Banting Lecture. From the triumvirate to the ominous octet: a new paradigm for the treatment of type 2 diabetes mellitus

Clinical association and diagnostic significance of miRNA-29a and miRNA-147b in type 2 diabetes mellitus

Background: Micro RNAs (miRs) expression is involved in the pathogenesis of type 2 diabetes mellitus (T2DM). This study investigates the expression levels of plasma miR-29a, miR-146a, and miR-147b and their correlations with clinical parameters in patients with T2DM. Methods: 105 patients with T2DM who categorized either as newly diagnosed T2DM (n=52) or treated T2DM (n=53) and 93 healthy individuals were included in this study. The expression levels of miR-29a, miR-146a, and miR-147b were quantified by real-time PCR and analyzed for possible association with T2DM. Results: The expressions of miR-29a and miR-147b were significantly increased in T2DM patients compared with healthy controls (P<0.0001). The expression levels of miR-29a in newly diagnosed T2DM patients were higher than that in the group of treated T2DM (P=0.002). The expression of studied miRs was correlated with several clinical parameters such as blood glucose levels, HbA1C, microalbuminuria, C-peptide, triglyceride levels as well as the HOMA-β index. The expression levels of miR-29a and miR-147b show a potential diagnostic performance to discriminate newly diagnostic T2DM (AUCs=0.77 and 0.84, respectively) and beta-cell dysfunction (AUCs= 0.62 and 0.75, respectively). Conclusions: The plasma miR-29a and miR-147b expression levels in T2DM patients are significantly associated with T2DM while miR-146a shows poor evidence in relation to T2DM. miR-147b shows potential as a biomarker for the diagnosis of T2DM and pancreatic beta cell dysfunction.

Brain Dopamine-Clock Interactions Regulate Cardiometabolic Physiology: Mechanisms of the Observed Cardioprotective Effects of Circadian-Timed Bromocriptine-QR Therapy in Type 2 Diabetes Subjects

Despite enormous global efforts within clinical research and medical practice to reduce cardiovascular disease(s) (CVD), it still remains the leading cause of death worldwide. While genetic factors clearly contribute to CVD etiology, the preponderance of epidemiological data indicate that a major common denominator among diverse ethnic populations from around the world contributing to CVD is the composite of Western lifestyle cofactors, particularly Western diets (high saturated fat/simple sugar [particularly high fructose and sucrose and to a lesser extent glucose] diets), psychosocial stress, depression, and altered sleep/wake architecture. Such Western lifestyle cofactors are potent drivers for the increased risk of metabolic syndrome and its attendant downstream CVD. The central nervous system (CNS) evolved to respond to and anticipate changes in the external (and internal) environment to adapt survival mechanisms to perceived stresses (challenges to normal biological function), including the aforementioned Western lifestyle cofactors. Within the CNS of vertebrates in the wild, the biological clock circuitry surveils the environment and has evolved mechanisms for the induction of the obese, insulin-resistant state as a survival mechanism against an anticipated ensuing season of low/no food availability. The peripheral tissues utilize fat as an energy source under muscle insulin resistance, while increased hepatic insulin resistance more readily supplies glucose to the brain. This neural clock function also orchestrates the reversal of the obese, insulin-resistant condition when the low food availability season ends. The circadian neural network that produces these seasonal shifts in metabolism is also responsive to Western lifestyle stressors that drive the CNS clock into survival mode. A major component of this natural or Western lifestyle stressor-induced CNS clock neurophysiological shift potentiating the obese, insulin-resistant state is a diminution of the circadian peak of dopaminergic input activity to the pacemaker clock center, suprachiasmatic nucleus. Pharmacologically preventing this loss of circadian peak dopaminergic activity both prevents and reverses existing metabolic syndrome in a wide variety of animal models of the disorder, including high fat-fed animals. Clinically, across a variety of different study designs, circadian-timed bromocriptine-QR (quick release) (a unique formulation of micronized bromocriptine-a dopamine D2 receptor agonist) therapy of type 2 diabetes subjects improved hyperglycemia, hyperlipidemia, hypertension, immune sterile inflammation, and/or adverse cardiovascular event rate. The present review details the seminal circadian science investigations delineating important roles for CNS circadian peak dopaminergic activity in the regulation of peripheral fuel metabolism and cardiovascular biology and also summarizes the clinical study findings of bromocriptine-QR therapy on cardiometabolic outcomes in type 2 diabetes subjects.

Gluconeogenesis Flux in Metabolic Disease

Gluconeogenesis is a critical biosynthetic process that helps maintain whole-body glucose homeostasis and becomes altered in certain medical diseases. We review gluconeogenic flux in various medical diseases, including common metabolic disorders, hormonal imbalances, specific inborn genetic errors, and cancer. We discuss how the altered gluconeogenic activity contributes to disease pathogenesis using data from experiments using isotopic tracer and spectroscopy methodologies. These in vitro, animal, and human studies provide insights into the changes in circulating levels of available gluconeogenesis substrates and the efficiency of converting those substrates to glucose by gluconeogenic organs. We highlight ongoing knowledge gaps, discuss emerging research areas, and suggest future investigations. A better understanding of altered gluconeogenesis flux may ultimately identify novel and targeted treatment strategies for such diseases.

HIV infection in adult Ugandans with new-onset type 2 diabetes: exploring its influence on the anthropometric and metabolic profile

OBJECTIVE

HIV infection increases the risk of type 2 diabetes and may influence its phenotypic profile. In this study, we aimed to compare the anthropometric and metabolic characteristics of HIV-infected and uninfected adult Ugandans with new-onset type 2 diabetes to evaluate the influence of HIV infection on specific surrogate markers of adiposity, insulin resistance, and pancreatic beta-cell function.

METHODS

We consecutively recruited 500 HIV-infected and uninfected adult Ugandans with new-onset type 2 diabetes (diagnosed in < 3 months) from seven tertiary hospitals over a 20-month period and compared their anthropometric and metabolic characteristics to identify any significant differences.

RESULTS

Of the 500 participants with new-onset type 2 diabetes, 59 (11.8%) had a self-reported history of HIV infection. Compared with HIV-uninfected participants with type 2 diabetes, participants with HIV infection and type 2 diabetes had a lower median (IQR) hip circumference (97.8 [91.0-106.0] cm vs. 104.0 [96.0-112.0], p = 0.002) and visceral fat level (8 [6-11] vs. 10 [7-12], p < 0.001) assessed using bioimpedance analysis. No statistically significant difference was noted with the markers of pancreatic beta-cell function (fasting, 30-minute, and 120-minute C-peptide concentrations, oral insulinogenic index, and homeostatic model assessment 2-beta cell function) and insulin resistance (homeostatic model assessment 2-insulin resistance) between both groups.

CONCLUSION

In our study population, HIV infection was not associated with increased adiposity, pancreatic beta-cell function, and insulin resistance. Large prospective studies are needed to investigate the effect of HIV on the pathogenesis of type 2 diabetes in adult Ugandans.

Exercise Prescription Principles among Physicians and Physical Therapists for Patients with Impaired Glucose Control: A Cross-Sectional Study

Exercise confers a multitude of benefits with limited adverse side effects, making it a powerful "medication" for a plethora of diseases. In people living with uncontrolled glucose levels, exercise can be an effective "medication" to assist in the management of hyperglycemia. We sought to survey healthcare providers (physicians and physical therapists) to determine the current state of exercise recommendation for people with glucose control issues. Healthcare providers were surveyed from six academic medical centers in the Midwest to determine the recommended exercise parameters (type, frequency, duration, intensity, and timing) for patients with glucose control issues. Data from 209 practitioners who completed the survey were used for analysis. Chi-square tests were used to determine differences in exercise recommendations between physical therapists (PTs) and physicians (MD/DOs). PTs and MD/DOs recommended similar exercise parameters. Of all respondents, 78.9% recommended exercise to patients with glucose control issues. Respondents who considered themselves to be active exercisers were more likely to recommend exercise than those who were not exercisers. Only 6.1% of all respondents recommended post-meal exercise. Healthcare providers overwhelmingly recommended exercise for people with glucose control issues, but the "timing" is not congruent with best practice recommendations.

Insulin and the kidneys: a contemporary view on the molecular basis

Insulin is a hormone that is composed of 51 amino acids and structurally organized as a hexamer comprising three heterodimers. Insulin is the central hormone involved in the control of glucose and lipid metabolism, aiding in processes such as body homeostasis and cell growth. Insulin is synthesized as a large preprohormone and has a leader sequence or signal peptide that appears to be responsible for transport to the endoplasmic reticulum membranes. The interaction of insulin with the kidneys is a dynamic and multicenter process, as it acts in multiple sites throughout the nephron. Insulin acts on a range of tissues, from the glomerulus to the renal tubule, by modulating different functions such as glomerular filtration, gluconeogenesis, natriuresis, glucose uptake, regulation of ion transport, and the prevention of apoptosis. On the other hand, there is sufficient evidence showing the insulin receptor's involvement in renal functions and its responsibility for the regulation of glucose homeostasis, which enables us to understand its contribution to the insulin resistance phenomenon and its association with the progression of diabetic kidney disease.

