One minute of stair climbing and descending reduces postprandial insulin and glucose with 3-min improving insulin resistance following a mixed meal in young adults: A Randomized Controlled Crossover Trial

Background

Glycemic markers, including postprandial glucose, insulin, and insulin resistance, are strong predictors of morbidity and mortality in individuals with and without diabetes. Stair-climbing and -descending (SCD) at a comfortable pace for 3 minutes after a sugary beverage (300 kilocalories; 100% carbohydrate) lowers insulin, with insulin sensitivity improving in 10 minutes. If similar benefits are seen following consumption of a mixed meal is unknown. We hypothesize SCD will improve these markers in a dose-response manner following a mixed meal.

Methods

In a randomized, controlled, crossover trial, young adults (N = 31) performed SCD for 0 (seated control), 1, 3, and 10 minutes after a mixed meal (650 kilocalories; 53% carbohydrates, 33% fat, and 14% protein). Differences in glucose, insulin, and insulin sensitivity (ISI) from baseline to 30 min were analyzed using a mixed-effects ANOVA.

Results

A significant fixed-effect was found for change in glucose [F(2.551,67.17) = 4.724,p = 0.007)], insulin [F(2.692,74.49) = 11.28,p < 0.001)], and ISI [F(2.127,56.00) = 5.848,p = 0.004)]. Compared to the seated control (0 minutes), changes in glucose were lower after 1 minute (-14.0 (-7.2)mg/dL,p < 0.001), 3 minutes (-18.4 (-7.0)mg/dL,p = 0.0007), and 10 minutes (-10.0 (-8.1)mg/dL,p = 0.039); changes in insulin were lower after 1 minute (-1.8 (-0.9)μIU/mL,p = 0.0011), 3 minutes (-2.8 (-0.9)μIU/mL,p < 0.001), and 10 minutes (-1.1 (-0.9)μIU/mL,p = 0.033); and changes in ISI were significantly higher after 3 minutes (2.4 (1.5),p < 0.001) and 10 minutes (1.3 (1.6),p = 0.014) but not 1 minute (1.2 (1.5),p = 0.059).

Conclusion

Postprandial glucose and insulin improved with 1 minute, and insulin resistance improved with 3 minutes, of SCD at a self-selected, comfortable pace, after consumption of a mixed meal in apparently healthy young adults.

Protocol

Trial registration: ClinicalTrials.gov Identifier: NCT04232475.

Polyelectrolyte-protein synergism: pH-responsive polyelectrolyte/insulin complexes as versatile carriers for targeted protein and drug delivery

The co-assembly of polyelectrolytes (PE) with proteins offers a promising approach for designing complex structures with customizable morphologies, charge distribution, and stability for targeted cargo delivery. However, the complexity of protein structure limits our ability to predict the properties of the formed nanoparticles, and our goal is to identify the key triggers of the morphological transition in protein/PE complexes and evaluate their ability to encapsulate multivalent ionic drugs. A positively charged PE can assemble with a protein at pH above isoelectric point due to the electrostatic attraction and disassemble at pH below isoelectric point due to the repulsion. The additional hydrophilic block of the polymer should stabilize the particles in solution and enable them to encapsulate a negatively charged drug in the presence of PE excess. We demonstrated that diblock copolymers, poly(ethylene oxide)-block-poly(N,N-dimethylaminoethyl methacrylate) and poly(ethylene oxide)-block-poly(N,N,N-trimethylammonioethyl methacrylate), consisting of a polycation block and a neutral hydrophilic block, reversibly co-assemble with insulin in pH range between 5 and 8. Using small-angle neutron and X-ray scattering (SANS, SAXS), we showed that insulin arrangement within formed particles is controlled by intermolecular electrostatic forces between protein molecules, and can be tuned by varying ionic strength. For the first time, we observed by fluorescence that formed protein/PE complexes with excess of positive charges exhibited potential for encapsulating and controlled release of negatively charged bivalent drugs, protoporphyrin-IX and zinc(II) protoporphyrin-IX, enabling the development of nanocarriers for combination therapies with adjustable charge, stability, internal structure, and size.

Spexin acts as a novel glucose-lowering factor in grass carp (Ctenopharyngodon idella)

At present, the physiological roles of various hormones in fish glucose metabolism have been elucidated. Spexin, a 14-amino acids polypeptide, is highly conserved in many species and has functions such as reducing body weight and improving insulin resistance. In this paper, the open reading frame (ORF) of spx21 in grass carp (Ctenopharyngodon idella) was cloned, and the tissue distribution of spx1 and spx2, their direct and indirect regulatory effects on glucose metabolism of grass carp were investigated. The ORF of spx2 gene in grass carp was 279 bp in length. Moreover, spx1 was highly expressed in the adipose tissue, while spx2 was highly expressed in the brain. In vitro, SPX1 and SPX2 showed opposite effects on the glycolytic pathway in the primary hepatocytes. In vivo, intraperitoneal injection of SPX1 and SPX2 significantly reduced serum glucose levels and increased hepatopancreas glycogen contents. Meanwhile, SPX1 and SPX2 promoted the expression of key genes of glycolysis (pk) and glycogen synthesis (gys) in the hepatopancreas at 3 h post injection. As for indirect effects, 1000 nM SPX1 and SPX2 significantly increased insulin-mediated liver type phosphofructokinase (pfkla) mRNA expression and enhanced the inhibitory effects of insulin on glucose-6-phosphatase (g6pase), phosphoenolpyruvate carboxykinase (pepck), glycogen phosphorylase L (pygl) mRNA expression. Our results show that SPX1 and SPX2 have similar indirect effects on the regulation of glucose metabolism that enhance insulin activity, but they exhibit opposite roles in terms of direct effects.

Schisandrin A Alleviates Spatial Learning and Memory Impairment in Diabetic Rats by Inhibiting Inflammatory Response and Through Modulation of the PI3K/AKT Pathway

Clinical and epidemiological research shows that people with diabetes mellitus frequently experience diabetic cognitive impairment. Schisandrin A (SchA), one of the lignans found in the dried fruit of Schisandra chinensis, has a variety of pharmacological effects on immune system control, apoptosis suppression, anti-oxidation and anti-inflammation. The goal of the current investigation was to clarify the probable neuro-protective effects of SchA against streptozotocin-induced diabetes deficiencies of the spatial learning and memory in rats. The outcomes show that SchA therapy effectively improved impaired glucose tolerance, fasting blood glucose level and serum insulin level in diabetic rats. Additionally, in the Morris water maze test, diabetic rats showed deficits in spatial learning and memory that were ameliorated by SchA treatment. Moreover, giving diabetic rats SchA reduced damage to the hippocampus structure and increased the production of synaptic proteins. Further research revealed that SchA therapy reduced diabetic-induced hippocampus neuron damage and the generation of Aβ, as demonstrated by the upregulated phosphorylation levels of insulin signaling pathway connected proteins and by the decreased expression levels of inflammatory-related factors. Collectively, these results suggested that SchA could improve diabetes-related impairments in spatial learning and memory, presumably by reducing inflammatory responses and regulating the insulin signaling system.

GLP1R and GIPR expression and signaling in pancreatic alpha cells, beta cells and delta cells

Glucagon-like peptide-1 receptor (GLP1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR) are transmembrane receptors involved in insulin, glucagon and somatostatin secretion from the pancreatic islet. Therapeutic targeting of GLP1R and GIPR restores blood glucose levels in part by influencing beta cell, alpha cell and delta cell function. Despite the importance of the incretin-mimetics for diabetes therapy, our understanding of GLP1R and GIPR expression patterns and signaling within the islet remain incomplete. Here, we present the evidence for GLP1R and GIPR expression in the major islet cell types, before addressing signaling pathway(s) engaged, as well as their influence on cell survival and function. While GLP1R is largely a beta cell-specific marker within the islet, GIPR is expressed in alpha cells, beta cells, and (possibly) delta cells. GLP1R and GIPR engage Gs-coupled pathways in most settings, although the exact outcome on hormone release depends on paracrine communication and promiscuous signaling. Biased agonism away from beta-arrestin is an emerging concept for improving therapeutic efficacy, and is also relevant for GLP1R/GIPR dual agonism. Lastly, dual agonists exert multiple effects on islet function through GIPR > GLP1R imbalance, increased GLP1R surface expression and cAMP signaling, as well as beneficial alpha cell-beta cell-delta cell crosstalk.

elegans insulin-like peptides

Insulin-like peptides are a group of hormones crucial for regulating metabolism, growth, and development in animals. Invertebrates, such as C. elegans, have been instrumental in understanding the molecular mechanisms of insulin-like peptides. Here, we review the 40 insulin-like peptide genes encoded in the C. elegans genome. Despite the large number, there is only one C. elegans insulin-like peptide receptor, called DAF-2. The insulin and insulin-like growth factor signaling (IIS) pathway is evolutionarily conserved from worms to humans. Thus C. elegans provides an excellent model to understand how these insulin-like peptides function. C. elegans is unique in that it possesses insulin-like peptides that have antagonistic properties, unlike all human insulin-like peptides, which are agonists. This review provides an overview of the current literature on C. elegans insulin-like peptide structures, processing, tissue localization, and regulation. We will also provide examples of insulin-like peptide signaling in C. elegans during growth, development, germline development, learning/memory, and longevity.

