Advances in Medical Therapy for Weight Loss and the Weight-Centric Management of Type 2 Diabetes Mellitus

The role of microRNAs in the healing of diabetic ulcers

MicroRNAs (miRNAs) are small protected molecules with a length of 18 to 25 nucleotides. Many studies have recently been conducted on miRNAs, illustrating their role in regulating many biological, physiological, and pathological activities, such as maintaining cellular signalling and regulating cellular pathways. The main role of miRNAs is to regulate the expression of genes after translation, which can lead to the destruction or suppression of translation by binding to mRNAs. As any change in the regulation of miRNAs is associated with several physiological abnormalities, such as type 2 diabetes and its complications, these molecules can be used for therapeutic purposes or as biomarkers for the diagnosis of diseases such as diabetes and its complications. In this review article, we will discuss important findings about the miRNAs and the role of these molecules in different phases of the wound-healing process of chronic wounds, especially diabetic ulcer.

Why Weight? An Analytic Review of Obesity Management, Diabetes Prevention, and Cardiovascular Risk Reduction

PURPOSE OF REVIEW

In this review, we examine one of the ironies of American health care-that we pay more for disease management than disease prevention. Instead of preventing type 2 diabetes (T2DM) by treating its precursor, obesity, we fail to provide sufficient insurance coverage for weight management only to fund the more costly burden of overt T2DM.

RECENT FINDINGS

There is a vital need for expanded insurance coverage to help foster a weight-centric approach to T2DM management. This includes broader coverage of anti-diabetic medications with evidence of cardiovascular risk reduction and mortality benefit, anti-obesity pharmacotherapy, bariatric surgery, weight loss devices, endoscopic bariatric therapies, and lifestyle interventions for the treatment of obesity. The fundamental question to ask is why weight? Why wait to go after obesity until its end-stage sequelae cause intractable conditions? Instead of managing the complications of T2DM, consider preventing them by tackling obesity.

Current concepts in management of weight regain following bariatric surgery

INTRODUCTION

Although bariatric surgery is the most effective and durable treatment for obesity, weight regain is common.

AREAS COVERED

In this article, we have critically reviewed data from retrospective and prospective studies pertaining to prevalence and predictors of weight regain following bariatric surgery, as well as the utility of behavioral and pharmacotherapeutic interventions to address post-surgical weight regain.

EXPERT COMMENTARY

The initial step in management of post-surgical weight regain is a comprehensive evaluation of the patient including a thorough assessment of contributing factors. While lifestyle interventions including diet, exercise and behavior modification are fundamental, they have limited efficacy which can be enhanced by pharmacotherapy. The optimal time to commence pharmacotherapy may be at weight plateau to maximize weight loss outcomes after bariatric surgery. Further prospective studies are needed to determine the best combination of behavioral and pharmacological therapies, and also the timing of pharmacotherapeutic intervention.

Changes in Body Weight Among People With Type 2 Diabetes Mellitus in the United States, NHANES 2005-2012

Purpose

To understand weight loss strategies, weight changes, goals, and behaviors in people with type 2 diabetes mellitus (T2DM) and whether these differ by ethnicity.

Methods

T2DM was identified by self-reported diagnosis using the NHANES 2005-2012 data, which also included measured and self-reported current body weight and height, self-reported weight the prior year, and self-reported aspired weight. Nineteen weight loss strategies were evaluated for association with ≥5% weight loss or weight gain versus <5% weight change.

Results

Among people with T2DM, 88.0% were overweight/obese (body mass index [BMI] ≥25 kg/m2) in the prior year and 86.1% the current year. About 60% of the overweight/obese took weight loss actions, mostly using diet-related methods with average weight lost <5%. Two most “effective” methods reported (smoking, taking laxatives/vomiting) are also potentially most harmful. Similar BMI distributions but different goals and behaviors about weight and weight loss were observed across ethnicity. Only physical activity meeting the recommended level and changing eating habits were consistently associated with favorable and statistically significant weight change.

Conclusions

Weight management in T2DM is an ongoing challenge, regardless of ethnicity/race. Among overweight/obese T2DM subjects, recommended level of physical activity and changing eating habits were associated with statistically significant favorable weight change.

Treatment of obesity in 2015

Obesity is a major health priority in the United States, as well as globally. It is associated with multiple comorbidities and reduced life expectancy. Effective management of obesity involves producing an intervention plan tailored to the individual patient. Potential contributory factors to weight gain, including dietary habits, physical inactivity, associated medical conditions, and medications, should be identified and addressed. Lifestyle interventions comprising diet modification, physical activity, and behavior therapy are foundational to the management of obesity. Caloric restriction is the most important component in achieving weight loss through negative energy balance, whereas sustained physical activity is important in maintaining the weight loss. Adjunctive therapies in the form of pharmacotherapy and bariatric surgery are required in patients who do not achieve targeted weight loss and health goals with lifestyle interventions. Currently there are 3 drugs approved for long-term management of obesity, orlistat, phentermine/topiramate extended release, and lorcaserin, and there are 2 on the horizon, bupropion/naltrexone and liraglutide. Bariatric surgery is an effective strategy recognized to produce durable weight loss with amelioration of obesity-related comorbidities and should be considered a treatment option in eligible patients.

