Evidence From a Systematic Review and Meta-Analysis: Classical Impaired Glucose Tolerance Should Be Divided Into Subgroups of Isolated Impaired Glucose Tolerance and Impaired Glucose Tolerance Combined With Impaired Fasting Glucose, According to the Risk of Progression to Diabetes

Current type 2 diabetes guidelines: Individualized treatment and how to make the most of metformin

Evidence-based guidelines provide the premise for the delivery of quality care to preserve health and prevent disabilities and premature death. The systematic gathering of observational, mechanistic and experimental data contributes to the hierarchy of evidence used to guide clinical practice. In the field of diabetes, metformin was discovered more than 100 years ago, and with 60 years of clinical use, it has stood the test of time regarding its value in the prevention and management of type 2 diabetes. Although some guidelines have challenged the role of metformin as the first-line glucose-lowering drug, it is important to point out that the cardiovascular-renal protective effects of sodium-glucose co-transporter-2 inhibitors and glucagon-like peptide-1 receptor agonists were gathered from patients with type 2 diabetes, the majority of whom were treated with metformin. Most national, regional and international guidelines recommend metformin as a foundation therapy with emphasis on avoidance of therapeutic inertia and early attainment of multiple treatment goals. Moreover, real-world evidence has confirmed the glucose-lowering and cardiovascular-renal benefits of metformin accompanied by an extremely low risk of lactic acidosis. In patients with type 2 diabetes and advanced chronic kidney disease (estimated glomerular filtration rate 15-30 mL/min/1.73m2), metformin discontinuation was associated with an increased risk of cardiovascular-renal events compared with metformin persistence. Meanwhile, it is understood that microbiota, nutrients and metformin can interact through the gut-brain-kidney axis to modulate homeostasis of bioactive molecules, systemic inflammation and energy metabolism. While these biological changes contribute to the multisystem effects of metformin, they may also explain the gastrointestinal side effects and vitamin B12 deficiency associated with metformin intolerance. By understanding the interactions between metformin, foods and microbiota, healthcare professionals are in a better position to optimize the use of metformin and mitigate potential side effects. The United Kingdom Prospective Diabetes Study and the Da Qing Diabetes Prevention Program commenced 40 years ago provided the first evidence that type 2 diabetes is preventable and treatable. To drive real-world impact from this evidence, payors, practitioners and planners need to co-design and implement an integrated, data-driven, metformin-based programme to detect people with undiagnosed diabetes and prediabetes (intermediate hyperglycaemia), notably impaired glucose tolerance, for early intervention. The systematic data collection will create real-world evidence to bring out the best of metformin and make healthcare sustainable, affordable and accessible.

Zinc Alpha-2 Glycoprotein, Acylated Ghrelin, and Zinc Levels in Prediabetics

BACKGROUND/AIM

Prediabetic stages of impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) exhibit differences in the sites of insulin resistance. Serum Zinc α-2 glycoprotein (ZAG), acylated ghrelin (AG), and zinc (Zn) levels can affect IFG, IGT, and diabetic glucose tolerance (DGT) differently. This study examined the importance of ZAG, AG, and serum Zn levels in prediabetic individuals with IFG, IGT, and DGT, compared to those with normal glucose levels.

PATIENTS AND METHODS

The study was conducted at İstanbul University Cerrahpaşa-Cerrahpaşa Faculty of Medicine. A total of n=151 volunteers were classified according to the WHO criteria for diabetes after undergoing an oral glucose tolerance test. Plasma and serum samples were measured by Inductively Coupled Plasma Optical Emission Spectroscopy, ELISA, and immunoassay.

RESULTS

Prediabetic conditions became more prominent with the decrease in ZAG levels. ZAG levels showed a negative correlation with acylated ghrelin and Homeostatic Model Assessment for assessing beta-cell function and insulin resistance. Zinc levels were significantly lower in DGT.

CONCLUSION

ZAG levels have regulatory effects on insulin resistance and plasma glucose levels are mediated by zinc and acylated ghrelin.

Effects of co-supplementation of chromium and magnesium on metabolic profiles, inflammation, and oxidative stress in impaired glucose tolerance

PURPOSE

To evaluate the effects of chromium (Cr) and magnesium (Mg) ions on metabolic profiles, inflammation, and oxidative stress with impaired glucose tolerance (IGT) and insulin resistance (IR).

