insulin Requirement in Type 2 Diabetes Mellitus Subjects Whose Dysglycemia Is Poorly Controlled on High-Dose Insulin: A Pilot Study

BACKGROUND

The concurrent use of a postprandial insulin sensitizing agent, such as bromocriptine-QR, a quick release formulation of bromocriptine, a dopamine D2 receptor agonist, may offer a strategy to improve glycemic control and limit/reduce insulin requirement in type 2 diabetes (T2DM) patients on high-dose insulin. This open label pilot study evaluated this potential utility of bromocriptine-QR.

METHODS

Ten T2DM subjects on metformin (1-2 gm/day) and high-dose (TDID ≥ 65 U/day) basal-bolus insulin were enrolled to receive once daily (morning) bromocriptine-QR (1.6-4.8 mg/day) for 24 weeks. Subjects with at least one postbaseline HbA1c measurement (N = 8) were analyzed for change from baseline HbA(1c), TDID, and postprandial glucose area under the curve of a four-hour mixed meal tolerance test (MMTT).

RESULTS

Compared to the baseline, average HbA1c decreased 1.76% (9.74 ± 0.56 to 7.98 ± 0.36, P = 0.01), average TDID decreased 27% (199 ± 33 to 147 ± 31, P = 0.009), and MMTT AUC(60-240) decreased 32% (P = 0.04) over the treatment period. The decline in HbA(1c) and TDID was observed at 8 weeks and sustained over the remaining 16-week study duration.

CONCLUSION

In this study, bromocriptine-QR therapy improved glycemic control and meal tolerance while reducing insulin requirement in T2DM subjects poorly controlled on high-dose insulin therapy.

Timed Bromocriptine-QR Therapy Reduces Progression of Cardiovascular Disease and Dysglycemia in Subjects with Well-Controlled Type 2 Diabetes Mellitus

BACKGROUND

Type 2 diabetes (T2DM) patients, including those in good glycemic control, have an increased risk of cardiovascular disease (CVD). Maintaining good glycemic control may reduce long-term CVD risk. However, other risk factors such as elevated vascular sympathetic tone and/or endothelial dysfunction may be stronger potentiators of CVD. This study evaluated the impact of bromocriptine-QR, a sympatholytic dopamine D2 receptor agonist, on progression of metabolic disease and CVD in T2DM subjects in good glycemic control (HbA1c ≤ 7.0%).

METHODS

1834 subjects (1219 bromocriptine-QR; 615 placebo) with baseline HbA1c ≤ 7.0% derived from the Cycloset Safety Trial (this trial is registered with ClinicalTrials.gov Identifier: NCT00377676), a 12-month, randomized, multicenter, placebo-controlled, double-blind study in T2DM, were evaluated. Treatment impact upon a prespecified composite CVD endpoint (first myocardial infarction, stroke, coronary revascularization, or hospitalization for angina/congestive heart failure) and the odds of losing glycemic control (HbA1c >7.0% after 52 weeks of therapy) were determined.

RESULTS

Bromocriptine-QR reduced the CVD endpoint by 48% (intention-to-treat; HR: 0.52 [0.28-0.98]) and 52% (on-treatment analysis; HR: 0.48 [0.24-0.95]). Bromocriptine-QR also reduced the odds of both losing glycemic control (OR: 0.63 (0.47-0.85), p = 0.002) and requiring treatment intensification to maintain HbA1c ≤ 7.0% (OR: 0.46 (0.31-0.69), p = 0.0002).

CONCLUSIONS

Bromocriptine-QR therapy slowed the progression of CVD and metabolic disease in T2DM subjects in good glycemic control.

Pharmacological treatment of diabetes in older people

The pharmacological management of diabetes in older people is complex and challenging. It requires a comprehensive understanding of the individual beyond the diabetes itself. Through the ageing years, the older individual presents with diabetes-related and non-related comorbidities and complications, develops functional limitations and psychological issues, and may lack social support and access to care. A disturbance in these categories, known as the four geriatric domains, will negatively affect diabetes self-management and self-efficacy, leading to poor outcomes and complications. Furthermore, older people with diabetes may be more interested in the management of other chronic conditions such as pain or impaired mobility, and diabetes may be lower in their list of priorities. Proper education must be provided to the older individual and caregivers, with continuous monitoring and counselling, especially when pharmacological interventions offer risks of side effects, adverse reactions and interactions with other medications. Informed shared medical decisions will help to improve adherence to the regimen; however, such discussions ought to be based on the best evidence available, which is unfortunately limited in this age group. We performed a review focused on pharmacological agents and summarize current evidence on their use for the treatment of diabetes in older people. We encourage clinicians to investigate and incorporate the four geriatrics domains in the selection and monitoring of these agents.

