Higher Insulin Concentrations Research Articles

Baseline phenotypes with preserved β-cell function and high insulin concentrations have the best improvements in glucose tolerance after weight loss: results from the prospective DEXLIFE and EGIR-RISC studies

BackgroundWeight loss and lifestyle intervention improve glucose tolerance delaying the onset of type 2 diabetes (T2D), but individual responses are highly variable. Determining the predictive factors linked to the beneficial effects of weight loss on glucose tolerance could provide tools for individualized prevention plans. Thus, the aim was to investigate the relationship between pre-intervention values of insulin sensitivity and secretion and the improvement in glucose metabolism after weight loss. MethodsIn the DEXLIFE cohort (373 individuals at high risk of T2D, assigned 3:1 to a 12-week lifestyle intervention or a control arm, Trial Registration: ISRCTN66987085), K-means clustering and logistic regression analysis were performed based on pre-intervention indices of insulin sensitivity, insulin secretion (AUC-I), and glucose-stimulated insulin response (ratio of incremental areas of insulin and glucose, iAUC I/G). The response to the intervention was evaluated in terms of reduction of OGTT-glucose concentration. Clusters' validation was done in the prospective EGIR-RISC cohort (n = 1538). ResultsFour replicable clusters with different glycemic and metabolomic profiles were identified. Individuals had similar weight loss, but improvement in glycemic profile and β-cell function was different among clusters, highly depending on pre-intervention insulin response to OGTT. Pre-intervention high insulin response was associated with the best improvement in AUC-G, while clusters with low AUC-I and iAUC I/G showed no beneficial effect of weight loss on glucose control, as also confirmed by the logistic regression model. ConclusionsIndividuals with preserved β-cell function and high insulin concentrations at baseline have the best improvement in glucose tolerance after weight loss.

Horse owner experiences and observations with the use of SGLT2i for the management of equine metabolic syndrome and hyperinsulinaemia‐associated laminitis

SummaryBackgroundSodium‐glucose cotransporter 2 inhibitors (SGLT2i) are being used increasingly in equine practice. While there is emerging clinical evidence of the safety and efficacy of these drugs, there are currently no reports to document owner experiences with treatment.ObjectiveThe objective of the study was to report owner experiences and observations following treatment with SGLT2i in horses.Study designA cross‐sectional online survey.MethodsHorse owners were recruited via social media, online forums and their veterinarians to participate in an anonymous online survey to document their experiences and observations when treating their horses with SGLT2i.ResultsThree hundred forty‐two responses met the inclusion criteria. Ertugliflozin was the most commonly prescribed SGLT2i (79.8%), and the most common reasons for treatment were high insulin concentrations (84.2%) and active laminitis (59.7%). 85.3% of owners reported their horses had an improved quality of life after commencing treatment, while 9.4% reported no change and 5.3% reported a worsening of clinical signs. Of owners who had considered euthanasia prior to treatment (n = 77), 80.5% reported their horse's level of pain to be either mild or absent after 30 days of treatment and 94.8% reported their horse's quality of life to be improved. Most owners (n = 220, 64.7%) reported they were either extremely satisfied or somewhat satisfied (n = 72, 21.2%) with treatment. Treatment concerns included safety/side effects, medication cost, availability and long‐term efficacy. 114 owners (33.3%) reported one or more initial adverse effects upon induction onto the medication, particularly excessive urination (n = 70, 20.5%), excessive drinking (n = 38, 11.1%), excessive weight loss (n = 34, 9.9%) and dullness (n = 26, 7.6%).Main limitationSampling bias through social media and veterinary practices and reliance on subjective owner reports.ConclusionThe use of SGLT2i in horses was associated with excellent rates of owner satisfaction and owner‐reported improved quality of life for the horse; however, some adverse effects were observed.

Dietary Energy Density Is Associated with Biomarkers of Chronic Diseases—A Cross-Sectional Study of School-Aged Children in Rural Mexico

