Serum 1,5-anhydroglucitol concentrations are a reliable index of glycemic control in type 2 diabetes with mild or moderate renal dysfunction

The relationship between serum 1,5-anhydroglucitol and adverse outcomes in acute coronary syndrome with and without chronic kidney disease patients

Purpose

Individuals with chronic kidney disease (CKD) face an elevated residual risk of cardiovascular events, but the relationship between this residual risk and 1,5-anhydroglucitol (1,5-AG) is uncertain. Our study aimed to examine the effect of 1,5-AG on major adverse cardiovascular events (MACEs) and all-cause mortality in acute coronary syndrome (ACS) individuals.

Methods

1253 ACS participants hospitalized were enrolled at Beijing Hospital between March 2017 and March 2020. All participants were classified into 2 groups based on their eGFR (60 ml/min/1.73 m2). The link between 1,5-AG and adverse outcome was investigated in non-CKD and CKD participants.

Results

CKD patients had reduced concentrations of 1,5-AG than those without CKD. Throughout a median follow-up duration of 43 months, 1,5-AG was an autonomous hazard factor for MACEs and all-cause mortality. 1,5-AG<14 μg/ml participants had greater MACEs and all-cause mortality risk than those with 1,5-AG≥14 μg/ml, regardless of renal function. Furthermore, concomitant reduced concentrations of 1,5-AG and CKD portended a dismal prognosis in ACS patients.

Conclusions

1,5-AG was autonomously linked to MACEs and all-cause mortality in ACS participants with both non-CKD and CKD. Co-presence of reduced concentrations of 1,5-AG and CKD may portend adverse clinical outcomes.

Treatment recommendations for glycogen storage disease type IB- associated neutropenia and neutrophil dysfunction with empagliflozin: Consensus from an international workshop

Glycogen storage disease type Ib (GSD Ib, biallelic variants in SLC37A4) is a rare disorder of glycogen metabolism complicated by neutropenia/neutrophil dysfunction. Since 2019, the SGLT2-inhibitor empagliflozin has provided a mechanism-based treatment option for the symptoms caused by neutropenia/neutrophil dysfunction (e.g. mucosal lesions, inflammatory bowel disease). Because of the rarity of GSD Ib, the published evidence on safety and efficacy of empagliflozin is still limited and does not allow to develop evidence-based guidelines. Here, an international group of experts provides 14 best practice consensus treatment recommendations based on expert practice and review of the published evidence. We recommend to start empagliflozin in all GSD Ib individuals with clinical or laboratory signs related to neutropenia/neutrophil dysfunction with a dose of 0.3-0.4 mg/kg/d given as a single dose in the morning. Treatment can be started in an outpatient setting. The dose should be adapted to the weight and in case of inadequate clinical treatment response or side effects. We strongly recommend to pause empagliflozin immediately in case of threatening dehydration and before planned longer surgeries. Discontinuation of G-CSF therapy should be attempted in all individuals. If available, 1,5-AG should be monitored. Individuals who have previously not tolerated starches should be encouraged to make a new attempt to introduce starch in their diet after initiation of empagliflozin treatment. We advise to monitor certain safety and efficacy parameters and recommend continuous, alternatively frequent glucose measurements during the introduction of empagliflozin. We provide specific recommendations for special circumstances like pregnancy and liver transplantation.

Association of Both Short-term and Long-term Glycemic Variability With the Development of Microalbuminuria in the ACCORD Trial

Both long- and short-term glycemic variability have been associated with incident diabetes complications. We evaluated their relative and potential additive effects on incident renal complications in the Action to Control Cardiovascular Risk in Diabetes trial. A marker of short-term glycemic variability, 1,5-anhydroglucitol (1,5-AG), was measured in 4,000 random 12-month postrandomization plasma samples (when hemoglobin A1c [HbA1c] was stable). Visit-to-visit fasting plasma glucose coefficient of variation (CV-FPG) was determined from 4 months postrandomization until the end point of microalbuminuria or macroalbuminuria. Using Cox proportional hazards models, high CV-FPG and low 1,5-AG were independently associated with microalbuminuria after adjusting for clinical risk factors. However, only the CV-FPG association remained after additional adjustment for average HbA1c. Only CV-FPG was a significant risk factor for macroalbuminuria. This post hoc analysis indicates that long-term rather than short-term glycemic variability better predicts the risk of renal disease in type 2 diabetes.

ARTICLE HIGHLIGHTS

The relative and potential additive effects of long- and short-term glycemic variability on the development of diabetic complications are unknown. We aimed to assess the individual and combined relationships of long-term visit-to-visit glycemic variability, measured as the coefficient of variation of fasting plasma glucose, and short-term glucose fluctuation, estimated by the biomarker 1,5-anhydroglucitol, with the development of proteinuria. Both estimates of glycemic variability were independently associated with microalbuminuria, but only long-term glycemic variability remained significant after adjusting for average hemoglobin A1c. Our findings suggest that longer-term visit-to-visit glucose variability improves renal disease prediction in type 2 diabetes.

