Effects of Dapagliflozin and Combination Therapy With Exenatide on Food-Cue Induced Brain Activation in Patients With Type 2 Diabetes

Hypothalamic sex-specific metabolic shift by canagliflozin during aging

The hypothalamus undergoes significant changes with aging and plays crucial roles in age-related metabolic alterations. Sodium-glucose co-transporter 2 inhibitors (SGLT2i) are anti-diabetic agents that promote glucose excretion, and metabolic homeostasis. Recent studies have shown that a SGLT2i, Canagliflozin (Cana), can extend the median survival of genetically heterogeneous UM-HET3 male mice and improve central metabolic control via increases in hypothalamic insulin responsiveness in aged males, as well as reduced age-associated hypothalamic inflammation. We studied the long- and short-term effects of Cana on hypothalamic metabolic control in UM-HET3 mice. Starting the treatment from 7 months of age, we show that 4 weeks of Cana treatment significantly reduced body weight and fat mass in male but not female mice that was associated with enhanced glucose tolerance and insulin sensitivity observed by 12 months. Indirect calorimetry showed that Cana treatment increased energy expenditure in male, but not female mice, at 12 months of age. Long-term Cana treatment increased metabolic rates in both sexes, and markedly increasing formation of both orexigenic and anorexigenic projections to the paraventricular nucleus of the hypothalamus (PVH) mostly in females by 25 months. Hypothalamic RNA-sequencing analysis revealed increased sex-specific genes and signaling pathways related to insulin signaling, glycogen catabolic pathway, neuropeptide signaling, and mitochondrial function upregulated by Cana, with males showing a more pronounced and sustained effect on metabolic pathways at both age groups. Overall, our data provide critical evidence for sex-specific mechanisms that are affected by Cana during aging suggesting key targets of hypothalamic Cana-induced neuroprotection for metabolic control.

Influence of Dapagliflozin Dosing on Low-Density Lipoprotein Cholesterol in Type 2 Diabetes Mellitus: A Systematic Literature Review and Meta-Analysis

A systematic literature review and meta-analysis was performed to evaluate the effects of dapagliflozin on low-density lipoprotein (LDL) cholesterol in type 2 diabetes mellitus. Data on changes in LDL cholesterol, adverse cardiac events (ACEs), glycated hemoglobin (HbA1c), and fasting blood glucose (FBG) were pooled in a meta-analysis. Data from dose comparison trials were separately pooled, and meta-analysis was conducted by using RevMan (5.4.1) and R (4.1.2). Dapagliflozin increased LDL cholesterol by 2.33 mg/dL (95% CI, 1.46 to 3.19; I2 = 0%; P < .00001), increased risk of ACEs by 1.56 (95% CI, 1.02 to 2.39; I2 = 0%; P < .04), decreased HbA1c by -0.41% (95% CI, -0.44 to -0.39; I2 = 85%; P < .00001), and decreased FBG by -13.51 mg/dL (95% CI, -14.43 to -12.59; I2 = 92%; P < .00001) versus any placebo or active comparator. Dapagliflozin 10 mg monotherapy increased LDL cholesterol by 1.71 mg/dL (95% CI, -1.20 to 4.62; I2 = 53%; P = .25) versus a 5 mg dose and by 1.04 mg/dL (95% CI, -1.17 to 3.26; I2 = 62%; P = .36) versus a 2.5 mg dose. Dapagliflozin 10 mg monotherapy increased LDL cholesterol by 3.13 mg/dL (95% CI, 1.31 to 4.95; I2 = 0%; P = .0008), increased the risk of ACEs by 1.26 (95% CI, 0.56 to 2.87; I2 = 0%; P = .58), decreased HbA1c by -0.4% (95% CI, -0.45 to -0.35; I2 = 89%; P < .00001), and decreased FBG by -8.39 mg/dL (95% CI, -10 to -6.77; I2 = 96%; P < .00001) versus a placebo or active comparator. Dapagliflozin monotherapy resulted in a minimal but statistically significantly (P = .0002) increase in LDL cholesterol. However, this minor change does not increase the risk of ACEs (P = .17) when compared with placebo or active comparator.