BackgroundDietary energy density (DED) is associated with chronic disease markers in adults. However, results in children are still controversial. ObjectiveTo evaluate the DED of children and its association with obesity and biomarkers of chronic disease. MethodsIn this cross-sectional study, we recruited 284 children (6–10 y) from rural Mexico. Dietary intake was assessed using three 24-h recalls. DED was calculated for “foods only” (DEDfo) and for “foods and beverages” (DEDfb). Weight, height, and body fat percent (dual-energy X-ray absorptiometry) were measured. Inflammatory cytokines, lipid profile, leptin, and insulin resistance were determined from a fasting blood sample. ResultsDEDfo was 1.91 ± 0.36 kcal/g and DEDfb was 1.36 ± 0.31 kcal/g. Higher DEDfo and DEDfb were associated with higher risk to have insulin resistance [odds ratio (OR) = 3.92, 95% confidence interval (CI): 1.66, 9.22, P < 0.01; OR = 3.51, 95% CI: 1.25, 9.87, P = 0.02, respectively]. Higher DEDfo was associated with higher risk of higher leptin levels (OR = 3.17, 95% CI: 1.01, 10.23). Also, DEDfo and DEDfb were associated with higher concentrations of cholesterol (β = 11.67, 95% CI: 1.81, 19.53, P = 0.03; and β = 11.74, 95% CI: 2.69, 20.74 P = 0.01, respectively) and higher odds of having high insulin concentrations (OR = 2.52, 95% CI: 1.26, 5.06, P = 0.01; and OR = 2.95, 95% CI: 1.30, 6.70, P = 0.01). DEDfo and DEDfb were not associated with any measure of obesity and inflammatory cytokines in the adjusted models. ConclusionsDED was associated with higher leptin and cholesterol concentrations, and having insulin resistance, but not with any measure of obesity or inflammation. Reducing DED may reduce risk of cardiovascular disease and improve insulin sensitivity in school-aged children.

Role of methyltransferase Set7 in obesity-related endothelial activation: functions beyond histone methylation

Abstract Introduction Obesity is associated with environmental changes such as hyperglycemia, hyperinsulinemia, inflammation, and elevated free fatty acids, all of which compromise endothelial function1,2. We have previously reported that in individuals with type 2 diabetes, lysine methyltransferase Set7 is involved in hyperglycemia-induced endothelial damage through monomethylation of histone 3 at lysine 4 (H3K4me1)3. Apart from such histone-driven epigenetic modulation, Set7-induced methylation of non-histone proteins is emerging as a novel mechanism underlying the (dys)regulation of many biological processes4. Purpose To investigate the role of Set7-related endothelial damage in cells exposed to different obesity-associated stimuli and to determine its impact on the protein methylome in these settings. Methods Human aortic endothelial cells (HAECs) were exposed to high concentrations of glucose, insulin, TNFa, or fatty acids (palmitate or oleate). Set7 overexpression, silencing, and inhibition studies were also performed in these cells. Gene and protein expression were assessed by RT-PCR and immunoblotting respectively, whereas production of the reactive oxygen species (ROS) was measured by electron spin resonance spectroscopy. Specific antibodies were used for the enrichment of lysine mono-, di-, and tri-methylated proteins and LC-MS/MS proteomic analysis was carried out for their identification. Results Each obesity model in HAECs increased the expression of nearly all the inflammatory markers tested and, except for TNFa, they also increased the expression of Set7. Significant changes in the global levels of H3K4me1, as well as of methylated proteins were also observed in these cells. Studies overexpressing a mutant form of Set7, which is lacking the SET domain, revealed that Set7 methyltransferase activity is required to define the protein methylome in HAECs. Similar results were obtained after Set7 silencing and inhibition. Despite no differences were observed in the production of ROS when modulating Set7 expression in HAECs, overexpression of an active form of Set7 and its silencing/inhibition resulted in a consistent up- and down-regulation, respectively, of several inflammatory mediators and adhesion molecules. Finally, proteomics analysis identified, for the first time, the protein methylome of endothelial cells, comprising almost 2,700 methylated proteins involved in essential biological processes such as RNA metabolism and cytoskeleton. Conclusions Our results indicate that Set7 may contribute to inflammatory changes in response to obesogenic insults. Moreover, our findings uncover a dual role of methyltransferase Set7 in governing the methylation of both histone and non-histone proteins in endothelial cells. These preliminary findings open a new field of research aiming to further elucidate the molecular mechanisms underlying the modulation of the protein methylome in the endothelium and its role in endothelial damage.

Unexpected evolution of a monster case of insulin-induced skin lipohypertrophy

In this journal, in 2020, we published the case of a 74-year-old female outpatient with type-2 diabetes mellitus who self-injected insulin four times a day according to the basal-bolus regimen, with an high glycemic variability and an high rate of severe hypoglycemic episodes. Three years before, we had found two extraordinarily large skin lipohypertrophies, with large underlying fluid collections with high insulin concentration. A long educational and intensive training completely repaired the skin lesions with the disappearance of the subcutaneous insulin reservoirs. Glycemic variability has been reduced dramatically, severe hypoglycemia has almost completely disappeared and the daily dose of insulin has been reduced by 38%. However, this extraordinary, albeit unexpected, result was achieved in five years.

Insulin and aging - a disappointing relationship.

