Pharmacological interventions for preventing or delaying onset of type 2 diabetes mellitus

Dalcetrapib Reduces Risk of New-Onset Diabetes in Patients With Coronary Heart Disease

OBJECTIVE

Incident type 2 diabetes is common among patients with recent acute coronary syndrome and is associated with an adverse prognosis. Some data suggest that cholesteryl ester transfer protein (CETP) inhibitors reduce incident type 2 diabetes. We compared the effect of treatment with the CETP inhibitor dalcetrapib or placebo on incident diabetes in patients with recent acute coronary syndrome.

RESEARCH DESIGN AND METHODS

In the dal-OUTCOMES trial, 15,871 patients were randomly assigned to treatment with dalcetrapib 600 mg daily or placebo, beginning 4-12 weeks after an acute coronary syndrome. Absence of diabetes at baseline was based on medical history, no use of antihyperglycemic medication, and hemoglobin A_1c and serum glucose levels below diagnostic thresholds. Among these patients, incident diabetes after randomization was defined by any diabetes-related adverse event, new use of antihyperglycemic medication, hemoglobin A_1c ≥6.5%, or a combination of at least two measurements of serum glucose ≥7.0 mmol/L (fasting) or ≥11.1 mmol/L (random).

RESULTS

At baseline, 10,645 patients (67% of the trial cohort) did not have diabetes. During a median follow-up of 30 months, incident diabetes was identified in 403 of 5,326 patients (7.6%) assigned to dalcetrapib and in 516 of 5,319 (9.7%) assigned to placebo, corresponding to absolute risk reduction of 2.1%, hazard ratio of 0.77 (95% CI 0.68-0.88; P < 0.001), and a need to treat 40 patients for 3 years to prevent 1 incident case of diabetes. Considering only those with prediabetes at baseline, the number needed to treat for 3 years to prevent 1 incident case of diabetes was 25. Dalcetrapib also decreased the number of patients who progressed from normoglycemia to prediabetes and increased the number who regressed from diabetes to no diabetes.

CONCLUSIONS

In patients with a recent acute coronary syndrome, incident diabetes is common and is reduced substantially by treatment with dalcetrapib.

Diet and prevention of type 2 diabetes mellitus: beyond weight loss and exercise

INTRODUCTION

Insulin resistance (IR) and pancreatic beta-cell dysfunction are core pathophysiologic features of type 2 diabetes mellitus (T2DM). Select lifestyle and pharmacologic interventions, including weight loss, physical activity, a Mediterranean diet intervention, and hypoglycemic agents, have been shown to prevent or delay T2DM. However, dietary factors other than weight loss may also impact risk, mainly through effects to enhance insulin sensitivity, although some may also directly or indirectly impact pancreatic beta-cell function.

AREAS COVERED

A literature review of observational studies and randomized controlled trials (RCTs) was conducted, and the research indicates dietary factors showing promise for reducing T2DM risk include higher intakes of cereal fibers, unsaturated fatty acids, magnesium, and polyphenols (e.g. anthocyanins), while reducing dietary glycemic load, added sugars, and high-sugar beverages.

EXPERT COMMENTARY

While these dietary factors are mainly supported by evidence from observational studies and RCTs of surrogate markers for T2DM, they are consistent with current recommendations to emphasize consumption of whole grains, nuts, seeds, legumes, seafood, fruits, and vegetables, while limiting intakes of saturated fatty acids, refined carbohydrates, and processed meats. Additional dietary intervention RCTs are needed to assess the efficacy of these promising dietary interventions for delaying or preventing the onset of T2DM.

Prevention of type 2 diabetes mellitus with acupuncture: Protocol for a systematic review and meta-analysis

BACKGROUND

Prediabetes is prevalent and significantly increases lifetime risk of progression to type 2 diabetes mellitus (T2DM). Acupuncture has been increasingly used for prediabetes in China but its effect is unclear. We aim to assess the efficacy and safety of acupuncture in preventing or delaying incident diabetes among individuals with prediabetes.