The gut microbe Bacteroides fragilis ameliorates renal fibrosis in mice

Renal fibrosis is an inevitable outcome of various manifestations of progressive chronic kidney diseases (CKD). The need for efficacious treatment regimen against renal fibrosis can therefore not be overemphasized. Here we show a novel protective role of Bacteroides fragilis (B. fragilis) in renal fibrosis in mice. We demonstrate decreased abundance of B. fragilis in the feces of CKD patients and unilateral ureteral obstruction (UUO) mice. Oral administration of live B. fragilis attenuates renal fibrosis in UUO and adenine mice models. Increased lipopolysaccharide (LPS) levels are decreased after B. fragilis administration. Results of metabolomics and proteomics studies show decreased level of 1,5-anhydroglucitol (1,5-AG), a substrate of SGLT2, which increases after B. fragilis administration via enhancement of renal SGLT2 expression. 1,5-AG is an agonist of TGR5 that attenuates renal fibrosis by inhibiting oxidative stress and inflammation. Madecassoside, a natural product found via in vitro screening promotes B. fragilis growth and remarkably ameliorates renal fibrosis. Our findings reveal the ameliorative role of B. fragilis in renal fibrosis via decreasing LPS and increasing 1,5-AG levels.

1,5-Anhydroglucitol as a Marker of Acute Hyperglycemia in Cardiovascular Events

1,5-anhydroglucitol (1,5-AG) is a biomarker of acute hyperglycemia in diabetology and also in cardiodiabetology. It is used to monitor fluctuating glucose levels. 1,5-AG is a monosaccharide that is biochemically similar to D-glucose and originates from the nutrition. The presence of 1,5-AG in blood and tissue is nearly constant due to reabsorption in the renal proximal tubule. In acute hyperglycemia, renal reabsorption is inhibited by glucose and 1,5- AG is excreted in the urine, while its serum level decreases rapidly. 1,5-AG reflects glucose excursions over 1-3 days to 2 weeks. In this regard, low levels of serum 1,5-AG can be a clinical marker of short- term glycemic derangements such as postprandial hyperglycemia, which is an important risk factor for the pathogenesis of coronary artery disease (CAD) as low levels of 1,5-AG reflect severe plaque calcification in CAD and correlate with high-density lipoprotein cholesterol (HDL-C) levels. For these reasons, 1,5-AG may also be a marker for atherosclerosis; in fact an even better marker than HbA1c or fructosamine which are normally used. 1,5-AG may also be a predictor of cardiovascular disease, left ventricular dysfunction after acute coronary syndrome (ACS), and mortality after ACS. This articles reviews the current knowledge on 1,5-AG related to its use as predictor for cardiovascular events.

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.

Review of methods for detecting glycemic disorders

Prediabetes (intermediate hyperglycemia) consists of two abnormalities, impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) detected by a standardized 75-gram oral glucose tolerance test (OGTT). Individuals with isolated IGT or combined IFG and IGT have increased risk for developing type 2 diabetes (T2D) and cardiovascular disease (CVD). Diagnosing prediabetes early and accurately is critical in order to refer high-risk individuals for intensive lifestyle modification. However, there is currently no international consensus for diagnosing prediabetes with HbA1c or glucose measurements based upon American Diabetes Association (ADA) and the World Health Organization (WHO) criteria that identify different populations at risk for progressing to diabetes. Various caveats affecting the accuracy of interpreting the HbA1c including genetics complicate this further. This review describes established methods for detecting glucose disorders based upon glucose and HbA1c parameters as well as novel approaches including the 1-hour plasma glucose (1-h PG), glucose challenge test (GCT), shape of the glucose curve, genetics, continuous glucose monitoring (CGM), measures of insulin secretion and sensitivity, metabolomics, and ancillary tools such as fructosamine, glycated albumin (GA), 1,5- anhydroglucitol (1,5-AG). Of the approaches considered, the 1-h PG has considerable potential as a biomarker for detecting glucose disorders if confirmed by additional data including health economic analysis. Whether the 1-h OGTT is superior to genetics and omics in providing greater precision for individualized treatment requires further investigation. These methods will need to demonstrate substantially superiority to simpler tools for detecting glucose disorders to justify their cost and complexity.

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

BACKGROUND

Serum 1,5-anhydroglucitol (1,5-AG) is a new glycemic marker which can reflect glucose fluctuation over 3 to 7 days and is now increasingly used to monitor glucose control and to screen for diabetes. However, 1,5-AG has not been widely used in China due to lack of epidemiological support. Our study aims to establish the reference intervals for a population with normal glucose tolerance in Jiangsu Province and to explore the determinants of these intervals.

METHOD

The study enrolled 646 healthy adults aged 20 to 70 years in Jiangsu Province in 2018 after oral glucose tolerance test. 1,5-AG, fasting and 2-hour glucose, UA, liver enzyme, serum lipid, creatinine, and glycosylated hemoglobin were measured. We calculated reference intervals using the parametric method and examined the relationship between 1,5-AG and influence factors.

RESULTS

The average age of the participants was 50.5 ± 9.0 years, and 69.5% of them were females. The reference intervals were 15.8 to 52.6 μg/mL for males and 14.3 to 48.0 μg/mL for females. Among females, the reference intervals were 13.9 to 45.3 and 14.6 to 49.6 μg/mL for menopausal and postmenopausal females, respectively. Males showed higher 1,5-AG concentrations than females, and postmenopausal females had higher 1,5-AG than menopausal females. There was a positive correlation between uric acid and 1,5-AG in both genders. Positive correlation between 1,5-AG and age was only observed in females.

CONCLUSION

We established reference intervals for 1,5-AG in Jiangsu Province, and the level of 1,5-AG is affected by sex, uric acid, and age.