Experimental studies in animal models of aging such as nematodes, fruit flies or mice have observed that decreased levels of insulin or insulin signaling promotes longevity. In humans, hyperinsulinemia and concomitant insulin resistance are associated with an elevated risk of age-related diseases suggestive of a shortened healthspan. Age-related disorders include neurodegenerative diseases, hypertension, cardiovascular disease, and type 2 diabetes. High ambient insulin concentrations promote increased lipogenesis and fat storage, heightened protein synthesis and accumulation of non-functional polypeptides due to limited turnover capacity. Moreover, there is impaired autophagy activity, and less endothelial NO synthase activity. These changes are associated with mitochondrial dysfunction and oxidative stress. The cellular stress induced by anabolic activity of insulin initiates an adaptive response aiming at maintaining homeostasis, characterized by activation of the transcription factor Nrf2, of AMP activated kinase, and an unfolded protein response. This protective response is more potent in the long-lived human species than in short-lived models of aging research resulting in a stronger pro-aging impact of insulin in nematodes and fruit flies. In humans, resistance to insulin-induced cell stress decreases with age, because of an increase of insulin and insulin resistance levels but less Nrf2 activation. These detrimental changes might be contained by adopting a lifestyle that promotes low insulin/insulin resistance levels and enhances an adaptive response to cellular stress, as observed with dietary restriction or exercise.

A rare case of autoimmune dysglycemia syndrome associated with systemic lupus erythematosus and dermatomyositis

Autoimmune dysglycemia syndrome (ADS) is a rare condition that presents as episodes of hypoglycemia as well as hyperglycemia and is classified as insulin autoimmune syndrome (IAS) and type B insulin resistance (TBIR). Autoimmunity plays a key role in the pathogenesis of this disorder, as evidenced by the presence of autoantibodies against endogenous insulin or the insulin receptor, and by its association with rheumatologic disorders. Treatment usually includes glycemic control and immunomodulatory agents. We report a case of a 31-year-old woman who was admitted for severe hypoglycemia. Further workup revealed underlying systemic lupus erythematosus (SLE) with renal involvement. During hospitalization, she continued to experience episodes of fasting hypoglycemia, as well as episodes of postprandial hyperglycemia. Hypoglycemia associated with a high serum insulin concentration and positive anti-insulin antibodies were consistent with IAS. Likewise, hyperglycemia and hypoglycemia in association with weight loss, acanthosis nigricans, polycystic ovarian syndrome, and normotriglyceridemia strongly suggested TBIR, although testing for antibodies against the insulin receptor was not available in Peru. Immunosuppressive therapy and metformin were indicated, resulting in remission of SLE and ADS. Years later, the patient exhibited features of dermatomyositis, such as Raynaud’s phenomenon, muscular weakness, heliotrope exanthema, and elevated muscle enzymes. Once again, the patient received immunosuppressive therapy. ADS is an infrequent cause of hypoglycemia, and the coexistence of its two pathophysiological mechanisms in a patient with SLE and subsequent development of dermatomyositis is even more rare. Our case is the first one reported describing this association.

Continuous glucose monitoring in a patient with insulinoma presenting with unawareness of postprandial hypoglycemia.

Unawareness of postprandial hypoglycemia for 5 years was identified in a 66-year-old man at a local clinic. The patient was referred to our hospital because of this first awareness of hypoglycemia (i.e. lightheadedness and impaired consciousness) developing after lunch. In a 75 g oral glucose tolerance test, the plasma glucose concentration was decreased to 32 mg/dL (1.8 mmol/L) at 150 min with relatively high concentrations of insulin (8.1 μU/mL), proinsulin (70.3 pmol/L), and C-peptide (4.63 ng/mL). In a prolonged fasting test, the plasma glucose concentration was decreased to 43 mg/dL (2.4 mmol/L) at 66 h with an insulin concentration of 1.4 μU/mL and a C-peptide concentration of 0.49 ng/mL. Computed tomography showed an 18 mm hyperenhancing tumor in the uncinate process of the pancreas. A selective arterial calcium stimulation test showed an elevated serum insulin concentration in the superior mesenteric artery. The patient was then diagnosed with insulinoma and received pancreaticoduodenectomy. Continuous glucose monitoring (CGM) using the Dexcom G6 system showed unawareness of hypoglycemia mainly during the daytime before surgery. When the sensor glucose value was reduced to 55 mg/dL (3.1 mmol/L), the Dexcom G6 system emitted an urgent low glucose alarm to the patient four times for 10 days. Two months after surgery, an overall increase in daily blood glucose concentrations and resolution of hypoglycemia were shown by CGM. We report a case of insulinoma with unawareness of postprandial hypoglycemia in the patient. The Dexcom G6 system was helpful for assessing preoperative hypoglycemia and for evaluating outcomes of treatment by surgery. Insulinoma occasionally leads to postprandial hypoglycemia. The CGM system is useful for revealing the presence of unnoticed hypoglycemia and for evaluating treatment outcomes after surgical resection. The Dexcom G6 system has an urgent low glucose alarm, making it particularly suitable for patients who are unaware of hypoglycemia.