Role of Growth Hormone in Adipose Tissue Insulin Resistance Amelioration After Bariatric Surgery in Adults with Obesity

Background: Bariatric surgery has a significant effect on weight loss and improves adipose tissue insulin resistance (adipose-IR); however, the underlying mechanism remains unclear. This study aimed to investigate the effect of growth hormone (GH) on adipose-IR improvement after bariatric surgery in patients with obesity. Methods: A prospective cohort study with 1-year follow-up was conducted in the China-Japan Friendship Hospital. Pre- and postoperative variables, including the body mass index (BMI), glucose and lipid metabolic indicators, and the adipose-IR index, were collected and analyzed at baseline and 3, 6, and 12 months after surgery in patients with obesity. Results: In total, seventy-two patients, including 25 males and 47 females, were included in the analysis. Furthermore, bariatric surgery resulted in a sharp decline in BMI (kg/m2) (from 39.45 ± 0.51 to 32.00 ± 0.63 at 3 months, 28.73 ± 0.56 at 6 months, and 27.25 ± 0.68 at 12 months) and adipose-IR index (mmol/L × pmol/L) (from 163.8 ± 9.38 to 94.39 ± 16.63, 43.71 ± 5.13, and 27.92 ± 2.67) and an increase in GH (ng/mL) (from 0.16 ± 0.02 to 0.61 ± 0.10, 1.02 ± 0.19, and 0.89 ± 0.20). Partial correlation analyses were performed with reduced BMI as a control, and elevated GH levels (ΔGH) were found to be positively correlated with reduced adipose-IR (absolute value of Δadipose-IR) index at 3 months (r = 0.413, P = 0.005), 6 months (r = 0.432, P < 0.001), and 12 months (r = 0.375, P = 0.031) after bariatric surgery. Conclusions: Bariatric surgery induces GH elevation and adipose-IR amelioration in patients with obesity. GH might be a potential metabolic regulator associated with adipose-IR improvement in patients with obesity after bariatric surgery.

The Wedding Bells Sound Really Good! iGlarLixi Fixed-Ratio Combination in the Treatment of Type 2 Diabetes: A Narrative Review

iGlarLixi is a fixed-ratio combination of insulin glargine 100 U/mL and lixisenatide used in the treatment of type 2 diabetes. iGlarLixi has proven clinical benefits in terms of glycemia, weight control, and safety, defined by the risk of hypoglycemia. It simultaneously targets many pathophysiologic abnormalities which are at the root of type 2 diabetes and thus presents a complementary mode of action. Finally, it may also address diabetes treatment burden, and, by decreasing the complexity of treatment, it may improve patient adherence and persistence and fight against clinical inertia. This article reviews the results of major randomized controlled trials in people with type 2 diabetes that compared iGlarLixi to other therapeutic regimens, representing different intensification strategies, such as basal supported oral therapy, oral antidiabetic drugs, and a combination of the latter with glucagon-like peptide 1 receptor agonists. Moreover, as a supplement to randomized trials, data from real-world evidence have also been included.

Genetic ablation of synaptotagmin-9 alters tomosyn-1 function to increase insulin secretion from pancreatic β-cells improving glucose clearance

Stimulus-coupled insulin secretion from the pancreatic islet β-cells involves the fusion of insulin granules to the plasma membrane (PM) via SNARE complex formation-a cellular process key for maintaining whole-body glucose homeostasis. Less is known about the role of endogenous inhibitors of SNARE complexes in insulin secretion. We show that an insulin granule protein synaptotagmin-9 (Syt9) deletion in mice increased glucose clearance and plasma insulin levels without affecting insulin action compared to the control mice. Upon glucose stimulation, increased biphasic and static insulin secretion were observed from ex vivo islets due to Syt9 loss. Syt9 colocalizes and binds with tomosyn-1 and the PM syntaxin-1A (Stx1A); Stx1A is required for forming SNARE complexes. Syt9 knockdown reduced tomosyn-1 protein abundance via proteasomal degradation and binding of tomosyn-1 to Stx1A. Furthermore, Stx1A-SNARE complex formation was increased, implicating Syt9-tomosyn-1-Stx1A complex is inhibitory in insulin secretion. Rescuing tomosyn-1 blocked the Syt9-knockdown-mediated increases in insulin secretion. This shows that the inhibitory effects of Syt9 on insulin secretion are mediated by tomosyn-1. We report a molecular mechanism by which β-cells modulate their secretory capacity rendering insulin granules nonfusogenic by forming the Syt9-tomosyn-1-Stx1A complex. Altogether, Syt9 loss in β-cells decreases tomosyn-1 protein abundance, increasing the formation of Stx1A-SNARE complexes, insulin secretion, and glucose clearance. These outcomes differ from the previously published work that identified Syt9 has either a positive or no effect of Syt9 on insulin secretion. Future work using β-cell-specific deletion of Syt9 mice is key for establishing the role of Syt9 in insulin secretion.

The Incidence and Management of Type 2 Diabetes Mellitus After Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) refers to a transient state of impaired glucose tolerance that develops during pregnancy, affecting a significant proportion of expectant mothers globally. This review aimed to comprehensively examine the subsequent incidence and management of type 2 diabetes mellitus (T2DM) in women who have previously experienced GDM. The transition from GDM to T2DM is a well-recognized continuum, with affected women facing an increased risk of developing T2DM postpartum. Several studies have demonstrated that women with a history of GDM face a substantially higher risk of developing T2DM compared to normoglycemic pregnant women. The long-term consequences of developing T2DM following GDM are significant, as it not only affects the health of the mother but also poses risks to the offspring. The most common risk factors associated with the progression of GDM to T2DM include pregnancy at an advanced age, insulin treatment during pregnancy, and delivering an overweight baby. As GDM women are at higher risk of developing T2DM, effective management strategies such as lifestyle changes, postpartum care, breastfeeding, screening tests, and gaining awareness of risk are crucial to mitigate the risk of T2DM in this population. The current review was conducted to guide healthcare providers and women with a history of GDM about the potential risks of T2DM and management strategies to prevent the condition. This review provides a summary of evidence on the incidence rate of T2DM in GDM patients, its associated risk factors, and approaches to mitigate this challenge.

Association between triglyceride-glucose index and low-density lipoprotein particle size in korean obese adults

BACKGROUND

Small dense low-density lipoprotein cholesterol (sdLDL-C) is the lipoprotein marker among the various lipoproteins that is most strongly related to atherosclerosis. Insulin resistance (IR) can alter lipid metabolism, and sdLDL-C is characteristic of diabetic dyslipidemia. Therefore, this study sought to inspect the relationship between the triglyceride-glucose (TyG) index and mean low-density lipoprotein (LDL) particle size.

METHODS

In this study, a total of 128 adults participated. The correlation coefficients between various lipoproteins and the TyG index were compared using Steiger's Z test and the Spearman correlation. The independent link between the TyG index and mean LDL particle size was demonstrated by multiple linear regression analysis. To identify the TyG index cutoff value for the predominance of sdLDL particles, receiver operating characteristic curves were plotted.

RESULTS

Mean LDL particle size correlated more strongly with the TyG index than did very low-density lipoprotein, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol. Regression analysis demonstrated that mean LDL particle size had a strong association with the TyG index (β coefficient = -0.038, P-value < 0.001). The TyG index optimal cutoff value for sdLDL particle predominance and the corresponding area under the curve (standard error: 0.028, 95% confidence interval: 0.842-0.952) were 8.72 and 0.897, respectively, which were close to the cutoff value of diabetes risk in Koreans.

CONCLUSIONS

Mean LDL particle size is more strongly correlated with the TyG index than do other lipid parameters. After correcting for confounding variables, mean LDL particle size is independently linked with the TyG index. The study indicates that the TyG index is strongly related to atherogenic sdLDL particles predominance.

Fixed-Dose Combination of Dapagliflozin + Sitagliptin + Metformin in Patients with Type 2 Diabetes Poorly Controlled with Metformin: Phase 3, Randomized Comparison with Dual Combinations

INTRODUCTION

This study compared efficacy and safety of triple drug fixed-dose combination (FDC) of dapagliflozin (DAPA) + sitagliptin (SITA) + metformin (MET) extended release (ER) with SITA + MET sustained release (SR) and DAPA + MET ER in patients with type 2 diabetes poorly controlled with metformin.

METHODS

This phase 3, randomized, open-label, active-controlled study included adult patients with glycated hemoglobin (HbA1c) ≥ 8% (64 mmol/mol) and ≤ 11% (97 mmol/mol), randomized in 1:1:1 ratio to receive either FDC of DAPA + SITA + MET ER (10 mg + 100 mg + 1000 mg) tablets once daily (n = 137) or co-administration of SITA + MET SR (100 mg + 1000 mg) tablets once daily (n = 139) or FDC of DAPA + MET ER (10 mg + 1000 mg) tablets once daily (n = 139). Primary endpoint was mean change in HbA1c from baseline to week 16.

RESULTS

Mean baseline HbA1c was approximately 9% (75 mmol/mol) in each treatment group. At week 16, adjusted mean reduction in HbA1c from baseline was significantly greater with DAPA + SITA + MET ER (- 1.73% [- 19.0 mmol/mol]) compared to SITA + MET SR (- 1.28% [- 14.1 mmol/mol]; difference of - 0.46% [- 5.1 mmol/mol], p < 0.001) and DAPA + MET ER (- 1.33% [- 14.6 mmol/mol]; difference - 0.4% [4.4 mmol/mol], p < 0.001). Similarly, at week 12, reduction in HbA1c from baseline was significantly greater with DAPA + SITA + MET ER compared to SITA + MET SR (p = 0.0006) and DAPA + MET ER (p = 0.0276). At week 16, DAPA + SITA + MET ER showed significant reduction in postprandial blood glucose compared to DAPA + MET ER (p = 0.0394) and significant reduction in fasting blood glucose with DAPA + SITA + MET ER compared to SITA + MET SR (p = 0.0226). The proportion of patients achieving HbA1c < 7.0% (53 mmol/mol) at week 16 was significantly higher with DAPA + SITA + MET ER (38.5%) versus SITA + MET SR (12.8%) (p < 0.001) and DAPA + MET ER (21.3%) (p = 0.0023). All study medications were well tolerated.

CONCLUSION

Triple FDC of DAPA + SITA + MET ER tablets once daily was significantly better in achieving glycemic control versus dual combination once daily in patients with type 2 diabetes poorly controlled with metformin without any significant safety concerns.

TRIAL REGISTRATION

CTRI/2021/11/038176, registered on 22 November 2021.

Metabolic and renal outcomes of empagliflozin in patients with type 2 diabetes mellitus attending Armed Forces Hospital in Saudi Arabia: Retrospective cohort study

OBJECTIVES

To explore the effects of empagliflozin (25 mg) on metabolic and renal parameters in patients with type 2 diabetes mellitus (T2DM).

METHODS

This retrospective observational comparative study was conducted at a military hospital in southern Saudi Arabia. All adults (aged >18 years) with T2DM who attended diabetic clinics between October 2021 to March 2022 (6 months), with or without insulin treatment, were eligible for inclusion in the study.