Glycemic control is impaired in the evening in prediabetes through multiple diurnal rhythms

AIMS

Recent studies suggest that circadian rhythms regulate glucose metabolism, weight loss, and even drug efficacy. Moreover, molecules targeted at the circadian clock show promise in treating metabolic disease. Therefore, this study set out to better characterize interactions among diurnal rhythms in prediabetes.

METHODS

Ten subjects with prediabetes completed oral glucose tolerance tests at 0700h and 1900h on the same day. Lipids and hormones were also measured.

RESULTS

Two-hour and three-hour glucose tolerances were worse in the evening by 40±52mg/dl (p=0.02) and 62±46mg/dl (p=0.001), respectively. These impairments were explained by lower insulin sensitivity (OGIS; 5.14±1.02 vs. 4.74±0.77mg/kg/min; p=0.03) and 2-hour AUC insulin levels (87.4±37.6 vs. 69.8±40.2mU∙hr/l; p=0.02) in the evening. Intriguingly, more insulin resistant subjects had weaker rhythms in insulin sensitivity (r=-0.66; p=0.04) but enhanced rhythms in insulin (r=-0.67; p=0.03) and cortisol (r=-0.78; p=0.008) levels. Importantly, the rhythms in cortisol primarily but also insulin sensitivity drove the declines in evening glucose tolerance (r=0.86; p=0.002).

CONCLUSIONS

Glycemic control is dramatically impaired in the evening in people with prediabetes, particularly when the cortisol rhythm is weak, but is unrelated to the rhythm in insulin levels. Therefore, food intake at dinnertime may need to be curbed in prediabetes.

Efficacy and safety of add on therapy of bromocriptine with metformin in Indian patients with type 2 diabetes mellitus: a randomized open labeled phase IV clinical trial

Objective:

To compare the effectiveness and safety of add on therapy of bromocriptine with metformin in type 2 diabetes mellitus (DM) patients.

Material and Methods:

Adult type 2 DM patients fulfilling the inclusion criteria were randomized in three groups. Group A received metformin (1000 mg/ day), while group B patients were treated with metformin (1000 mg/day) plus bromocriptine (0.8 mg/day) and group C received metformin (1000 mg/day) plus bromocriptine (1.6 mg/day) for 12 weeks. Fasting plasma glucose (FPG), postprandial plasma glucose (PPPG), and body weight were measured at week 4, 8, and 12 visits and glycosylated hemoglobin (HbA_1C) at week 12 visit.

Results:

Metformin alone and in combination with bromocriptine in escalating dose (0.8 mg/day and 1.6 mg/day) significantly (P < 0.05) decreased FPG and PPPG levels at weeks 4, 8, and 12 compared with pretreatment values. HbA_1C level in all three treatment groups significantly (P < 0.05) decreased at week 12 as compared with pretreatment baseline value. HbA_1C level in groups B and C significantly (P < 0.05) decreased as compared with group A at week 12. Addition of bromocriptine to metformin also significantly (P < 0.05) decreased FPG and PPPG levels in a dose-dependent manner as compared with metformin alone. Intergroup analysis did not show any statistically significant change in weight of study subjects at different intervals.

Conclusion:

The combination of bromocriptine with metformin significantly decreased FPG, PPPG, and HbA_1C compared with metformin alone in type 2 DM patients in a dose-dependent manner.

Risk of heart failure following treatment with dopamine agonists in Parkinson's disease patients

INTRODUCTION

Dopamine agonists (DAs) are frequently used to treat early or advanced Parkinson's disease (PD) patients. They have been shown to be efficacious for the treatment of motor symptoms and for delaying levodopa-induced dyskinesias. However, their utilization is limited by the risk of adverse drug reactions, some of which affect the cardiovascular system. Recently, the US FDA identified a possible association between exposure to pramipexole and the risk of heart failure.

AREAS COVERED

This article begins by reviewing the pharmacodynamic and cardiovascular effects of DAs on PD patients. Pharmacoepidemiological studies about the association between DAs and heart failure are then evaluated.

EXPERT OPINION

Four nested case-control studies were reviewed. In general, results showed higher heart failure risk following use of pramipexole or cabergoline. Although the effects of cabergoline may be explained by the induction of cardiac valve fibrosis, the basis for the significantly increased risk associated with pramipexole is unclear. It remains to be determined if these are dose-related effects, at what point they occur during the course of treatment, and if the risk is the same for all patients irrespective of other potential modifying factors, such as age and sex.