Celebrating a Century of Insulin Discovery: A Critical Appraisal of the Emerging Alternative Insulin Delivery Systems.

Since the discovery of insulin, continuous developments of this peptide have led to better management of diabetes mellitus, thus leading to a decrease in diabetes-related mortality. Despite these developments, we have seen an increase in diabetes cases, which has further necessitated more innovative methods for diabetes management. The subcutaneous administration of insulin remains the mainstay therapy for type 1 diabetes mellitus. However, despite the availability of insulin analogues with improved pharmacokinetics, challenges with conventional administration exist. The challenges associated with insulin injections include hypoglycaemic episodes, needle phobia, and injection-site inflammation, which all have been reported to reduce patient compliance. Ongoing research on diabetes management strives to develop therapies that provide improved glycaemic control with minimal side effects. In part, for these reasons, we have seen an increase in the search and development of alternative insulin delivery systems that are envisaged to circumvent the shortfalls associated with the conventional administration route. Several alternative drug delivery systems, such as oral, pulmonary, buccal, nasal, and transdermal, have been explored in the last century. These efforts have not been without victory, as we have seen the emergence of pulmonary (Exubera and Afrezza) and buccal insulin delivery systems licenced for therapeutic use. Despite the success seen in these two systems, their marketability and popularity have been severely compromised due to reported safety concerns. Although oral insulin delivery has always shown promise in the past decades; however, it was only limited to preclinical trials. The main challenge associated with this delivery route is poor bioavailability, which necessitates high insulin concentration to be administered. Due to recent developments, oral insulin has reached phase 3 clinical trials. It is believed that patients would prefer oral insulin as their preference is often observed for oral antidiabetics over injected ones. In the last decade, transdermal insulin has also gained interest, where delivery of insulin with a concomitant reduction in blood glucose concentration has been demonstrated in vivo. However, at present, there are no clinical studies that have reported the efficacy of transdermal insulin administration. With technological advancement, there is a potential to develop yet another insulin delivery system that would likely enter the markets. As these novel delivery systems have been found to be effective, emerging competing products should be welcome and appreciated.

EPR Viscometric Measurements Using a 13C-Labeled Triarylmethyl Radical in Protein-based Biotherapeutics and Human Synovial Fluids.

The viscosity measurements are of clinical significance for evaluation of the potential pathological conditions of biological lubricants such as synovial fluids of joints, and for formulation and characterization of peptide- and protein-based biotherapeutics. Due to inherent potential therapeutic activity, protein drugs have proven to be one of the most efficient therapeutic agents in treatment of several life-threatening disorders, such as diabetes and autoimmune diseases. However, home-use applications for treating chronic inflammatory diseases, such as diabetes and rheumatoid arthritis, necessitate the development of high-concentration insulin and monoclonal antibodies formulations for patient self-administration. High protein concentrations can affect viscosity of the corresponding drug solutions complicating their manufacture and administration. The measurements of the viscosity of new insulin analogs and monoclonal antibodies solutions under development is of practical importance to avoid unwanted highly viscous, and therefore, painful for injection drug formulations. Recently, we have demonstrated capability of the electron paramagnetic resonance (EPR) viscometry using viscosity-sensitive 13C-labeled trityl spin probe (13C1-dFT) to report the viscosity of human blood, and interstitial fluids measured in various organs in mice ex-vivo and in anesthetized mice, in vivo. In the present work, we demonstrate utility of the EPR viscometry using 13C1-dFT to measure microviscosity of commercial insulin samples, antibodies solution, and human synovial fluids using small microliter volume samples (5-50 μL). This viscometry analysis approach provides useful tool to control formulations and administration of new biopharmaceuticals, and for evaluation of the state of synovial fluids of importance for clinical applications.