The Clinical Utility of Salivary Biomarkers in the Identification of Type 2 Diabetes Risk and Metabolic Syndrome

Type 2 diabetes is traditionally diagnosed by the use of an oral glucose tolerance test and/or HbA1c, both of which require serum collection. Various biomarkers, which are measurable biological substances that provide clinical insight on disease state, have also been effective in the early identification and risk prediction of inflammatory diseases. Measuring biomarker concentrations has traditionally been obtained through serum collection as well. However, numerous biomarkers are detectable in saliva. Salivary analysis has more recently been introduced into research as a potential non-invasive, cost-effective diagnostic for the early identification of type 2 diabetes risk in adults and youth. Therefore, the purpose of this review was to compare 6 established inflammatory biomarkers of type 2 diabetes, in serum and saliva, and determine if similar diagnostic effectiveness is seen in saliva. A lack of standardized salivary analysis, processing, and collection accounts for errors and inconsistencies in conclusive data amongst studies. Proposing a national standardization in salivary analysis, coupled with increased data and research on the utility of saliva as a diagnostic, poses the potential for salivary analysis to be used in diagnostic settings.

Update on biomarkers of glycemic control

Attaining and maintaining good glycemic control is a cornerstone of diabetes care. The monitoring of glycemic control is currently based on the self-monitoring of blood glucose (SMBG) and laboratory testing for hemoglobin A1c (HbA1c), which is a surrogate biochemical marker of the average glycemia level over the previous 2-3 mo period. Although hyperglycemia is a key biochemical feature of diabetes, both the level of and exposure to high glucose, as well as glycemic variability, contribute to the pathogenesis of diabetic complications and follow different patterns in type 1 and type 2 diabetes. HbA1c provides a valuable, standardized and evidence-based parameter that is relevant for clinical decision making, but several biological and analytical confounders limit its accuracy in reflecting true glycemia. It has become apparent in recent years that other glycated proteins such as fructosamine, glycated albumin, and the nutritional monosaccharide 1,5-anhydroglucitol, as well as integrated measures from direct glucose testing by an SMBG/continuous glucose monitoring system, may provide valuable complementary data, particularly in circumstances when HbA1c results may be unreliable or are insufficient to assess the risk of adverse outcomes. Long-term associations of these alternative biomarkers of glycemia with the risk of complications need to be investigated in order to provide clinically relevant cut-off values and to validate their utility in diverse populations of diabetes patients.

Correlation of Serum 1,5-AG with Uric Acid in Type 2 Diabetes Mellitus with Different Renal Functions

AIM

Recent studies found that levels of serum uric acid (SUA) were positively associated with serum 1,5-anhydroglucitol (1,5-AG) in subjects with type 2 diabetes mellitus (T2DM). In the current study, we investigated the association between 1,5-AG and UA in T2DM patients with different renal functions.

METHODS

A total of 405 T2DM patients, 213 men and 192 women, participated in the study. Patients' clinical information was collected, and serum 1,5-AG, SUA, and other clinical characteristics were measured. Correlation analyses were carried out to analyze their correlation with serum 1,5-AG and SUA.

RESULTS

The male group showed higher levels of SUA than the female group (282.1 ± 91.2 and 244.7 ± 71.89 μmol/L, respectively, P < 0.01). Pearson's correlation coefficients determine that SUA was positively associated with 1,5-AG in both men (r = 0.213, P < 0.05) and women (r = 0.223, P < 0.05), and such relationship can be influenced by the renal function. The positive association still existed with moderate impaired renal function. Moreover, 1,5-AG had a negative association with haemoglobin A1c (HbA1c) in T2DM subjects with eGFR ≥ 30 mL/min/1.73 m² (P < 0.01).

CONCLUSION

The positive association between SUA and 1,5-AG still exists in T2DM with moderate renal failure. 1,5-AG can still reflect the glucose levels in patients with CKD stages 1-3.

Metabolomics reveal mitochondrial and fatty acid metabolism disorders that contribute to the development of DKD in T2DM patients

Diabetic kidney disease (DKD) is the leading cause of ESRD; however, early intervention can greatly prevent the progression of DKD; thus, sensitive biomarkers for DKD are still required. This study was aimed at the identification of potential biomarkers and revelation of underlying pathways in DKD patients by non-targeted metabolomics. Gas chromatography-mass spectrometry was used to analyze urine obtained from the control and type 2 diabetes mellitus (T2DM) and DKD patients, and the renal histological changes in DKD patients were assessed. The DKD group showed increased level of uric acid, 1,5-anhydroglucitol, hippuric acid, stearic acid, and palmitic acid and reduced level of uracil, glycine, aconitic acid, isocitric acid, 4-hydroxybutyrate, 2-deoxyerythritol, and glycolic acid as compared to the control and T2DM groups. Further analysis indicated that many of the changed metabolites were involved in mitochondrial and fatty acid (FA) metabolism, and combined mitochondrial and FA metabolites showed better diagnosis values for DKD. Histological results confirmed that renal expression of key proteins was reduced in DKD patients with respect to mitochondrial biogenesis (PGC-1α, p-AMPK) and FA oxidation (PPAR-α, CPT-1) as compared to that in the control and T2DM groups. This study highlighted that both mitochondrial and FA metabolism were disturbed in DKD, and thus, they could serve as combined biomarkers for the prediction of DKD.

Usefulness of glycated albumin as a biomarker for glucose control and prognostic factor in chronic kidney disease patients on dialysis (CKD-G5D)

In chronic kidney disease patients on dialysis (CKD-G5D) accurate assessment of glycemic control is vital to improve their outcome and survival. The best glycemic marker for glucose control in these patients is still debated because several clinical and pharmacological factors may affect the ability of the available biomarkers to reflect the patient's glycemic status properly. This review discusses the role of glycated albumin (GA) both as a biomarker for glucose control and as a prognostic factor in CKD-G5D; it also looks at the pros and cons of GA in comparison to the other markers and its usefulness in hemodialysis and peritoneal dialysis.