METHODS

The following 8 databases will be searched from inception to September 1, 2018: the Cochrane Central Register of Controlled Trials (CENTRAL) on the Cochrane Library, PubMed, Embase, Chinese National Knowledge Infrastructure database, Chinese Biomedical Literature database, Chinese Scientific Journal database, Wan Fang database, and Clinical Trials. The incidence of diabetes and regression toward normoglycemia will be accepted as the primary outcomes. The Cochrane Risk of Bias tool will be used to evaluate the methodologic quality of eligible studies. Meta-analysis will be performed by Review Manager 5.3.

RESULTS

This study will provide a high-quality synthesis of current evidence of acupuncture in the prevention of T2DM from several aspects including the incidence of diabetes, regression toward normoglycemia, fasting plasma glucose, 2-hour plasma glucose level after a 75-g oral glucose tolerance test, glycosylated hemoglobin level, body mass index, and adverse drug events.

CONCLUSIONS

The conclusion of this review will provide evidence to judge whether acupuncture is an effective and safe intervention for prediabetes.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42018111236.

Different intervention strategies for preventing type 2 diabetes mellitus in China: A systematic review and network meta-analysis of randomized controlled trials

Different strategies are increasingly used for early intervention in prediabetes in China, but the effects of these strategies on incident diabetes have not yet been confirmed. The aim of the present study was to assess systematically the effects of different strategies for preventing diabetes, aimed at Chinese people with prediabetes. Seven electronic databases were searched to identify eligible trials published from inception to September 20, 2016. Randomized controlled trials with a minimum follow-up duration of 6 months were included. Standard pairwise meta-analysis with a random-effects model and network meta-analysis with a frequentist framework were performed. A total of 63 studies, including 11 intervention strategies, were included. Compared with placebo, all strategies, except for lipid-affecting drugs and sitagliptin, reduced the rate of incident diabetes with different levels of effectiveness, ranging from 0.18 (95% confidence interval [CI] 0.12, 0.27) to 0.39 (95% CI 0.20, 0.75). Ranking probability analysis indicated that metformin and β-cell-stimulating drugs reduced the risk of diabetes most, with probabilities of 87.4% and 81%, respectively. Ethnicity and cultural factors should be considered for diabetes prevention. Most of the included trials were of poor methodological quality, however, and the results should be interpreted with caution.

Neurturin and a GLP-1 Analogue Act Synergistically to Alleviate Diabetes in Zucker Diabetic Fatty Rats

Neurturin (NRTN), a member of the glial-derived neurotrophic factor family, was identified from an embryonic chicken pancreatic cDNA library in a screen for secreted factors. In this study, we assessed the potential antidiabetic activities of NRTN relative to liraglutide, a glucagon-like peptide 1 receptor agonist, in Zucker diabetic fatty (ZDF) rats. Subcutaneous administration of NRTN to 8-week-old male ZDF rats prevented the development of hyperglycemia and improved metabolic parameters similar to liraglutide. NRTN treatment increased pancreatic insulin content and β-cell mass and prevented deterioration of islet organization. However, unlike liraglutide-treated rats, NRTN-mediated improvements were not associated with reduced body weight or food intake. Acute NRTN treatment did not activate c-Fos expression in key feeding behavior and metabolic centers in ZDF rat brain or directly enhance glucose-stimulated insulin secretion from pancreatic β-cells. Treating 10-week-old ZDF rats with sustained hyperglycemia with liraglutide resulted in some alleviation of hyperglycemia, whereas NRTN was not as effective despite improving plasma lipids and fasting glucose levels. Interestingly, coadministration of NRTN and liraglutide normalized hyperglycemia and other metabolic parameters, demonstrating that combining therapies with distinct mechanism(s) can alleviate advanced diabetes. This emphasizes that therapeutic combinations can be more effective to manage diabetes in individuals with uncontrolled hyperglycemia.

