Elevated Fasting Insulin Levels Research Articles

Effects of a Carbohydrate Meal on Lipolysis

Background: Due to the increasing prevalence of obesity and type 2 diabetes, effective dietary recommendations are needed. Previously, we developed the low-insulin method: by avoiding insulinogenic, i.e., insulin-release-triggering foods, insulin secretion becomes reduced, lipolysis is stimulated, and energy production is shifted to ketosis with excess ketone bodies exhaled in the form of acetone. Now, we investigate how quickly stable ketosis (defined as fasting breath acetone concentration ≥ 7.0 ppm) is achieved, whether and for how long a carbohydrate meal inhibits ketosis, and whether the responses differ in healthy adults with different insulin levels. Methods: An oral glucose tolerance test was conducted, and body composition and fasting insulin were determined at the beginning and end of the 14-day study. Participants (n = 10) followed a ketogenic diet and performed continuous glucose monitoring. Ketosis levels were determined by measuring breath acetone concentrations. On day 8, two white bread rolls with jam (72 g carbohydrates) were consumed for breakfast. Results: After seven days, all participants achieved stable ketosis (defined as fasting breath acetone concentration ≥ 7.0 ppm), which dropped from 8.2 to 5.7 ppm (p = 0.0014) after the carbohydrate meal. It took five days to achieve stable ketosis again. The stratification of participants into tertiles according to their fasting insulin levels demonstrated that individuals with low fasting insulin levels achieved stable ketosis again after two days and those with medium insulin levels after five days, while those with high baseline values did not reach stable ketosis by the end of the study. Conclusions: By carbohydrate restriction, stable ketosis can be achieved within one week. However, a single carbohydrate meal inhibits ketosis for several days. This effect is pronounced in individuals with elevated fasting insulin levels.

Enhanced ECCD36 signaling promotes skeletal muscle insulin resistance in female mice.

Consumption of a Western diet (WD) increases CD36 expression in vascular, hepatic, and skeletal muscle tissues promoting lipid metabolic disorders and insulin resistance. We further examined the role of endothelial cell-specific CD36 (ECCD36) signaling in contributing to skeletal muscle lipid metabolic disorders, insulin resistance, and their underlying molecular mechanisms. Female ECCD36 wild-type (ECCD36+/+) and knock-out (ECCD36-/-) mice, aged 6 wk, were provided with either a WD or a standard chow diet for a duration of 16 wk. ECCD36+/+ WD mice were characterized by elevated fasting plasma glucose and insulin levels, increased homeostatic model assessment for insulin resistance, and glucose intolerance that was blunted in ECCD36-/- mice. Improved insulin sensitivity in ECCD36-/- mice was characterized by increased phosphoinositide 3-kinases/protein kinase B signaling that further augmented glucose transporter type 4 expression and glucose uptake. Meanwhile, 16 wk of WD feeding also increased skeletal muscle free fatty acid (FFA) and lipid accumulation, without any observed changes in plasma FFA levels. These lipid metabolic disorders were blunted in ECCD36-/- mice. Moreover, ECCD36 also mediated in vitro palmitic acid-induced lipid accumulation in cultured ECs, subsequently leading to the release of FFAs into the culture media. Furthermore, consumption of a WD increased FFA oxidation, mitochondrial dysfunction, impaired mitochondrial respiratory, skeletal muscle fiber type transition, and fibrosis. These WD-induced abnormalities were blunted in ECCD36-/- mice. These findings demonstrate that endothelial-specific ECCD36 signaling participates in skeletal muscle FFA uptake, ectopic lipid accumulation, mitochondrial dysfunction, insulin resistance, and associated skeletal muscle dysfunction in diet-induced obesity.NEW & NOTEWORTHY ECCD36 exerts "extra endothelial cell" actions in skeletal muscle insulin resistance. ECCD36 is a major mediator of Western diet-induced lipid metabolic disorders and insulin resistance in skeletal muscle. Mitochondrial dysfunction is associated with diet-induced CD36 activation and related skeletal muscle insulin resistance.

Impact of imidacloprid exposure on gestational hyperglycemia: A multi-omics analysis