The pancreas does not contribute to the non-adrenergic-non-cholinergic stimulation of heart rate in digesting pythons

Vertebrates elevate heart rate when metabolism increases during digestion. Part of this tachycardia is due to a non-adrenergic-non-cholinergic (NANC) stimulation of the cardiac pacemaker, and it has been suggested these NANC factors are circulating hormones that are released from either gastrointestinal or endocrine glands. The NANC stimulation is particularly pronounced in species with large metabolic responses to digestion, such as reptiles. To investigate the possibility that the pancreas may release hormones that exert positive chronotropic effects on the digesting Burmese python heart, a species with very large postprandial changes in heart rate and oxygen uptake, we evaluate how pancreatectomy affects postprandial heart rate before and after autonomic blockade of the muscarinic and the beta-adrenergic receptors. We also measured the rates of oxygen consumption and evaluated the short-term control of the heart using the spectral analysis of heart rate variability and the baroreflex sequence method. Digestion caused the ubiquitous tachycardia, but the intrinsic heart rate (revealed after the combination of atropine and propranolol) was not affected by pancreatectomy and therefore hormones, such as glucagon and insulin, do not appear to contribute to the regulation of heart rate during digestion in Burmese pythons.

Vitamin D3 mitigates type 2 diabetes induced by a high carbohydrate-high fat diet in rats: Role of the purinergic system

This study evaluated the effect of vitamin D3 (VIT D3) supplementation on the enzymatic activities and density of ectonucleoside triphosphate diphosphohydrolase (E-NTPDase), ecto-5-nucleotidase (E-5'-NT), adenosine deaminase (ADA), as well as the density of P2 × 7R, P2Y12R, A1R, A2AR receptors, IL-1β, and oxidative parameters in type 2 diabetic rats. Forty male Wistar rats were fed a high carbohydrate-high fat diet (HCHFD) and received an intraperitoneal injection containing a single dose of streptozotocin (STZ, 35 mg/kg). Animals were divided into four groups: 1) control; 2) control/VIT D3 12 µg/kg; 3) diabetic; and 4) diabetic/VIT D3 12 µg/kg. Results show that VIT D3 reduced blood glucose, ATP hydrolysis, ADA activity, P2Y12R density (platelets), as well as ATP, ADP, and AMP hydrolysis and ADA activity (synaptosomes). Moreover, VIT D3 increased insulin levels and AMP hydrolysis (platelets) and improved antioxidant defense. Therefore, we suggest that VIT D3 treatment modulates hyperglycemia-induced changes via purinergic enzymes and receptor expression, consequently attenuating insulin homeostasis dysregulation in the diabetic state.

Insulin-stimulated translocation of the fatty acid transporter CD36 to the plasma membrane is mediated by the small GTPase Rac1 in adipocytes

Cluster of differentiation 36 (CD36) is a scavenger receptor (SR), recognizing diverse extracellular ligands in various types of mammalian cells. Long-chain fatty acids (FAs), which are important constituents of phospholipids and triglycerides, also utilize CD36 as a predominant membrane transporter, being incorporated from the circulation across the plasma membrane in several cell types, including cardiac and skeletal myocytes and adipocytes. CD36 is localized in intracellular vesicles as well as the plasma membrane, and its distribution is modulated by extracellular stimuli. Herein, we aimed to clarify the molecular basis of insulin-stimulated translocation of CD36, which leads to the enhanced uptake of long-chain FAs, in adipocytes. To this end, we developed a novel exofacial epitope-tagged reporter to specifically detect cell surface-localized CD36. By employing this reporter, we demonstrate that the small GTPase Rac1 plays a pivotal role in insulin-stimulated translocation of CD36 to the plasma membrane in 3T3-L1 adipocytes. Additionally, phosphoinositide 3-kinase and the protein kinase Akt2 are shown to be involved in the regulation of Rac1. Downstream of Rac1, another small GTPase RalA directs CD36 translocation. Collectively, these results suggest that CD36 is translocated to the plasma membrane by insulin through mechanisms similar to those for the glucose transporter GLUT4 in adipocytes.

Biorelevant subcutaneous in vitro test predicts the release of human and fast acting insulin formulations

The administration of insulins by subcutaneous injection is nowadays widely prevalent. The injection site is located below the dermis and composed of cells and the extracellular matrix formed of a network of macromolecules such as hyaluronic acid and collagen. Following an injection, the insulins from the formulated products are timely released as drug molecules from the injection site into systemic circulation. In this publication, we show the development of an in vitro setup utilizing a hydrogel composed of a special collagen-hyaluronic acid mixture that mimics the extracellular matrix. Another setup was used for differentiation of the commercially available and research insulin formulations by determining the in vitro permeation characteristics with the results that were correlated with the human in vivo data. Significant differentiation was achieved at 90 % confidence level between the permeation curves of insulin glulisine containing formulations (U100 and a concentrated research formulation), while in case of the insulin lispro containing formulations (U100 and U200) the permeation curves showed similarity. These results demonstrated that the in vitro setup may be used as a tool for formulation development and drug candidate profiling as it is able to differentiate or show similarities between the agglomeration states and concentration of the active pharmaceutical ingredients.

Continuous glucose monitoring with structured education in adults with type 2 diabetes managed by multiple daily insulin injections: a multicentre randomised controlled trial

AIMS/HYPOTHESIS

The aim of this study was to compare the effectiveness of stand-alone intermittently scanned continuous glucose monitoring (isCGM) with or without a structured education programme and blood glucose monitoring (BGM) in adults with type 2 diabetes on multiple daily insulin injections (MDI).

METHODS

In this 24 week randomised open-label multicentre trial, adults with type 2 diabetes on intensive insulin therapy with HbA1c levels of 58-108 mmol/mol (7.5-12.0%) were randomly assigned in a 1:1:1 ratio to isCGM with a structured education programme on adjusting insulin dose and timing according to graphical patterns in CGM (intervention group), isCGM with conventional education (control group 1) or BGM with conventional education (control group 2). Block randomisation was conducted by an independent statistician. Due to the nature of the intervention, blinding of participants and investigators was not possible. The primary outcome was change in HbA1c from baseline at 24 weeks, assessed using ANCOVA with the baseline value as a covariate.

RESULTS

A total of 159 individuals were randomised (n=53 for each group); 148 were included in the full analysis set, with 52 in the intervention group, 49 in control group 1 and 47 in control group 2. The mean (± SD) HbA1c level at baseline was 68.19±10.94 mmol/mol (8.39±1.00%). The least squares mean change (± SEM) from baseline HbA1c at 24 weeks was -10.96±1.35 mmol/mol (-1.00±0.12%) in the intervention group, -6.87±1.39 mmol/mol (-0.63±0.13%) in control group 1 (p=0.0367 vs intervention group) and -6.32±1.42 mmol/mol (-0.58±0.13%) in control group 2 (p=0.0193 vs intervention group). Adverse events occurred in 28.85% (15/52) of individuals in the intervention group, 26.42% (14/53) in control group 1 and 48.08% (25/52) in control group 2.

CONCLUSIONS/INTERPRETATION

Stand-alone isCGM offers a greater reduction in HbA1c in adults with type 2 diabetes on MDI when education on the interpretation of graphical patterns in CGM is provided.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04926623.

FUNDING

This study was supported by Daewoong Pharmaceutical Co., Ltd.

Sustained insulin treatment restoring metabolic status, body weight, and cognition in an anorexia nervosa-like animal model in mice

INTRODUCTION

Anorexia Nervosa (AN) is a psycho-socio-biological disease characterized by severe weight loss as result of dieting and hyperactivity. Effective treatments are scarce, despite its significant prevalence and mortality. AN patients show lower basal insulin levels and increased metabolic clearance, leading to weight loss, cognitive deficits, and hormonal imbalances. Low-dose polymer insulin could potentially reverse these effects by restoring brain function, reducing fear of weight gain, encouraging food intake, and restoring fat depots. This study evaluates an insulin delivery system designed for sustained release and AN treatment.

METHODS

AN-like model was established through dietary restriction (DR). On days 1-25, mice were on DR, and on days 26-31 they were on ad libitum regimen. An insulin-loaded delivery system was administered subcutaneously (1% w/w insulin). The impact of insulin treatment on gene expression in the hippocampus (cognition, regulation of stress, neurogenesis) and hypothalamus (eating behavior, mood) was assessed. Behavioral assays were conducted to evaluate motor activity and cognitive function.

RESULTS

The delivery system demonstrated sustained insulin release, maintaining therapeutic plasma levels. Diet restriction mice treated with the insulin delivery system showed body weight restoration. Gene expression analysis revealed enhanced expression of CB1 and CB2 genes associated with improved eating behavior and cognition, while POMC expression was reduced. Insulin-polymer treatment restored cognitive function and decreased hyperactivity in the AN-like model.

CONCLUSION

The PSA-RA-based insulin delivery system effectively restores metabolic balance, body weight, and cognitive function in the AN model. Its ability to steadily release insulin makes it a promising candidate for AN treatment."