From diabetes to diverse domains: the multifaceted roles of GLP-1 receptor agonists

Glucagon-like Peptide-1 (GLP-1) receptor agonists (GLP-1RAs) emerged as a primary treatment for type-2 diabetes mellitus (T2DM), however, their multifaceted effects on various target organs beyond glycemic control opened a new era of treatment. We conducted a comprehensive literature search using databases including Scopus, Google Scholar, PubMed, and the Cochrane Library to identify clinical, in-vivo, and in-vitro studies focusing on the diverse effects of GLP-1 receptor agonists. Eligible studies were selected based on their relevance to the varied roles of GLP-1RAs in T2DM management and their impact on other physiological functions. Numerous studies have reported the efficacy of GLP-1RAs in improving outcomes in T2DM, with demonstrated benefits including glucose-dependent insulinotropic actions, modulation of insulin signaling pathways, and reductions in glycemic excursions. Additionally, GLP-1 receptors are expressed in various tissues and organs, suggesting their widespread physiological functions beyond glycemic control potentially include neuroprotective, anti-inflammatory, cardioprotective, and metabolic benefits. However, further scientific studies are still underway to maximize the benefits of GLP-1RAs and to discover additional roles in improving health benefits. This article sought to review not only the actions of GLP1RAs in the treatment of T2DM but also explore its effects on potential targets in other disorders.

Changes in daily intake of nutrients and foods including confectionery after the initiation of empagliflozin in Japanese patients with type 2 diabetes: a pilot study

INTRODUCTION

It is unclear how dietary intake changes after sodium-glucose cotransporter 2 inhibitor (SGLT2i) treatment is started in patients with type 2 diabetes.

METHODS

We performed a non-controlled, open-label study that enrolled 51 patients with type 2 diabetes. The patients were newly administered empagliflozin, and their dietary habits were examined using a self-administered diet history questionnaire at the beginning of the study and after 24 weeks. We investigated the association of changes in HbA1c and body weight with changes in energy, nutrient, and food group intakes.

RESULTS

At 24 weeks after the start of the study, HbA1c improved significantly and body weight decreased. In the food group, only the intake of confectionery increased, and there were no significant differences in the association between changes in HbA1c and body weight and changes in energy, nutrient, and food group intakes after 24 weeks. However, a significant negative correlation was found between change in HbA1c after 4 weeks and change in energy intake after 24 weeks, and principal component analysis showed an association between change in HbA1c levels after 4 weeks and change in energy intake and some food group intakes including confectionery after 24 weeks.

CONCLUSION

In this study, after 24 weeks of treatment with empagliflozin, only intake of confectionery increased. Early assessment by dietitians after initiation of SGLT2i treatment might be important because our data suggested that the reduction in blood glucose levels after the start of empagliflozin was associated with a subsequent increase in energy intake.

TRIAL REGISTRATION

University Hospital Medical Information Network-Clinical Trials Registry (UMIN-CTR) on September 5, 2016 (registration ID, UMIN000002309|| http://www.umin.ac.jp/ctr/ ).

