Reference intervals for serum 1,5-anhydroglucitol of a population with normal glucose tolerance in Jiangsu Province

Measurement of serum 1,5-AG provides insights for diabetes management and the anti-viral immune response

BACKGROUND

Achieving an in-range glycated haemoglobin (HbA1c) is essential for managing diabetes mellitus (DM). However, this parameter provides an estimate of long-term blood glucose control rather than daily glycaemic variations. Glycaemic variability can be more predictive than HbA1c in terms of identifying those at risk for diabetes complications, including risk of severe respiratory virus infections and is usually measured via a continuous glucose monitor (CGM). For individuals for whom a CGM is not available, serum 1,5 anhydroglucitol (1,5-AG) level has shown potential as an alternative method for monitoring glycaemic variability. Despite this, at present 1,5-AG is not routinely used in the clinical assessment of DM. Here, we aim to determine whether assessing 1,5-AG, in addition to HbA1c, is of any potential clinical utility to the management of DM for patients.

METHODS

Using machine learning and data derived from 78 patients with type I DM (for whom CGM data is available) we show that the combination of 1,5-AG and HbA1c improves the prediction of a patient's glycemia risk index (GRI) compared to HbA1c alone.

RESULTS

The GRI is an essential tool in the management of DM as it reflects both clinical priorities and patient centred outcomes. The inclusion of 1,5-AG in this prediction was particularly important for individuals who had very high or very low GRI. Furthermore, in the context of glycaemic variability and susceptibility to severe respiratory virus infections, we show that reduced 1,5-AG in the plasma is associated with reduced ex vivo CD4 + T cell cytokine responses to influenza virus in individuals with a matched HbA1c.

CONCLUSIONS

Taken together, these data argue for an increased monitoring of 1,5-AG in the clinic for individuals without a CGM to provide additional insights for diabetes management.

The clinical potential of 1,5-anhydroglucitol as biomarker in diabetes mellitus

A crucial measure of diabetes management is to monitor blood glucose, which often requires continuous blood collection, leading to economic burden and discomfort. Blood glucose and glycated hemoglobin A1c serve as traditional indicators of glucose monitoring. But now glycated albumin, fructosamine, and 1,5-anhydroglucitol (1,5-AG) have been gaining more attention. 1,5-AG is a chemically stable monosaccharide that exists in the human body. Its serum concentration remains stable when blood glucose levels are normal. However, it decreases when blood glucose exceeds the renal glucose threshold. Studies have shown that 1.5-AG reflects blood glucose changes in 1 to 2 weeks; therefore, decreased levels of serum 1,5-AG can serve as a clinical indicator of short-term blood glucose disturbances. Recent studies have shown that 1,5-AG can be used not only for the screening and managing of diabetes but also for predicting diabetes-related adverse events and islet β cell function in prediabetic patients. In addition, saliva 1,5-AG demonstrates potential value in the screening and diagnosis of diabetes. This review focuses on the biological characteristics, detection methods, and clinical application of 1,5-AG to promote understanding and applicable research of 1,5-AG in the future.

Reduced graphene oxide-persimmon tannin/Pt@Pd nanozyme-based cascade colorimetric sensor for detection of 1,5-anhydroglucitol

1,5-anhydroglucitol (1,5-AG) is of considerable clinical relevance as a biochemical marker of glucose metabolism in the assessment and monitoring of diabetes. Herein, a simple colorimetric biosensor was constructed for the identification and detection of 1,5-AG by using pyranose oxidase (PROD) enzyme cascaded with reduced graphene oxide/persimmon tannin/Pt@Pd (RGO-PT/Pt@Pd NPs) nanozyme. The as-prepared RGO-PT/Pt@Pd NPs had excellent peroxidase-like activity and can be applied as a nanozyme. First, PROD enzyme reacts with the target 1,5-AG, decomposing 1,5-AG into 1,5-anhydrofuctose (1,5-AF) and H2O2. At this point, the highly catalytic RGO-PT/Pt@Pd NPs nanozyme produces a cascade with PROD enzyme which catalyzes the decomposition of H2O2 to produce O2. This in turn oxidizes the substrate 3,3',5,5'-tetramethylbenzidine (TMB) and produces a color change in the solution. Finally, the detection of 1,5-AG was achieved by measuring the absorption peak at 652 nm with an ultraviolet visible (UV-vis) spectrophotometer. Under optimal conditions, the linear operating range of the 1,5-AG enzyme cascade colorimetric sensor was 1.0-100.0 μg/mL, and the limit of detection (LOD) was 0.81 μg/mL. The proposed colorimetric biosensor was successfully applied to detect 1,5-AG in spiked human serum samples with the recoveries of 97.2-103.9% and RSDs of 1.94-4.48%. It provides a promising developmental assay for clinical detection of 1,5-AG.