Biosimilars production in Africa opportunities & challenges

The healthcare systems of African nations heavily rely on importing and repackaging biological medicine. More than 70% of the pharmaceutical products consumed in Africa are imported. The localization of biosimilar production can have a positive impact on the availability and cost of these products by reducing the expenses for African governments and making essential healthcare products more accessible to the population. However, it is evident that the developing countries, particularly African nations, face various obstacles and difficulties in localizing biosimilar production. These challenges encompass development, manufacturing, evaluation, and registration processes. In this review, we will highlight the significant hurdles and achievements encountered during the localization process of biosimilars.

Effect of special types of bread with select herbal components on postprandial glucose levels in diabetic patients

BACKGROUND

Nutrition recommendations in patients with type 2 diabetes mellitus (T2DM) are to consume rye or integral bread instead of white bread. A positive effect on glucoregulation has been achieved by enriching food with various biologically active substances of herbal origin, so we formulated an herbal mixture that can be used as a supplement for a special type of bread (STB) to achieve better effects on postprandial glucose and insulin levels in patients with T2DM.

AIM

To compare organoleptic characteristics and effects of two types of bread on postprandial glucose and insulin levels in T2DM patients.

METHODS

This trial included 97 patients with T2DM. A parallel group of 16 healthy subjects was also investigated. All participants were given 50 g of rye bread and the same amount of a STB with an herbal mixture on 2 consecutive days. Postprandial blood glucose and insulin levels were compared at the 30^th, 60^th, 90^th and 120^th min. A questionnaire was used for subjective estimation of the organoleptic and satiety features of the two types of bread.

RESULTS

Compared to patients who consumed rye bread, significantly lower postprandial blood glucose and insulin concentrations were found in T2DM patients who consumed STB. No relevant differences were found among the healthy subjects. Subjectively estimated organoleptic and satiety characteristics are better for STB than for rye bread.

CONCLUSION

STB have better effects than rye bread on postprandial glucoregulation in T2DM patients. Subjectively estimated organoleptic and satiety characteristics are better for STB than for rye bread. Therefore, STB can be recommended for nutrition in T2DM patients.

Autophagy enhances the differentiation of insulin-producing cells from Wharton's jelly-derived mesenchymal stem cells

Autophagy disruption suppresses insulin production and induces diabetes. The role of autophagy in the differentiation of Wharton's jelly (WJ)-derived mesenchymal stem cells (WJSCs) into insulin-producing cells (IPCs) was investigated in this experimental study. The WJSCs were incubated in a differentiation medium (DM) with or without an autophagy inhibitor (3-methyladenine: 3MA). The differentiation of IPCs was confirmed by flow cytometry analysis of PDX-1 and insulin-positive cells, insulin secretion, and the high expression of β cell-specific genes, Glucose transporter 2 (GLUT-2), and INSULIN. Autophagy has been assessed by calculating the percentage of Acridine orange (AO)-positive cells, expression of autophagy-related genes, and the LC3B/LC3A ratio. β cell-specific genes were up-regulated in the DM group, and 3MA decreased their expression. In the DM+3MA-treated cells, the expression of GLUT-2 and INSULIN genes and insulin secretion decreased compared to the DM group. In cells treated with 3MA, there was a significant decrease in the percentage of PDX-1 and insulin-positive cells compared to 3MA-untreated cells. Additionally, in the group receiving both DM and 3MA treatment, the expression of autophagy-related genes, the LC3B/LC3A protein ratio, and the percentage of AO-stained cells were significantly reduced compared to the group receiving only DM treatment. These findings suggest autophagy is essential for β cell differentiation and insulin secretion.

Possible role of metformin as an antidepressant in diabetes

OBJECTIVE

Metformin (MET) is a drug used in the treatment of type 2 diabetes due to its insulin receptor sensitizing properties and anti-hepatic gluconeogenesis effect. One of the comorbidities in diabetes is the depression. This review aimed at summarizing the results of the available MET, depression and diabetes studies to clarify the possible role of MET in the depression during diabetes.

METHODS

A bibliographic search on PubMed, Embase, PsycINFO, Web of Science, Cochrane Central for studies referring to MET, depression and diabetes.

RESULTS

Several studies have associated depression to the chronic inflammation that characterizes diabetes. Additionally MET is an anti-inflammatory molecule that generally acts by activating AMPK and inhibiting the NF-kB factor. In the context of diabetes, MET can act directly as an anti-inflammatory drug as well as inhibiting other pro-inflammatory molecules. In this regard, MET may inhibit the pro-inflammatory effects of angiotensin II. By facilitating the action of insulin and reducing hepatic gluconeogenesis, MET reduces circulating glucose levels, decreasing the formation of advanced glycation end products and therefore inflammation. During diabetes, the gut microbiota and the permeability of the intestinal barrier are altered, causing high levels of circulating lipopolysaccharides (LPS), which induce inflammation. MET can normalize the microbiota and the intestinal barrier permeability reducing the levels of LPS and inflammation. Clinical and experimental studies show the anti-depressant effect of MET mediated by different mechanisms both at the peripheral level and in the central nervous system.

CONCLUSION

Therefore, MET as an anti-inflammatory drug can decrease symptoms of depression and represents a therapeutic approach to improve the psychological state of patients with diabetes. Additionally, insulin also has an anti-inflammatory effect that could act together with MET.

Association between exposure to outdoor artificial light at night during pregnancy and glucose homeostasis: A prospective cohort study

BACKGROUND

Outdoor artificial light at night (ALAN) has been linked to an elevated risk of diabetes, but the available literature on the relationships between ALAN and glucose homeostasis in pregnancy is limited.

METHODS

A prospective cohort study of 6730 pregnant women was conducted in Hefei, China. Outdoor ALAN exposure was estimated using satellite data with individual addresses at a spatial resolution of approximately 1 km, and the average ALAN intensity was calculated. Gestational diabetes mellitus (GDM) was diagnosed based on a standard 75-g oral glucose tolerance test. Multivariable linear regression and logistic regression were used to estimate the relationships between ALAN and glucose homeostasis.

RESULTS

Outdoor ALAN was associated with elevated glucose homeostasis markers in the first trimester, but not GDM risk. An increase in the interquartile range of outdoor ALAN values was related to a 0.02 (95% confidence interval [CI]: 0.00, 0.03) mmol/L higher fasting plasma glucose, a 0.42 (95% CI: 0.30, 0.54) μU/mL increase in insulin and a 0.09 (95% CI: 0.07, 0.12) increase in homeostatic model assessment of insulin resistance (HOMA-IR) during the first trimester. Subgroup analyses showed that the associations between outdoor ALAN exposure and fasting plasma glucose, insulin, and HOMA-IR were more pronounced among pregnant women who conceived in summer and autumn.

CONCLUSIONS

The results provided evidence that brighter outdoor ALAN in the first trimester was related to elevated glucose intolerance in pregnancy, especially in pregnant women conceived in summer and autumn, and effective strategies are needed to prevent and manage light pollution.

Glucagon augments the secretion of FGF21 and GDF15 in MASLD by indirect mechanisms

INTRODUCTION

Glucagon receptor agonism is currently explored for the treatment of obesity and metabolic dysfunction-associated steatotic liver disease (MASLD). The metabolic effects of glucagon receptor agonism may in part be mediated by increases in circulating levels of Fibroblast Growth Factor 21 (FGF21) and Growth Differentiation Factor 15 (GDF15). The effect of glucagon agonism on FGF21 and GDF15 levels remains uncertain, especially in the context of elevated insulin levels commonly observed in metabolic diseases.

METHODS

We investigated the effect of a single bolus of glucagon and a continuous infusion of glucagon on plasma concentrations of FGF21 and GDF15 in conditions of endogenous low or high insulin levels. The studies included individuals with overweight with and without MASLD, healthy controls (CON) and individuals with type 1 diabetes (T1D). The direct effect of glucagon on FGF21 and GDF15 was evaluated using our in-house developed isolated perfused mouse liver model.

RESULTS

FGF21 and GDF15 correlated with plasma levels of insulin, but not glucagon, and their secretion were highly increased in MASLD compared with CON and T1D. Furthermore, FGF21 levels in individuals with overweight with or without MASLD did not increase after glucagon stimulation when insulin levels were kept constant. FGF21 and GDF15 levels were unaffected by direct stimulation with glucagon in the isolated perfused mouse liver.

CONCLUSION

The glucagon-induced secretion of FGF21 and GDF15 are augmented in MASLD and may depend on insulin. Thus, glucagon receptor agonism may augment its metabolic benefits in patients with MASLD through enhanced secretion of FGF21 and GDF15.

Development of an electrochemical impedance spectroscopy immunosensor for insulin monitoring employing pyrroloquinoline quinone as an ingestible redox probe

Contemporary electrochemical impedance spectroscopy (EIS)-based biosensors face limitations in their applicability for in vivo measurements, primarily due to the necessity of using a redox probe capable of undergoing oxidation and reduction reactions in solution. Although previous investigations have demonstrated the effectiveness of EIS-based biosensors in detecting various target analytes using potassium ferricyanide as a redox probe, its unsuitability for blood or serum measurements, attributed to its inherent toxicity, poses a significant challenge. In response to this challenge, our study adopted a unique approach, focusing on the use of ingestible materials, by exploring naturally occurring substances within the body, with a specific emphasis on pyrroloquinoline quinone (PQQ). Following an assessment of PQQ's electrochemical attributes, we conducted a comprehensive series of EIS measurements. This involved the thorough characterization of the sensor's evolution, starting from the bare electrode and progressing to the immobilization of antibodies. The sensor's performance was then evaluated through the quantification of insulin concentrations ranging from 1 pM to 100 nM. A single frequency was identified for insulin measurements, offering a pathway for potential in vivo applications by combining PQQ as a redox probe with EIS measurements. This innovative approach holds promise for advancing the field of in vivo biosensing based on the EIS method.