The influence of mare's lactational status during early pregnancy on metabolism of foals up to 28 days of age

The influence of a mare's nutrition on the fetus plays a significant role in future health, growth and performance, affecting insulin and glucose control systems. When maternal nutrition is altered through concentrate supplementation, higher insulin concentrations are required to maintain euglycemia in the mare, which can lead to metabolic reprogramming in the foal. The "easy keeper" condition (obese animals and/or difficult to lose weight), as well as susceptibility to endocrinopathic laminitis can result from this intrauterine reprogramming. It is common to use lactating mares as embryo recipients, however, little is known about the effect on the mare's metabolism and influence on the foal's development. Our study aimed to compare the insulin, glucose and others metabolism markers of foals born from lactating (L) and non-lactating (NL) recipient mares, from day 1-28 of life. We used 12 normal foals, offspring of Mangalarga Paulista mares aged 5 to 15 years. Mares from the lactating group continued lactation from ovulation until a maximum of 170 days of pregnancy. Foal evaluations were performed the day after birth (D1) and at 7, 14, 21 and 28 days of age. Glucose (mg/dL), insulin (µU/mL), triglycerides (mg/dL), non-esterified fatty acids (NEFA; mmol/dL) and cortisol (µg/dL) were analyzed. We used factorial arrangements between groups (L, NL) and time (D1, D7,D14, D21 and D28). The results presented are the mean and standard error of the mean. There was no statistically significant interaction in any of the variables. There was no difference between groups, but insulin, glucose, triglycerides and cortisol changed over time. Insulin concentrations were lower on D1 and equal at other times (D1:3.82±0.27; D7:6.28±0.59; D14:7.89±0.98; D21:6.97±0.69; D28:5.87±0.88; P=0.002). Glucose was lower on D28, which was equal to D21 (D1:144.83±5.27; D7:148.33±3.96; D14: 147.25±4.27; D21: 140.25±3.04; D28: 133.33±3.75; P=0.02). Triglycerides were higher on D1 and D7, on D14 were equal to these times and to D21 and on D28 were lower than other times, being equal to D21 (D1: 72.64±21.95; D7: 65.59±8.38; D14: 51.92±7.73; D21: 41±3.47; D28: 34.05±2.84; P<0.01). Cortisol was higher on D1 and lower on all other times (D1: 0.83±0.09; D7: 0.42±0.06; D14: 0.43±0.04; D21: 0.57±0.06; D28: 0.6±0.07; P=0.003). In conclusion, some characteristics change with foal age such as insulin, glucose, triglycerides and cortisol. The lactating recipient mare status during the initial third of pregnancy does not influence the postnatal characteristics of the foal up to 28 days of life. Acknowledgements: FAPESP (2017/05425-0 and 2020/10260-3) and CAPES for financial support.

Does insulin make breast cancer cells resistant to doxorubicin toxicity?

The effects of insulin on the doxorubicin (Dox) sensitivity of breast cancer cell line MCF-7 and its Dox-resistant counterpart MCF-7/Dox were studied and glucose metabolism, content of essential minerals, and the expression of several microRNAs in these cells upon exposure to insulin and Dox were compared. Cell viability colorimetric assay, colorimetric enzymatic technique, flow cytometry, immunocytochemical techniques, inductively-coupled plasma atomic emission spectroscopy, and quantitative polymerase chain reaction were used in the study. We found that insulin in high concentration significantly suppressed Dox toxicity, especially in parental MCF-7 cell line. The increase in proliferative activity triggered by insulin in MCF-7 but not MCF-7/Dox cells occurred in the setting of the increased level of specific binding sites for insulin and increased glucose uptake. Insulin treatment of MCF-7 cells in low and high concentrations resulted in the increase of Mg, Ca, and Zn content while in DOX-resistant cells, only Mg content increased upon exposure to insulin. High concentration of insulin increased the expression of kinase Akt1, P-glycoprotein 1 (P-gp1) and DNA excision repair protein ERCC-1 in MCF-7 cells, while in MCF-7/Dox cells, Akt1 expression decreased, and cytoplasmic expression of P-gp1 increased. In addition, insulin treatment affected expression of miR-122-5p, miR-133a-3p, miR-200b-3p, and miR-320a-3p. The decreased manifestation of biological effects of insulin in Dox-resistant cells could be partly explained by the different patterns of energy metabolism in MCF-7 cells and their Dox-resistant counterpart.

Transcriptional response of endometrial cells to Insulin, cultured using microfluidics.