RESULTS

Following the initiation of empagliflozin treatment, statistically significant reductions in patient weight (kg) were observed at 1, 3-5, and 6 months. In addition, low-density lipoprotein levels significantly decreased 3-5 months post-treatment initiation (p=0.011). However, serum creatinine level decreased gradually with time during the treatment with empagliflozin, from 87.45±31.78 (0.105) to 78.39±27.43 (0.033). Furthermore, after empagliflozin treatment, the urinary albumin-to-creatinine ratio significantly decreased at 3-5 and 6 months. Moreover, HbA1c levels exhibited statistically significant decreases at 3-5 months (p<0.001) and at 6 months (p<0.001) following the initiation of empagliflozin treatment. Notably, systolic and diastolic blood pressure significantly reduced 6 months after empagliflozin treatment.

CONCLUSION

In the current study, empagliflozin has demonstrated efficacy in controlling blood pressure and body weight, and improving renal function, short-term dyslipidemia, and glycemic control in patients with T2DM.

Global Prevalence of Prediabetes

OBJECTIVE

To estimate the global, regional, and national prevalence of prediabetes, defined by impaired glucose tolerance (IGT) or impaired fasting glucose (IFG).

RESEARCH DESIGN AND METHODS

We reviewed 7,014 publications for high-quality estimates of IGT (2-h glucose, 7.8-11.0 mmol/L [140-199 mg/dL]) and IFG (fasting glucose, 6.1-6.9 mmol/L [110-125 mg/dL]) prevalence for each country. We used logistic regression to generate prevalence estimates for IGT and IFG among adults aged 20-79 years in 2021 and projections for 2045. For countries without in-country data, we extrapolated estimates from countries with available data with similar geography, income, ethnicity, and language. Estimates were standardized to the age distribution for each country from the United Nations.

RESULTS

Approximately two-thirds of countries did not have high-quality IGT or IFG data. There were 50 high-quality studies for IGT from 43 countries and 43 high-quality studies for IFG from 40 countries. Eleven countries had data for both IGT and IFG. The global prevalence of IGT in 2021 was 9.1% (464 million) and is projected to increase to 10.0% (638 million) in 2045. The global prevalence of IFG in 2021 was 5.8% (298 million) and is projected to increase to 6.5% (414 million) in 2045. The 2021 prevalence of IGT and IFG was highest in high-income countries. In 2045, the largest relative growth in cases of IGT and IFG would be in low-income countries.

CONCLUSIONS

The global burden of prediabetes is substantial and growing. Enhancing prediabetes surveillance is necessary to effectively implement diabetes prevention policies and interventions.

Cardiovascular and Renal Outcomes With Sodium-Glucose Cotransporter-2 Inhibitors and Dipeptidyl Peptidase-4 Inhibitors Combination Therapy: A Meta-Analysis of Randomized Cardiovascular Outcome Trials

OBJECTIVE

The cardiovascular (CV) and renal benefits of sodium-glucose cotransporter-2 inhibitors (SGLT2i) in people with type 2 diabetes are well known. However, similar beneficial effects of SGLT2i in combination with dipeptidyl peptidase-4 inhibitors (DPP4i) are unknown. It is of interest to explore a trial-level meta-analysis to fill this knowledge gap.

METHODS

A literature search was conducted in the PubMed and Embase databases until January 31, 2023. All CV outcome trials (CVOTs) reporting the CV and renal outcomes of SGLT2i with or without background DPP4i therapy against the placebo were retrieved. A meta-analysis was subsequently conducted by applying the inverse variance-weighted averages of pooled logarithmic hazard ratio using primarily random-effects analysis.

RESULTS

This meta-analysis showed that the beneficial 3-point major adverse cardiovascular events composite (3 CVOTs; N = 32 418), the composite of CV death or heart failure hospitalization (hHF) (4 CVOTs; N = 37 687), hHF (3 CVOTs; N = 27 545), CV death (4 CVOTs; N = 34 565), and renal outcomes (2 CVOTs; N = 25 406) with SGLT2i were similar with or without background DPP4i therapy against the placebo (Pheterogeneity = .71, .07, .87, .72, and .25; respectively). However, against the placebo, the summary estimates for the 3-point major adverse cardiovascular events composite, hHF, and renal outcomes were stronger with SGLT2i alone, whereas the summary estimates for CV death or hHF composite were larger with SGLT2i with background DPP4i therapy.

CONCLUSION

Beneficial CV and renal effects of SGLT2i are similar against the placebo regardless of background DPP4i therapy.

Noncanonical Regulation of cAMP-Dependent Insulin Secretion and Its Implications in Type 2 Diabetes

Impaired glucose tolerance (IGT) and β-cell dysfunction in insulin resistance associated with obesity lead to type 2 diabetes (T2D). Glucose-stimulated insulin secretion (GSIS) from β-cells occurs via a canonical pathway that involves glucose metabolism, ATP generation, inactivation of K ATP channels, plasma membrane depolarization, and increases in cytosolic concentrations of [Ca 2+ ] c . However, optimal insulin secretion requires amplification of GSIS by increases in cyclic adenosine monophosphate (cAMP) signaling. The cAMP effectors protein kinase A (PKA) and exchange factor activated by cyclic-AMP (Epac) regulate membrane depolarization, gene expression, and trafficking and fusion of insulin granules to the plasma membrane for amplifying GSIS. The widely recognized lipid signaling generated within β-cells by the β-isoform of Ca 2+ -independent phospholipase A 2 enzyme (iPLA 2 β) participates in cAMP-stimulated insulin secretion (cSIS). Recent work has identified the role of a G-protein coupled receptor (GPCR) activated signaling by the complement 1q like-3 (C1ql3) secreted protein in inhibiting cSIS. In the IGT state, cSIS is attenuated, and the β-cell function is reduced. Interestingly, while β-cell-specific deletion of iPLA 2 β reduces cAMP-mediated amplification of GSIS, the loss of iPLA 2 β in macrophages (MØ) confers protection against the development of glucose intolerance associated with diet-induced obesity (DIO). In this article, we discuss canonical (glucose and cAMP) and novel noncanonical (iPLA 2 β and C1ql3) pathways and how they may affect β-cell (dys)function in the context of impaired glucose intolerance associated with obesity and T2D. In conclusion, we provide a perspective that in IGT states, targeting noncanonical pathways along with canonical pathways could be a more comprehensive approach for restoring β-cell function in T2D. © 2023 American Physiological Society. Compr Physiol 13:5023-5049, 2023.

The role of TyG index in predicting the incidence of diabetes in Chinese elderly men: a 20-year retrospective study

Background

The triglyceride glucose index (TyG index) has been regarded as a reliable surrogate marker of insulin resistance and an independent predictor of diabetes. However, few studies have reported the association between the TyG index and diabetes in the elderly population. Accordingly, this study aimed to investigate the association between the TyG index and diabetes progression in elderly Chinese.

Methods

Baseline medical history, fasting plasma glucose (FPG), glucose levels during the oral glucose tolerance test (OGTT) after 1-hour (1h-PG) and 2-hour (2h-PG), and triglyceride (TG) were obtained from a cohort of 862 elderly (aged ≥ 60 years) Chinese in the Beijing urban area between 1998 and 1999. A follow-up visit was conducted between 1998 and 2019 to assess incident diabetes. TyG index was calculated by the following formula ln[TG (mg/dL) × FPG (mg(dL)/2]. The predictive values of TyG index, lipids, and glucose levels during OGTT were assessed alone and also in a clinical prediction model comprising traditional risk factors using concordance index (C-index). Areas under the receiver operating characteristics curves (AUC) and 95% CIs were calculated.

Results

After 20 years of follow-up, there were 544 cases of incident type 2 diabetes mellitus (63.1% of incidence). The multivariable HRs (95% CI) for TyG index, FPG, 1h-PG and 2h-PG, high-density lipoprotein-cholesterol (HDL-c), and TG were 1.525 (1.290-1.804), 1.350 (1.181-1.544), 1.337 (1.282-1.395), 1.401 (1.327-1.480), 0.505 (0.375-0.681), and 1.120 (1.053-1.192), respectively. The corresponding C-index were 0.623, 0.617, 0.704, 0.694, 0.631, and 0.610, respectively. The AUC (95% CI) for the TyG index, FPG, 1h-PG, 2h-PG, HDL-c, and TG were 0.608 (0.569-0.647), 0.587 (0.548-0.625), 0.766 (0.734-0.797), 0.713 (0.679-0.747), 0.397 (0.358-0.435), and 0.588 (0.549-0.628). The AUC of the TyG index was higher than that of TG but did not differ with FPG and HDL-c. In addition, the AUCs of 1h-PG and 2h-PG were higher than that of the TyG index.

Conclusions

Elevated TyG index is independently correlated with an increased risk of incident diabetes in the elderly male population, but it is not superior to OGTT 1h-PG and 2h-PG in predicting the risk of diabetes.

Microbiota and Glucidic Metabolism: A Link with Multiple Aspects and Perspectives

The global prevalence of overweight and obesity has dramatically increased in the last few decades, with a significant socioeconomic burden. In this narrative review, we include clinical studies aiming to provide the necessary knowledge on the role of the gut microbiota in the development of diabetic pathology and glucose-metabolism-related disorders. In particular, the role of a certain microbial composition of the fermentative type seems to emerge without a specific link to the development in certain subjects of obesity and the chronic inflammation of the adipose tissues, which underlies the pathological development of all the diseases related to glucose metabolism and metabolic syndrome. The gut microbiota plays an important role in glucose tolerance. Conclusion. New knowledge and new information is presented on the development of individualized therapies for patients affected by all the conditions related to reduced glucose tolerance and insulin resistance.

CETP and SGLT2 inhibitor combination therapy improves glycemic control

Importance

Cholesteryl ester transfer protein (CETP) inhibition has been associated with decreased risk of new-onset diabetes in past clinical trials exploring their efficacy in cardiovascular disease and can potentially be repurposed to treat metabolic disease. Notably, as an oral drug it can potentially be used to supplement existing oral drugs such as sodium-glucose cotransporter 2 (SGLT2) inhibitors before patients are required to take injectable drugs such as insulin.