Imidacloprid (IMI), a commonly utilized neonicotinoid insecticide, has been identified to adversely impact glucose homeostasis. Pregnant women are believed to be more sensitive to toxins than non-pregnant women, and the impact of IMI exposure on gestational hyperglycemia remain unclear. To explore the impact, pregnant mice fed a high-fat diet were exposed to different doses (0.06, 0.6, 6 mg/kg bw/day) of IMI by gavage. Glucose homeostasis-related parameters were measured. The glucose homeostasis influenced by IMI treatment was explored through integrating gut microbiota, metabolomic and transcriptomic analysis. Results showed that IMI-H (6 mg/kg bw/day) exposure notably restricted gestational weight gain and perturbed glucose homeostasis characterized by reduced glucose tolerance and insulin sensitivity, alongside elevated levels of fasting blood glucose and insulin. Multi-omics analysis revealed that IMI-H exposure induced significant changes in the richness and composition of the gut microbiome. The metabolite profiles of serum samples and cecal contents, and transcriptome of liver and ileum were all affected by IMI-H treatment. The altered gut microbiota, metabolites and genes exhibited significant correlations with glucose homeostasis-related parameters. These differential metabolites and genes were implicated in various metabolic pathways including bile secretion, glucagon signaling pathway, lipid metabolism, fatty acid metabolism. Significant correlations were observed between the altered gut microbiota and caecum metabolome as well as liver transcriptome. For example, the abundance of Oscillibacter was strongly correlated with gut microflora-related metabolites (Icosenoic acid, Lysosulfatide, and fluticasone) and liver differential genes (Grin3b, Lifr, and Spta1). Together, IMI exposure resulted in significant changes in microbial composition, along with alterations in certain metabolites and genes associated with metabolic process, which may promote gestational hyperglycemia.

T2DM may exert a protective effect against digestive system tumors in East Asian populations: a Mendelian randomization analysis.

Type 2 diabetes mellitus (T2DM) was associated with digestive system tumors. We analyzed publicly available data from GWAS studies using Mendelian randomization methods to clarify its causal relationship and mechanisms. Five common digestive system tumors and four diabetes-related phenotypes were included. Inverse variance weighted method was the main analytical method. Meta-analysis was used to summarize results of multiple data sources. Horizontal pleiotropy was tested using Egger-intercept method and validated by MRPRESSO method. Heterogeneity and sensitivity analysis were conducted by Cochran's Q test and leave-one-out method, respectively. T2DM is associated with a reduced risk of esophageal (OR: 0.77, 95% CI: 0.71 to 0.83, P< 0.001), gastric (OR: 0.87, 95% CI: 0.84 to 0.90, P< 0.001) and colorectal cancer (OR: 0.88, 95% CI: 0.85 to 0.91, P< 0.001) and hepatocellular carcinoma (OR: 0.92, 95% CI: 0.86 to 0.97, P = 0.005) and an increased risk of pancreatic cancer (OR: 1.92, 95% CI: 1.47 to 2.50, P< 0.001) in East Asian population. T2DM causes decreased fasting insulin levels (OR = 0.966, 95% CI: 0.95 to 0.98, P< 0.001) and increased glycated hemoglobin levels (OR=1.41, 95% CI: 1.39 to 1.44, P<0.001). Elevated fasting insulin levels increase the risk of esophageal cancer (OR = 10.35, 95% CI: 1.10 to 97.25, P = 0.041), while increased glycated hemoglobin levels increase pancreatic cancer risk (OR=2.33, 95% CI: 1.37 to 3.97, P=0.002) but decrease gastric cancer risk (OR=0.801, 95% CI: 0.65 to 0.99, P=0.044). T2DM is associated with a reduced risk of esophageal, gastric and colorectal cancer and hepatocellular carcinoma in East Asian populations. The causal relationships between T2DM with esophageal and gastric cancer are partially mediated by decreased fasting insulin and increased glycated hemoglobin levels, respectively. T2DM indirectly increases the risk of pancreatic cancer by increasing glycated hemoglobin levels.

Gender as a threat for type 2 diabetes mellitus: Elevated fasting glucose, insulin, and HOMA-IR levels in females.

Objective: The research aimed to compare serum levels of fasting plasma glucose, 2hrpp, fasting insulin, Homeostasis Model Assessment of Insulin Resistance (HOMA-IR), and waist-to-height ratio in individuals with a diabetic background. Study Design: Cross-sectional Observational draft. Setting: District Headquarters Hospital, Gujranwala. Period: December 22, 2020, to December 22, 2022. Material &amp; Methods: Overall, 80 healthy participants, 20-50 years old, were recruited and graded into two groups based on gender. Group A comprised males, and Group B comprised females. All participants demonstrated normal glucose tolerance centered on the oral glucose tolerance test. Results: Females exhibited significantly higher mean levels of fasting plasma glucose (p=0.01), fasting plasma insulin (p=0.004), and Homeostasis Model Assessment of Insulin Resistance (p=0.007) compared to males. Homeostasis Model Assessment of Insulin Resistance and waist-to-height ratio exhibited a positive correlation (p=0.001). Conclusion: Females with a positive family history may present an amplified threat of Type 2 Diabetes Mellitus.

Insulin-like growth factor binding protein-1 and insulin in polycystic ovary syndrome: a systematic review and meta-analysis.