Obesity is a rapidly growing public health issue among women of reproductive age associated with decreased reproductive function including implantation failure. This can result from a myriad of factors including impaired gametes and endometrial dysfunction. The mechanisms of how obesity-related hyperinsulinaemia disrupts endometrial function are poorly understood. We investigated potential mechanisms by which insulin alters endometrial transcript expression. Ishikawa cells were seeded into a microfluidics device attached to a syringe pump to deliver a constant flow rate of 1uL/min of the following: 1) control 2) vehicle control (acetic acid) or, 3) Insulin (10 ng/ml) for 24 hours (n=3 biological replicates). Insulin-induced transcriptomic response of endometrial epithelial cells was determined via RNA sequencing, and DAVID and Webgestalt to identify Gene Ontology (GO) terms and signalling pathways. A Total of 29 transcripts showed differential expression levels across two comparison groups (control v vehicle control; vehicle control v insulin). Nine transcripts were differentially expressed in vehicle control v insulin comparison (p<0.05). Functional annotation analysis of transcripts altered by insulin (n=9) identified three significantly enriched GO terms: SRP-dependent cotranslational protein targeting to membrane, poly(A) binding, and RNA binding (p<0.05). Over-representation analysis found three significantly enriched signalling pathways relating to insulin-induced transcriptomic response: protein export, glutathione metabolism, and ribosome pathways (p<0.05). Transfection of siRNA for RASPN successfully knocked down expression (p<0.05) but this did not have any effect on cellular morphology. Insulin-induced dysregulation of biological functions and pathways highlight potential mechanisms by which high insulin concentrations within maternal circulation may perturb endometrial receptivity.

The Gengnianchun recipe attenuates insulin resistance-induced diminished ovarian reserve through inhibiting the senescence of granulosa cells.

Insulin resistance (IR) is found in patients with polycystic ovary syndrome (PCOS), but the effects and mechanisms of IR on diminished ovarian reserve (DOR) remain unclear. This study set out to investigate the effects of IR on ovarian reserve; to explore the effects of high concentrations of insulin on the function of ovarian cells in vitro; and to validate the hypothesis that the Gengnianchun recipe (GNC) helps to attenuate DOR caused by IR through reducing the senescence of granulosa cells. Estrus cycle, follicle count, and sex hormone levels were detected to evaluate ovarian function in mice with IR caused by feeding a high-fat diet (HFD). In addition, KGN cells (human granulosa cell line) were treated with high concentrations of insulin. The staining for senescence-associatedβ-galactosidase (SA-β-gal), cell cycle, and expression levels of mRNA and gene proteins related to cell aging were detected in KGN cells treated with high concentrations of insulin. Mice treated with an HFD were fed metformin, GNC, or saline solution for 6 weeks by oral gavage. HOMA-IR, the area under the curve (AUC) of the oral glucose tolerance test (OGTT), levels of fasting blood glucose (FBG), and fasting serum insulin (FINS) were examined to confirm the IR status. Then estrus cycle, follicle count, and sex hormone levels were detected to evaluate ovarian function. Expression levels of mRNA and gene proteins related to cell aging were detected in the ovarian tissue of mice in each group. The results demonstrated that IR reduced murine ovarian reserves, and high doses of insulin caused granulosa cells to senesce. There was a considerable improvement in HFD-induced IR status in the metformin (Met) and GNC treatment groups. In addition, the expression levels of aging-associated biomarkers were much lower in GNC mice than Met mice; and both the latter groups had considerably lower levels than the HFD group. Moreover, higher follicle counts in different stages and shorter diestrus in the Met or GNC groups compared to the HFD group indicated that ovarian aging could be largely reversed. This work showed that: IR impaired ovarian reserve; high concentrations of insulin induced granulosa cell aging; and GNC attenuated ovarian function through inhibiting IR-induced cell aging.

Antioxidant, Cytotoxic, and Insulinotropic Activities of Several Leaves Extracts of Medicinal Plants

The prevalence of diabetes mellitus and cancer is increasing; thus, research into efficient treatments utilizing active compounds derived from medicinal plants has focused on these diseases. Through the agro maritime 4.0 approach, medicinal plants are explored in the archipelago of Indonesia, particularly on Tinjil Island, Banten Province. The medicinal plants identified on the island include Morinda citrifolia, Terminalia catappa, and Gnetum gnemon. Therefore, this study aimed to evaluate the in vitro of aqueous extracts of leaves of those three plant species. All aqueous extracts were analyzed for total phenolic content and further tested for antioxidant activity using the DPPH method (2,2-diphenyl-1-picrylhydrazyl), MTT cytotoxic activity (3-[4,5-dimethylthiazole-2-yl]-2- 5-diphenyl-tetrazolium-bromide) in MCF-7- (ATCC HTB 22) and Burkitt’s Lymphoma Raji (ATCC CCL 86) cells, and insulinotropic activity in pancreatic BRIN BD11 cells. The results showed that the total phenolic content of T. catappa was significantly higher (9.21 ± 2.49 mg GAE/g extract sample) compared to M. citrifolia (3.00 ± 0.35 mg GAE/g) and G. gnemon (7.47 ± 0.33 mg GAE/g). Compared to the other two extracts, T. catappa extract has the best DPPH antioxidant activity of IC50 7.44 ± 0.77 µg/mL (p&lt;0.05). MTT cytotoxic activity in all samples did not inhibit the proliferation of Raji cells but did the proliferation of MCF-7 cells. The IC50 for the best cytotoxic activity was shown in M. citrifolia (8.06 µg/mL). T. catappa triggered insulin secretion at 62.5 µg/mL with the highest insulin concentration (54.55 mg/mL). The aqueous extract of T. catappa leaves shows potential as an antioxidant and insulinotropic agent, while M. citrifolia leaves have a cytotoxic effect with anticancer potential.