Positive interplay between FFAR4/GPR120, DPP-IV inhibition and GLP-1 in beta cell proliferation and glucose homeostasis in obese high fat fed mice

G-protein coupled receptor-120 (GPR120; FFAR4) is a free fatty acid receptor, widely researched for its glucoregulatory and insulin release activities. This study aimed to investigate the metabolic advantage of FFAR4/GPR120activation using combination therapy. C57BL/6 mice, fed a High Fat Diet (HFD) for 120 days to induce obesity-diabetes, were subsequently treated with a single daily oral dose of FFAR4/GPR120 agonist Compound A (CpdA) (0.1μmol/kg) alone or in combination with sitagliptin (50mg/kg) for 21 days. After 21-days, glucose homeostasis, islet morphology, plasma hormones and lipids, tissue genes (qPCR) and protein expression (immunocytochemistry) were assessed. Oral administration of CpdA improved glucose tolerance (34% p<0.001) and increased circulating insulin (38% p<0.001). Addition of CpdA with the dipeptidyl peptidase-IV (DPP-IV) inhibitor, sitagliptin, further improved insulin release (44%) compared to sitagliptin alone and reduced fat mass (p<0.05). CpdA alone (50%) and in combination with sitagliptin (89%) induced marked reductions in LDL-cholesterol, with greater effects in combination (p<0.05). All treatment regimens restored pancreatic islet and beta-cell area and mass, complemented with significantly elevated beta-cell proliferation rates. A marked increase in circulating GLP-1 (53%) was observed, with further increases in combination (38%). With treatment, mice presented with increased Gcg (proglucagon) gene expression in the jejunum (130% increase) and ileum (120% increase), indicative of GLP-1 synthesis and secretion. These data highlight the therapeutic promise of FFAR4/GPR120 activation and the potential for combined benefit with incretin enhancing DPP-IV inhibitors in the regulation of beta cell proliferation and diabetes.

Insulin regulation of regional lipolysis in upper-body obese and lean humans

BACKGROUND

Upper body obesity (UBO) results in insulin resistance with regards to free fatty acid (FFA) release; how this differs by fat depot and sex between UBO and lean adults is unknown. We tested the hypothesis that insulin suppression of FFA release from the splanchnic bed, leg fat and upper body non-splanchnic (UBNS) adipose tissue would be impaired in UBO.

METHODS

Fourteen UBO (7 men, 7 women) and 14 healthy, normal weight (7 men, 7 women) volunteers participated in studies that included femoral artery, femoral vein and hepatic vein catheterization. We then measured leg and splanchnic plasma flow as well as FFA kinetics (using isotopic tracers) under overnight fasting, low- and high-dose insulin infusion using the insulin clamp technique.

RESULTS

We found the expected insulin resistance in UBO; the most quantitatively important difference between UBO and lean adults was greater FFA release from UBNS adipose tissue when plasma insulin concentrations are in the post-prandial, physiological range. There were obesity, but not sex differences in the regulation of splanchnic FFA release and sex differences in the regulation of leg FFA release.

CONCLUSION

Reversing the defects in insulin-regulated UBNS adipose tissue FFA release would have the greatest impact on systemic FFA abnormalities in UBO.

TRIAL REGISTRATION

(not applicable)Funding: These studies were supported by grants DK45343 and DK40484 from the U.S. Public Health Service, and the Novo Nordic Foundation (grant numbers NNF18OC0031804 and NNF16OC0021406) and the Independent Research Fund Denmark (grant number 8020-00420B).

Optimization of Naringenin-loaded nanoparticles for targeting of Vanin-1, iNOS, and MCP-1 signaling pathway in HFD-induced obesity

Naringenin, a natural dihydrochalcone flavonoid, exhibits diverse pharmacological properties. This study investigates the hypolipidemic effects of Nar-NPs on obese mice. The characteristics of Nar-NPs, including morphology, particle size, zeta potential, UV-vis, and FT-IR spectra, were examined. The anti-obesity properties of Nar-NPs were evaluated in obese rats, considering LD50, 1/20 LD50, and 1/50 LD50 for treatment preparation. Results indicated that synthesized Nar-NPs were uniform, spherical, and well-dispersed, with a size of 130.06 ± 1.98 nm and with a zeta potential of -25.6 ± 0.8 mV. Nar-NPs exhibited enhancement in the cumulative release of naringenin (56.87 ± 2.45 %) as compared to pure naringenin suspension 87.83 ± 1.84 % in 24 h of the study. The LD50 of Nar-NPs was determined as 412.5 mg/kg.b.w. HFD induced elevated glycemic, oxidative stress, and inflammatory biomarkers while reducing HDL-C, GSH, and superoxide dismutase (SOD) levels. Administration of Nar-NPs significantly mitigated body weight, glucose, insulin, leptin, TC, TG, SREBP1c, pAMPK, PPAR-α, as well as vanin-1, MCP-1, and iNOS mRNA gene expression. Histological investigations supported the biochemical and PCR findings. In a nutshell, the study suggests that the Nar-NPs could serve as a promising and viable pharmacological strategy for the treatment of obesity-related disorders.

Knowledge, attitude, and practice of insulin among diabetic patients and pharmacists in Egypt: "cross-sectional observational study"

BACKGROUND

Diabetes recently has been identified as a growing epidemic. Although insulin's vital role in both types of diabetes, it is considered one of the harmful medications if used incorrectly. In Egypt, effective usage of insulin remains a challenge due to insufficient knowledge of insulin and diabetes management, leading to errors in insulin therapy. As pharmacists are experts in pharmacological knowledge, they are uniquely situated to assess adherence to treatment regimens, the effect of drug therapy, or potential alterations in drug therapy to meet patient goals. To provide effective patient education and counseling, community pharmacists in Egypt should be efficiently knowledgeable about diabetes and insulin.

OBJECTIVE

To identify the knowledge, attitude, and practice of pharmacists and patients about insulin. To identify pharmacists' educational preparedness and confidence in counseling diabetic patients.

METHODS

A descriptive, cross-sectional study was conducted with two knowledge, attitude, and practice surveys. This study was carried out from September 2016 to February 2023. Face-to-face interviews were conducted with patients, and a paper-based questionnaire was administered to pharmacists. The two questionnaires were adapted from previous studies.

RESULTS

A total of 492 patients and 465 pharmacists participated in this study. The mean knowledge score of correct answers among patients and pharmacists was 10.67 ± 1.9 and 15 ± 3.6. Most of the patients and pharmacists had a positive attitude regarding insulin's role in improving health and to better control blood glucose. On the negative side, around half of the patients reported that they believe that regular use of insulin leads to addiction, while only 14.5% of the pharmacists believed that insulin could cause addiction. Self-confidence scores for pharmacists differed statistically with sex, years of experience, and pharmacist's direct exposure to diabetic patients.

CONCLUSIONS

This study uncovers considerable deficiencies in patients' and pharmacists' knowledge about insulin therapy. This study also strongly recommends higher education and a more structured pharmacist training schedule.

Evaluation of Insulin Dosing Strategies for Hyperkalemia Management at an Academic Medical Center

PURPOSE

While intravenous (IV) insulin is often administered at a fixed dose of 10 units for acute hyperkalemia, optimal dosing for minimizing hypoglycemia while effectively reversing hyperkalemia has not been established. The purpose of this analysis was to evaluate the effect of insulin dosing strategies on hypoglycemia in patients with hyperkalemia.

METHODS

Adult patients presenting to an academic medical center who received IV insulin for hyperkalemia between 2016 and 2020 were retrospectively identified. Patients treated with 10 units of insulin (fixed) were compared to those who received < 10 units (reduced). The primary outcome was the incidence of hypoglycemia (blood glucose < 70 mg/dL) within 12 hours of insulin administration. Secondary outcomes included the incidence of severe hypoglycemia (blood glucose < 40 mg/dL) and change in potassium. Multivariable analyses were used to assess for risk factors for hypoglycemia and severe hypoglycemia.

FINDINGS

Of the 2576 patients included, 305 (11.8%) received reduced dosing and 2271 (88.2%) received fixed dosing. Hypoglycemia occurred in 16.7% of the reduced group and 15.9% of the fixed group (P = 0.70). Severe hypoglycemia occurred in 2.3% of the reduced group and 2.5% of the fixed group (P = 0.86). Median potassium reduction from baseline to first check post-insulin was less with reduced dosing (-0.6 mEq/L vs -0.8 mEq/L, P < 0.001). On multivariable regression analysis, greater weight-based insulin dose and ED location were significant predictors for hypoglycemia and severe hypoglycemia. Location in the intensive care unit was associated with a decreased risk of hypoglycemia. Higher pre-insulin glucose was protective for hypoglycemia and severe hypoglycemia.