Insulin-like growth factor binding protein-1 (IGFBP-1) is considered a decline in polycystic ovary syndrome (PCOS), but it remains controversial that whether such reduction is attributed to obesity. This systematic review aims to explore whether IGFBP-1 is reduced in PCOS, and whether such reduction is associated with obesity. Our pooled study included 12 studies with a total of 450 participants. IGFBP-1 levels in PCOS were significantly lower than that in non-PCOS (SMD (95%CI)=-0.49(-0.89, -0.09), P=0.02). No significant difference in IGFBP-1 levels between patients with or without PCOS classified by BMI. Whilst, stratification by PCOS status revealed a significant decrease in IGFBP-1 in overweight (SMD (95%CI)=-0.92(-1.46, -0.37), P=0.001). When comparing fasting insulin in the same way, PCOS patients had significantly elevated fasting insulin level but not statistically declined IGFBP-1 after classified by BMI. This meta-analysis provides evidence that the decrease of IGFBP-1 in PCOS was more strongly influenced by comorbid obesity than by PCOS itself. Additionally, contrast to previous findings that insulin significantly suppresses IGFBP-1, our results suggested that the suppression of PCOS-related hyperinsulinemia on IGFBP-1 seemed diminished. Overall, our work may provide a novel perspective on the mechanism between insulin and IGFBP-1 underlying PCOS development.

Specific Genotypes Associated with Differences in Fasting Insulin Levels and Body Mass Index in Healthy Young Males: Implications for Gene–Nutrient Interactions—an Exploratory Study

BackgroundGenetic variation may significantly impact an individual's susceptibility to diseases, particularly when combined with specific nutrients. Additionally, genetic variations can lead to interindividual differences in metabolic responses. ObjectiveThe present study explores the association between gene variants and observed interindividual differences in metabolic responses. MethodsThe study included 30 healthy males (aged 20–34) who underwent a fasting period and subsequently consumed a standardized meal. Blood samples were collected both before and after the meal to assess metabolic changes. BMI served as an indirect measure for assessing physiological responses associated with body composition. Appetite changes were assessed using an online Visual Analog 100-point Scale. Buccal swabs were collected to analyze genetic variants in single nucleotide polymorphisms (SNPs). ResultsThe data underwent multiple regression analysis, revealing significant associations with 3 SNPs and their metabolic status: the insulin-receptor substrate 1 (IRS1) gene variant rs2943641, genotypes CT and CC, with elevated fasting insulin levels (R2 = 0.639, P = < 0.0001); the mitochondrial uncoupling protein 1 (UCP1) gene variant rs1800592, genotypes GG and GA, with increased BMI (R2 = 0.261, P = 0.007); and the peroxisome proliferator-activated receptor γ2 (PPARγ2) gene variant rs1801282, genotypes GG and GC, with increased BMI (R2 = 0.200, P = 0.024). ConclusionsTherefore, our study established significant associations between these 3 SNPs and differences in fasting insulin levels and BMI within our cohort.

SAT034 Exploring The Role Of Zfp664 In Hepatic Glucose Regulation

Abstract Disclosure: A. Tsay: None. J. Wang: None. Genome wide association studies (GWAS) identify the association between variants at genomic loci and common diseases. These variants consist of single nucleotide polymorphisms (SNPs), which can be localized within coding or non-coding regions. The former could affect the functions of proteins encoded by these genes. The latter could modulate the expression of genes contained or localized nearby these SNPs. Several SNPs associated with metabolic disease such as diabetes, obesity, and dyslipidemia are found in and nearby the human ZNF664 gene, which encodes a zinc finger protein that is predicted to be a transcriptional regulator. The mouse homolog of ZNF664 is Zfp664, whose amino acid sequence is identical to ZNF664. To learn whether Zfp664 contains a transcriptional activation or repression function, the expression plasmid harboring the cDNA of full length or deletion mutants of mouse Zfp664 fused to yeast GAL4 DNA binding domain (DBD) was transfected into HEK293T cells along with a luciferase reporter plasmid containing 5 copies of the GAL4 binding sites. We saw decreased luciferase activity in cells overexpressing the GAL4 DBD and full length Zfp664 fusion protein. Thus, Zfp664 acts as a transcriptional repressor. The deletion analysis identified that amino acid 7 to 95 of Zfp664 was required for its transcriptional repressive activity. To test the metabolic function of hepatic Zfp664, 8 weeks old male C57Bl/6J mice were infected with adeno-associated virus (AAV) expressing either scramble small hairpin RNA (shRNA, as a control) or shRNA targeting Zfp664 and then fed a normal chow diet or western diet (42% kcal from fat, 0.2% total cholesterol) for 12 weeks. We found that mice infected with AAV expressing Zfp664 shRNA had a lower expression of Zfp664 in the liver but not in epididymal white adipose tissue and gastrocnemius muscle. Under chow diet feeding, not only did hepatic Zfp664 knockdown not affect glucose tolerance and insulin sensitivity, but it also did not affect fasting glucose, insulin, triglyceride, and total cholesterol levels. In contrast, in mice fed a western diet, hepatic Zfp664 knockdown worsened glucose tolerance and elevated fasting insulin levels. Moreover, the expression of hepatic gluconeogenic genes, such as phosphoenolpyruvate carboxykinase (Pck1) and the catalytic subunit of glucose-6-phosphatase (G6pc), was increased. The fasting plasma triglyceride and total cholesterol levels were not affected by hepatic Zfp664 knockdown in western diet fed mice. Overall, these results discover the novel role of Zfp664 in the regulation of hepatic glucose homeostasis. Presentation: Saturday, June 17, 2023

Circadian disruption impairs glucose homeostasis in male but not in female mice and is dependent on gonadal sex hormones.