The insulin resistant brain: impact on whole-body metabolism and body fat distribution

Insulin exerts its actions not only on peripheral organs but is also transported into the brain where it performs distinct functions in various brain regions. This review highlights recent advancements in our understanding of insulin's actions within the brain, with a specific emphasis on investigations in humans. It summarises current knowledge on the transport of insulin into the brain. Subsequently, it showcases robust evidence demonstrating the existence and physiological consequences of brain insulin action, while also introducing the presence of brain insulin resistance in humans. This pathophysiological condition goes along with an impaired acute modulation of peripheral metabolism in response to brain insulin action, particularly in the postprandial state. Furthermore, brain insulin resistance has been associated with long-term adiposity and an unfavourable adipose tissue distribution, thus implicating it in the pathogenesis of subgroups of obesity and (pre)diabetes that are characterised by distinct patterns of body fat distribution. Encouragingly, emerging evidence suggests that brain insulin resistance could represent a treatable entity, thereby opening up novel therapeutic avenues to improve systemic metabolism and enhance brain functions, including cognition. The review closes with an outlook towards prospective research directions aimed at further elucidating the clinical implications of brain insulin resistance. It emphasises the critical need to establish feasible diagnostic measures and effective therapeutic interventions.

Preclinical Studies of Canagliflozin, a Sodium-Glucose Co-Transporter 2 Inhibitor, and Donepezil Combined Therapy in Alzheimer's Disease

The incidence of neurodegenerative diseases, such as Alzheimer's disease (AD), is continuously growing worldwide, which leads to a heavy economic and societal burden. The lack of a safe and effective causal therapy in cognitive decline is an aggravating factor and requires investigations into the repurposing of commonly used drugs. Sodium-glucose co-transporter 2 inhibitors (SGLT2i) are a new and efficient class of hypoglycemic drugs and, due to their pleiotropic effects, have indications that go beyond diabetes. There is emerging data from murine studies that SGLT2i can cross the blood-brain barrier and may have neuroprotective effects, such as increasing the brain-derived neurotrophic factor (BDNF), reducing the amyloid burden, inhibiting acetylcholinesterase (AChE) and restoring the circadian rhythm in the mammalian target of rapamycin (mTOR) activation. The current study investigates the effect of an SGLT2i and donepezil, under a separate or combined 21-day treatment on AD-relevant behaviors and brain pathology in mice. The SGLT2i canagliflozin was found to significantly improve the novelty preference index and the percentage of time spent in the open arms of the maze in the novel object recognition and elevated plus maze test, respectively. In addition, canagliflozin therapy decreased AChE activity, mTOR and glial fibrillary acidic protein expression. The results also recorded the acetylcholine M1 receptor in canagliflozin-treated mice compared to the scopolamine group. In the hippocampus, the SGLT2i canagliflozin reduced the microgliosis and astrogliosis in males, but not in female mice. These findings emphasize the value of SGLT2i in clinical practice. By inhibiting AChE activity, canagliflozin represents a compound that resembles AD-registered therapies in this respect, supporting the need for further evaluation in dementia clinical trials.

Altered Metabolic Phenotypes and Hypothalamic Neuronal Activity Triggered by Sodium-Glucose Cotransporter 2 Inhibition

BACKGRUOUND

Sodium-glucose cotransporter 2 (SGLT-2) inhibitors are currently used to treat patients with diabetes. Previous studies have demonstrated that treatment with SGLT-2 inhibitors is accompanied by altered metabolic phenotypes. However, it has not been investigated whether the hypothalamic circuit participates in the development of the compensatory metabolic phenotypes triggered by the treatment with SGLT-2 inhibitors.

METHODS

Mice were fed a standard diet or high-fat diet and treated with dapagliflozin, an SGLT-2 inhibitor. Food intake and energy expenditure were observed using indirect calorimetry system. The activity of hypothalamic neurons in response to dapagliflozin treatment was evaluated by immunohistochemistry with c-Fos antibody. Quantitative real-time polymerase chain reaction was performed to determine gene expression patterns in the hypothalamus of dapagliflozin-treated mice.

RESULTS

Dapagliflozin-treated mice displayed enhanced food intake and reduced energy expenditure. Altered neuronal activities were observed in multiple hypothalamic nuclei in association with appetite regulation. Additionally, we found elevated immunosignals of agouti-related peptide neurons in the paraventricular nucleus of the hypothalamus.