Effects of Obex in Overweight and Obese Subjects With or Without Impaired Fasting Glucose: A Pilot Study

Obex is a dietary supplement to help weight loss. The purpose of this study was to evaluate the effect of Obex in overweight/obese participants with or without impaired fasting glucose. This was an open-label pilot study conducted with 40 overweight and obese subjects, 23-60 years old with a body mass index of 25-44 kg/m² (20 participants with impaired fasting glucose [IFG] and 20 with normal glucose levels). Participants received Obex at a dose of one sachet before the two main meals of each day for 3 months. In addition to anthropometric measures and blood pressure (BP), fasting plasma glucose, lipid profile, insulin, creatinine, and uric acid were determined. Insulin resistance (HOMA-IR) and beta-cell function (HOMA-B) were assessed. Three indirect indices were used to calculate insulin sensitivity. Compared to baseline, Obex significantly reduced body weight, body mass index, waist circumference, waist/hip ratio, and waist/height ratio in both groups of participants (p <.05). In individuals without IFG, Obex improved HDL-c (high-density lipoprotein cholesterol) (p <.0001) and lowered BP (p <.05). After 3 months of Obex, subjects with IFG showed a reduction in fasting glucose concentrations (p <.0001). Compared to baseline, this group also showed improved insulin sensitivity and HDL-c (p <.05). In conclusion, the consumption of Obex contributed to weight reduction, improved glucose tolerance and insulin sensitivity, as well as HDL-c, and appears to be safe in overweight/obese adults with impaired fasting glucose. Obex may be beneficial for weight loss, indicating that further studies are required.

Renoprotective effect of berberine via regulating the PGE2 -EP1-Gαq-Ca(2+) signalling pathway in glomerular mesangial cells of diabetic rats

G‐protein coupled receptor‐mediated pathogenesis is of great importance in the development of diabetic complications, but the detailed mechanisms have not yet been clarified. Therefore, we aimed to explore the roles of the prostaglandin E2 receptor 1 (EP1)‐mediated signalling pathway and develop a corresponding treatment for diabetic nephropathy (DN). To create the DN model, rats fed a high‐fat and high‐glucose diet were injected with a single dose of streptozotocin (35 mg/kg, i.p.). Then, rats were either treated or not with berberine (100 mg/kg per day, i.g., 8 weeks). Cells were isolated from the renal cortex and cultured in high‐sugar medium with 20% foetal bovine serum. Prostaglandin E₂ (PGE₂) levels were determined by ELISA, and cells were identified by fluorescence immunoassay. We measured the biochemical characteristics and observed morphological changes by periodic‐acid‐Schiff staining. The expression of the EP1 receptor and the roles of GRK2 and β‐arrestin2 were identified using western blotting and flow cytometry. Downstream proteins were detected by western blot, while molecular changes were assessed by ELISA and laser confocal scanning microscopy. Berberine not only improved the majority of biochemical and renal functional parameters but also improved the histopathological alterations. A significant increase in PGE₂ level, EP1 membrane expression and Gαq expression, and concentration of Ca²⁺ were observed, accompanied by increased GRK2 and β‐arrestin2 levels soon afterwards. Berberine decreased the abnormal concentration of Ca²⁺, the increased levels of PGE₂, the high expression of EP1 and Gαq and suppressed the proliferation of mesangial cells. The EP1 receptor, a critical therapeutic target of the signalling pathway, contributed to mesangial cell abnormalities, which are linked to renal injury in DN. The observed renoprotective effects of berberine via regulating the PGE₂‐EP1‐Gαq‐Ca²⁺ signalling pathway indicating that berberine could be a promising anti‐DN medicine in the future.

Targeting metabolic disorders by natural products

The most prevalent metabolic disorders are diabetes mellitus, obesity, dyslipidemia, osteoporosis and metabolic syndrome, which are developed when normal metabolic processes are disturbed. The most common pathophysiologies of the above disorders are oxidative stress, Nrf2 pathways, epigenetic, and change in miRNA expression. There is a challenge in the prevention and treatment of metabolic disorders due to severe adverse effects of some synthetic drugs, their high cost, lack of safety and poverty in some conditions, and insufficient accessibility for the general population in the world. With increasing interest in shifting from synthetic drugs to phytotherapy as an alternative treatment, there is still a gap in scientific evidences of plant-derived therapeutic benefits. One reason may be slow rate of translation of animal studies' findings into human clinical trials. Since metabolic disorders are multifactorial, it seems that poly-herbal medications, or drug-herbal combination are needed for their treatment. However, further researches to determine the most effective plant-derived metabolites, and their cellular mechanism in order to set priorities for well-designed animal and clinical trials, and also more studies with strong scientific evidences such as systematic review and meta-analysis of controlled studies are needed.