Circadian disruption (CD) is the consequence of a mismatch between endogenous circadian rhythms and behavior, and frequently occurs in shift workers. CD has often been linked to impairment of glucose and lipid homeostasis. It is, however, unknown if these effects are sex dependent. Here, we subjected male and female C57BL/6J mice to 6-h light phase advancements every 3 days to induce CD and assessed glucose and lipid homeostasis. Within this model, we studied the involvement of gonadal sex hormones by injecting mice with gonadotropin-releasing hormone-antagonist degarelix. We demonstrate that CD has sex-specific effects on glucose homeostasis, as CD elevated fasting insulin levels in male mice while increasing fasting glucose levels in female mice, which appeared to be independent of behavior, food intake, and energy expenditure. Absence of gonadal sex hormones lowered plasma insulin levels in male mice subjected to CD while it delayed glucose clearance in female mice subjected to CD. CD elevated plasma triglyceride (TG) levels and delayed plasma clearance of TG-rich lipoproteins in both sexes, coinciding with reduced TG-derived FA uptake by adipose tissues. Absence of gonadal sex hormones did not notably alter the effects of CD on lipid metabolism. We conclude that CD causes sex-dependent effects on glucose metabolism, as aggravated by male gonadal sex hormones and partly rescued by female gonadal sex hormones. Future studies on CD should consider the inclusion of both sexes, which may eventually contribute to personalized advice for shift workers.

IDF21-0029 Maternal separation aggravated pancreatic oxidative and inflammatory damage in chronic socially defeated adult male rats

Background: It is believed that psychosocial stress as one of the main sources of stress in humans may play an essential role in developing chronic degenerative metabolic diseases. Early life adverse experiences were supposed to affect the response to stress in later life. Aim: This research was done to test the effect of maternal separation on the metabolic response to chronic social defeat stress (CSDS) at young adulthood. In this respect, the possible contribution of oxidative stress and inflammatory damage to the pancreas along with insulin resistance in response to CSDS exposure in young adult male rats who experienced early life maternal separation was explored. Method: During the first 2 weeks of life, male Wistar rats were exposed to either maternal separation (MS) or left undisturbed with their mothers (Std). Starting on postnatal date 50, the animals of each group were either left undisturbed in the standard group housing (Con) or underwent chronic social defeat stress (CSDS) for 3 weeks. Thus, totally there were 4 groups (n=6/group). Then, fasting plasma corticosterone, insulin, and glucose levels were measured and insulin resistance was calculated. Pancreatic Catalase (CAT) activity, reduced Glutathione (GSH), Malondialdehyde (MDA) and interleukin-1 beta contents were measured. Results: In this study, MS-CSDS animals showed an elevated fasting plasma corticosterone and insulin levels along with insulin resistance in comparison with standard-reared controls (Std-Con); however, neither early nor adult life adversity affected fasting glucose levels. Likewise, CAT activity, MDA, and Il-1β contents of pancreatic tissue were increased only in MS-CSDS rats compared to Std-Cons. Discussion: The finding of this study shows that maternal separation intensifies vulnerability to develop HPA axis over-activation, insulin resistance, pancreatic oxidative and inflammatory damage associated with chronic exposure to social defeat stress in young adult male rats, which could play an important role in mediating the effects of chronic stress‐related risk of diabetes mellitus. Abnormal responses to stress in adults, who were exposed to stress in early life, almost occurred because of increasing basal tone of central CRFergic activity and coincident intensified HPA axis responsiveness. It may be secondary to facilitation of noradrenergic neurocircuits, central glucocorticoid resistance, and/or dampened regional GABAergic tone that have been observed to happen in response to maternal separation stress. Elevated levels of circulating glucocorticoid have been reported to influence the insulin signaling cascade at the level of insulin receptor and insulin-sensitive glucose transporter 4 (GLUT4) functionality, which may contribute to insulin resistance. In the face of insulin resistance, the β cells adapt by increasing insulin secretion, leading to peripheral compensatory hyperinsulinemia as a protective measure to maintain normal glucose concentrations without hypoglycemia. Augmented pancreatic oxidative stress in MS-CSDS animals may exceeded the increased compensatory antioxidant mechanisms, as evidenced by excessive peroxidation of cell membrane lipids. Based on the central role of IL-1β in the destruction of pancreatic β cells, raised pancreatic IL-1β content could be related to oxidative stress-mediated β cell damage and development of diabetes in response to CSDS exposure in young adult rats who underwent early life maternal separation.