CONCLUSION

This study suggests the functional involvement of the hypothalamus in the development of the compensatory metabolic phenotypes induced by SGLT-2 inhibitor treatment.

GLP-1RAs caused gastrointestinal adverse reactions of drug withdrawal: a system review and network meta-analysis

Background

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) significantly reduce postprandial blood glucose, inhibit appetite, and delay gastrointestinal emptying. However, it is controversial that some patients are intolerant to GLP-1RAs.

Methods

PubMed, Embase, Web of Science, and Cochrane Library were searched for randomized controlled trials (RCTs) using GLP-1RAs with documented withdrawal due to gastrointestinal adverse reactions (GI AEs) from their inception to September 28, 2022. After extracting the information incorporated into the studies, a random-effects network meta-analysis was performed within a frequentist framework.

Results

64 RCTs were finally enrolled, which included six major categories of the GLP-1RA. The sample size of the GLP-1RAs treatment group was 16,783 cases. The risk of intolerable gastrointestinal adverse reactions of Liraglutide and Semaglutide was higher than that of Dulaglutide. Meanwhile, the higher the dose of the same GLP-1RA preparation, the more likely to cause these adverse reactions. These intolerable GI AEs were not significantly related to drug homology or formulations and may be related to the degree of suppression of the appetite center.

Conclusion

Dulaglutide caused the lowest intolerable GI AEs, while Liraglutide and Semaglutide were the highest. For Semaglutide, the higher the dose, the more likely it is to drive GI AEs. Meanwhile, the risk of these GI AEs is independent of the different formulations of the drug. All these findings can effectively guide individualized treatment.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022359346, identifier CRD42022359346.

Brain Activation in Response to Low-Calorie Food Pictures: An Explorative Analysis of a Randomized Trial With Dapagliflozin and Exenatide

BACKGROUND AND AIM

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) induce less weight loss than expected. This may be explained by SGLT2i-induced alterations in central reward and satiety circuits, contributing to increased appetite and food intake. This hyperphagia may be specific to high-calorie foods. Glucagon-like peptide-1 receptor agonists (GLP-1RA) are associated with lower preferences for high-calorie foods, and with decreased activation in areas regulating satiety and reward in response to high-calorie food pictures, which may reflect this lower preference for energy-dense foods. To optimize treatment, we need a better understanding of how intake is controlled, and how [(un)healthy] food choices are made. The aim of the study was to investigate the effects of dapagliflozin, exenatide, and their combination on brain activation in response to low-calorie food pictures.

METHODS

We performed an exploratory analysis of a larger, 16-week, double-blind, randomized, placebo-controlled trial. Sixty-eight subjects with obesity and type 2 diabetes were randomized to dapagliflozin, exenatide, dapagliflozin plus exenatide, or double placebo. Using functional MRI, the effects of treatments on brain responses to low-calorie food pictures were assessed after 10 days and 16 weeks.

RESULTS

Dapagliflozin versus placebo decreased activity in response to low-calorie food pictures, in the caudate nucleus, insula, and amygdala after 10 days, and in the insula after 16 weeks. Exenatide versus placebo increased activation in the putamen in response to low-calorie food pictures after 10 days, but not after 16 weeks. Dapagliflozin plus exenatide versus placebo had no effect on brain responses, but after 10 days dapagliflozin plus exenatide versus dapagliflozin increased activity in the insula and amygdala in response to low-calorie food pictures.

CONCLUSION

Dapagliflozin decreased activation in response to low-calorie food pictures, which may reflect a specific decreased preference for low-calorie foods, in combination with the previously found increased activation in response to high-calorie foods, which may reflect a specific preference for high-calorie foods, and may hamper SGLT2i-induced weight loss. Exenatide treatment increased activation in response to low-calorie foods. Combination treatment may lead to more favorable brain responses to low-calorie food cues, as we observed that the dapagliflozin-induced decreased response to low-calorie food pictures had disappeared.