First-trimester diet quality in association with maternal subcutaneous and visceral adipose tissue thicknesses and glucose homeostasis during pregnancy

We aimed to characterise the associations between first-trimester diet quality, adiposity, and glucose homeostasis measurements throughout pregnancy in a sample of 104 healthy pregnant women. Three Web-based 24-h recalls were completed, from which the Alternate Healthy Eating Index (AHEI) was calculated. At each trimester (12.5 ± 0.7, 22.8 ± 1.0, and 33.6 ± 1.3 weeks of gestation), fasting glucose and insulin were measured to compute an insulin resistance index (HOMA-IR). Subcutaneous and visceral adipose tissue thicknesses were estimated by ultrasound at the end of the first trimester. Inverse associations were observed between the first-trimester AHEI and first-trimester fasting insulin (r = 0.24; p < 0.05), and HOMA-IR (r = −0.22; p < 0.05), as well as third-trimester fasting insulin (r = −0.20; p < 0.05). A trend was also observed between first-trimester AHEI and first-trimester SAT thickness (r = −0.17; p < 0.1). Pre- and early-pregnancy adiposity measurements were identified as high predictors fasting insulin concentrations throughout pregnancy. Higher early-pregnancy diet quality is associated with more favourable metabolic measurements during pregnancy.

Improving human mesenchymal stem cell-derived hepatic cell energy metabolism by manipulating glucose homeostasis and glucocorticoid signaling.

The development of reliable hepatic in vitro models may provide insights into disease mechanisms, linking hepatocyte dysmetabolism and related pathologies. However, several of the existing models depend on using high concentrations of hepatocyte differentiation-promoting compounds, namely glucose, insulin, and dexamethasone, which is among the reasons that have hampered their use for modeling metabolism-related diseases. This work focused on modulating glucose homeostasis and glucocorticoid concentration to improve the suitability of a mesenchymal stem-cell (MSC)-derived hepatocyte-like cell (HLC) human model for studying hepatic insulin action and disease modeling. We have investigated the role of insulin, glucose and dexamethasone on mitochondrial function, insulin signaling and carbohydrate metabolism, namely AKT phosphorylation, glycogen storage ability, glycolysis and gluconeogenesis, as well as fatty acid oxidation and bile acid metabolism gene expression in HLCs. In addition, we evaluated cell morphological features, albumin and urea production, the presence of hepatic-specific markers, biotransformation ability and mitochondrial function. Using glucose, insulin and dexamethasone levels close to physiological concentrations improved insulin responsiveness in HLCs, as demonstrated by AKT phosphorylation, upregulation of glycolysis and downregulation of Irs2 and gluconeogenesis and fatty acid oxidation pathways. Ammonia detoxification, EROD and UGT activities and sensitivity to paracetamol cytotoxicity were also enhanced under more physiologically relevant conditions. HLCs kept under reduced concentrations of glucose, insulin and dexamethasone presented an improved hepatic phenotype and insulin sensitivity demonstrating superior potential as an in vitro platform for modeling energy metabolism-related disorders, namely for the investigation of the insulin signaling pathway.

Abnormal prolactin secretion is associated with changes in metabolic health biomarkers in acyclic female African elephants (Loxodonta africana)

Circulating prolactin aberrations (chronically high or low concentrations) have been shown to have strong associations with ovarian dysfunction in African female elephants. However, despite the well-established pleiotropic role that prolactin plays in human health, comprehensive metabolic effects from chronically elevated or suppressed prolactin have yet to be investigated in this species. In humans, in addition to amenorrhea, hyperprolactinemic women have shown increased risks for accelerated atherosclerosis, hyperandrogenemia, lowered metabolism, and insulin resistance. The aim of the study was to determine if elephants with long-term abnormal prolactin secretion were also experiencing alterations in metabolic biomarkers. One year of serum samples, collected biweekly, were obtained from female African elephants (n = 74) housed in North American zoos and categorized based on ovarian cyclicity and prolactin status: normal cycling, normal prolactin (NORMAL, n = 25), acyclic, high prolactin (HIGH, n = 25), or acyclic, low prolactin (LOW, n = 24). Each sample was further analyzed for measures of metabolic function, glucose metabolism, and cardiovascular health. Overall, thyroid hormones were significantly lower in both HIGH (TSH, T3, T4) and LOW (TSH) prolactin elephants compared to NORMAL counterparts. Additionally, HIGH prolactin elephants exhibited lower glucose, G:I ratios, and low-density lipoprotein values, but higher cholesterol concentrations compared to normal cycling females. Overall, LOW prolactin elephants exhibited higher body condition scores and G:I ratios, and higher concentrations of insulin, high-density lipoproteins, cortisol and testosterone, but decreased triglyceride values compared to NORMAL elephants in the study. Data suggest that HIGH prolactin elephants may be experiencing hypothyroidism as a comorbidity, whereas LOW prolactin elephants may be exhibiting aspects of insulin resistance, albeit different from human clinical data. Specific studies are suggested that would help elucidate the underlying mechanisms at play and increase our understanding of prolactin’s role in elephant physiology.