Intergenerational effects of preconception opioids on glucose homeostasis and hepatic transcription in adult male rats

Adolescence represents a period of significant neurodevelopment during which adverse experiences can lead to prolonged effects on disease vulnerability, including effects that can impact future offspring. Adolescence is a common period for the initiation of drug use, including the use of opioids. Beyond effects on central reward, opioids also impact glucose metabolism, which can impact the risk of diabetes. Moreover, recent animal models suggest that the effects of adolescent opioids can effect glucose metabolism in future offspring. Indeed, we demonstrated that the adult male offspring of females exposed to morphine for 10 days during adolescence (referred to as MORF1 males) are predisposed to the adverse effects of an obesogenic diet. As adults, MORF1 males fed a high fat moderate sucrose diet (FSD) for just 6 weeks had increased fasting glucose and insulin levels when compared to age-matched offspring of females exposed to saline during adolescence (SALF1 males). Clinically, a similar profile of impaired fasting glucose has been associated with hepatic insulin resistance and an increased risk of non-alcoholic fatty liver disease. Thus, in the current study, we used RNA sequencing to determine whether adult MORF1 males demonstrate significant alterations in the hepatic transcriptome suggestive of alterations in metabolism. Age-matched SALF1 and MORF1 males were fed either FSD or control diet (CD) for 8 weeks. Similar to our previous observations, FSD-maintained MORF1 males gained more weight and displayed both fasting hyperglycemia and hyperinsulinemia when compared to FSD-maintained SALF1 males, with no significant effect on glucagon. No differences in bodyweight or fasting-induce glucose were observed in control diet (CD)-maintained F1 males, although there was a trend for CD MORF1 males to display elevated levels of fasting insulin. Unexpectedly, transcriptional analyses revealed profound differences in the hepatic transcriptome of CD-maintained MORF1 and SALF1 (1686 differentially expressed genes) with no significant differences between FSD-maintained MORF1 and SALF1 males. As changes in the hepatic transcriptome were not revealed under 8 weeks FSD conditions, we extended the feeding paradigm and conducted a glucose tolerance test to determine whether impaired fasting glucose observed in FSD MORF1 males was due to peripheral insulin resistance. Impaired glucose tolerance was observed in both CD and FSD MORF1 males, and to a more limited extent in FSD SALF1 males. These findings implicate intergenerational effects of adolescent morphine exposure on the risk of developing insulin resistance and associated comorbidities, even in the absence of an obesogenic diet.

Genetic Obesity in Children: Overview of Possible Diagnoses with a Focus on SH2B1 Deletion

Introduction: Genetic obesity is rare and quite challenging for pediatricians in terms of early identification. Src-homology-2 (SH2) B adapter protein 1 (SH2B1) is an important component in the leptin-melanocortin pathway and is found to play an important role in leptin and insulin signaling and therefore in the pathogenesis of obesity and diabetes. Microdeletions in chromosome 16p11.2, encompassing the SH2B1 gene, are known to be associated with obesity, insulin resistance, hyperphagia, and developmental delay. The aim of our study is to report on a case series of young individuals with 16p11.2 microdeletions, including the SH2B1 gene, and provide detailed information on body mass index (BMI) development and obesity-associated comorbidities. In this way, we want to raise awareness of this syndromic form of obesity as a differential diagnosis of genetic obesity. Methods: We describe the phenotype of 7 children (3 male; age range: 2.8–18.0 years) with 16p11.2 microdeletions, encompassing the SH2B1 gene, and present their BMI trajectories from birth onward. Screening for obesity-associated comorbidities was performed at the time of genetic diagnosis. Results: All children presented with severe, early-onset obesity already at the age of 5 years combined with variable developmental delay. Five patients presented with elevated fasting insulin levels, 1 patient developed diabetes mellitus type 2, 4 patients had dyslipidemia, and 4 developed nonalcoholic fatty-liver disease. Discussion/Conclusion: Chromosomal microdeletions in 16p11.2, including the SH2B1 gene, in children are associated with severe, early-onset obesity and comorbidities associated with insulin resistance. Early genetic testing in suspicious patients and early screening for comorbidities are recommended.

The Epidemiological Boehringer Ingelheim Employee Study (Part 3): Association of Elevated Fasting Insulin Levels but Not HOMA-IR With Increased Intima Media Thickness and Arteriosclerosis in Middle-Aged Persons.