IMPLICATIONS

The incidence of hypoglycemia was similar among both groups. Greater weight-based insulin dose was a significant risk factor for hypoglycemia, while higher baseline glucose levels were associated with a decreased risk, indicating that patient-specific insulin dosing for hyperkalemia may be warranted.

Associations Among Diabetes Medication Use, Serum Magnesium, and Insulin Resistance in a Cohort of Older Puerto Rican Adults

BACKGROUND

Hypomagnesemia is commonly observed in individuals with diabetes, but how diabetes medications alter magnesium (Mg) status remains unclear.

OBJECTIVE

We aimed to 1) examine the association between diabetes medication and hypomagnesemia and 2) evaluate whether serum Mg mediates the association between diabetes medication and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) in a prospective cohort.

METHODS

Adults from the Boston Puerto Rican Health Study were included (n=1106). Multivariable logistic regression models were used to estimate odds ratio (OR) and 95% confidence interval (CI) for cross-sectional association between diabetes medication and hypomagnesemia (serum Mg < 0.75 mmol/L). Longitudinal mediation analysis was performed to evaluate the direct and indirect (via serum Mg) associations between diabetes medication and 4-year (y) HOMA-IR in 341 participants with baseline hemoglobin A1c (HbA1c) ≥ 6.5%.

RESULTS

Mean age at baseline was 59.0±7.6 y, with 28.0% male and 45.8% with hypomagnesemia. Use of metformin [OR (95% CI) = 3.72 (2.53, 5.48)], sulfonylureas [OR (95% CI) = 1.68 (1.00, 2.83)], and glitazones [OR (95% CI) = 2.09 (1.10, 3.95)], but not insulin, was associated with higher odds of hypomagnesemia. Use of multiple diabetes medications and longer duration of use were associated with higher odds of hypomagnesemia. Serum Mg partially mediated the association between metformin and HOMA-IR [indirect association: β (95% CI) = 1.11 (0.15, 2.07)], which weakened the direct association [β (95% CI) = -5.16 (-9.02, -1.30)] by 22% [total association: β (95% CI) = -4.05 (-7.59, -0.51)]. Similarly, serum Mg mediated 17% of the association between sulfonylureas and elevated HOMA-IR. However, the mediation by serum Mg was weak for insulin and glitazones.

CONCLUSIONS

Diabetes medication, especially metformin, was associated with elevated odds of hypomagnesemia, which may weaken the association between metformin and lowering of HOMA-IR. The causal inference needs to be confirmed in further studies.

A simplified longitudinal model for the development of Type 2 Diabetes Mellitus

Obesity and diabetes are a progressively more and more deleterious hallmark of modern, well fed societies. In order to study the potential impact of strategies designed to obviate the pathological consequences of detrimental lifestyles, a model for the development of Type 2 diabetes geared towards large population simulations would be useful. The present work introduces such a model, representing in simplified fashion the interplay between average glycemia, average insulinemia and functional beta-cell mass, and incorporating the effects of excess food intake or, conversely, of physical activity levels. Qualitative properties of the model are formally established and simulations are shown as examples of its use.

Developmental programming: Testosterone excess masculinizes female pancreatic transcriptome and function in sheep

Hyperandrogenic disorders, such as polycystic ovary syndrome, are often associated with metabolic disruptions such as insulin resistance and hyperinsulinemia. Studies in sheep, a precocial model of translational relevance, provide evidence that in utero exposure to excess testosterone during days 30-90 of gestation (the sexually dimorphic window where males naturally experience elevated androgens) programs insulin resistance and hyperinsulinemia in female offspring. Extending earlier findings that adverse effects of testosterone excess are evident in fetal day 90 pancreas, the end of testosterone treatment, the present study provides evidence that transcriptomic and phenotypic effects of in utero testosterone excess on female pancreas persist after cessation of treatment, suggesting lasting organizational changes, and induce a male-like phenotype in female pancreas. These findings demonstrate that the female pancreas is susceptible to programmed masculinization during the sexually dimorphic window of fetal development and shed light on underlying connections between hyperandrogenism and metabolic homeostasis.

The Current and Future Role of Insulin Therapy in the Management of Type 2 Diabetes: A Narrative Review

Early initiation of intensive insulin therapy has been demonstrated to be effective in controlling glycemia and possibly preserving beta-cell function. Innovations in insulin formulations and delivery systems continue. However, we have seen an acceleration in the development of new classes of diabetes medications for individuals with type 2 diabetes and obesity, such as, for example, glucagon-like peptide-1 receptor agonists (GLP-1 RAs). These formulations have been shown to confer significant benefits in achieving good glycemic control with reduced hypoglycemia risk, weight loss, and cardiorenal protection. Therefore, it is reasonable to question whether there is still a role for insulin therapy in the management of type 2 diabetes. However, there are clear limitations inherent to GLP-1 RA therapy, including high rates of suboptimal adherence and treatment discontinuation due to high cost and side effects, which diminish long-term efficacy, and supply issues. In addition, newer formulations have shown improvements in convenience and tolerability, and have been shown to be even more effective when used in conjunction with basal insulin. In this narrative review, we discuss current evidence that supports GLP-1 RA use in combination with insulin therapy and the potential pitfalls of reliance on GLP-1 RAs as a substitute for insulin therapy.

Circadian alignment of food intake and glycaemic control by time-restricted eating: A systematic review and meta-analysis

Daily rhythms of metabolic function are supported by molecular circadian clock systems that are strongly regulated by feeding and fasting. Intermittent fasting diets have been associated with weight loss and improved metabolism. However, the effects of time-restricted eating (TRE) on glycemic parameters are still under debate. In this review, we aim to systematically analyze the effects of TRE on glycemic parameters. We searched on PubMed, EMBASE, and the Cochrane Library for controlled studies in which subjects followed TRE for at least 4 weeks. 20 studies were included in the qualitative systematic review, and 18 studies (n = 1169 subjects) were included in the meta-analysis. Overall, TRE had no significant effect on fasting glucose (Hedges's g = -0.08; 95% CI:-0.31,0.16; p = 0.52), but it did reduce HbA1c levels (Hedges's g = -0.27; 95% CI: -0.47, -0.06; p = 0.01). TRE significantly reduced fasting insulin (Hedges's g = -0.40; 95% CI: -0.73,-0.08; p = 0.01) and showed a tendency to decrease HOMA-IR (Hedges's g = -0.32; 95% CI:-0.66,0.02; p = 0.06). Interestingly, a cumulative analysis showed that the beneficial effects of TRE regarding glucose levels were less apparent as studies with later TRE windows (lTRE) were being included. Indeed, a subgroup analysis of the early TRE (eTRE) studies revealed that fasting glucose was significantly reduced by eTRE (Hedges's g = -0.38; 95% CI:-0.62, -0.14; p < 0.01). Our meta-analysis suggests that TRE can reduce HbA1c and insulin levels, and that timing of food intake is a crucial factor in the metabolic benefit of TRE, as only eTRE is capable of reducing fasting glucose levels in subjects with overweight or obesity.PROSPERO registration number CRD42023405946.

Ab initio modeling of human IRS1 protein to find novel target to dock with drug MH to mitigate T2DM diabetes by insulin signaling

IRS1 is a cytoplasmic adaptor protein that helps in cellular growth, glucose metabolism, proliferation, and differentiation. Highly disordered (insulin receptor substrate 1) IRS1 protein sequence (mol.wt- 131,590.97 da) has been used to develop model using ab initio modeling technique by I-Tassar tool and Discovery Studio/ DogSite Server to decipher a novel active site. The constructed protein model has been submitted with PMDB Id- PM0082210. GRAVY index of IRS1 model ( - 0.675) indicated surface protein-water interaction. Protparam tool instability index (75.22) demonstrated disorderedness combined with loops owing to prolines/glycines. After refinement, the Ramachandran plot showed that 88 percent of AAs were present in the allowed region and only 0.5% in the disallowed region. Novel IRS1 model protein has 10 α-helices, 22 β-sheets, 20 β-hairpins, 5 β-bulges, 47 strands, 105 β-turns, and 8 γ-turns. Docking of IRS1 with drug MH demonstrated interaction of Ser-70, Thr-18, and Pro-69 with C-H bonds; Gln-71, and Glu-113 with hydrogen bonds; while both Glu-114 and Glu-113 with salt-bridge connection. Permissible 1.0-1.5 Å range of RMSD fluctuation between 20 and 45 ns was obtained in simulation of IRS1 and IRS1-met complex confirmed that both complexes were stable during whole simulation process. RMSF result showed that except positions 57AA and 114AA, the binding of drug had no severe effects on the flexibility of the IRS1 and IRS1-met complex. The RoG value of compactness and rigidity showed little change in IRS1 protein. SASA value of IRS1 indicated non-significant fluctuation between IRS1 and drug MH means ligand (drug) and IRS1 receptor form stable structure. Hydrogen bond strength of IRS1 and IRS1-met was 81.2 and 76.4, respectively, which suggested stable interaction.