METHODS

120 individuals with IGT and IR were randomly divided into four groups treated with (1) chromium, (2) magnesium, (3) chromium and magnesium or (4) placebo. Metabolic and inflammatory indicators were measured at baseline and after 3 months intervention.

RESULTS

Comparison among groups showed that fasting plasma glucose (FPG), 2 h post glucose (2hPPG), fasting insulin (FINS) and homeostatic model assessment for insulin resistance (HOMA-IR) in Cr + Mg group were significantly decreased compared with the other three groups (p < .05), and high density lipoprotein (HDL-c) levels were higher. 8-iso prostaglandin F2 alpha (8-iso-PGF2a) decreased in Cr, Mg, and Cr + Mg groups compared with placebo (p < .05), and 8-iso-PGF2a decreased in Cr + Mg groups compared with Cr group and Mg groups (p > .05). Intra-group comparison showed that the levels of FPG, 2hPPG and FINS in Cr + Mg group were significantly decreased after intervention (p < .05), and FINS in Mg group was significantly decreased (p < .01). The levels of HDL-c and triacylglycerol (TG) in Cr + Mg group were significantly improved (p < .05). The level of HDL-c in Mg group was significantly improved compared with baseline (p < .05). Compared with baseline, high-sensitivity C-reactive protein (hsCRP) levels in Cr + Mg group and Mg group were significantly decreased (p < .05).

CONCLUSIONS

The co-supplementation of Cr and Mg improves glycemic and lipid levels and reduces the inflammatory response and oxidative stress profiles of individuals with impaired glucose tolerance and insulin resistance.

Neuropathy in prediabetes

Diabetic neuropathies are the most frequent complications of diabetes, contributing to high morbidity, excess mortality, reduced quality of life, and increased healthcare costs. Prediabetes is characterised by glucose levels within an intermediate range above normoglycaemia yet below the diagnostic threshold for diabetes. In 2021, 10.6% and 6.2% of adults worldwide were estimated to have impaired glucose tolerance and impaired fasting glucose, respectively, the majority of whom are unaware of having prediabetes. Evidence has accumulated suggesting that prediabetes is a predictor of cardiovascular disease (CVD) and increased mortality. The past 2 decades have witnessed an extensive debate, particularly among diabetologists and neurologists, as to whether prediabetes is associated with peripheral neuropathy. In this review, we elaborate on the current evidence, particularly from population-based studies supporting an increased risk of distal sensorimotor polyneuropathy (DSPN) and cardiovascular autonomic neuropathy (CAN) in people with prediabetes. Moreover, we discuss whether lifestyle interventions showing efficacy in preventing or delaying the transition from prediabetes to diabetes in persons with prediabetes may also exert favourable effects on the development and progression of DSPN and CAN. This review should help in raising the awareness of and translating the current knowledge on neuropathies in people with prediabetes into clinical practice and public health. The current recommendation that adults who are overweight or obese should be screened for prediabetes and referred to or offered preventive interventions should ultimately culminate in preventing not only CVD but also prediabetic neuropathy.

Prevalence and Predictors of Prediabetes in Adolescents and Young Adults with Turner Syndrome: A Cross-Sectional Study from Eastern India

Background

Individuals with Turner syndrome (TS) have a high risk for prediabetes/type 2 Diabetes Mellitus (T2DM). There is scarce data regarding risk factors for prediabetes in TS, specially from South Asia.

Methods

We conducted a cross-sectional study on girls with TS aged 12-30 years who had achieved pubertal stage B3 and above-spontaneously or with oestrogen. Anthropometric measurements and biochemical tests were conducted, and medical records were reviewed for details about pubertal onset and progression, growth hormone (GH) and oestrogen therapy.