Background: Recently published genetic studies have indicated a causal link between elevated insulin levels and cardiovascular disease (CVD) risk. We, therefore, hypothesized that increased fasting insulin levels are also associated with precursors of CVD such as endothelial lesions.Methods: Middle-aged (≥40 years, n = 1,639) employees were followed up for the occurrence of increased intima media thickness (IMT ≥ 1 mm) or plaques in abdominal or cervical arteries (arteriosclerosis). Multivariable logistic regression analyses determined the incidence of increased IMT or arteriosclerosis. Adjusted relative risk (ARR) for increased IMT and arteriosclerosis was calculated by using Mantel-Haenszel analysis.Results: Increased IMT was diagnosed in 238 participants (15 %) and 328 (20 %) developed arteriosclerosis after 5 years of follow-up. Logistic regression analysis identified fasting insulin, BMI and smoking as risk factors for both cardiovascular endpoints (all p < 0.05), whereas age and diastolic blood pressure were risk factors for increased IMT only, and male sex was associated with incident arteriosclerosis only (all p < 0.01). Additional adjustment for BMI change during follow-up did not modify these associations (including fasting insulin), but adjustment for fasting insulin change during follow-up removed BMI as risk factor for both cardiovascular endpoints. Fasting insulin change during follow-up but not BMI change associated with increased IMT and arteriosclerosis (both p < 0.001). ARR analysis indicated that high fasting insulin and BMI added to age and sex as risk factors. Homeostatic model assessment of insulin resistance (HOMA-IR) did not associate with either cardiovascular endpoint in any model and smoking did not increase the risk conferred by high fasting insulin levels.Conclusions: Higher fasting insulin levels and increases in fasting insulin over time are associated with atherogenic progression and supersede BMI as well as HOMA-IR as risk factors.

Anti-Müllerian Hormone Accelerates Pathological Process of Insulin Resistance in Polycystic Ovary Syndrome Patients.

Insulin resistance (IR) is one of the most common features of polycystic ovary syndrome (PCOS), which is related to obesity. Whether increased anti-Müllerian hormone (AMH) levels in PCOS are involved in the pathogenesis of insulin resistance remains unclear. We investigated serum levels of leptin and AMH along with basic clinical and metabolic parameters in 114 PCOS patients and 181 non-PCOS women. PCOS patients presented higher fasting blood glucose, insulin concentrations and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) in addition to body mass index (BMI), lipids profiles and hormone levels. HOMA-IR showed a positive correlation with BMI, AMH, leptin, and low-density lipoprotein-cholesterol (LDL-c) levels. Interestingly, AMH is strongly positively correlated with HOMA-IR and insulin concentrations for 1st and 2nd hours of glucose treatment after fasting. Among PCOS women with BMI≥25 kg/m2, high AMH level group showed an increased HOMA-IR when compared to normal AMH level. However, among PCOS women with normal BMI, women with high AMH presented an elevated fasting insulin levels but not HOMA-IR when compared to normal AMH group. In vitro treatment of isolated islet cells with high concentration of leptin (200 ng/ml) or high leptin plus high concentration of AMH (1 ng/ml) significantly enhanced insulin secretion. Importantly, co-treatment of AMH plus leptin upregulates the expression of pro-apoptotic proteins, such as Bax, caspase-3, and caspase-8 after incubating with a high level of glucose. These results suggest that AMH may involve in the pathological process of pancreatic β-cells in obese PCOS women.

“The Unusual Suspect” - Insulin Autoimmune Syndrome, an Extremely Rare Cause of Hypoglycemia

Background: Insulin autoimmune syndrome (IAS), also called Hirata syndrome, is a rare diagnosis which is characterized by hypoglycemia, normal or elevated fasting insulin level, and elevated anti-insulin antibody titers. Clinical Case: 45-year-old nondiabetic Caucasian female presented to the emergency department (ED) with chief complaint of near-syncope. She reported difficulty concentrating and feeling faint roughly 1 hour after consuming breakfast. Upon ED arrival, fingerstick glucose (FSG) was 47 mg/dL. Her symptoms resolved with ingestion of orange juice and repeat blood glucose (BG) 15 minutes later was 120 mg/dL. She reported similar symptoms in the last 5 years happening “every few months” without a predictable pattern; twice with witnessed loss of consciousness. Workup for syncope in the past included normal neurologic, cardiac, and tilt-table testing. She had no prior low FSG/BG recorded, no personal history of bariatric surgery or family history of diabetes mellitus and no access to antihyperglycemic medications. Past medical history included ulcerative colitis and medications included sulfasalazine and multivitamins. Pertinent review of systems was negative for weight loss, nausea, and diarrhea. Vital signs were within normal limits. Physical exam was unremarkable. Height was 165 cm, weight 67.8 kg and body mass index 24.9 kg/m2. Blood draw after overnight fast revealed BG of 78 mg/dL, C-peptide 0.7 ng/mL (ref range 0.8–3.5), insulin 10 µIU/mL (3–19), proinsulin <1.6 pmol/L (<8.0), insulin-like growth factor-2 (IGF-2) 339 ng/mL (180–580) and insulin antibody level 10.0 U/mL (0.0–0.4). She was managed conservatively with frequent small meals and patient has continued to do well without recurrence of symptoms. Conclusion: IAS is an exceedingly rare disease entity with about 460 cases described in literature, mostly in patients of Asian descent. Workup for hypoglycemia in non-diabetic patients should include insulin antibody titers to rule out IAS. There appears to be a genetic predisposition to developing IAS in patients with major histocompatibility complex (MHC) genes HLA-DQA1, HLA-DQB1 and HLA-DRB1. It is now being more frequently described in patients of non-Asian descent, particularly those with other autoimmune or plasma cell dyscrasias. It is also associated with drugs containing sulfhydryl groups and viral infections. Treatment should be tailored to severity of disease. Most drug induced IAS resolves after cessation of culprit drug. Conservative management is usually the first step with frequent, low carbohydrate meals with diazoxide or octreotide as adjunctive options. Immunosuppression (high-dose prednisolone or rituximab) and plasma exchanged are reserved severe or refractory cases.