Cost-effectiveness analysis of metformin versus insulin in the treatment of gestational diabetes mellitus

OBJECTIVE

Although there have been many studies on gestational diabetes mellitus (GDM) treatment, there is still a knowledge gap regarding the comparative cost-effectiveness of metformin and insulin in the treatment phase. Existing studies have focused on treatment efficacy and drug safety, but relatively little has been explored regarding cost-effectiveness analysis. In particular, no comprehensive study has evaluated the cost-effectiveness of metformin and insulin for GDM treatment. Therefore, this study aimed to fill this knowledge gap by conducting a cost-effectiveness analysis of these two treatments for GDM.

METHODS

A decision-analytic model was used to compare the cost-effectiveness of metformin and insulin in China. Probabilities, costs, and utilities were derived from the literature. The cost and quality-adjusted life years (QALYs) were calculated using the roll-back method. The strategy was considered cost-effective if the incremental cost-effectiveness ratio (ICER) was below the willingness-to-pay (WTP) threshold of ¥242,938 per QALY. Sensitivity analyses were also conducted to assess the robustness of the results.

RESULTS

The roll-back analysis indicated that insulin was not cost-effective compared to metformin, resulting in increased costs and decreased QALYs, with a negative ICER. These findings suggested that metformin is a cost-effective option than insulin. Furthermore, the sensitivity analysis showed that the model was robust.

CONCLUSIONS

Compared with insulin, metformin is a cost-effective treatment option for GDM.

Glucose-responsive insulin microneedle patches for long-acting delivery and release visualization

Limited drug loading and incomplete drug release are two major obstacles that traditional polymeric microneedles (MNs) have to overcome. For smart controlled-release MNs, since drug release duration is uncertain, a clear indication of the finish of drug release is also important for patient guidance on the timing of the next dose. In this study, MN with a triple structure of a glucose-responsive shell, loaded insulin powders and a colored propelling inner core (inspired by the mechanism of osmotic pump) was innovatively constructed. The MN patch could release insulin according to blood glucose levels (BGLs) and had excellent drug loading, more complete drug release, and good drug stability, which significantly prolonged the normoglycemic time. An approximately 0.3 cm2 patch has a hypoglycemic effect on diabetic mice for up to 24 h. Moreover, the fading of the inner core could indicate the release process of the loaded drug and can help to facilitate uninterrupted closed loop therapy for patients. The designed triple MN structure is also suitable, and can be used in the design of other smart MN drug delivery systems to further improve their drug loading capacity and simultaneously achieve more complete, smart controlled and visualized drug release.

Impact of the timing of metformin administration on glycaemic and glucagon-like peptide-1 responses to intraduodenal glucose infusion in type 2 diabetes: a double-blind, randomised, placebo-controlled, crossover study

AIMS/HYPOTHESIS

Metformin lowers postprandial glycaemic excursions in individuals with type 2 diabetes by modulating gastrointestinal function, including the stimulation of glucagon-like peptide-1 (GLP-1). The impact of varying the timing of metformin administration on postprandial glucose metabolism is poorly defined. We evaluated the effects of metformin, administered at different intervals before an intraduodenal glucose infusion, on the subsequent glycaemic, insulinaemic and GLP-1 responses in metformin-treated type 2 diabetes.

METHODS

Sixteen participants with type 2 diabetes that was relatively well-controlled by metformin monotherapy were studied on four separate days in a crossover design. On each day, participants were randomised to receive a bolus infusion of metformin (1000 mg in 50 ml 0.9% saline) via a nasoduodenal catheter at t = -60, -30 or 0 min (and saline at the other timepoints) or saline at all timepoints (control), followed by an intraduodenal glucose infusion of 12.56 kJ/min (3 kcal/min) at t = 0-60 min. The treatments were blinded to both participants and investigators involved in the study procedures. Plasma glucose, insulin and total GLP-1 levels were measured every 30 min between t = -60 min and t = 120 min.

RESULTS

There was a treatment-by-time interaction for metformin in reducing plasma glucose levels and increasing plasma GLP-1 and insulin levels (p<0.05 for each). The reduction in plasma glucose levels was greater when metformin was administered at t = -60 or -30 min vs t = 0 min (p<0.05 for each), and the increases in plasma GLP-1 levels were evident only when metformin was administered at t = -60 or -30 min (p<0.05 for each). Although metformin did not influence insulin sensitivity, it enhanced glucose-induced insulin secretion (p<0.05), and the increases in plasma insulin levels were comparable on the 3 days when metformin was given.

CONCLUSIONS/INTERPRETATION

In well-controlled metformin-treated type 2 diabetes, glucose-lowering by metformin is greater when it is given before, rather than with, enteral glucose, and this is associated with a greater GLP-1 response. These observations suggest that administration of metformin before meals may optimise its effect in improving postprandial glycaemic control.

TRIAL REGISTRATION

www.anzctr.org.au ACTRN12621000878875 FUNDING: The study was not funded by a specific research grant.

Sonic hedgehog signalling pathway contributes in age-related disorders and Alzheimer's disease

Alzheimer's disease (AD) is caused by the aging process and manifested by cognitive deficits and progressive memory loss. During aging, several conditions, including hypertension, diabetes, and cholesterol, have been identified as potential causes of AD by affecting Sonic hedgehog (Shh) signalling. In addition to being essential for cell differentiation and proliferation, Shh signalling is involved in tissue repair and the prevention of neurodegeneration. Neurogenesis is dependent on Shh signalling; inhibition of this pathway results in neurodegeneration. Several protein-protein interactions that are involved in Shh signalling are implicated in the pathophysiology of AD like overexpression of the protein nexin-1 inhibits the Shh pathway in AD. A protein called Growth Arrest Specific-1 works with another protein called cysteine dioxygenase (CDO) to boost Shh signalling. CDO is involved in the development of the central nervous system (CNS). Shh signalling strengthened the blood brain barrier and therefore prevent the entry of amyloid beta and other toxins to the brain from periphery. Further, several traditional remedies used for AD and dementia, including Epigallocatechin gallate, yokukansan, Lycium barbarum polysaccharides, salvianolic acid, and baicalin, are known to stimulate the Shh pathway. In this review, we elaborated that the Shh signalling exerts a substantial influence on the pathogenesis of AD. In this article, we have tried to explore the various possible connections between the Shh signalling and various known pathologies of AD.

Therapeutic inertia in treatment of older adults with type II diabetes at high risk for hypoglycemia

Patients 80 years or older with HbA1c <7.0% (53 mmol/mol) treated with multiple daily insulin injections had low rates of rapid-acting insulin deprescription and initiation of diabetes medications with lower risk of hypoglycemia. Further investigation is needed to elucidate factors contributing to potentially inappropriately aggressive treatment of these patients.

Appetite hormone dysregulation and executive dysfunction among adolescents with bipolar disorder and disruptive mood dysregulation disorder

Appetite hormone dysregulation may play a role in the pathomechanisms of bipolar disorder and chronic irritability. However, its association with executive dysfunction in adolescents with bipolar disorder and those with disruptive mood dysregulation disorder (DMDD) remains unclear. We included 20 adolescents with bipolar disorder, 20 adolescents with DMDD, and 47 healthy controls. Fasting serum levels of appetite hormones, including leptin, ghrelin, insulin, and adiponectin were examined. All participants completed the Wisconsin Card Sorting Test. Generalized linear models with adjustments for age, sex, body mass index, and clinical symptoms revealed that patients with DMDD had elevated fasting log-transformed insulin levels (p = .023) compared to the control group. Adolescents with DMDD performed worse in terms of the number of tries required to complete tasks associated with the first category (p = .035), and adolescents with bipolar disorder performed worse in terms of the number of categories completed (p = .035). A positive correlation was observed between log-transformed insulin levels and the number of tries required for the first category (β = 1.847, p = .032). Adolescents with DMDD, but not those with bipolar disorder, were more likely to exhibit appetite hormone dysregulation compared to healthy controls. Increased insulin levels were also related to executive dysfunction in these patients. Prospective studies should elucidate the temporal association between appetite hormone dysregulation, executive dysfunction, and emotional dysregulation.

Why the increase? Examining the rise in prescription medication expenditures in the United States between 2011 and 2020

The objective of this cross-sectional analysis was to identify determinants of increasing medicine expenditures in the US between 2011 and 2020. Prescription medication expenditures from the 2011-2020 Medical Expenditures Panel Survey (MEPS) were used to calculate total annual medication expenditures by payer categories (Out-of-pocket, Medicare, Medicaid, TRICARE/Veterans Administration/CHAMPVA (TVAC), Other Government Sources, Private Insurance, and Other Sources). From here, expenditures were stratified by therapeutic category using Multum Lexicon Drug Class to examine trends in expenditures by therapeutic area. Linear regression was used to identify temporal trends in medication expenditures. From 2011 to 2020, total annual prescription medication expenditures rose from $341.49 to $473.12 billion per year with metabolic agents being the most costly category. Among the metabolic agents, antidiabetic agents were the most costly therapeutic area, with an increasing trend observed from $27.15 to $89.17 billion over the same period. Medicare, Medicaid, Private Insurance, TVAC, and Other Sources also saw an increasing trend in antidiabetic agent expenditure, while no trend was observed for Out-of-pocket and Other Government Sources. Insulin had the highest expenditure among antidiabetic agents. Further studies are warranted to explore specific factors contributing to the increasing trend.