Update on Safety Issues Related to Antihyperglycemic Therapy

The American Diabetes Association emphasizes the importance of individualized patient care in the management of diabetes. One of the important considerations in choosing an antihyperglycemic agent is its side-effect and safety profile. This article reviews the common and clinically significant side effects of each class of agents, including ways to prevent and overcome their occurrence.

Drug treatment of type 2 diabetes mellitus in patients for whom metformin is contraindicated

Metformin is considered an initial drug of choice for type 2 diabetes mellitus by leading recommendations. When contraindications to its use exist or patients cannot tolerate it due to adverse effects, clinicians have a variety of other classes of agents to treat hyperglycemia associated with type 2 diabetes mellitus. Each class of agent has its own benefit and safety profile. There are numerous factors to consider when selecting another agent in lieu of metformin including, but not limited to, overall efficacy in A1c reduction, adverse effect profile, cost, and patient preference. The number of factors influencing the decision process presents challenges and often no one specific agent is ideal. Each pharmacotherapeutic class of agents alternative to metformin for the treatment of hyperglycemia in type 2 diabetes mellitus as initial monotherapy is reviewed.

Cardiovascular safety profile of currently available diabetic drugs

BACKGROUND

Cardiovascular disease is the leading cause of morbidity and mortality among patients with diabetes, underscoring the importance of choosing drugs that do not increase cardiovascular risk and reduce the risk of cardiovascular events. Since 2008, the US Food and Drug Administration has recommended that new drugs for type 2 diabetes undergo clinical trials to demonstrate cardiovascular safety in addition to glycemic benefit. In 2012, the European Medicines Agency issued a similar recommendation.

METHODS

We searched the PubMed, Cochrane CENTRAL, EMBASE, and CINAHL databases from inception through August 2013 and compiled and reviewed the existing data on the cardiovascular safety profiles of currently available diabetic drugs.

RESULTS

While intensive glycemic control in diabetics has been consistently shown to reduce the risk of microvascular complications, the data on macrovascular risk reduction have not been as clear, and questions have been raised about possible increases in cardiovascular morbidity and mortality.

CONCLUSION

Careful selection of drug therapy-paying particular attention to cardiovascular safety-is important in optimizing diabetic therapy.

Adipose tissue macrophages (ATM) of obese patients are releasing increased levels of prolactin during an inflammatory challenge: a role for prolactin in diabesity?

BACKGROUND

Obesity, characterized by low grade inflammation, induces adipose tissue macrophage (ATM) infiltration in white adipose tissue (AT) in both humans and rodents, thus contributing to insulin resistance. Previous studies have shown altered prolactin secretion in obesity, however, studies linking ATM infiltration and prolactin (PRL) secretion to the pathogenesis of the metabolic syndrome, obesity and diabetes are lacking.

METHODS/RESULTS

In vivo, qPCR and Western blot analysis demonstrated that prolactin expression was increased in AT of obese rats and also in human AT from obese, obese pre-diabetic and obese diabetic compared to lean counterparts. Immunohistochemistry of obese rat and human AT sections demonstrated a specific expression of prolactin in macrophages. In vitro, we demonstrated that hyperglycemia and inflammation stimulated macrophages (human THP-1 cell line and sorted rat ATM) to express PRL, when challenged with different glucose concentrations with or without IL1β. In in vivo and in vitro experiments, we assessed the expression of Pit-1 (PRL-specific transcription factor) and found that its expression was parallel to PRL expression.

CONCLUSIONS

In this study, we show that rodent and human macrophages synthesize prolactin in response to inflammation and high glucose concentrations.

GENERAL SIGNIFICANCE

Our data shed new light on the potential role of macrophages in the physiopathology of diabesity via the PRL expression and on its expression mechanism and regulation.

Bromocriptine, a Dopamine (d2) Receptor Agonist, Used Alone and in Combination with Glipizide in Sub-Therapeutic Doses to Ameliorate Hyperglycaemia

INTRODUCTION

Bromocriptine, an ergot derivative, is an agonist at the dopamine 2 receptor and a sympatholytic. It is a well established drug in Parkinsonism, hyperprolactinaemia and acromegaly and it has various other clinical indications like induction of ovulation in female infertility. Bromocriptine has been evaluated in alloxan induced diabetic rats for its anti-hyperglycaemic effect with and without simultaneous use of glipizide.