Protocatechuic acid improves hepatic insulin resistance and restores vascular oxidative status in type-2 diabetic rats

This work explored influences of protocatechuic acid (PCA) on type 2 diabetes (T2D)-associated hepatic insulin resistance and other metabolic, hepatic and vascular irregularities using the rat model of high fat diet (HFD)+high fructose+low dose streptozotocin (STZ).Twenty-four male Wister rats were used. Twelve rats were ad libitum supplied with HFD and high fructose drinking water (25 % w/v) for 60 days. On day 30, they received a single injection of STZ (35 mg/kg, i.p). On day 32, they were divided into two subgroups (n = 6/each): T2D + PCA, received PCA (100 mg/kg/day, orally) and T2D, received PCA vehicle till the end of experiment. Rats provided with regular diet and fructose-free drinking water, with or without PCA treatment, served as PCA and control groups (n = 6/each), respectively.PCA treatment significantly reduced the elevated levels of fasting glycemia and insulin, AUCOGTT, AUCITT, and HOMA-IR index, while it boosted HOMA-β and insulinogenic index values in T2D rats. PCA ameliorated serum lipid levels and hepatic function parameters and mitigated hepatosteatosis in T2D rats. Mechanistically, PCA mitigated hepatic lipid peroxidation and restored reduced glutathione (GSH) and superoxide dismutase (SOD) to near-normal levels. Moreover, PCA enhanced hepatic protein levels of P-AKTser473 and hepatic mRNA expression of insulin receptor substrate 1 (IRS1), phosphatidylinositol 3 kinase (PI3K)-p85 and AKT2.Furthermore, PCA ameliorated aortic oxidative stress in T2D rats, possibly via reducing serum levels of advanced glycation end products (AGEs) and diminishing vascular expression of RAGE and NOX4 mRNA.Collectively, PCA may improve hepatic insulin resistance and vascular oxidative status by modulating IRS1/PI3K/AKT2 and AGE-RAGE-NOX4 pathways, respectively.

Maternal exposure to phenanthrene during gestation disturbs glucose homeostasis in adult mouse offspring

Epidemiological studies have indicated that polycyclic aromatic hydrocarbons were related to diabetes and insulin resistance. However, studies in mammals on the development of diabetes caused by polycyclic aromatic hydrocarbons are lacking. Pregnant mice were orally exposed to phenanthrene (0, 60 and 600 μg kg−1 body weight) once every 3 days during gestation. In adult mouse offspring, in-utero phenanthrene exposure caused glucose intolerance and decreased insulin levels in females, while caused elevated fasting blood glucose and insulin levels in males. Serum resistin and interleukin-6 levels were elevated in offspring of both sexes. Serum adiponectin levels were decreased in females but increased in males. The insulin receptor signals were upregulated in the liver and downregulated in the skeletal muscle of F1 females, while they were inhibited in both tissues of F1 males. The visceral fat weight and body weight of the treated mice were not increased, suggesting that phenanthrene is not an obesogen, which is supported by the nonsignificant alteration in pparγ transcription in visceral adipose tissue. The transcription of retn in visceral adipose tissue was upregulated in both sexes, and that of adipoq was downregulated in females but upregulated in males, which were matched with the promoter methylation levels of these genes. The results indicated that phenanthrene exposure during gestation could disturb adipocytokine levels via epigenetic modification in adult offspring, and further influence glucose metabolism. These results might be helpful for understanding nonobesogenic pollutant-induced insulin resistance and preventing against diabetes without obesity.

Caloric restriction recovers impaired β-cell-β-cell gap junction coupling, calcium oscillation coordination, and insulin secretion in prediabetic mice.