Objective

To identify whether CETP inhibitors could be used as an oral add-on to SGLT2 inhibition to improve glycemic control.

Design Setting and Participants

2×2 factorial Mendelian Randomization (MR) is performed on the general population of UK Biobank participants with European ancestry.

Exposures

Previously constructed genetic scores for CETP and SGLT2 function are combined in a 2×2 factorial framework to characterize the associations between joint CETP and SGLT2 inhibition compared to either alone.

Main Outcomes and Measures

Glycated hemoglobin and type-2 diabetes incidence.

Results

Data on 233,765 UK Biobank participants suggests that individuals with genetic inhibition of both CETP and SGLT2 have significantly lower glycated hemoglobin levels (mmol/mol) than control (Effect size: -0.136; 95% CI: -0.190 to -0.081; p-value: 1.09E-06), SGLT2 inhibition alone (Effect size: -0.082; 95% CI: -0.140 to -0.024; p-value: 0.00558), and CETP inhibition alone (Effect size: -0.08479; 95% CI: -0.136 to -0.033; p-value: 0.00118). Furthermore, joint CETP and SGLT2 inhibition is associated with decreased incidence of diabetes (log-odds ratio) compared to control (Effect size: -0.068; 95% CI: -0.115 to -0.021; p-value: 4.44E-03) and SGLT2 inhibition alone (Effect size: -0.062; 95% CI: -0.112 to -0.012; p-value: 0.0149).

Conclusions and Relevance

Our results suggest that CETP and SGLT2 inhibitor therapy may improve glycemic control over SGLT2 inhibitors alone. Future clinical trials can explore whether CETP inhibitors can be repurposed to treat metabolic disease and provide an oral therapeutic option to benefit high-risk patients before escalation to injectable drugs such as insulin or glucagon-like peptide 1 (GLP1) receptor agonists.

Genetics of diabetes

Diabetes mellitus is a complicated disease characterized by a complex interplay of genetic, epigenetic, and environmental variables. It is one of the world's fastest-growing diseases, with 783 million adults expected to be affected by 2045. Devastating macrovascular consequences (cerebrovascular disease, cardiovascular disease, and peripheral vascular disease) and microvascular complications (like retinopathy, nephropathy, and neuropathy) increase mortality, blindness, kidney failure, and overall quality of life in individuals with diabetes. Clinical risk factors and glycemic management alone cannot predict the development of vascular problems; multiple genetic investigations have revealed a clear hereditary component to both diabetes and its related complications. In the twenty-first century, technological advancements (genome-wide association studies, next-generation sequencing, and exome-sequencing) have led to the identification of genetic variants associated with diabetes, however, these variants can only explain a small proportion of the total heritability of the condition. In this review, we address some of the likely explanations for this "missing heritability", for diabetes such as the significance of uncommon variants, gene-environment interactions, and epigenetics. Current discoveries clinical value, management of diabetes, and future research directions are also discussed.

Cyanidin-3-O-glucoside as a Nutrigenomic Factor in Type 2 Diabetes and Its Prominent Impact on Health

Type 2 diabetes (T2D) accounts for a global health problem. It is a complex disease as a result of the combination of environmental as well as genetic factors. Morbidity is still increasing across the world. One of the possibilities for the prevention and mitigation of the negative consequences of type 2 diabetes is a nutritional diet rich in bioactive compounds such as polyphenols. This review is focused on cyanidin-3-O-glucosidase (C3G), which belongs to the anthocyanins subclass, and its anti-diabetic properties. There are numerous pieces of evidence that C3G exerts positive effects on diabetic parameters, including in vitro and in vivo studies. It is involved in alleviating inflammation, reducing blood glucose, controlling postprandial hyperglycemia, and gene expression related to the development of T2D. C3G is one of the beneficial polyphenolic compounds that may help to overcome the public health problems associated with T2D.

Rapid Decline in β-Cell Function and Increasing Adiposity Are Associated With Conversion to Type 2 Diabetes in At-Risk Latino Youth

Youth-onset type 2 diabetes (T2D) is becoming increasingly prevalent, especially among Latino youth, and there is limited information on its pathophysiology and causative factors. Here, we describe findings from a longitudinal cohort study in 262 Latino children with overweight/obesity at risk of developing T2D with annual measures of oral and intravenous glucose tolerance (IVGTT), body composition, and fat distribution. Logistic binomial regression was used to identify significant predictors in those who developed T2D compared with matched control participants, and mixed-effects growth models were used to compare rates of change in metabolic versus adiposity measures between groups. Overall conversion rate to T2D at year 5 was 2% (n = 6). Rate of decline in disposition index (DI), measured with an IVGTT, over 5 years was three times higher in case patients (-341.7 units per year) compared with the extended cohort (-106.7 units per year) and 20 times higher compared with control participants (-15.2 units per year). Case patients had significantly higher annual increases in fasting glucose, hemoglobin A1c (HbA1c), waist circumference, and trunk fat, and there was an inverse correlation between rate of decline in DI and rates of increase in adiposity measures. T2D development in at-risk Latino youth is associated with a substantial and rapid decrease in DI that is directly correlated with increases in fasting glucose, HbA1c, and adiposity.

ARTICLE HIGHLIGHTS

Youth-onset type 2 diabetes is becoming increasingly prevalent, especially among Latino youth, and there is limited information on its pathophysiology and causative factors. Overall conversion rate to type 2 diabetes over 5 years was 2%. In youth who converted to type 2 diabetes, disposition index decreased rapidly by 85% compared with that in patients who did not convert during the study period. There was an inverse correlation between rate of decline in disposition index and rates of increase in various adiposity measures.

Diabetes and cirrhosis: Current concepts on diagnosis and management

Type 2 diabetes mellitus is often associated with cirrhosis as comorbidities, acute illness, medications, and other conditions profoundly alter glucose metabolism. Both conditions are closely related in NAFLD, the leading cause of chronic liver disease, and given its rising burden worldwide, management of type 2 diabetes mellitus in cirrhosis will be an increasingly common dilemma. Having diabetes increases cirrhosis-related complications, including HCC as well as overall mortality. In the absence of effective treatments for cirrhosis, patients with type 2 diabetes mellitus should be systematically screened as early as possible for NAFLD-related fibrosis/cirrhosis using noninvasive tools, starting with a FIB-4 index followed by transient elastography, if available. In people with cirrhosis, an early diagnosis of diabetes is critical for an optimal management strategy (ie, nutritional goals, and glycemic targets). Diagnosis of diabetes may be missed if based on A1C in patients with cirrhosis and impaired liver function (Child-Pugh B-C) as anemia may turn the test unreliable. Clinicians must also become aware of their high risk of hypoglycemia, especially in decompensated cirrhosis where insulin is the only therapy. Care should be within multidisciplinary teams (nutritionists, obesity management teams, endocrinologists, hepatologists, and others) and take advantage of novel glucose-monitoring devices. Clinicians should become familiar with the safety and efficacy of diabetes medications for patients with advanced fibrosis and compensated cirrhosis. Management is conditioned by whether the patient has either compensated or decompensated cirrhosis. This review gives an update on the complex relationship between cirrhosis and type 2 diabetes mellitus, with a focus on its diagnosis and treatment, and highlights knowledge gaps and future directions.

Antioxidant action of xanthine oxidase inhibitor febuxostat protects the liver and blood vasculature in SHRSP5/Dmcr rats

BACKGROUND

Xanthine oxidase (XO) generates reactive oxygen species during uric acid production. Therefore, XO inhibitors, which suppress oxidative stress, may effectively treat non-alcoholic steatohepatitis (NASH) and atherosclerosis via uric acid reduction. In this study, we examined the antioxidant effect of the XO inhibitor febuxostat on NASH and atherosclerosis in stroke-prone spontaneously hypertensive 5 (SHRSP5/Dmcr) rats.

METHODS

SHRSP5/Dmcr rats were divided into three groups: SHRSP5/Dmcr + high-fat and high-cholesterol (HFC) diet [control group, n = 5], SHRSP5/Dmcr + HFC diet + 10% fructose (40 ml/day) [fructose group, n = 5], and SHRSP5/Dmcr + HFC diet + 10% fructose (40 ml/day) + febuxostat (1.0 mg/kg/day) [febuxostat group, n = 5]. Glucose and insulin resistance, blood biochemistry, histopathological staining, endothelial function, and oxidative stress markers were evaluated.

RESULTS

Febuxostat reduced the plasma uric acid levels. Oxidative stress-related genes were downregulated, whereas antioxidant factor-related genes were upregulated in the febuxostat group compared with those in the fructose group. Febuxostat also ameliorated inflammation, fibrosis, and lipid accumulation in the liver. Mesenteric lipid deposition decreased in the arteries, and aortic endothelial function improved in the febuxostat group.

CONCLUSIONS

Overall, the XO inhibitor febuxostat exerted protective effects against NASH and atherosclerosis in SHRSP5/Dmcr rats.

Genome-wide association study and functional characterization identifies candidate genes for insulin-stimulated glucose uptake

Distinct tissue-specific mechanisms mediate insulin action in fasting and postprandial states. Previous genetic studies have largely focused on insulin resistance in the fasting state, where hepatic insulin action dominates. Here we studied genetic variants influencing insulin levels measured 2 h after a glucose challenge in >55,000 participants from three ancestry groups. We identified ten new loci (P < 5 × 10-8) not previously associated with postchallenge insulin resistance, eight of which were shown to share their genetic architecture with type 2 diabetes in colocalization analyses. We investigated candidate genes at a subset of associated loci in cultured cells and identified nine candidate genes newly implicated in the expression or trafficking of GLUT4, the key glucose transporter in postprandial glucose uptake in muscle and fat. By focusing on postprandial insulin resistance, we highlighted the mechanisms of action at type 2 diabetes loci that are not adequately captured by studies of fasting glycemic traits.