Metabolic vs. hedonic obesity: a conceptual distinction and its clinical implications

Body weight is determined via both metabolic and hedonic mechanisms. Metabolic regulation of body weight centres around the 'body weight set point', which is programmed by energy balance circuitry in the hypothalamus and other specific brain regions. The metabolic body weight set point has a genetic basis, but exposure to an obesogenic environment may elicit allostatic responses and upward drift of the set point, leading to a higher maintained body weight. However, an elevated steady-state body weight may also be achieved without an alteration of the metabolic set point, via sustained hedonic over-eating, which is governed by the reward system of the brain and can override homeostatic metabolic signals. While hedonic signals are potent influences in determining food intake, metabolic regulation involves the active control of both food intake and energy expenditure. When overweight is due to elevation of the metabolic set point ('metabolic obesity'), energy expenditure theoretically falls onto the standard energy-mass regression line. In contrast, when a steady-state weight is above the metabolic set point due to hedonic over-eating ('hedonic obesity'), a persistent compensatory increase in energy expenditure per unit metabolic mass may be demonstrable. Recognition of the two types of obesity may lead to more effective treatment and prevention of obesity.

Systems analysis and the prediction and prevention of Type 2 diabetes mellitus

Prevalence of Type 2 diabetes has increased at an alarming rate, highlighting the need to correctly predict the development of this disease in order to allow intervention and thus, slow progression of the disease and resulting metabolic derangement. There have been many recent 'advances' geared toward the detection of pre-diabetes, including genome wide association studies and metabolomics. Although these approaches generate a large amount of data with a single blood sample, studies have indicated limited success using genetic and metabolomics information alone for identification of disease risk. Clinical assessment of the disposition index (DI), based on the hyperbolic law of glucose tolerance, is a powerful predictor of Type 2 diabetes, but is not easily assessed in the clinical setting. Thus, it is evident that combining genetic or metabolomic approaches for a more simple assessment of DI may provide a useful tool to identify those at highest risk for Type 2 diabetes, allowing for intervention and prevention.

Effects of LX4211, a dual SGLT1/SGLT2 inhibitor, plus sitagliptin on postprandial active GLP-1 and glycemic control in type 2 diabetes

BACKGROUND

Combination therapy is required to provide adequate glycemic control in many patients with type 2 diabetes mellitus (T2DM). Because sodium-dependent glucose transporter (SGLT)-1 inhibition results in an increased release of glucagon-like peptide (GLP)-1, and because dipeptidyl peptidase (DPP)-4 inhibitors prevent its inactivation, the 2 mechanisms together provide an intriguing potential combination therapy.

OBJECTIVES

This combination was explored in preclinical models and then tested in patients with T2DM to compare the effects of single-dose LX4211 400 mg and sitagliptin 100 mg, administered as monotherapy or in combination, on GLP-1, peptide tyrosine tyrosine (PYY), gastric inhibitory peptide (GIP), glucose, and insulin.

METHODS

Preclinical: Obese male C57BL6J mice were assigned to 1 of 4 treatment groups: LX4211 60 mg/kg, sitagliptin 30 mg/kg, LX4211 + sitagliptin, or inactive vehicle. Clinical: This 3-treatment, 3-crossover, randomized, open-label study was conducted at a single center. Patients on metformin monotherapy were washed out from metformin and were randomly assigned to receive sequences of single-dose LX4211, sitagliptin, or the combination. In both studies, blood was collected for the analysis of pharmacodynamic variables (GLP-1, PYY, GIP, glucose, and insulin). In the clinical study, urine was collected to assess urinary glucose excretion.

RESULTS

Preclinical: 120 mice were treated and assessed (5/time point/treatment group). With repeat daily dosing, the combination was associated with apparently synergistic increases in active GLP-1 relative to monotherapy with either agent; this finding was supported by findings from an additional 14-day repeated-dose experiment. Clinical: 18 patients were enrolled and treated (mean age, 49 years; 56% male; 89% white). The LX4211 + sitagliptin combination was associated with significantly increased active GLP-1, total GLP-1, and total PYY; with a significant reduction in total GIP; and with a significantly improved blood glucose level, with less insulin, compared with sitagliptin monotherapy. LX4211 was associated with a significant increase in total GLP-1 and PYY and a reduced total GIP, likely due to a reduction in SGLT1-mediated intestinal glucose absorption, whereas sitagliptin was associated with suppression of all 3 peptides relative to baseline. All treatments were well tolerated, with no evidence of diarrhea with LX4211 treatment.

CONCLUSIONS

The findings from the preclinical studies suggest that the LX4211 + sitagliptin combination produced synergistic increases in active GLP-1 after a meal challenge containing glucose. These initial clinical results also suggest that a LX4211 + DPP-4 inhibitor combination may provide an option in patients with T2DM. The potential long-term clinical benefits of such combination treatment need to be confirmed in large clinical trials. ClinicalTrials.gov identifier: NCT01441232.