Beyond self-monitored plasma glucose and HbA1c: the role of non-traditional glycaemic markers in gestational diabetes mellitus

Strict glycaemic management is the cornerstone of metabolic control in gestational diabetes mellitus (GDM). Current monitoring standards involve self-monitoring plasma glucose (SMBG) and haemoglobin A1c (HbA1c). However, both have important limitations. SMBG only reflects instantaneous blood glucose and the inconvenience of self-collecting blood frequently results in poor compliance. HbA1c provides information on blood glucose levels from the previous 2 to 3 months and it is influenced by iron-deficient states, common during pregnancy. There is an urgent need for new shorter-term glycaemic markers, as glycated albumin, fructosamine or 1,5-anhydroglucitol. Glycated albumin seems especially interesting as it provides information on blood glucose levels over the foregoing 2-3 weeks and it is not influenced by iron deficiency or the dilutional anaemia of pregnancy. Fructosamine has a precise and inexpensive measurement and it is not affected by haemoglobin characteristics. This review further discusses the potential value of these non-traditional indicators of glycaemic control in patients with GDM, outlining their possible future applications.

1,5-Anhydroglucitol predicts CKD progression in macroalbuminuric diabetic kidney disease: results from non-targeted metabolomics

INTRODUCTION

Metabolomics allows exploration of novel biomarkers and provides insights on metabolic pathways associated with disease. To date, metabolomics studies on CKD have been largely limited to Caucasian populations and have mostly examined surrogate end points.

OBJECTIVE

In this study, we evaluated the role of metabolites in predicting a primary outcome defined as dialysis need, doubling of serum creatinine or death in Brazilian macroalbuminuric DKD patients.

METHODS

Non-targeted metabolomics was performed on plasma from 56 DKD patients. Technical triplicates were done. Metabolites were identified using Agilent Fiehn GC/MS Metabolomics and NIST libraries (Agilent MassHunter Work-station Quantitative Analysis, version B.06.00). After data cleaning, 186 metabolites were left for analyses.

RESULTS

During a median follow-up time of 2.5 years, the PO occurred in 17 patients (30.3%). In non-parametric testing, 13 metabolites were associated with the PO. In univariate Cox regression, only 1,5-anhydroglucitol (HR 0.10; 95% CI 0.01-0.63, p = .01), norvaline and L-aspartic acid were associated with the PO. After adjustment for baseline renal function, 1,5-anhydroglucitol (HR 0.10; 95% CI 0.02-0.63, p = .01), norvaline (HR 0.01; 95% CI 0.001-0.4, p = .01) and aspartic acid (HR 0.12; 95% CI 0.02-0.64, p = .01) remained significantly and inversely associated with the PO.

CONCLUSION

Our results show that lower levels of 1,5-anhydroglucitol, norvaline and L-aspartic acid are associated with progression of macroalbuminuric DKD. While norvaline and L-aspartic acid point to interesting metabolic pathways, 1,5-anhydroglucitol is of particular interest since it has been previously shown to be associated with incident CKD. This inverse biomarker of hyperglycemia should be further explored as a new tool in DKD.

Determination of glycated albumin using boronic acid-derived agarose beads on paper-based devices

Self-monitoring of glycated albumin (GA), a useful glycemic marker, is an established method for preventing diabetes complications. Here, the paper-based lateral flow assay devices were developed for the sensitive detection of GA and the total human serum albumin (tHSA) in self-monitoring diabetes patients. Boronic acid-derived agarose beads were packed into a hole on a lateral flow channel. These well-coordinated agarose beads were used to capture GA through specific cis-diol interactions and to enhance the colorimetric signals by concentrating the target molecules. The devices exhibited large dynamic ranges (from 10 μg/ml to 10 mg/ml for GA and from 10 mg/ml to 50 mg/ml for tHSA) and low detection limits (7.1 μg/ml for GA and 4.7 mg/ml for tHSA), which cover the range of GA concentration in healthy plasma, which is 0.21-1.65 mg/ml (0.6%-3%). In determining the unknown GA concentrations in two commercial human plasma samples, the relative percentage difference between the values found by a standard ELISA kit and those found by our developed devices was 2.62% and 8.80%, which are within an acceptable range. The measurements of GA and tHSA were completed within 20 min for the total sample-to-answer diagnosis, fulfilling the demand for rapid analysis. Furthermore, the recovery values ranged from 99.4% to 110% in device accuracy tests. These results indicate that the developed paper-based device with boronic acid-derived agarose beads is a promising platform for GA and tHSA detection as applied to self-monitoring systems.

Serum 1,5-anhydroglucitol when used with fasting plasma glucose improves the efficiency of diabetes screening in a Chinese population

Serum 1,5-anhydroglucitol (1,5-AG) levels can not only accurately reflect the mean blood glucose over the previous 1–2 weeks in diabetic patients but also offers the advantage of representing postprandial glucose. To evaluate the clinical significance of 1,5-AG in diabetes detection, especially when used in combination with fasting plasma glucose (FPG), a total of 3098 participants at high risk for diabetes (1467 men, 1631 women) were enrolled. A total of 1471 (47.5%) participants were diagnosed with diabetes, and the mean 1,5-AG level in the diabetic group was significantly lower than that in non-diabetic group [12.5 (7.8–17.5) μg/mL vs. 20.5 (15.3–26.4) μg/mL, P < 0.001]. The optimal cut-off point was 15.9 μg/mL, for which the sensitivity, specificity, and area under the curve (AUC) were 69.2%, 72.3%, and 0.781, respectively. For the combination of FPG and 1,5-AG, the sensitivity, specificity, and AUC improved to 82.5%, 83.5%, and 0.912, respectively. This method helped 75.8% of the participants avoid an oral glucose tolerance test (OGTT), reducing the need to carry out the OGTT by 43.9% compared to the use of the FPG criterion only. In conclusion, the addition of FPG to serum 1,5-AG improves the efficiency of diabetes screening in the Chinese population.