Results

Out of 129 patients with TS in our database, 99 met the criteria for inclusion, mean age 18.33+/-3.78 years and mean BMI 20.57+/- 3.71 kg/m2. Prevalence of prediabetes was 23.23%. Plasma-glucose measured after 75 g-oral-anhydrous-glucose-load (OGTT-PPG) identified five additional prediabetes cases, who had normal fasting plasma glucose (FPG) or HbA1c%. Compared to those without prediabetes, TS with prediabetes (n = 23) had higher mean body weight, BMI, waist circumference (WC) [42.02+/- 5.83 vs 36.22+/-8.07, 22.77+/-2.78 vs 19.91+/- 3.72, 85.26+/- 3.52 vs 81.08+/- 4.59, pall < 0.03 ], higher median WC-to-height ratio (WHtR) and WC-to-hip ratio (WHR)((0.64 [0.6-0.69] vs 0.59[0.56- 0.66], 0.9[0.84-1.12] vs 0.85[0.75-1.01], pboth < 0.02), and higher LDL-cholesterol, triglycerides, and greater prevalence of hepatosteatosis (47.1% vs 21.1%, P < 0.01). Among GH recipients (n = 36), those with prediabetes had delayed initiation and shorter duration of GH therapy. There were no differences in cardiometabolic parameters or the prevalence of diabetes between different karyotypic variants of TS. BMI, WC and WHR had significant positive correlation with FBG, OGTT-PPG and HbA1c% (pall < 0.004). Delay in oestrogen initiation had a significant correlation with OGTT-PPG (Spearman's-rho = 0.69, P < 0.004). BMI, WHR and pubertal status were independent predictors for prediabetes (OR: 1.27 [1.03-1.57]), 1.18 [1.04-1.34]) and 0.09[0.02-0.38], respectively, pall < 0.02), but karyotype was not. BMI had the highest sensitivity [cut-off: 21.04 kg/m2 (sensitivity: 82.6%, specificity: 62.2%) and WHR had the highest specificity [cut-off: 0.89 (sensitivity: 73.9%, specificity 78.4%)] for predicting prediabetes.

Conclusion

Indian girls with TS have a high risk for prediabetes, irrespective of underlying karyotype and should be screened with oral glucose challenge to identify prediabetes. Timely intervention against central obesity and early initiation of GH and oestrogen should be ensured in TS. Late presenting girls should be closely monitored for dysglycaemia before and during treatment with GH and/or oestrogen.

Distinct Roles for Brain and Pancreas in Basal and Postprandial Glucose Homeostasis

The glucose homeostasis system ensures that the circulating glucose level is maintained within narrow physiological limits both in the fasting (or basal) state and following a nutrient challenge. Although glucose homeostasis is traditionally conceptualized as a single overarching system, evidence reviewed here suggests that basal glycemia and glucose tolerance are governed by distinct control systems. Specifically, whereas glucose tolerance appears to be determined largely by interactions between insulin secretion and insulin sensitivity, basal-state glucose homeostasis is predominated by insulin-independent mechanisms governed largely by the brain. In addition to a new perspective on how glucose homeostasis is achieved, this "dual control system" hypothesis offers a feasible and testable explanation for observations that are otherwise difficult to reconcile and sheds new light on the integration of central and peripheral metabolic control mechanisms. The implications of this model for the pathogenesis and treatment of impaired fasting glucose, impaired glucose tolerance, and type 2 diabetes are also discussed.

Signaling and Gene Expression in Skeletal Muscles in Type 2 Diabetes: Current Results and OMICS Perspectives

Skeletal muscles mainly contribute to the emergence of insulin resistance, impaired glucose tolerance and the development of type 2 diabetes. Molecular mechanisms that regulate glucose uptake are diverse, including the insulin-dependent as most important, and others as also significant. They involve a wide range of proteins that control intracellular traffic and exposure of glucose transporters on the cell surface to create an extensive regulatory network. Here, we highlight advantages of the omics approaches to explore the insulin-regulated proteins and genes in human skeletal muscle with varying degrees of metabolic disorders. We discuss methodological aspects of the assessment of metabolic dysregulation and molecular responses of human skeletal muscle to insulin. The known molecular mechanisms of glucose uptake regulation and the first results of phosphoproteomic and transcriptomic studies are reviewed, which unveiled a large-scale array of insulin targets in muscle cells. They demonstrate that a clear depiction of changes that occur during metabolic dysfunction requires systemic and combined analysis at different levels of regulation, including signaling pathways, transcription factors, and gene expression. Such analysis seems promising to explore yet undescribed regulatory mechanisms of glucose uptake by skeletal muscle and identify the key regulators as potential therapeutic targets.