Appetite-regulating hormones modulate odor perception and odor-evoked activity in hypothalamus and olfactory cortices.

Odors guide food seeking, and food intake modulates olfactory function. This interaction is mediated by appetite-regulating hormones like ghrelin, insulin, and leptin, which alter activity in the rodent olfactory bulb, but their effects on downstream olfactory cortices have not yet been established in humans. The olfactory tract connects the olfactory bulb to the cortex through 3 main striae, terminating in the piriform cortex (PirC), amygdala (AMY), olfactory tubercule (OT), and anterior olfactory nucleus (AON). Here, we test the hypothesis that appetite-regulating hormones modulate olfactory processing in the endpoints of the olfactory tract and the hypothalamus. We collected odor-evoked functional magnetic resonance imaging (fMRI) responses and plasma levels of ghrelin, insulin, and leptin from human subjects (n = 25) after a standardized meal. We found that a hormonal composite measure, capturing variance relating positively to insulin and negatively to ghrelin, correlated inversely with odor intensity ratings and fMRI responses to odorized vs. clean air in the hypothalamus, OT, and AON. No significant correlations were found with activity in PirC or AMY, the endpoints of the lateral stria. Exploratory whole-brain analyses revealed significant correlations near the diagonal band of Broca and parahippocampal gyrus. These results demonstrate that high (low) blood plasma concentrations of insulin (ghrelin) decrease perceived odor intensity and odor-evoked activity in the cortical targets of the medial and intermediate striae of the olfactory tract, as well as the hypothalamus. These findings expand our understanding of the cortical mechanisms by which metabolic hormones in humans modulate olfactory processing after a meal.

LBSUN294 Insulin-induced Abdominal Acanthosis Nigricans From High Doses Of Insulin U-500

Abstract Introduction Dermatological complications associated with insulin therapy include lipoatrophy, lipohypertrophy, and acanthosis nigricans. We have a rare case of severe acanthosis nigricans from repeated insulin injection. Case A 63-year-old man with diabetes mellitus type 2 presented with an elevated blood glucose of 584mg/dL. He reported "high" glucose levels, despite adherence to his insulin regimen. He only injected insulin in his abdomen. Over 20 years, his insulin doses increased from Lantus 65 units BID and Humalog 35 units TID to Lantus units 110 BID and Humalog 65 units TID. It was later changed to U-500 at 160 units TID. His Hba1c ranged from 10.7% to 15.4%, most recently 13.6%. Physical examination revealed hyperpigmented and thickened plaques, localized to two large areas lateral to his umbilicus. During his hospital stay, insulin was administered on his arms and thighs. Glucose levels improved on Levemir 55 units daily and Lispro 20 units TID. He was discharged on Insulin U-500 40 units TID with instructions to avoid injecting on his abdomen and to rotate injection sites. Discussion Acanthosis nigricans is associated with insulin resistance or hyperinsulinemia. Insulin has a similar structure to insulin-like growth factor (IGF-1). At higher insulin concentrations, it can bind to IGF-1 receptors on keratinocytes and fibroblasts, leading to skin proliferation. Other suggested mechanisms include the involvement of fibroblast and epidermal growth factor. Histopathological findings show hyperkeratosis, papillomatosis, and thickened dermis. Immunochemical findings show positive IGF-1 antibodies in basal epithelial and prickle cell layers. In patients with poor glycemic control and increasing doses of insulin, it is important to assess for insulin-related skin changes. Besides routine visual inspection, skin thickening can be assessed by stroking the skin side-to-side in a sweeping motion instead of palpation. Conclusion Our patient with poorly type 2 diabetes required escalating doses of insulin over the years. He developed severe acanthosis nigricans on his abdomen leading to poor absorption of insulin. This case highlights the importance of routine visual inspection and tactile examination of insulin injection sites for skin changes, as well as repeated counseling regarding insulin site rotation.