Do glycoalbumin levels preferentially reflect changes in postprandial glucose excursions?

AIMS

To evaluate whether plasma glycated albumin, which provides an integrated measure of plasma glucose levels over the preceding 2-4 weeks, better reflects changes in postprandial glucose excursions than HbA_1c .

METHODS

People with suboptimum glycaemic control on dual oral therapy were enrolled in the Treating-to-Target-in-Type 2 diabetes (4-T) trial, in which participants were randomized to the addition of once-daily basal insulin, twice-daily biphasic insulin or thrice-daily prandial insulin. Glycated albumin levels were assayed enzymatically from baseline and 1-year fasting plasma samples. We evaluated robust correlations of glycated albumin and HbA_1c both with fasting and postprandial glucose levels at these two time points, and with insulin-induced changes in the postprandial excursion.

RESULTS

Requisite data were available for 625 of the participants in the 4-T trial. Their mean (±sd) age was 62 ± 10 years and body weight was 85.8 ± 15.9 kg, and their median (interquartile range) diabetes duration was 9 (6, 13) years. Partial correlations at baseline and 1 year between postprandial glucose excursions and glycated albumin/HbA_1c , after adjusting for fasting glucose, were 0.27/0.15 and 0.22/0.18, respectively. Glycated albumin, compared with HbA_1c , explained 66% more of the variation in postprandial glucose excursions at baseline. At 1 year, postprandial glucose excursions on basal, biphasic and prandial and insulin therapy were reduced by 0.43, 0.78 and 1.88 mmol/l, respectively. These reductions were associated with changes in both glycated albumin and HbA_1c (P < 0.01), with a stronger association for glycated albumin.

CONCLUSION

Changes in glycated albumin and HbA_1c reflect changes in postprandial glucose excursions to a similar extent.

Serum 1,5-anhydroglucitol level as a screening tool for diabetes mellitus in a community-based population at high risk of diabetes

AIMS

Early diagnosis of diabetes yields significant clinical benefits; however, currently available diagnostic tools for community-based population are limited. This study aimed to assess the value of serum 1,5-anhydroglucitol (1,5-AG) for the diagnosis and screening of diabetes mellitus in a community-based population at high risk of diabetes.

METHODS

In this diagnostic test, 1170 participants underwent a 75-g oral glucose tolerance test. Venous blood samples were collected for fasting blood glucose (FBG), 2-h postprandial blood glucose (PBG), and glycosylated hemoglobin A1c (HbA1c) measurements. Serum 1,5-AG levels were detected by the GlycoMark assay, and a receiver operating characteristic (ROC) curve was generated to assess their diagnostic value for diabetes.

RESULTS

A total of 298 adults were diagnosed with diabetes, indicating a prevalence of 25.47%. Partial Pearson correlation analysis adjusted for age and body mass index showed that serum 1,5-AG level was negatively correlated with FBG, PBG, and HbA1c (all P < 0.01). Areas under the curves (AUCs) for serum 1,5-AG, FBG, PBG, and HbA1c in identifying diabetes were 0.920, 0.874, 0.933, and 0.887, respectively. According to the ROC curve, the optimal cutoff value of serum 1,5-AG for diagnosing diabetes was 11.18 μg/ml, which yielded a sensitivity of 92.6% and a specificity of 82.3%, respectively. Comparisons between 1,5-AG and HbA1c showed that both the AUC and sensitivity of 1,5-AG were higher than those of HbA1c (both P < 0.01).

CONCLUSIONS

Serum 1,5-AG is a simple and effective marker with high sensitivity and specificity for identifying diabetes in populations at high risk of diabetes.

Excretion rates of 1,5-anhydro-D-glucitol, uric acid and microalbuminuria as glycemic control indexes in patients with type 2 diabetes

1,5-anhydroglucitol (1,5-AG), uric acid and urinary proteins are excreted into the urine with increasing glucosuria. In the present retrospective study we analyzed whether these factors could be used as indicators for type 2 diabetes mellitus (T2DM) glucose control in 6,766 (T2DM) patients. There were 3,988 cases (58.9%) with HbA1c ≤ 6.5%, 853 cases (12.61%) with HbA1c levels ranging from 6.5% to 7% and 1,925 cases (28.5%) with HbA1c > 7%. HbA1c percentages were correlated with age, MA and 1,5-AG serum concentrations (P < 0.001). The serum uric acid concentration (P < 0.001) was significantly lower in elevated MA (P < 0.001) and 24-hour urinary protein (P = 0.024) patients. Hb1Ac percentages (P < 0.001) were significantly enhanced in patients with 1,5-AG serum concentrations ≤10 mg/L compared to >10 mg/L. With a derived receiver operating characteristic (ROC) curve, a 1,5-AG cut-off value of 11.55 mg/L for hyperglycemia could be diagnosed with a specificity of 71.2 (69.7–72.6) and a sensitivity of 75.3 (73.6–76.9). The serum 1,5-AG concentration is a marker for hyperglycemia and may be particularly useful as an indicator for short-term glycemic excursions in order to improve treatments in T2DM patients.