The diabetogenic effects of pesticides: Evidence based on epidemiological and toxicological studies

While the use of pesticides has improved grain productivity and controlled vector-borne diseases, the widespread use of pesticides has resulted in ubiquitous environmental residues that pose health risks to humans. A number of studies have linked pesticide exposure to diabetes and glucose dyshomeostasis. This article reviews the occurrence of pesticides in the environment and human exposure, the associations between pesticide exposures and diabetes based on epidemiological investigations, as well as the diabetogenic effects of pesticides based on the data from in vivo and in vitro studies. The potential mechanisms by which pesticides disrupt glucose homeostasis include induction of lipotoxicity, oxidative stress, inflammation, acetylcholine accumulation, and gut microbiota dysbiosis. The gaps between laboratory toxicology research and epidemiological studies lead to an urgent research need on the diabetogenic effects of herbicides and current-use insecticides, low-dose pesticide exposure research, the diabetogenic effects of pesticides in children, and assessment of toxicity and risks of combined exposure to multiple pesticides with other chemicals.

Diabetes mellitus type 2 as an underlying, comorbid or consequent state of mental disorders

Somatic disturbances that occur in parallel with psychiatric diseases are a major challenge in clinical practice. Various factors contribute to the development of mental and somatic disorders. Type 2 diabetes mellitus (T2DM) is a significant health burden worldwide, and the prevalence of diabetes in adults is increasing. The comorbidity of diabetes and mental disorders is very common. By sharing a bidirectional link, both T2DM and mental disorders influence each other in various manners, but the exact mechanisms underlying this link are not yet elucidated. The potential mechanisms of both mental disorders and T2DM are related to immune and inflammatory system dysfunction, oxidative stress, endothelial dysfunction, and metabolic disturbances. Moreover, diabetes is also a risk factor for cognitive dysfunction that can range from subtle diabetes-associated cognitive decline to pre-dementia and dementia. A complex re-lationship between the gut and the brain also represents a new therapeutic approach since gut-brain signalling pathways regulate food intake and hepatic glucose production. The aim of this minireview is to summarize and present the latest data on mutual pathogenic pathways in these disorders, emphasizing their complexity and interweaving. We also focused on the cognitive performances and changes in neurodegenerative disorders. The importance of implementing integrated approaches in treating both of these states is highlighted, along with the need for individual therapeutic strategies.

Annona cherimola Miller and Its Flavonoids, an Important Source of Products for the Treatment of Diabetes Mellitus: In Vivo and In Silico Evaluations

The antihyperglycemic activity of ethanolic extract from Annona cherimola Miller (EEAch) and its products were evaluated using in vivo and in silico assays. An α-glucosidase inhibition was evaluated with oral sucrose tolerance tests (OSTT) and molecular docking studies using acarbose as the control. SGLT1 inhibition was evaluated with an oral glucose tolerance test (OGTT) and molecular docking studies using canagliflozin as the control. Among all products tested, EEAc, the aqueous residual fraction (AcRFr), rutin, and myricetin reduced the hyperglycemia in DM2 mice. During the carbohydrate tolerance tests, all the treatments reduced the postprandial peak such as the control drugs. In the molecular docking studies, rutin showed more affinity in inhibiting α-glucosidase enzymes and myricetin in inhibiting the SGLT1 cotransporter, showing ∆G values of -6.03 and -3.32 kcal/mol^-1, respectively, in α-glucosidase enzymes. In the case of the SGLT1 cotransporter, molecular docking showed ∆G values of 22.82 and -7.89 in rutin and myricetin, respectively. This research sorts in vivo and in silico pharmacological studies regarding the use of A. cherimola leaves as a source for the development of new potential antidiabetic agents for T2D control, such as flavonoids rutin and myricetin.

Association of the triglyceride-glucose index with subclinical left ventricular dysfunction in type 2 diabetes mellitus patients: A retrospective cross-sectional study

AIMS/INTRODUCTION

The triglyceride-glucose (TyG) index is a simple and reliable indicator of insulin resistance, and is associated with the development and poor outcomes of cardiovascular disease. Subclinical left ventricular dysfunction (SLVD) is frequently detected in approximately one-third of diabetes patients, but it has not been established whether the TyG index correlates with SLVD. We carried out this research to evaluate the relationship between the TyG index and SLVD in type 2 diabetes mellitus patients.

MATERIALS AND METHODS

This was a cross-sectional and observational study of 183 type 2 diabetes mellitus inpatients at Nanjing Drum Tower Hospital, Nanjing, China. The TyG index and homeostasis model assessment 2 estimates for insulin resistance (HOMA2-IR) were calculated from biochemical measurements, and speckle-tracking echocardiography was carried out. According to global longitudinal strain (GLS) by echocardiography, participants were categorized into the SLVD (GLS <18%) group or the non-SLVD (GLS ≥18%) group.

RESULTS

In comparison with non-SLVD participants, SLVD participants had higher insulin resistance, as reflected by elevated TyG and HOMA2-IR indices, as well as a higher body mass index, waist circumference and triglyceride level (P < 0.05 for each). When grouped by TyG index tertiles, an elevated TyG index was correlated with other cardiometabolic risk factors, as well as a decrease in GLS. In the multivariate logistic regression analyses, the TyG index was an independent risk factor for SLVD in type 2 diabetes mellitus patients (odds ratio 2.047, 95% confidence interval 1.07-3.914, P  = 0.03), whereas HOMA2-IR was not.

CONCLUSIONS

The TyG index is independently associated with SLVD in type 2 diabetes mellitus patients and is a more reliable indicator of SLVD than HOMA2-IR.

Is TNF alpha a mediator in the co-existence of malaria and type 2 diabetes in a malaria endemic population?

Malaria remains a disease of public health importance globally, especially in sub-Saharan Africa. Malaria deaths reduced globally steadily between 2000-2019, however there was a 10% increase in 2020 due to disruptions in medical service during the COVID-19 pandemic. Globally, about 96% of malaria deaths occurred in 29 countries; out of which, four countries (Nigeria, the Democratic Republic of the Congo, the Niger, and the United Republic of Tanzania) accounted for just over half of the malaria deaths. Nigeria leads the four countries with the highest malaria deaths (accounting for 31% globally). Parallelly, sub-Saharan Africa is faced with a rise in the incidence of Type 2 diabetes (T2D). Until recently, T2D was a disease of adulthood and old age. However, this is changing as T2D in children and adolescents is becoming an increasingly important public health problem. Nigeria has been reported to have the highest burden of diabetes in Africa with a prevalence of 5.77% in the country. Several studies conducted in the last decade investigating the interaction between malaria and T2D in developing countries have led to the emergence of the intra-uterine hypothesis. The hypothesis has arisen as a possible explanation for the rise of T2D in malaria endemic areas; malaria in pregnancy could lead to intra-uterine stress which could contribute to low birth weight and may be a potential cause of T2D later in life. Hence, previous, and continuous exposure to malaria infection leads to a higher risk of T2D. Current and emerging evidence suggests that an inflammation-mediated link exists between malaria and eventual T2D emergence. The inflammatory process thus, is an important link for the co-existence of malaria and T2D because these two diseases are inflammatory-related. A key feature of T2D is systemic inflammation, characterized by the upregulation of inflammatory cytokines such as tumor necrosis factor alpha (TNF-α) which leads to impaired insulin signaling. Malaria infection is an inflammatory disease in which TNF-α also plays a major role. TNF-α plays an important role in the pathogenesis and development of malaria and T2D. We therefore hypothesize that TNF-α is an important link in the increasing co-existence of T2D.

Glycocalyx engineering with heparan sulfate mimetics attenuates Wnt activity during adipogenesis to promote glucose uptake and metabolism

Adipose tissue plays a crucial role in maintaining metabolic homeostasis by storing lipids and glucose from circulation as intracellular fat. As peripheral tissues like adipose tissue become insulin resistant, decompensation of blood glucose levels occurs causing type 2 diabetes (T2D). Currently, modulating the glycocalyx, a layer of cell-surface glycans, is an underexplored pharmacological treatment strategy to improve glucose homeostasis in T2D patients. Here, we show a novel role for cell-surface heparan sulfate (HS) in establishing glucose uptake capacity and metabolic utilization in differentiated adipocytes. Using a combination of chemical and genetic interventions, we identified that HS modulates this metabolic phenotype by attenuating levels of Wnt signaling during adipogenesis. By engineering, the glycocalyx of pre-adipocytes with exogenous synthetic HS mimetics, we were able to enhance glucose clearance capacity after differentiation through modulation of Wnt ligand availability. These findings establish the cellular glycocalyx as a possible new target for therapeutic intervention in T2D patients by enhancing glucose clearance capacity independent of insulin secretion.

Clonal Blumea lacera (Burm. f.) DC. ameliorates diabetic conditions by modulating carbohydrate and lipid hydrolases: a combine in vivo experimental and chemico-biological interaction study

Blumea lacera (Burm. f.) DC. is an aromatic annual herb that has traditionally been used to treat or protect against diabetes. Although it has infallible uses, its supply is limited due to its short lifespan. In this study, we aim to investigate the anti-diabetic potential of its micropropagated plants in type 2 diabetic mammalian (mouse) model and further expand the molecular mechanistic understanding of its activity. The water extract of the micropropagated plants was tested in mice with streptozotocin-induced diabetes. The extract effectively suppressed glucose levels prevented weight loss, and improved dyslipidemia in mice. Additionally, it improved liver injury as well as all investigated toxicity indicators, including serum glutamate-pyruvate transaminase, serum glutamic oxaloacetic transaminase, and serum anti-inflammatory marker C-reactive protein. The intramolecular interaction study revealed that the innate polyphenolic constituents of this plant more profoundly inhibited α-amylase, α-glucosidase, and lipase compared to the standard. The prolific bioactive compounds of the micropropagated plant could be attributed to these superior anti-diabetic effects, presumably via an elaborate inhibition of carbohydrate and lipid hydrolyzing enzymes. Thus, the obtained results provide solid experimental proof of the year-round utility of micropropagated plants as a standard source plant material of Blumea lacera (Burm. f.) DC. for drug research and therapeutic production.

