Pancreatic beta cell function and insulin resistance profiles in first-degree relatives of patients with prediabetes and type 2 diabetes.

AIMS: To evaluate insulin secretion and insulin resistance profiles in individuals with family history of prediabetes and type 2 diabetes. METHODS: This was a cross-sectional study to evaluate clinical and metabolic profiles between individuals with type 2 diabetes, prediabetes and their relatives. There were 911 subjects divided into five groups: (i) normoglycemic (NG), (ii) type 2 diabetes, (iii) prediabetes, (iv) first-degree relatives of patients with type 2 diabetes (famT2D), and (v) first-degree relatives of patients with prediabetes (famPD); anthropometrical, biochemical and nutritional evaluation, as well as insulin resistance and pancreatic beta cell function measurement was performed by oral glucose tolerance to compare between groups. RESULTS: The most prevalent type 2 diabetes risk factors were dyslipidemia (81%), family history of type 2 diabetes (76%), central obesity (73%), male sex (63%), and sedentary lifestyle (60%), and most of them were progressively associated to prediabetes and type 2 diabetes groups. Insulin sensitivity was lower in famT2D groups in comparison to NG group (p < 0.0001). FamPD and famT2D had a 10% lower pancreatic beta cell function (DI) than the NG group (NG group 2.78 ± 1.0, famPD 2.5 ± 0.85, famT2D 2.4 ± 0.75, p˂0.001). CONCLUSIONS: FamPD and famT2D patients had lower pancreatic beta cell function than NG patients, highlighting that defects in insulin secretion and insulin sensitivity appear long time before the development of hyperglycemia in patients genetically predisposed.

Insulin Dynamics and Pathophysiology in Youth-Onset Type 2 Diabetes.

Youth-onset type 2 diabetes (T2D) is increasing around the globe. The increased disease burden of youth-onset T2D portends substantial consequences for the health outcomes of young people and for health care systems. The pathophysiology of this condition is characterized by insulin resistance and initial insulin hypersecretion +/- an inherent insulin secretory defect, with progressive loss of stimulated insulin secretion leading to pancreatic ß-cell failure. Research studies focusing on youth-onset T2D have illuminated key differences for youth- versus adult-onset T2D, with youth having more profound insulin resistance and quicker progression to loss of sufficient insulin secretion to maintain euglycemia. Therapies targeted to improve both insulin resistance and, importantly, maintain sufficient insulin secretory function over the lifespan in youth-onset T2D are needed.

Genetic and inflammatory factors underlying gestational diabetes mellitus: a review.

Gestational diabetes mellitus (GDM) poses a significant global health concern, impacting both maternal and fetal well-being. Early detection and treatment are imperative to mitigate adverse outcomes during pregnancy. This review delves into the pivotal role of insulin function and the influence of genetic variants, including SLC30A8, CDKAL1, TCF7L2, IRS1, and GCK, in GDM development. These genetic variations affect beta-cell function and insulin activity in crucial tissues, such as muscle, disrupting glucose regulation during pregnancy. We propose a hypothesis that this variation may disrupt zinc transport, consequently impairing insulin production and secretion, thereby contributing to GDM onset. Furthermore, we discussed the involvement of inflammatory pathways, such as TNF-alpha and IL-6, in predisposing individuals to GDM. Genetic modulation of these pathways may exacerbate glucose metabolism dysregulation observed in GDM patients. We also discussed how GDM affects cardiovascular disease (CVD) through a direct correlation between pregnancy and cardiometabolic function, increasing atherosclerosis, decreased vascular function, dyslipidemia, and hypertension in women with GDM history. However, further research is imperative to unravel the intricate interplay between inflammatory pathways, genetics, and GDM. This understanding is pivotal for devising targeted gene therapies and pharmacological interventions to rectify genetic variations in SLC30A8, CDKAL1, TCF7L2, IRS1, GCK, and other pertinent genes. Ultimately, this review offers insights into the pathophysiological mechanisms of GDM, providing a foundation for developing strategies to mitigate its impact.