Relationship of glycemic control markers - 1,5 anhydroglucitol, fructosamine, and glycated hemoglobin among Asian Indians with different degrees of glucose intolerance

OBJECTIVE

1,5 anhydroglucitol (1,5 AG) is emerging as a marker of short-term glycemic control. We measured levels of 1,5 AG, fructosamine (FA), and glycated hemoglobin (HbA1c) in Asian Indians with different degrees of glucose intolerance.

MATERIALS AND METHODS

We recruited 210 individuals with normal glucose tolerance (NGT; n = 60), impaired glucose tolerance (IGT; n = 50), and Type 2 diabetes mellitus (T2DM; n = 100) from a large tertiary diabetes center in Chennai in Southern India. Anthropometric measurements were obtained using standardized techniques. Serum 1,5 AG (enzymatic colorimetric assay), FA (NBT/kinetic), and HbA1c (high-performance liquid chromatography) estimations were performed.

RESULTS

1,5 AG levels were significantly lower in the T2DM followed by IGT compared with the NGT group (7.9 vs. 18.8 vs. 21.8 µg/ml, P < 0.05). FA and HbA1c were higher in T2DM and IGT compared with NGT individuals (313 vs. 237 vs. 200 µmol/L, P < 0.001) (8.3 vs. 5.8 vs. 5.3%, P < 0.001).1,5 AG showed a significant negative correlation with FA (r = -0.618, P < 0.001) and HbA1c (r = -0.700, P < 0.001). 1,5 AG decreased with increasing quartiles of postprandial glucose (P for trend <0.001). However, even among individuals with HbA1c ≤7%, 27% individuals had decreased 1,5 AG plasma level (<10 µg/ml).

CONCLUSION

Circulatory levels of 1,5 AG correlate negatively with FA and HbA1c, and may provide an additional marker to assess glycemic control in patients with Type 2 diabetes.

Effect of renal function on serum concentration of 1,5-anhydroglucitol in type 2 diabetic patients in chronic kidney disease stages I-III: A comparative study with HbA1c and glycated albumin

BACKGROUND

1,5-Anhydroglucitol (1,5-AG) is a new blood glucose control marker reflecting temporary glucose elevations. However, 1,5-AG is of limited value in patients with advanced renal insufficiency. The aim of the present study was to assess the correlation between 1,5-AG levels and renal function in patients with earlier stages of nephropathy compared with another two markers of diabetes control, namely HbA1c and glycated albumin (GA).

METHODS

The following parameters were measured in 377 patients with type 2 diabetes: HbA1c, serum concentrations of 1,5-AG, GA and creatinine, hemoglobin, urinary albumin/creatinine ratio, and urinary excretion of α1 -microglobulin (A1M). Estimated glomerular filtration rate (eGFR) was calculated according to the Cockgroft-Gault formula.

RESULTS

There was a negative correlation between 1,5-AG and renal function (r = -0.18; P < 0.001). Concentrations of 1,5-AG were, on average, 27.2% lower in patients with glomerular hyperfiltration (eGFR >120 mL/min) compared with patients with moderate renal impairment (eGFR 30-59 mL/min; P = 0.016). In contrast, HbA1c, GA levels and urinary A1M excretion did not differ between the two patient groups. The mean age of patients with eGFR 30-59 mL/min was substantially higher than that of patients with glomerular hyperfiltration (P < 0.001). Thus, an age-related change in the renal glucose threshold could be the reason for the observed correlation between 1,5-AG and renal function.

CONCLUSIONS

In clinical practice, age and renal function must be taken into consideration when interpreting 1,5-AG levels, even in the absence of advanced renal impairment.

Indicators of glycemic control in patients with gestational diabetes mellitus and pregnant women with diabetes mellitus

Recently, it has become clear that mild abnormal glucose tolerance increases the incidence of perinatal maternal-infant complications, and so the definition and diagnostic criteria of gestational diabetes mellitus (GDM) have been changed. Therefore, in patients with GDM and pregnant women with diabetes mellitus, even stricter glycemic control than before is required to reduce the incidence of perinatal maternal-infant complications. Strict glycemic control cannot be attained without an indicator of glycemic control; this review proposes a reliable indicator. The gold standard indicator of glycemic control in patients with diabetes mellitus is hemoglobin A1c (HbA1c); however, we have demonstrated that HbA1c does not reflect glycemic control accurately during pregnancy because of iron deficiency. It has also become clear that glycated albumin, another indicator of glycemic control, is not influenced by iron deficiency and therefore might be a better indicator of glycemic control in patients with GDM and pregnant women with diabetes mellitus. However, large-population epidemiological studies are necessary in order to confirm our proposal. Here, we outline the most recent findings about the indicators of glycemic control during pregnancy including fructosamine and 1,5-anhydroglucitol.

Metabolomics – the complementary field in systems biology: a review on obesity and type 2 diabetes

This paper highlights the metabolomic roles in systems biology towards the elucidation of metabolic mechanisms in obesity and type 2 diabetes.