The Relationship Between Dietary Patterns and Glycemic Variability in People with Impaired Glucose Tolerance

BACKGROUND

Diurnal glucose fluctuations are increased in prediabetes and might be affected by specific dietary patterns.

OBJECTIVES

The present study assessed the relationship between glycemic variability (GV) and dietary regimen in people with normal glucose tolerance (NGT) and impaired glucose tolerance (IGT).

METHODS

Forty-one NGT (mean age: 45.0 ± 9.0 y, mean BMI: 32.0 ± 7.0 kg/m2) and 53 IGT (mean age: 48.4 ± 11.2 y, mean BMI: 31.3 ± 5.9 kg/m2) subjects were enrolled in this cross-sectional study. The FreeStyleLibre Pro sensor was used for 14 d, and several parameters of GV were calculated. The participants were provided with a diet diary to record all meals. ANOVA analysis, Pearson correlation, and stepwise forward regression were performed.

RESULTS

Despite no difference in diet patterns between the 2 groups, GV parameters were higher in IGT than in NGT. GV worsened with an increase in overall daily carbohydrate and refined grain consumption and improved with the increase in whole grain intake in IGT. GV parameters were positively related [r = 0.14-0.53; all P < 0.02 for SD, continuous overall net glycemic action 1 (CONGA1), J-index, lability index (LI), glycemic risk assessment diabetes equation, M-value, and mean absolute glucose (MAG)], and low blood glucose index (LBGI) inversely (r = -0.37, P = 0.006) related to the total percentage of carbohydrate, but not to the distribution of carbohydrate between the main meals in the IGT group. A negative relationship existed between total protein consumption and GV indices (r = -0.27 to -0.52; P < 0.05 for SD, CONGA1, J-index, LI, M-value, and MAG). The total EI was related to GV parameters (r = 0.27-0.32; P < 0.05 for CONGA1, J-index, LI, and M-value; and r = -0.30, P = 0.028 for LBGI).

CONCLUSIONS

The primary outcome results showed that insulin sensitivity, calories, and carbohydrate content are predictors of GV in individuals with IGT. Overall, the secondary analyses suggested that carbohydrate and daily consumption of refined grains might be associated with higher GV, whereas whole grains and daily protein intake were related to lower GV in people with IGT.

Nonalcoholic Fatty Liver Disease in Lean/Nonobese and Obese Individuals: A Comprehensive Review on Prevalence, Pathogenesis, Clinical Outcomes, and Treatment

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide, with an estimated prevalence of 25% globally. NAFLD is closely associated with metabolic syndrome, which are both becoming increasingly more common with increasing rates of insulin resistance, dyslipidemia, and hypertension. Although NAFLD is strongly associated with obesity, lean or nonobese NAFLD is a relatively new phenotype and occurs in patients without increased waist circumference and with or without visceral fat. Currently, there is limited literature comparing and illustrating the differences between lean/nonobese and obese NAFLD patients with regard to risk factors, pathophysiology, and clinical outcomes. In this review, we aim to define and further delineate different phenotypes of NAFLD and present a comprehensive review on the prevalence, incidence, risk factors, genetic predisposition, and pathophysiology. Furthermore, we discuss and compare the clinical outcomes, such as insulin resistance, dyslipidemia, hypertension, coronary artery disease, mortality, and progression to nonalcoholic steatohepatitis, among lean/nonobese and obese NAFLD patients. Finally, we summarize the most up to date current management of NAFLD, including lifestyle interventions, pharmacologic therapies, and surgical options.

Sanhuang xiexin decoction synergizes insulin/PI3K-Akt/FoxO signaling pathway to inhibit hepatic glucose production and alleviate T2DM

ETHNOPHARMACOLOGICAL RELEVANCE

Sanhuang Xiexin Decoction (SHXXD) is a classic prescription for the treatment of diabetes. Excessive hepatic glucose production (HGP) is a major determinant of the occurrence and development of diabetes. Inhibition of HGP can significantly improve type 2 diabetes mellitus (T2DM).

AIM OF THE STUDY

To investigate the mechanism by which SHXXD inhibits HGP.

MATERIALS AND METHODS

First, a mouse model of T2DM was established through high-fat diet (HFD) feeding combined with streptozotocin (STZ) injection to determine the pharmacodynamic effect of SHXXD in T2DM mice. Then, the possible pathways induced by SHXXD in the treatment of T2DM were predicted by network pharmacology combined with transcriptomics (including target prediction, network analysis and enrichment analysis). Finally, the specific mechanism of SHXXD was elucidated by in vitro experiments.

RESULTS

In vivo experiments showed that SHXXD reduced fasting blood glucose and alleviated weight loss in T2DM mice. Improved glucose clearance rates and insulin sensitivity improve dyslipidemia, liver tissue structural abnormalities and inflammatory cell infiltration as well as increase glycogen storage in T2DM mice. The results of network pharmacology and transcriptome analysis showed that SHXXD contained 378 compounds and 2625 targets. In total, 292 intersection targets were identified between the differentially expressed genes (DEGs) of the liver tissue insulin resistance (IR) related dataset GSE23343. KEGG enrichment analysis showed that the insulin/PI3K-Akt/FoxO signaling pathway may be related to SHXXD-mediated improvements in T2DM. In vitro experimental results showed that SHXXD increased glucose consumption by HepG2-IR cells and improved their insulin sensitivity. RT‒qPCR and Western blotting results showed that SHXXD inhibited hepatic gluconeogenesis through the insulin/PI3K-Akt/FoxO signaling pathway by promoting IGFIR, PIK3R1 and AKT2 expression and subsequently inhibiting PEPCK and FBP1 expression via phosphorylation of Foxo1. In addition, PI3K/Akt deactivated p-GSK3β through phosphorylation, thereby promoting GS expression and increasing glycogen synthesis.

CONCLUSIONS

SHXXD can target the liver to cooperate with the insulin/PI3K-Akt/FoxO signaling pathway to inhibit HGP to alleviate T2DM.

Skeptical Look at the Clinical Implication of Metabolic Syndrome in Childhood Obesity

Metabolic syndrome (MetS) is defined by a cluster of several cardio-metabolic risk factors, specifically visceral obesity, hypertension, dyslipidemia, and impaired glucose metabolism, which together increase risks of developing future cardiovascular disease (CVD) and type 2 diabetes mellitus (T2D). This article is a narrative review of the literature and a summary of the main observations, conclusions, and perspectives raised in the literature and the study projects of the Working Group of Childhood Obesity (WGChO) of the Italian Society of Paediatric Endocrinology and Diabetology (ISPED) on MetS in childhood obesity. Although there is an agreement on the distinctive features of MetS, no international diagnostic criteria in a pediatric population exist. Moreover, to date, the prevalence of MetS in childhood is not certain and thus the true value of diagnosis of MetS in youth as well as its clinical implications, is unclear. The aim of this narrative review is to summarize the pathogenesis and current role of MetS in children and adolescents with particular reference to applicability in clinical practice in childhood obesity.

Diagnosis and Management of Prediabetes: A Review

Importance

Prediabetes, an intermediate stage between normal glucose regulation and diabetes, affects 1 in 3 adults in the US and approximately 720 million individuals worldwide.

Observations

Prediabetes is defined by a fasting glucose level of 100 to 125 mg/dL, a glucose level of 140 to 199 mg/dL measured 2 hours after a 75-g oral glucose load, or glycated hemoglobin level (HbA1C) of 5.7% to 6.4% or 6.0% to 6.4%. In the US, approximately 10% of people with prediabetes progress to having diabetes each year. A meta-analysis found that prediabetes at baseline was associated with increased mortality and increased cardiovascular event rates (excess absolute risk, 7.36 per 10 000 person-years for mortality and 8.75 per 10 000 person-years for cardiovascular disease during 6.6 years). Intensive lifestyle modification, consisting of calorie restriction, increased physical activity (≥150 min/wk), self-monitoring, and motivational support, decreased the incidence of diabetes by 6.2 cases per 100 person-years during a 3-year period. Metformin decreased the risk of diabetes among individuals with prediabetes by 3.2 cases per 100 person-years during 3 years. Metformin is most effective for women with prior gestational diabetes and for individuals younger than 60 years with body mass index of 35 or greater, fasting plasma glucose level of 110 mg/dL or higher, or HbA1c level of 6.0% or higher.

Conclusions and Relevance

Prediabetes is associated with increased risk of diabetes, cardiovascular events, and mortality. First-line therapy for prediabetes is lifestyle modification that includes weight loss and exercise or metformin. Lifestyle modification is associated with a larger benefit than metformin.

The effects of early short-term insulin treatment vs. glimepiride on beta cell function in newly diagnosed type 2 diabetes with HbA1c above 9

BACKGROUND

Type 2 diabetes mellitus (T2D) is a complex metabolic impairment. Beta cell (BC) failure is the most challenging among its pathogenetic mechanisms. Recognizing reversible contributors to BC failure could guide individualized approach to early T2D treatment. The aim of this study was to compare early short-term insulin treatment vs. glimepiride, both added to metformin, on BC function, glycemic and lipid control, during 12-month follow-up.

METHODS

Eighty newly diagnosed T2D patients, 30-65 years of age, presenting with HbA1c ≥ 9% were enrolled in the study. They were randomly assigned to single-month initial insulin therapy (INS) added to metformin, or to glimepiride and metformin (OAD) as only treatment. Subjects assigned to initial insulin intervention were thereafter switched to OAD. C-peptide (C-Pep) was analyzed at baseline and 2 hours after standardized test meal (STM). All subjects were STM-retested after 3 and 12 months. HbA1c, serum lipids, BMI, HOMA IR, and HOMA B were assessed over follow-up.

RESULTS

HbA1c was lower in INS vs OAD at 3-months: 6.26 ± 0.18% vs 6.78 ± 0.10% (p = 0.016), remaining so by 12 months (p =0.056). BMI-adjusted ΔC-Pep was greater in INS vs. OAD at 3 months (4.60 ± 0.59 vs. 3.21 ± 0.34 m2 /kg; p = 0.044), persisting by 12months (4.57 ± 0.56 vs. 3.04 ± 0.34 m2/kg; p = 0.023). Average ΔC-Pep improvement from recruitment to 3 months was 100.8% in INS,vs. 51.3% in OAD. Prevalence of STM-ΔC-Pep response greater than 2.4 ng/mL had risen 3.2-fold by 12 months in the INS, vs. 2.4-fold only in the OAD group (p = 0.018).