ß-Cell Insulin Resistance Plays a Causal Role in Fat-Induced ß-Cell Dysfunction In Vitro and In Vivo.

In the classical insulin target tissues of liver, muscle, and adipose tissue, chronically elevated levels of free fatty acids (FFA) impair insulin signaling. Insulin signaling molecules are also present in ß-cells where they play a role in ß-cell function. Therefore, inhibition of the insulin/insulin-like growth factor 1 pathway may be involved in fat-induced ß-cell dysfunction. To address the role of ß-cell insulin resistance in FFA-induced ß-cell dysfunction we co-infused bisperoxovanadate (BPV) with oleate or olive oil for 48 hours in rats. BPV, a tyrosine phosphatase inhibitor, acts as an insulin mimetic and is devoid of any antioxidant effect that could prevent ß-cell dysfunction, unlike most insulin sensitizers. Following fat infusion, rats either underwent hyperglycemic clamps for assessment of ß-cell function in vivo or islets were isolated for ex vivo assessment of glucose-stimulated insulin secretion (GSIS). We also incubated islets with oleate or palmitate and BPV for in vitro assessment of GSIS and Akt (protein kinase B) phosphorylation. Next, mice with ß-cell specific deletion of PTEN (phosphatase and tensin homolog; negative regulator of insulin signaling) and littermate controls were infused with oleate for 48 hours, followed by hyperglycemic clamps or ex vivo evaluation of GSIS. In rat experiments, BPV protected against fat-induced impairment of ß-cell function in vivo, ex vivo, and in vitro. In mice, ß-cell specific deletion of PTEN protected against oleate-induced ß-cell dysfunction in vivo and ex vivo. These data support the hypothesis that ß-cell insulin resistance plays a causal role in FFA-induced ß-cell dysfunction.

Unraveling the epigenetic fabric of type 2 diabetes mellitus: pathogenic mechanisms and therapeutic implications.

Type 2 diabetes mellitus (T2DM) is a rapidly escalating global health concern, with its prevalence projected to increase significantly in the near future. This review delves into the intricate role of epigenetic modifications - including DNA methylation, histone acetylation, and micro-ribonucleic acid (miRNA) expression - in the pathogenesis and progression of T2DM. We critically examine how these epigenetic changes contribute to the onset and exacerbation of T2DM by influencing key pathogenic processes such as obesity, insulin resistance, ß-cell dysfunction, cellular senescence, and mitochondrial dysfunction. Furthermore, we explore the involvement of epigenetic dysregulation in T2DM-associated complications, including diabetic retinopathy, atherosclerosis, neuropathy, and cardiomyopathy. This review highlights recent studies that underscore the diagnostic and therapeutic potential of targeting epigenetic modifications in T2DM. We also provide an overview of the impact of lifestyle factors such as exercise and diet on the epigenetic landscape of T2DM, underscoring their relevance in disease management. Our synthesis of the current literature aims to illuminate the complex epigenetic underpinnings of T2DM, offering insights into novel preventative and therapeutic strategies that could revolutionize its management.

Disfunción beta pancreática

La disfunción beta pancreática es una realidad fisiopatológica que conduce a una pérdida gradual en la eficacia de los opciones terapéuticas utilizadas en la DM. La evidencia actual establece que tanto en los diabéticos como en la condición de prediabetes, la disfunción de la célula beta es el primer defecto demostrable con limitación de la capacidad de compensación en presencia de resistencia a la insulina. Cada vez toma más importancia la necesidad de mantener el control glucémico a largo plazo utilizando opciones terapéuticas que aseguren la preservación del funcionamiento de la masa beta pancreática.

The dysfunction pancreatic beta is a physiopatological reality that conducts to a gradual loss in the efficacy of the therapeutic options utilized in the DM. The current evidence establishes that so much in the diabetic as in the condition of prediabetes, the dysfunction of the cell beta is the first demonstrable defect with limitation of the capacity of clearing in the presence of resistance to the insulin. Each time takes more importance the need to maintain the control glucémico long-term utilizing therapeutic options that assure the preservation of the operation of the pancreatic mass.