1,5-Anhydroglucitol promotes pre-B acute lymphocytic leukemia progression by driving glycolysis and reactive oxygen species formation

BACKGROUND

Precursor B-cell acute lymphoblastic leukemia (pre-B ALL) is the most common hematological malignancy in children. Cellular metabolic reorganization is closely related to the progression and treatment of leukemia. We found that the level of 1,5-anhydroglucitol (1,5-AG), which is structurally similar to glucose, was elevated in children with pre-B ALL. However, the effect of 1,5-AG on pre-B ALL was unclear. Here, we aimed to reveal the roles and mechanisms of 1,5-AG in pre-B ALL progression.

METHODS

The peripheral blood plasma level of children with initial diagnosis of pre-B ALL and that of healthy children was measured using untargeted metabolomic analysis. Cell Counting Kit-8 assay, RNA sequencing, siRNA transfection, real-time quantitative PCR, and western blot were performed using pre-B ALL cell lines Reh and HAL-01. Cell cycle, cell apoptosis, ROS levels, and the positivity rate of CD19 were assessed using flow cytometry. Oxygen consumption rates and extracellular acidification rate were measured using XFe24 Extracellular Flux Analyzer. The lactate and nicotinamide adenine dinucleotide phosphate levels were measured using kits. The effect of 1,5-AG on pre-B ALL progression was verified using the In Vivo Imaging System in a xenotransplantation leukemia model.

RESULTS

We confirmed that 1,5-AG promoted the proliferation, viability, and intracellular glycolysis of pre-B ALL cells. Mechanistically, 1,5-AG promotes glycolysis while inhibiting mitochondrial respiration by upregulating pyruvate dehydrogenase kinase 4 (PDK4). Furthermore, high levels of intracellular glycolysis promote pre-B ALL progression by activating the reactive oxygen species (ROS)-dependent mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway. Conversely, N-acetylcysteine or vitamin C, an antioxidant, effectively inhibited 1,5-AG-mediated progression of leukemia cells.

CONCLUSIONS

Our study reveals a previously undiscovered role of 1,5-AG in pre-B ALL, which contributes to an in-depth understanding of anaerobic glycolysis in the progression of pre-B ALL and provides new targets for the clinical treatment of pre-B ALL.

Diabetes mellitus in chronic kidney disease: Biomarkers beyond HbA1c to estimate glycemic control and diabetes-dependent morbidity and mortality

Diabetes mellitus (DM) is the leading cause of chronic kidney disease (CKD). Optimal glycemic control contributes to improved outcomes in patients with DM, particularly for microvascular damage, but blood glucose levels are too variable to provide an accurate assessment and instead markers averaging long-term glycemic load are used. The most established glycemic biomarker of long-term glycemic control is HbA1c. Nevertheless, HbA1c has pitfalls that limit its accuracy to estimate glycemic control, including the presence of altered red blood cell survival, hemoglobin glycation and suboptimal performance of HbA1c assays. Alternative methods to evaluate glycemic control in patients with DM include glycated albumin, fructosamine, 1-5 anhydroglucitol, continuous glucose measurement, self-monitoring of blood glucose and random blood glucose concentration measurements. Accordingly, our aim was to review the advantages and pitfalls of these methods in the context of CKD.