DISCUSSION

Early short-term insulin intervention in newly diagnosed T2D improves beta cell function more than glimepiride, both added to metformin, resulting in a superior and longer lasting glycemic and lipid control.

Early type 2 diabetes treatment intensification with glucagon-like peptide-1 receptor agonists in primary care: An Australian perspective on guidelines and the global evidence

Early and intensive management of type 2 diabetes has been shown to delay disease progression, reduce the risk of cardiorenal complications and prolong time to treatment failure. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are being increasingly recognized for their potential in early disease management, with recent guideline updates recommending second-line use of this injectable drug class alongside oral glucose-lowering drugs. GLP-1RAs target at least six of the eight core defects implicated in the pathogenesis of type 2 diabetes and offer significant glycaemic and weight-related improvements over other second-line agents in head-to-head trials. In addition, placebo-controlled clinical trials have shown cardiovascular protection with GLP-1RA use. Even so, this therapeutic class is underused in primary care, largely owing to clinical inertia and patient-related barriers to early intensification with GLP-1RAs. Fortunately, clinicians can overcome barriers to treatment acceptance through patient education and training, and management of treatment expectations. In this review we comment on global and Australian guideline updates and evidence in support of early intensification with this therapeutic class, and provide clinicians with practical advice for GLP-1RA use in primary care.

Association between nonalcoholic fatty liver disease and peripheral neuropathy in US population, a cross-sectional study

Nonalcoholic fatty liver disease (NAFLD) has become an important risk of type 2 diabetes mellitus (T2DM). Peripheral neuropathy (PN) is regarded as one of the main microvascular complications of diabetes. But the association of NAFLD with PN is still unclear. We aimed to investigate the association between NAFLD and PN in US population by conducting a cross-sectional study. We enrolled 3029 participants aged 40-85 years from National Health and Nutrition Examination Survey (NHANES) 1999-2004. NAFLD was defined as a US Fatty Liver Index (FLI) score ≥ 30, and PN was defined as having one or more insensate areas on either foot. Participants were divided into two groups (with or without PN). We performed multivariate logistic regression models to evaluate the association between NAFLD and PN. Subgroup analyses were used to find out whether the association was stable in different stratified groups. Sensitivity analyses were conducted to assess the robustness of the results. All the analyses were weighted. Among the individuals, 524 (17.3%) had PN and 1250 (41.27%) had NAFLD. In the multivariate logistic regression models, NAFLD was associated with an increased risk of PN (OR 1.44 [1.03 ~ 2.02]) after fully adjusting for covariates. In the subgroup analyses, NAFLD was significantly associated with PN in the age group (40-64 years), compared with those in the age group (65-85 years), (P for interaction: 0.004). The results of association of NAFLD with PN were stable in sensitivity analyses. In this cross-sectional study among US adults aged 40-85 years old, NAFLD was associated with an increased likelihood of prevalent PN.

Excess body weight: Novel insights into its roles in obesity comorbidities

Excess body weight is a global health problem due to sedentary lifestyle and unhealthy diet, affecting 2 billion population worldwide. Obesity is a major risk factor for metabolic diseases. Notably, the metabolic risk of obesity largely depends on body weight distribution, of which visceral adipose tissues but not subcutaneous fats are closely associated with obesity comorbidities, including type 2 diabetes, non-alcoholic fatty liver disease, cardiovascular disease and certain types of cancer. Latest multi-omics and mechanistical studies reported the crucial involvement of genetic and epigenetic alterations, adipokines dysregulation, immunity changes, imbalance of white and brown adipose tissues, and gut microbial dysbiosis in mediating the pathogenic association between visceral adipose tissues and comorbidities. In this review, we explore the epidemiology of excess body weight and the up-to-date mechanism of how excess body weight and obesity lead to chronic complications. We also examine the utilization of visceral fat measurement as an accurate clinical parameter for risk assessment in healthy individuals and clinical outcome prediction in obese subjects. In addition, current approaches for the prevention and treatment of excess body weight and its related metabolic comorbidities are further discussed. DATA AVAILABILITY: No data was used for the research described in the article.

Pharmacological and mechanistic study of PS1, a Pdia4 inhibitor, in β-cell pathogenesis and diabetes in db/db mice

Pdia4 has been characterized as a key protein that positively regulates β-cell failure and diabetes via ROS regulation. Here, we investigated the function and mechanism of PS1, a Pdia4 inhibitor, in β-cells and diabetes. We found that PS1 had an IC₅₀ of 4 μM for Pdia4. Furthermore, PS1 alone and in combination with metformin significantly reversed diabetes in db/db mice, 6 to 7 mice per group, as evidenced by blood glucose, glycosylated hemoglobin A1c (Hb_A1c), glucose tolerance test, diabetic incidence, survival and longevity (P < 0.05 or less). Accordingly, PS1 reduced cell death and dysfunction in the pancreatic β-islets of db/db mice as exemplified by serum insulin, serum c-peptide, reactive oxygen species (ROS), islet atrophy, and homeostatic model assessment (HOMA) indices (P < 0.05 or less). Moreover, PS1 decreased cell death in the β-islets of db/db mice. Mechanistic studies showed that PS1 significantly increased cell survival and insulin secretion in Min6 cells in response to high glucose (P < 0.05 or less). This increase could be attributed to a reduction in ROS production and the activity of electron transport chain complex 1 (ETC C1) and Nox in Min6 cells by PS1. Further, we found that PS1 inhibited the enzymatic activity of Pdia4 and mitigated the interaction between Pdia4 and Ndufs3 or p22 in Min6 cells (P < 0.01 or less). Taken together, this work demonstrates that PS1 negatively regulated β-cell pathogenesis and diabetes via reduction of ROS production involving the Pdia4/Ndufs3 and Pdia4/p22 cascades.

Antimicrobial protein REG3A regulates glucose homeostasis and insulin resistance in obese diabetic mice

Innate immune mediators of pathogen clearance, including the secreted C-type lectins REG3 of the antimicrobial peptide (AMP) family, are known to be involved in the regulation of tissue repair and homeostasis. Their role in metabolic homeostasis remains unknown. Here we show that an increase in human REG3A improves glucose and lipid homeostasis in nutritional and genetic mouse models of obesity and type 2 diabetes. Mice overexpressing REG3A in the liver show improved glucose homeostasis, which is reflected in better insulin sensitivity in normal weight and obese states. Delivery of recombinant REG3A protein to leptin-deficient ob/ob mice or wild-type mice on a high-fat diet also improves glucose homeostasis. This is accompanied by reduced oxidative protein damage, increased AMPK phosphorylation and insulin-stimulated glucose uptake in skeletal muscle tissue. Oxidative damage in differentiated C2C12 myotubes is greatly attenuated by REG3A, as is the increase in gp130-mediated AMPK activation. In contrast, Akt-mediated insulin action, which is impaired by oxidative stress, is not restored by REG3A. These data highlight the importance of REG3A in controlling oxidative protein damage involved in energy and metabolic pathways during obesity and diabetes, and provide additional insight into the dual function of host-immune defense and metabolic regulation for AMP.

A healthful plant-based eating pattern is longitudinally associated with higher insulin sensitivity in Australian adults

BACKGROUND

A healthful plant-based eating pattern is associated with lower type 2 diabetes risk; however, the association with its preceding state, compromised insulin sensitivity, is less well-established, particularly in younger populations with repeated measures of diet over time.

OBJECTIVE

We aimed to examine the longitudinal relationship between a healthful plant-based eating pattern and insulin sensitivity in young to middle-aged adults.

METHODS

We included 667 participants from the Childhood Determinants of Adult Health (CDAH) study, a population-based cohort in Australia. Healthful plant-based diet index (hPDI) scores were derived from food frequency questionnaire data. Plant foods considered 'healthful' were scored positively (e.g., whole grains, fruit, vegetables), with all remaining foods scored reversely (e.g., refined grains, soft drinks, meat). Updated homeostatic model assessment (HOMA2) estimated insulin sensitivity from fasting insulin and glucose concentrations. We used linear mixed-effects regression to analyse data from two time points: CDAH-1 (2004-06, aged 26-36 years) and CDAH-3 (2017-19, aged 36-49 years). hPDI scores were modelled as between- and within-person effects (i.e., a participant's overall mean and their deviation from said mean at each time point, respectively).

RESULTS

The median follow-up duration was 13 years. In our primary analysis, each 10-unit difference in hPDI score was associated with higher log-HOMA2 insulin sensitivity [95% confidence interval], with between-person (β = 0.11 [0.05, 0.17], P < .001) and within-person effects (β = 0.10 [0.04, 0.16], P = .001). The within-person effect persisted despite accounting for compliance with dietary guidelines. Adjustment for waist circumference attenuated the between-person effect by 70% (P = .26) and the within-person effect by 40% (P = .04).

CONCLUSIONS

In young to middle-aged Australian adults, a healthful plant-based eating pattern (determined using hPDI scores) was longitudinally associated with higher insulin sensitivity, and therefore, potentially lower type 2 diabetes risk later in life.