METHODS

Diabetes was induced in albino rats by giving a single subcutaneous injection of alloxan in a dose of 150 mg/kg body weight. After 72 hours of giving alloxan injection, depending upon their blood glucose levels (350mg/dl and above), the rats were included into the study and they were divided into four groups, each comprising of 6 rats (n=24): Group 1 which was taken as control was given distilled water. Group 2 was treated with glipizide, a standard drug. Group 3 was treated with the test drug, bromocriptine and Group 4 was treated with sub therapeutic doses of test and standard drugs. The drugs were given to the diabetic rats once daily by oral route for 30 consecutive days, in order to assess their effects in terms of reduction in blood glucose levels. Blood glucose was estimated on 0(th), 10(th), 20(th), and 30(th) days of the study at fixed time intervals.

RESULTS AND CONCLUSION

Bromocriptine, which was used alone, lowered the blood glucose levels appreciably; whereas the concomitant administration of bromocriptine and glipizide in sub therapeutic doses produced a much more appreciable reduction. The results which were obtained in the group which received simultaneous administration of test and standard drugs in sub therapeutic doses were comparable to those of the group which received reference drug, glipizide. Hence, it can be concluded that bromocriptine may serve as a valuable adjunct to available anti-diabetic medication.

Review of insulin-dependent and insulin-independent agents for treating patients with type 2 diabetes mellitus and potential role for sodium-glucose co-transporter 2 inhibitors

Diabetes, especially type 2 diabetes mellitus (T2DM), continues to be a global health care problem. Although the beneficial effects of glycemic control are well established, in the United States, > 40% of adults with diabetes fail to achieve target glycated hemoglobin levels. Antidiabetic drug classes vary with respect to their mechanisms of action, glucose-lowering potential, and safety and tolerability profiles. Antidiabetic drug classes include some agents that depend on the presence or action of insulin for their therapeutic effect. As the disease state of T2DM progresses, patient pancreatic β-cell function declines, and therapies that stimulate insulin secretion or improve insulin sensitivity become less effective for this population. Therefore, the development of additional antidiabetic agents with novel mechanisms of action that can be used alone or in combination with currently approved medications may help patients achieve glycemic control. Agents that have comparable glucose-lowering capabilities but different mechanisms of action may fill treatment gaps or meet the needs of patient subpopulations. For example, inhibitors of sodium-glucose co-transporter 2 (SGLT2) represent an emerging class of glucose-lowering agents. The SGLT2 inhibitors reduce glucose reabsorption by the kidney, leading to increased urinary glucose excretion and caloric loss. In clinical trials, these agents have been shown to improve glycemic control and to reduce body weight in patients with T2DM. Additionally, SGLT2 inhibitors pose a low risk for hypoglycemia and are generally well tolerated; however, their use has been associated with an increase in the frequency of genital infections and, in some studies, urinary tract infections. Sodium-glucose co-transporter 2 inhibitors may provide an alternative or an addition to existing therapies for the treatment of patients with T2DM.

Physiologic and weight-focused treatment strategies for managing type 2 diabetes mellitus: the metformin, glucagon-like peptide-1 receptor agonist, and insulin (MGI) approach

The prevalence of type 2 diabetes mellitus (T2DM) is rising in association with an increase in obesity rates. Current treatment options for patients with T2DM include lifestyle modifications and numerous antidiabetic medications. Despite the availability of effective and well-tolerated treatments, many patients do not achieve recommended glycemic targets. Lack of efficacy is complicated by the wide range of available agents and little specificity in treatment guidelines, thus challenging clinicians to understand the relative benefits and risks of individual options for each patient. In this article, lifestyle intervention strategies and current antidiabetic agents are evaluated for their efficacy, safety, and weight-loss potential. Because of the heterogeneous and progressive nature of T2DM, physicians should advocate approaches that emphasize weight management, limit the risk of hypoglycemia and adverse events, and focus on the core pathophysiologic defects in patients with T2DM. A healthy, plant-based diet that is low in saturated fat and refined carbohydrates but high in whole grains, vegetables, legumes, and fruits, coupled with resistance and aerobic exercise regimens, are recommended for patients with T2DM. When necessary, drug intervention, described in this article as the MGI (metformin, glucagon-like peptide-1 receptor agonist, and insulin) approach, should begin with metformin and progress to the early addition of glucagon-like peptide-1 receptor agonists because of their weight loss potential and ability to target multiple pathophysiologic defects in patients with T2DM. For most patients, treatments that induce weight gain and hypoglycemia should be avoided. Long-acting insulin should be initiated if glycemic control is not achieved with metformin and glucagon-like peptide-1 receptor agonist combination therapy, focusing on long-acting insulin analogs that induce the least weight gain and have the lowest hypoglycemic risk. Ultimately, a patient-centered treatment approach that addresses the core pathologies of T2DM and obesity will not only increase overall efficacy and the likelihood that a patient adheres to treatment, but may also improve a patient's mental well-being and quality of life.