Development of an isotope dilution mass spectrometry assay for the quantification of insulin based on signature peptide analysis

An isotope dilution mass spectrometry (IDMS) method that involves peptide-based protein analysis was developed to accurately quantify insulin. In this study, a signature peptide (GFFYTPK) obtained from tryptic digestion of insulin was selected as a surrogate for insulin. Then, the optimal conditions for signature peptide analysis through mass spectrometry detection and enzymatic digestion were determined. The analytical performance of this method was assessed and validated using porcine insulin-certified reference material. The linear range of the insulin calibration curve ranged from 0.05 ~ 2 mass ratios, with recoveries ranging from 96.15 to approximately 101.15%. The limit of detection was 0.19 ng/mL, and the limit of quantification was 0.63 ng/mL. The quantitative results corresponded well with a certified value that was obtained from measuring a porcine insulin reference material with amino acid-based IDMS. In addition, the target peptide GFFYTPK can be found in other species of insulin. This method was also applied for the quantification of human insulin-certified reference material. Finally, we applied the method to quantify the concentrations of simulated serum insulin. These findings suggested that this signature peptide-based IDMS approach can accurately quantify insulin levels, can assign a certified value to insulin reference materials, and has the potential to quantify serum insulin with traceable measurements.

Effects of alpha-2-adrenoceptor agonism and antagonism on equine blood insulin and glucose concentrations after oral carbohydrate load

Alpha-2-adrenoceptor agonist detomidine is a commonly used sedative agent in horses. In addition to the sedative effect, detomidine has been reported to elicit changes in energy metabolism such as hypoinsulinaemia and hyperglycaemia. This study aimed to investigate the effects of detomidine with and without peripherally acting alpha-2-adrenoceptor antagonist vatinoxan on insulin and blood glucose (BG) concentrations in horses after a standard dose of oral carbohydrates. Sixteen horses were assigned to four intravenous treatments in a randomised cross-over design: saline (SAL), detomidine (0.02 mg/kg; DET), vatinoxan (0.2 mg/kg; VAT), and a combination of detomidine and vatinoxan (DET+VAT). Horses were administered corn syrup (0.45 mL/kg) immediately before each treatment. Blood samples were collected until 360 min. The differences between treatments were evaluated with repeated measures analysis of covariance and change from baseline was used as a response. P<0.05 was considered significant. After oral carbohydrate load, DET reduced insulin (median 30 min nadir 3.7, min-max 0.6-7.4 µIU/mL) significantly compared with SAL (P<0.0001; 17.4, 9.3-65.4 µIU/mL) and DET+VAT (P=0.0005; 6.4, 2.9-12.9 µIU/mL). BG increased significantly after DET (peak; 130.5, 8.8-15.8 mmol/L) compared with SAL (P<0.0001; 8.7, 6.9-12.4 mmol/L) and DET+VAT (P<0.0001; 8.5, 6.8-10.6 mmol/L). Vatinoxan alone reduced BG (peak median 7.6, 7.0-9.9 mmol/L) compared with SAL (P=0.02) and delayed insulin responses to carbohydrates. In conclusion, vatinoxan alleviated the detomidine-induced changes (DET+VAT compared to DET) in insulin and BG after oral carbohydrate load. Additionally, vatinoxan is potentially able to modulate BG concentration and insulin response after oral carbohydrate administration in horses, but more research is warranted.

The Role of Biotechnology in Latest Therapeutic Approaches for Diabetes Mellitus

The Article Abstract is not available.  

Intermittent fasting protects β-cell identity and function in a type-2 diabetes model

Type 2 diabetes (T2DM) is caused by the interaction of multiple genes and environmental factors. T2DM is characterized by hyperglycemia, insulin secretion deficiency and insulin resistance. Chronic hyperglycemia induces β-cell dysfunction, loss of β-cell mass/identity and β-cell dedifferentiation. Intermittent fasting (IF) a commonly used dietary regimen for weight-loss, also induces metabolic benefits including reduced blood glucose, improved insulin sensitivity, reduced adiposity, inflammation, oxidative-stress and increased fatty-acid oxidation; however, the mechanisms underlying these effects in pancreatic β-cells remain elusive. KK and KKAy, mouse models of polygenic T2DM spontaneously develop hyperglycemia, glucose intolerance, glucosuria, impaired insulin secretion and insulin resistance. To determine the long-term effects of IF on T2DM, 6-weeks old KK and KKAy mice were subjected to IF for 16 weeks. While KKAy mice fed ad-libitum demonstrated severe hyperglycemia (460 mg/dL) at 6 weeks of age, KK mice showed blood glucose levels of 230 mg/dL, but progressively became severely diabetic by 22-weeks. Strikingly, both KK and KKAy mice subjected to IF showed reduced blood glucose and plasma insulin levels, decreased body weight gain, reduced plasma triglycerides and cholesterol, and improved insulin sensitivity. They also demonstrated enhanced expression of the β-cell transcription factors NKX6.1, MAFA and PDX1, and decreased expression of ALDH1a3 suggesting protection from loss of β-cell identity by IF. IF normalized glucose stimulated insulin secretion in islets from KK and KKAy mice, demonstrating improved β-cell function. In addition, hepatic steatosis, gluconeogenesis and inflammation was decreased particularly in KKAy-IF mice, indicating peripheral benefits of IF. These results have important implications as an optional intervention for preservation of β-cell identity and function in T2DM.

Insulin interacts with PPARγ agonists to promote bovine adipocyte differentiation

Insulin is a potent adipogenic hormone that triggers a series of transcription factors that regulate the differentiation of preadipocytes into mature adipocytes. Ciglitazone specifically binds to peroxisome proliferator-activated receptor-γ (PPARγ), thereby promoting adipocyte differentiation. As a natural ligand of PPARγ, oleic acid (OA) can promote the translocation of PPARγ into the nucleus, regulate the expression of downstream genes, and promote adipocyte differentiation. We hypothesized that ciglitazone and oleic acid interact with insulin to enhance bovine preadipocyte differentiation. Preadipocytes were cultured 96 h in differentiation medium containing 10 mg/L insulin (I), 10 mg/L insulin + 10 µM cycloglitazone (IC), 10 mg/L insulin + 100 µM oleic acid (IO), or 10 mg/L insulin + 10 µM cycloglitazone+100 µM oleic acid (ICO). Control preadipocytes (CON) were cultured in differentiation medium (containing 5% fetal calf serum). The effects on the differentiation of Yanbian cattle preadipocytes were examined using molecular and transcriptomic techniques, including differentially expressed genes (DEGs) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis. I, IC, IO, and ICO treatments produced higher concentrations of triglycerides (TAG) and lipid droplet accumulation in preadipocytes compared with CON treatment (P < 0.05). Co-treatment of insulin and PPARγ agonists significantly increased the expression of genes involved in regulating adipogenesis and fatty acid synthesis. (P < 0.05). Differential expression analysis identified 1488, 1764, 1974 and 1368 DEGs in the I, IC, IO and ICO groups, respectively. KEGG pathway analysis revealed DEGs mainly enriched in PPAR signalling, FOXO signaling pathway and fatty acid metabolism. These results indicate that OA, as PPARγ agonist, can more effectively promote the expression of bovine lipogenesis genes and the content of TAG and adiponectin when working together with insulin, and stimulate the differentiation of bovine preadipocytes. These findings provide a basis for further screening of relevant genes and transcription factors in intramuscular fat deposition and meat quality to enhance breeding programs.

Developmental programming: An exploratory analysis of pancreatic islet compromise in female sheep resulting from gestational BPA exposure

Developmental exposure to endocrine disruptors like bisphenol A (BPA) are implicated in later-life metabolic dysfunction. Leveraging a unique sheep model of developmental programming, we conducted an exploratory analysis of the programming effects of BPA on the endocrine pancreas. Pregnant ewes were administered environmentally relevant doses of BPA during gestational days (GD) 30-90, and pancreata from female fetuses and adult offspring were analyzed. Prenatal BPA exposure induced a trend toward decreased islet insulin staining and β-cell count, increased glucagon staining and α-cell count, and increased α-cell/β-cell ratio. Findings were most consistent in fetal pancreata assessed at GD90 and in adult offspring exposed to the lowest BPA dose. While not assessed in fetuses, adult islet fibrosis was increased. Collectively, these data provide further evidence that early-life BPA exposure is a likely threat to human metabolic health. Future studies should corroborate these findings and decipher the molecular mechanisms of BPA's developmental endocrine toxicity.

Epinephrine also acts on beta cells and insulin secretion

In a recent review examining neurotransmitter modulation of insulin secretion, the significant impact of epinephrine was not addressed. Its primary action involves inhibiting insulin release via alpha-adrenergic receptors, thereby reducing the response to insulin secretion stimulators, through the activation of K+ channels and resulting in membrane hyperpolarization in beta cells.

Long-term pasireotide therapy in acromegaly: extensive real-life experience of a referral center

PURPOSE

Pasireotide is a novel therapeutic option for patients with acromegaly resistant to first-generation somatostatin receptor ligands. To date, real-life data are still scant, therefore, the aim of the current study is to evaluate the impact of long-term pasireotide therapy on disease control, pituitary tumor size, gluco-insulinemic and lipid profile in a real-life setting.