Diabetic kidney disease: a report from an ADA Consensus Conference

The incidence and prevalence of diabetes mellitus have grown significantly throughout the world, due primarily to the increase in type 2 diabetes. This overall increase in the number of people with diabetes has had a major impact on development of diabetic kidney disease (DKD), one of the most frequent complications of both types of diabetes. DKD is the leading cause of end-stage renal disease (ESRD), accounting for approximately 50% of cases in the developed world. Although incidence rates for ESRD attributable to DKD have recently stabilized, these rates continue to rise in high-risk groups such as middle-aged African Americans, Native Americans, and Hispanics. The costs of care for people with DKD are extraordinarily high. In the Medicare population alone, DKD-related expenditures among this mostly older group were nearly $25 billion in 2011. Due to the high human and societal costs, the Consensus Conference on Chronic Kidney Disease and Diabetes was convened by the American Diabetes Association in collaboration with the American Society of Nephrology and the National Kidney Foundation to appraise issues regarding patient management, highlighting current practices and new directions. Major topic areas in DKD included 1) identification and monitoring, 2) cardiovascular disease and management of dyslipidemia, 3) hypertension and use of renin-angiotensin-aldosterone system blockade and mineralocorticoid receptor blockade, 4) glycemia measurement, hypoglycemia, and drug therapies, 5) nutrition and general care in advanced-stage chronic kidney disease, 6) children and adolescents, and 7) multidisciplinary approaches and medical home models for health care delivery. This current state summary and research recommendations are designed to guide advances in care and the generation of new knowledge that will meaningfully improve life for people with DKD.

1,5-Anhydroglucitol and glycated albumin in glycemia

The main purpose of treating diabetes is to prevent the onset and the progression of diabetic chronic complications. Since the mechanism of onset of chronic complications is still not well understood, the main strategy to achieve this purpose is to bring the plasma glucose level in diabetic patients as close as possible to that in healthy subjects and try to maintain good glycemic control over the long term. Glycated hemoglobin (HbA1c), glycated albumin (GA), fructosamine, and 1,5-anhydroglucitol (1,5 AG) are used for evaluating glycemic control. At present, HbA1c is widely used as a gold standard index for glycemic control in clinical practice. While HbA1c reflects the long-term glycemic control state (for the past 1-2 months), it does not accurately reflect glycemic control in the clinical state in which glycemic control improves or deteriorates in the short-term. It is also known that HbA1c in patients with hematological disorders such as anemia and variant hemoglobin shows an abnormal value. In addition, HbA1c mainly reflects the mean plasma glucose but does not reflect the postprandial plasma glucose. On the other hand, GA and 1,5-AG reflect intermediate- or short-term glycemic control and are not influenced by hemoglobin metabolism. While 1,5-AG is known to reflect the postprandial plasma glucose, it was shown recently that GA also reflects the postprandial plasma glucose. This chapter summarizes the measurement methods, usage methods, evidence, and problems concerning such indices for glycemic control.

Metabolic profiling in diabetes

Metabolic profiling, or metabolomics, has developed into a mature science in recent years. It has major applications in the study of metabolic disorders. This review addresses issues relevant to the choice of the metabolomics platform, study design and data analysis in diabetes research, and presents recent advances using metabolomics in the identification of markers for altered metabolic pathways, biomarker discovery, challenge studies, metabolic markers of drug efficacy and off-target effects. The role of genetic variance and intermediate metabolic phenotypes and its relevance to diabetes research is also addressed.

Beyond HbA1c and glucose: the role of nontraditional glycemic markers in diabetes diagnosis, prognosis, and management

Fasting glucose and hemoglobin A1c (HbA1c) are the standard measures for diagnosis and monitoring of diabetes. There has been recent interest in nontraditional markers of hyperglycemia, including fructosamine, glycated albumin, and 1,5-anhydroglucitol (1,5-AG), as alternatives or adjuncts to standard measures. There is a growing literature linking these nontraditional markers with microvascular and macrovascular complications. Fructosamine and glycated albumin have also been shown to improve identification of persons with diabetes. However, long-term prospective studies with clinical outcomes are lacking. Some modern laboratory assays for fructosamine, glycated albumin, and 1,5-AG have excellent performance. Expanded use of these tests has the potential to improve diabetes care as these measures may overcome limitations of HbA1c in certain patients, complement traditional measures by providing additional information on shorter-term glycemic control, and improve risk stratification for diabetes and its complications. Nonetheless, studies are needed to demonstrate if their routine use will benefit patients and improve outcomes.

Use of complementary markers in assessing glycaemic control in people with diabetic kidney disease undergoing iron or erythropoietin treatment

AIMS

HbA(1c) values are unreliable in patients with diabetes who have chronic kidney disease who receive iron and/or erythropoiesis stimulating agents. The study aimed to evaluate the utility of the complementary glycaemic markers glycated albumin, fructosamine and 1,5 anhydroglucitol in this group of patients.

METHODS

A prospective study of patients with Type 2 diabetes and chronic kidney disease stage IIIB/IV undergoing intravenous iron or erythropoiesis-stimulating agent therapy. Glycaemic control was monitored using HbA(1c), seven-point daily glucose thrice weekly, continuous glucose monitoring, glycated albumin, fructosamine and 1,5 anhydroglucitol.

RESULTS

Fifteen patients [9 men; median age 72 years (interquartile range 68-74), follow-up period (16.4 ± 3.7 weeks)] received parenteral iron; 15 patients [11 men; 70 years (interquartile range 62-75), (17.3 ± 3.3 weeks)] received erythropoiesis-stimulating agent. HbA(1c) fell following treatment with both iron [57 mmol/mol (7.4%) to 53 mmol/mol (7.0%), P < 0.001] and erythropoiesis-stimulating agent [56 mmol/mol (7.3%) to 49 mmol/mol (6.6%), P = 0.01] despite mean blood glucose remaining unchanged (iron: 9.55 to 9.71 mmol/l, P = 0.07; erythropoiesis-stimulating agent: 8.72 to 8.78 mmol/l, P = 0.89). Unlike HbA1c , the glycated albumin, fructosamine and 1,5 anhydroglucitol levels did not change following iron [glycated albumin (16.8 to 16.3%, P = 0.10); fructosamine (259.5 to 256 μmol/l, P = 0.89); 1,5 anhydroglucitol (54.2 to 50.9 μmol/l, P = 0.89)] or erythropoiesis-stimulating agent [glycated albumin (17.9 to 17.5%, P = 0.29), fructosamine (324.3 to 306.0 μmol/l, P = 0.52), 1,5 anhydroglucitol (58.2 to 46.7 μmol/l, P = 0.35)]. Despite this, HbA(1c) was consistently the marker most closely related to mean blood glucose before and after each treatment (R range 0.7-0.88).