The efficacy and safety of combined GLP-1RA and basal insulin therapy among inadequately controlled T2D with premixed insulin therapy

This study investigated the effect of a combination of glucagon-like peptide-1 receptor agonist (GLP-1 RA) and basal insulin (BI) in poorly controlled type 2 diabetes mellitus previously treated with premixed insulin. The possible therapeutic benefit of the subject is mainly hoped to provide a direction for optimizing treatment options to reduce the risk of hypoglycemia and weight gain. A single-arm, open-label study was conducted. The antidiabetic regimen was switched to GLP-1 RA plus BI to replace previous treatment with premixed insulin in type 2 diabetes mellitus subjects. After 3 months of treatment modification, GLP-1 RA plus BI was compared for superior outcomes by continuous glucose monitoring system. There were 34 subjects at the beginning, 4 withdrew due to gastrointestinal discomfort, and finally 30 subjects completed the trial, of which 43% were male; the average age was 58 ± 9 years old, and the average duration of diabetes was 12 ± 6 years, the baseline glycated hemoglobin level was 8.6 ± 0.9 %. The initial insulin dose of premixed insulin was 61 ± 18 units, and the final insulin dose of GLP-1 RA + BI was 32 ± 12 units (P < .001). Time out of range (from 59%-42%), time-in-range (from 39%-56%) as well as glucose variability index including standard deviation also improved, mean magnitude of glycemic excursions, mean daily difference and continuous population in continuous glucose monitoring system, continuous overall net glycemic action (CONGA). Also noted was a decrease in body weight (from 70.9 kg-68.6 kg) and body mass index (all P values < .05). It provided important information for physicians to decide to modify therapeutic strategy as individualized needs.

Dopamine receptor agonists mechanism of actions on glucose lowering and their connections with prolactin actions

Robust experiment evidence suggests that prolactin can enhance beta-cell proliferation and increase insulin secretion and sensitivity. Apart from acting as an endocrine hormone, it also function as an adipokine and act on adipocytes to modulate adipogenesis, lipid metabolism and inflammation. Several cross-sectional epidemiologic studies consistently showed that circulating prolactin levels positive correlated with increased insulin sensitivity, lower glucose and lipid levels, and lower prevalence of T2D and metabolic syndrome. Bromocriptine, a dopamine receptor agonist used to treat prolactinoma, is approved by Food and Drug Administration for treatment in type 2 diabetes mellitus since 2009. Prolactin lowering suppress insulin secretion and decrease insulin sensitivity, therefore dopamine receptor agonists which act at the pituitary to lower serum prolactin levels are expected to impair glucose tolerance. Making it more complicating, studies exploring the glucose-lowering mechanism of bromocriptine and cabergoline have resulted in contradictory results; while some demonstrated actions independently on prolactin status, others showed glucose lowering partly explained by prolactin level. Previous studies showed that a moderate increase in central intraventricular prolactin levels stimulates hypothalamic dopamine with a decreased serum prolactin level and improved glucose metabolism. Additionally, sharp wave-ripples from the hippocampus modulates peripheral glucose level within 10 minutes, providing evidence for a mechanistic link between hypothalamus and blood glucose control. Central insulin in the mesolimbic system have been shown to suppress dopamine levels thus comprising a feedback control loop. Central dopamine and prolactin levels plays a key role in the glucose homeostasis control, and their dysregulation could lead to the pathognomonic central insulin resistance depicted in the “ominous octet”. This review aims to provide an in-depth discussion on the glucose-lowering mechanism of dopamine receptor agonists and on the diverse prolactin and dopamine actions on metabolism targets.

Antihyperglycemic Potential of Spondias mangifera Fruits via Inhibition of 11β-HSD Type 1 Enzyme: In Silico and In Vivo Approach

The 11 β- hydroxysteroid dehydrogenase 1 (11 β-HSD1) is hypothesized to play a role in the pathogenesis of type 2 diabetes and its related complications. Because high glucocorticoid levels are a risk factor for metabolic disorders, 11β-HSD1 might be a viable therapeutic target. In this investigation, docking experiments were performed on the main constituents of Spondias mangifera (SM) oleanolic acid, β-amyrin, and β-sitosterol to ascertain their affinity and binding interaction in the human 11β-hydroxysteroid dehydrogenase-1 enzyme’s active region. The results of in vitro 11β HSD1 inhibitory assay demonstrated that the extract of S. mangifera had a significant (p < 0.05) decrease in the 11-HSD1% inhibition (63.97%) in comparison to STZ (31.79%). Additionally, a non-insulin-dependent diabetic mice model was used to examine the sub-acute anti-hyperlipidemic and anti-diabetic effects of SM fruits. Results revealed that, in comparison to the diabetic control group, SM fruit extract (SMFE) extract at doses of 200 and 400 mg/kg body weight considerably (p < 0.05 and p < 0.01) lowered blood glucose levels at 21 and 28 days, as well as significantly decreased total cholesterol (TC) and triglycerides (TG) and enhanced the levels of high-density lipoprotein (HDL). After 120 and 180 s of receiving 200 and 400 mg/kg SMFE, respectively, disease control mice showed significantly poorer blood glucose tolerance (p < 0.05 and p < 0.01). SMFE extract 200 (p < 0.05), SMFE extract 400 (p < 0.01), and Glibenclamide at a dosage of 5 mg/kg body weight all resulted in statistically significant weight increase (p < 0.01) when compared to the diabetic control group after 28 days of treatment. According to in silico, in vitro, and in vivo validation, SMFE is a prospective medication with anti-diabetic and hypoglycemic effects.

Association of triglyceride-glucose index with atherosclerotic cardiovascular disease and mortality among familial hypercholesterolemia patients

BACKGROUND

Familial hypercholesterolemia (FH) is an inherited metabolic disorder with a high level of low-density lipoprotein cholesterol and the worse prognosis. The triglyceride-glucose (TyG) index, an emerging tool to reflect insulin resistance (IR), is positively associated with a higher risk of atherosclerotic cardiovascular disease (ASCVD) in healthy individuals, but the value of TyG index has never been evaluated in FH patients. This study aimed to determine the association between the TyG index and glucose metabolic indicators, insulin resistance (IR) status, the risk of ASCVD and mortality among FH patients.

METHODS

Data from National Health and Nutrition Examination Survey (NHANES) 1999-2018 were utilized. 941 FH individuals with TyG index information were included and categorized into three groups: < 8.5, 8.5-9.0, and > 9.0. Spearman correlation analysis was used to test the association of TyG index and various established glucose metabolism-related indicators. Logistic and Cox regression analysis were used to assess the association of TyG index with ASCVD and mortality. The possible nonlinear relationships between TyG index and the all-cause or cardiovascular death were further evaluated on a continuous scale with restricted cubic spline (RCS) curves.

RESULTS

TyG index was positively associated with fasting glucose, HbA1c, fasting insulin and the homeostatic model assessment of insulin resistance (HOMA-IR) index (all p < 0.001). The risk of ASCVD increased by 74% with every 1 unit increase of TyG index (95%CI: 1.15-2.63, p = 0.01). During the median 114-month follow-up, 151 all-cause death and 57 cardiovascular death were recorded. Strong U/J-shaped relations were observed according to the RCS results (p = 0.0083 and 0.0046 for all-cause and cardiovascular death). A higher TyG index was independently associated with both all-cause death and cardiovascular death. Results remained similar among FH patients with IR (HOMA-IR ≥ 2.69). Moreover, addition of TyG index showed helpful discrimination of both survival from all-cause death and cardiovascular death (p < 0.05).

CONCLUSION

TyG index was applicable to reflect glucose metabolism status in FH adults, and a high TyG index was an independent risk factor of both ASCVD and mortality.

Dexamethasone leads to Zn2+ accumulation and increased unbound Zn2+ in C2C12 muscle and 3T3-L1 adipose cells

Skeletal muscle atrophy is associated with increases in circulating glucocorticoid levels and insulin resistance. Zinc accumulates in atrophic muscle, but the relationship between atrophy, insulin resistance, and Zn²⁺ homeostasis remains unclear. In this study, the effect of the glucocorticoid dexamethasone (DEX) on insulin and Zn²⁺ homeostasis was explored. Treatment of differentiated C2C12 skeletal myotubes and 3T3-L1 adipocytes with DEX significantly increased mRNA expression of the metal-binding proteins Mt1 and 2 and altered energy storage as shown by the increased size of lipid droplets in 3T3-L1 cells. In C2C12 cells the total cellular Zn²⁺ was higher after DEX treatment, and in both C2C12 and 3T3-L1 adipocytes, free unbound Zn²⁺ was increased. Insulin treatment led to a gradual increase in free Zn²⁺ in C2C12 cells, and no significant change in DEX-treated cells such that concentrations were similar 10 min after insulin treatment. These data demonstrate that DEX disturbs Zn²⁺ homeostasis in muscle and fat cells. Further study of the molecular pathways involved to identify novel therapeutic targets for treatment of skeletal muscle atrophy is warranted.

The standardized Jamu pahitan, an Indonesian antidiabetic formulation, stimulating the glucose uptake and insulin secretion in the in-vitro models

Jamu pahitan is a polyherbal formulation commonly used for the traditional management of diabetes in Indonesia and is mainly prepared from Andrographis paniculata (Burm.f.) Nees. It is widely varied in herbal composition for every region has their own plant component addition to the formulation. A version of the formulation used in the greater Surakarta area contained five plant constituents. This study evaluated the in-vitro glucose uptake and insulin secretion stimulatory activities of Jamu pahitan to provide scientific evidence on its efficacy and safety of use. The water and ethanol extracts of three Jamu pahitan formulations were prepared. The total phenolic content (TPC) of the extracts was evaluated by the standard Folin-Ciocalteau method. Their effects on the viability of L6 skeletal muscle and RIN-m5F pancreatic cells were evaluated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The glucose utilized by L6 myotubes treated with Jamu pahitan was assessed indirectly by the glucose oxidase method. The insulin secreted by RIN-m5F treated with the formulation extracts was analyzed by the enzyme-linked immunosorbent assay (ELISA). The correlation between TPC and the profile of safety and efficacy of the formulation was statistically evaluated. The water extracts of Jamu pahitan were safe and exerted significant glucose uptake and insulin secretion stimulatory activity in L6 and RIN-m5F, respectively. The ethanol extracts showed more potent effects than their water counterpart, albeit they exerted cytotoxic effects on the cells at the higher tested concentrations. The formulations at lower concentrations stimulated the proliferation of RIN-m5F. In addition, the TPC was strongly correlated with the glucose uptake and insulin secretion stimulatory activities and also the IC₅₀ of the cells in positive manner. The present study supported the use of Jamu pahitan for the traditional management of diabetes in Indonesia by stimulating glucose uptake in the muscle cells and improving insulin secretion in β-cells.