METHODS

Retrospective study of data prospectively collected, evaluating hormonal, tumoral, and metabolic data of 28 patients with acromegaly administered with pasireotide in a pituitary tertiary referral center.

RESULTS

Within the first 12 months of treatment, 70.4% of patients achieved normal IGF-I levels, which was maintained at 36-month evaluation in these responders patients. Patients who started with pasireotide 60 mg monthly exhibited significantly lower IGF-I levels after 36 months (p = 0.05) as compared to patients administered first with pasireotide 20 or 40 mg monthly. The maximal tumoral diameter was significantly decreased after 12 months of pasireotide (p < 0.001) and a further reduction was registered throughout the following months, with 41.2% of patients achieving a significant reduction (> 25% of baseline measurement) after 36 months of treatment. Fasting glucose significantly increased during the first 6 months (p < 0.001) with a gradual rise in diabetes prevalence during the following months, resulting diabetes prevalence after 36 months of pasireotide significantly increased compared to baseline (p = 0.003), although with glycated hemoglobin levels within the normal range. Diabetes was managed using oral glucose-lowering drugs or glucagon-like peptide 1 agonists, with no patient requiring insulin therapy. Pasireotide improved lipid profile, mainly during the first 12 months of treatment, by increasing HDL and decreasing triglycerides levels.

CONCLUSION

Pasireotide is effective and safe in the long-term. Hyperglycemia is a common event and is manageable even without insulin treatment.

Insulin and glycolysis dependency of cardioprotection by nicotinamide riboside

Decreased nicotinamide adenine dinucleotide (NAD+) levels contribute to various pathologies such as ageing, diabetes, heart failure and ischemia-reperfusion injury (IRI). Nicotinamide riboside (NR) has emerged as a promising therapeutic NAD+ precursor due to efficient NAD+ elevation and was recently shown to be the only agent able to reduce cardiac IRI in models employing clinically relevant anesthesia. However, through which metabolic pathway(s) NR mediates IRI protection remains unknown. Furthermore, the influence of insulin, a known modulator of cardioprotective efficacy, on the protective effects of NR has not been investigated. Here, we used the isolated mouse heart allowing cardiac metabolic control to investigate: (1) whether NR can protect the isolated heart against IRI, (2) the metabolic pathways underlying NR-mediated protection, and (3) whether insulin abrogates NR protection. NR protection against cardiac IRI and effects on metabolic pathways employing metabolomics for determination of changes in metabolic intermediates, and 13C-glucose fluxomics for determination of metabolic pathway activities (glycolysis, pentose phosphate pathway (PPP) and mitochondrial/tricarboxylic acid cycle (TCA cycle) activities), were examined in isolated C57BL/6N mouse hearts perfused with either (a) glucose + fatty acids (FA) ("mild glycolysis group"), (b) lactate + pyruvate + FA ("no glycolysis group"), or (c) glucose + FA + insulin ("high glycolysis group"). NR increased cardiac NAD+ in all three metabolic groups. In glucose + FA perfused hearts, NR reduced IR injury, increased glycolytic intermediate phosphoenolpyruvate (PEP), TCA intermediate succinate and PPP intermediates ribose-5P (R5P) / sedoheptulose-7P (S7P), and was associated with activated glycolysis, without changes in TCA cycle or PPP activities. In the "no glycolysis" hearts, NR protection was lost, whereas NR still increased S7P. In the insulin hearts, glycolysis was largely accelerated, and NR protection abrogated. NR still increased PPP intermediates, with now high 13C-labeling of S7P, but NR was unable to increase metabolic pathway activities, including glycolysis. Protection by NR against IRI is only present in hearts with low glycolysis, and is associated with activation of glycolysis. When activation of glycolysis was prevented, through either examining "no glycolysis" hearts or "high glycolysis" hearts, NR protection was abolished. The data suggest that NR's acute cardioprotective effects are mediated through glycolysis activation and are lost in the presence of insulin because of already elevated glycolysis.

A mathematical model of obesity-induced type 2 diabetes and efficacy of anti-diabetic weight reducing drug

The dominant paradigm for modeling the obesity-induced T2DM (type 2 diabetes mellitus) today focuses on glucose and insulin regulatory systems, diabetes pathways, and diagnostic test evaluations. The problem with this approach is that it is not possible to explicitly account for the glucose transport mechanism from the blood to the liver, where the glucose is stored, and from the liver to the blood. This makes it inaccurate, if not incorrect, to properly model the concentration of glucose in the blood in comparison to actual glycated hemoglobin (A1C) test results. In this paper, we develop a mathematical model of glucose dynamics by a system of ODEs. The model includes the mechanism of glucose transport from the blood to the liver, and from the liver to the blood, and explains how obesity is likely to lead to T2DM. We use the model to evaluate the efficacy of an anti-T2DM drug that also reduces weight.

Differential CpG methylation at Nnat in the early establishment of beta cell heterogeneity

AIMS/HYPOTHESIS

Beta cells within the pancreatic islet represent a heterogenous population wherein individual sub-groups of cells make distinct contributions to the overall control of insulin secretion. These include a subpopulation of highly connected 'hub' cells, important for the propagation of intercellular Ca2+ waves. Functional subpopulations have also been demonstrated in human beta cells, with an altered subtype distribution apparent in type 2 diabetes. At present, the molecular mechanisms through which beta cell hierarchy is established are poorly understood. Changes at the level of the epigenome provide one such possibility, which we explore here by focusing on the imprinted gene Nnat (encoding neuronatin [NNAT]), which is required for normal insulin synthesis and secretion.

METHODS

Single-cell RNA-seq datasets were examined using Seurat 4.0 and ClusterProfiler running under R. Transgenic mice expressing enhanced GFP under the control of the Nnat enhancer/promoter regions were generated for FACS of beta cells and downstream analysis of CpG methylation by bisulphite sequencing and RNA-seq, respectively. Animals deleted for the de novo methyltransferase DNA methyltransferase 3 alpha (DNMT3A) from the pancreatic progenitor stage were used to explore control of promoter methylation. Proteomics was performed using affinity purification mass spectrometry and Ca2+ dynamics explored by rapid confocal imaging of Cal-520 AM and Cal-590 AM. Insulin secretion was measured using homogeneous time-resolved fluorescence imaging.

RESULTS

Nnat mRNA was differentially expressed in a discrete beta cell population in a developmental stage- and DNA methylation (DNMT3A)-dependent manner. Thus, pseudo-time analysis of embryonic datasets demonstrated the early establishment of Nnat-positive and -negative subpopulations during embryogenesis. NNAT expression is also restricted to a subset of beta cells across the human islet that is maintained throughout adult life. NNAT+ beta cells also displayed a discrete transcriptome at adult stages, representing a subpopulation specialised for insulin production, and were diminished in db/db mice. 'Hub' cells were less abundant in the NNAT+ population, consistent with epigenetic control of this functional specialisation.

CONCLUSIONS/INTERPRETATION

These findings demonstrate that differential DNA methylation at Nnat represents a novel means through which beta cell heterogeneity is established during development. We therefore hypothesise that changes in methylation at this locus may contribute to a loss of beta cell hierarchy and connectivity, potentially contributing to defective insulin secretion in some forms of diabetes.

DATA AVAILABILITY

The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD048465.

Rikkunshito increases peripheral incretin-hormone levels in humans and rats

BACKGROUND

It was reported that rikkunshito (TJ-43) improved the cisplatin-induced decreases in the active form of ghrelin in plasma; however, other effects on gastrointestinal hormones have not been investigated.

AIM

To investigate the effects of TJ-43 on peripheral levels of incretin hormones, including gastric inhibitory polypeptide (GIP) and glucagon-like polypeptide-1 (GLP-1), in humans and rats.

METHODS

Patients were divided into two groups, namely patients who received TJ-43 immediately following surgery [TJ-43(+) group] and those who received TJ-43 on postoperative day 21 [TJ-43(-) group], and the plasma levels of active GIP and active GLP-1 were assessed. In animal experiments, rats were treated with TJ-43 [rat (r)TJ-43(+) group] or without [rTJ-43(-) group] by gavage for 4 wk, and the plasma active GIP and active GLP-1 levels were measured. The expression of incretin hormones in the gastrointestinal tract and insulin in the pancreas were investigated by immunohistochemistry. Furthermore, the cyclic adenosine monophosphate activities were assessed in pancreatic tissues from rats treated with or without TJ-43 in vivo, and the blood glucose levels and plasma insulin levels were measured in rats treated with or without TJ-43 in oral glucose tolerance tests.

RESULTS

In humans, the active incretin hormone levels increased, and values were significantly greater in the TJ-43(+) group compared those in the TJ-43(-) group. In rats, the plasma active incretin levels significantly increased in the rTJ-43(+) group compared with those in the rTJ-43(-) group. GIP and GLP-1 expressions were enhanced by TJ-43 treatment. Moreover, plasma insulin levels increased and blood glucose levels were blunted in the rTJ-43(+) group.

CONCLUSION

The results show that TJ-43 may be beneficial for patients who undergo pancreatic surgery.