CONCLUSIONS

These data indicate that HbA(1c) was statistically most closely related to mean blood glucose, but clinical trends in glycaemia in patients undergoing iron or erythropoiesis-stimulating agent therapy are likely best assessed by including one of these additional glycaemic markers.

Using hemoglobin A1c to derive mean blood glucose in peritoneal dialysis patients

BACKGROUND

Although hemoglobin A1c (HbA1c) has been widely used as a clinical assessment tool for outcome analyses related to glycemic control, the relationship between HbA1c and average blood glucose (BG) specific to peritoneal dialysis (PD) patients with diabetes has not been characterized. We sought to develop HbA1c-BG equation models for PD patients.

METHODS

We examined associations between HbA1c and random serum BG values over time in a contemporary 5-year (2001-2006) cohort of DaVita PD patients with diabetes. We identified 850 patients (mean age: 58 ± 13 years, 56% male) with 4,566 paired measurements of HbA1c and BG. The bootstrapping method was used to estimate average BG and corresponding HbA1c.

RESULTS

Linear regression analyses yielded the following HbA1c-BG equations: (1) BG (mg/dl) = 24.1 + 28.6 × HbA1c - 12.2 × albumin [adjusted R(2) (R(2)adj = 0.454)], (2) BG = 55.3 + 28.8 × HbA1c - 10.2 × albumin - 3.3 × Hb (R(2)adj = 0.457), and (3) BG = 69.5 + 28.7 × HbA1c - 10.1 × albumin - 3.7 × Hb - 0.1 × age + race/ethnicity (-10.1 African Americans, -5.4 other race/ethnicities; R(2)adj = 0.457). All models showed greater explanatory power of BG variation than previously established HbA1c-BG equation models defined within non-PD cohorts [R(2)adj = 0.446 for both the Diabetes Control and Complications Trial (DCCT) and the A1c-Derived Average Glucose (ADAG) equations].

CONCLUSIONS

The association between HbA1c and BG in PD patients is different than that of patients with normal kidney function. Our analysis suggests that equations incorporating serum albumin and/or Hb values better estimate the HbA1c-BG relationship in PD patients compared to equations using HbA1c alone.

Developing an HbA(1c)-based equation to estimate blood glucose in maintenance hemodialysis patients

OBJECTIVE

Hemoglobin A1c (HbA(1c)) has been widely used as a clinically important assessment tool for outcome analyses related to glycemic control. However, because of special conditions in dialysis patients, including the uremic milieu, there is no HbA(1c) blood glucose (BG) equation specific for patients on dialysis. In this study, we sought to develop HbA(1c)-BG equation models for hemodialysis patients.

RESEARCH DESIGN AND METHODS

We examined associations between HbA(1c) and random serum BG over time in a contemporary cohort of diabetic patients with hemodialysis treated in DaVita dialysis clinics. We identified 11,986 patients (63 ± 12 years old and 49% male) with 69,764 paired measurements of HbA(1c) and BG over the course of 5 years (2001-2006). Bootstrapping method was used to estimate average BG and corresponding HbA(1c) levels. The association was adjusted by patient factors using linear regression.

RESULTS

Linear regression analyses yielded the following three regression equations: BG = 59.2 + 29.4 × HbA(1c) - 20.8 × Alb (R(2) = 0.483); BG = 104.8 + 29.7 × HbA(1c) - 18.4 × Alb - 4.7 × Hb (R(2) = 0.486); and BG = 82.9 + 30.7 × HbA(1c) - 16.5 × Alb - 5.4 × Hb + 0.3 × age + race (R(2) = 0.491). All our models showed stronger association than previous equation models (R(2) = 0.468 in the Diabetes Control and Complications Trial and A1c-Derived Average Glucose equations).

CONCLUSIONS

The association between HbA(1c) and BG in hemodialysis patients is different than that of patients with normal kidney function. Our analysis suggests that equations including serum albumin or hemoglobin are better for hemodialysis patients.

1,5-Anhydroglucitol in diabetes mellitus

The measure of glycated hemoglobin (HbA1c) concentration is the gold standard of glycemic control index in diabetes management and is well known as a marker for diabetes complications. However, HbA1c level neither accurately reflect glucose fluctuations, nor does it provide a clear indication of glycemic control in recent days or weeks. HbA1c concentration measurement can be confounded in patients with anemia, hemoglobinopathy, liver disease, or renal impairment. 1,5-Anhydroglucitol (1,5-AG) structurally resembles glucose. It can be influenced by diet or medication, gender and race, especially severe renal disease and various pathological conditions. Most notably, 1,5-AG level is reflective of short-term glucose status, postprandial hyperglycemia, and glycemic variability which are not captured by HbA1c assay. 1,5-AG may suggest an alternative index of subtypes of diabetes and a warning sign of diabetes complications. This review provides an overview of our current understanding of the role of 1,5-AG marker in diabetes. However, further investigations on the associations between this glycemic marker and diabetes complications are needed.