Caloric restriction can decrease the incidence of metabolic diseases, such as obesity and Type 2 diabetes mellitus. The mechanisms underlying the benefits of caloric restriction involved in insulin secretion and glucose homeostasis are not fully understood. Intercellular communication within the islets of Langerhans, mediated by Connexin36 (Cx36) gap junctions, regulates insulin secretion dynamics and glucose homeostasis. The goal of this study was to determine whether caloric restriction can protect against decreases in Cx36 gap junction coupling and altered islet function induced in models of obesity and prediabetes. C57BL6 mice were fed with a high-fat diet (HFD), showing indications of prediabetes after 2 mo, including weight gain, insulin resistance, and elevated fasting glucose and insulin levels. Subsequently, mice were submitted to 1 mo of 40% caloric restriction (2 g/day of HFD). Mice under 40% caloric restriction showed reversal in weight gain and recovered insulin sensitivity, fasting glucose, and insulin levels. In islets of mice fed the HFD, caloric restriction protected against obesity-induced decreases in gap junction coupling and preserved glucose-stimulated calcium signaling, including Ca2+ oscillation coordination and oscillation amplitude. Caloric restriction also promoted a slight increase in glucose metabolism, as measured by increased NAD(P)H autofluorescence, as well as recovering glucose-stimulated insulin secretion. We conclude that declines in Cx36 gap junction coupling that occur in obesity can be completely recovered by caloric restriction and obesity reversal, improving Ca2+ dynamics and insulin secretion regulation. This suggests a critical role for caloric restriction in the context of obesity to prevent islet dysfunction.

Stress of life events and anxiety as mediators of the association between insomnia and triglycerides in college students

Purpose This study examined interrelationships among insomnia, stress, anxiety, and metabolic risk factors. Methods: A total of 124 college students were included in the analysis (age = 21 ± 1 years). Insomnia, stress of life events, and anxiety were assessed using self-reported questionnaires. Fasting blood samples were assayed for glucose, insulin, total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-cholesterol), and low-density lipoprotein cholesterol (LDL-cholesterol). Results: Insomnia was positively associated with stress of life events (β = 0.28, p < .001) and anxiety (β = 0.46, p < .001). Insomnia was related to elevated fasting insulin (β = 0.12, p = .04) and triglyceride level (β = 1.85, p < .001). An inverse association was found between insomnia and HDL-cholesterol (β = −0.45, p = .03). Sobel's test for mediation showed that stress of life events (p = .020) and anxiety (p = .013) mediated the relationship between insomnia and hypertriglyceridemia. Conclusions: Reducing stress and anxiety among college students with insomnia may influence subsequent cardiovascular health.

The role of impaired glucose and lipid metabolism and liver enzyme abnormalities in the formation of multiple acrochordons: a case-control study

Background Acrochordons, one of skin tumors, are protrusions of the loose fibrous tissue. In various studies, they have found to be associated with abnormal lipid profile, diabetes, cardiovascular disease, obesity, abnormal liver enzymes and genetic factors. In our case-control study, we aimed to determine possible associations of multiple acrochordons with obesity, impaired glucose and lipid metabolism, thyroid disorders, anemia and liver enzymes abnormalities.Methods Sixty-five patients (32 male, 33 female) with at least 8 skin tags and age- and gender-matched 60 controls without skin tags (30 male, 30 female) were enrolled to the study. We noted patients’ and controls’ age, height, weight, body mass index (BMI) and detailed medical history. Locations of acrochordons were recorded for the patient group. We recorded values of fasting plasma glucose, insulin, homeostatic model assessment insulin resistance (HOMA-IR), total cholesterol, triglyceride, high-density lipoprotein (HDL), low-density lipoprotein (LDL), free T3 (fT3), free T4 (fT4), thyroid-stimulating hormone (TSH), hemoglobin, ferritin, vitamin B12, aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP).Results Our study has shown a genetic predisposition to the development of multiple skin tags (P=0.0001). The mean BMI was statistically significant between the patients and controls (P&amp;lt;0.0001). In addition, we have found that when fasting plasma glucose, AST and GGT levels increase, the possibility of the forming of multiple acrochordons also increases (P=0.048, P=0.003, P=0.013). We determined that increasing of BMI is a risk factor for both genders (P=0.003, P&amp;lt;0.0001, respectively). We found that elevated fasting plasma glucose, insulin, HOMA-IR, total cholesterol, triglyceride, AST, ALT and GGT levels increase possibility of the forming of multiple acrochordons in females (P=0.037, P=0.022, P=0.013, P=0.03, P=0.007, P&amp;lt;0.0001, P=0.015, P=0.005, respectively).Conclusion Our results show that multiple acrochordons may be the cutaneous signs of abnormal glucose and lipid metabolism and liver enzyme abnormalities. Thus, we suggest that clinicians should see appropriate bloodtests for patients with multiple skin tags and manage them accordingly.