1,5-Anhydroglucitol reflects postprandial hyperglycemia and a decreased insulinogenic index, even in subjects with prediabetes and well-controlled type 2 diabetes

Metabolomic Alteration in Adipose Monocyte Chemotactic Protein-1 Deficient Mice Fed a High-Fat Diet

Monocyte chemotactic protein-1 (MCP-1), a small inducible cytokine, is involved in obesity-related chronic disorders. Adipocytes produce MCP-1 that is elevated in obese humans and in rodent models of obesity. This study examined the hepatic metabolomic alterations caused by adipose-specific MCP-1 deficiency in a rodent model of obesity. Wide-type (WT) and adipose-specific Mcp-1 knockdown mice (Mcp-1 -/-) were each assigned randomly to 2 groups and fed the standard AIN93G diet or a high-fat diet (HFD) for 12 weeks. Compared to the AIN93G diet, the HFD increased body weight, body fat mass, and plasma concentrations of insulin and leptin, regardless of genotype. There were no differences in these variables between WT and Mcp-1 -/- mice when they were fed the same diet. Eighty-seven of 172 identified metabolites met the criteria for metabolomic comparisons among the 4 groups. Thirty-nine metabolites differed significantly between the 2 dietary treatments and 15 differed when Mcp-1 -/- mice were compared to WT mice. The metabolites that significantly differed in both comparisons included those involved in amino acid, energy, lipid, nucleotide, and vitamin metabolism. Network analysis found that both HFD and adipose Mcp-1 knockdown may considerably impact amino acid metabolism as evidenced by alteration in the aminoacyl-tRNA biosynthesis pathways, in addition to alteration in the phenylalanine, tyrosine, and tryptophan biosynthesis pathway in Mcp-1 -/- mice. However, decreased signals of amino acid metabolites in mice fed the HFD and increased signals of amino acid metabolites in Mcp-1 -/- mice indicate that HFD may have down-regulated and adipose Mcp-1 knockdown may have up-regulated amino acid metabolism.

Dispersion of Serum 1,5 Anhydroglucitol Values in patients with Type 2 Diabetes at goal of HbA1c

AIM

To investigate the relationship of 1,5 anhydroglucitol (1,5 AG) with HbA1c in patients with type 2 diabetes (T2D) with different ranges of glycemic control.

METHODS

One hundred outpatients with T2D ≥ 18 years old were studied. In addition, HbA1c, glycemia, 1,5 AG, lipids, albuminuria, estimated glomerular filtration rate, and clinical data were registered.

RESULTS

The patient's median age was 62.5 years, with a median of 10 years with T2D. Those with HbA1c <7 % had higher 1,5 AG than those with HbA1c ≥ 7 %, 16.8 ug/ml vs. 4.90 (p=0.00001).1,5 AG correlated inversely with HbA1c (r= -0.7910, p=0.00001), glycemia (r= -0.6307, p=0.00001), cholesterol (r= -0.2257, p= 0.0239), LDL-cholesterol (r= -0.2240 , p=0.0266), albuminuria (r= -0.3644, p=0.0002) and heart rate (r= -0.267 ,p=0.0072). Those on insulin therapy also had lower 1,5 AG (p=0.000). The scatter plot of 1,5 AG and HbA1c fitted a second-degree fractional polynomic regression model, with dispersion of 1 5 AG when HbA1c < 7.5%. An HbA1c ≥ 7.5 % predicted a 1,5 AG <10 ug/ml CONCLUSION: Dispersion of 1,5 AG values at HbA1c < 7.5 % indicates postprandial glucose excursions that may impair glucose control and increase the cardiovascular risk in these patients.

Prognostic value of 1,5-anhydro-D-glucitol incorporating syntax score in acute coronary syndrome

The utility of adding information on 1,5-anhydro-D-glucitol (1,5-AG), a marker for postprandial hyperglycemia, to a pre-existing scoring system in acute coronary syndrome (ACS) patients is unknown. This retrospective cohort study included 266 ACS patients. The end point was major adverse cardiac and cerebral events (MACCE) through 5 years of follow-up. To evaluate incremental benefits of combining 1,5-AG with the syntax score, we applied time-dependent receiver operating curve (ROC) analysis, net reclassification improvement (NRI), integrated discrimination improvement (IDI) and decision curve analysis (DCA). Temporal changes to the area under time-dependent ROC curves showed that addition of 1,5-AG parameters to syntax score did not provide any incremental value (area under the curve for syntax alone, 0.673 (95% confidence interval (CI), 0.599-0.747) vs. with 1,5-AG combined, 0.671 (95%CI 0.596-0.746; Delong p = 0.65). Incorporating 1,5-AG into syntax score yielded a significant NRI of 0.291 (95%CI 0.015-0.567) and IDI of 0.055 (95%CI 0.018-0.093), while DCA analysis showed the limited net benefit in combination with 1,5-AG and syntax score. 1,5-AG values exhibited significant discriminatory utility for detecting MACCE within the ACS population. However, 1,5-AG levels contributed limited utility beyond syntax score based on time-dependent ROC and DCA analyses.Trial registration: UMIN000023837.

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.

1,5-anhydroglucitol is a good predictor for the treatment effect of the Sodium-Glucose cotransporter 2 inhibitor in Japanese patients with type 2 diabetes mellitus

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1,5-AG is the novel predictor of HbA1c reduction with SGLT2 inhibitors.

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1,5-AG is a useful predictor that is unaffected by the use of other diabetic drugs.

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The most appropriate 1,5-AG cutoff level is 7.65 µg/mL.

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In patients with 1,5-AG >7.7 µg/mL, SGLT2 inhibitors do not reduce HbA1c as much.

Background and Aims

The suitable selection of appropriate medicines is one of important factor in successful diabetes care. We looked for clinical indicators that could predict the effects of SGLT2 inhibitors in advance.

Methods and Results

In a single-center, this retrospective study was designed to examine predictive indices of the effectiveness of SGLT2 inhibitors. Using the medical records of 169 patients, we investigated the differences in clinical data between a group with improved glycemic control and a group with less improved glycemic control. 32 weeks of treatment with SGLT2 inhibitors decreased the HbA1c levels by 0.71%. The glucose-lowering effect was associated with improvement of the liver function. The maximum BMI change was independent of the rate of the HbA1c reduction. The HbA1c reduction was greater in patients with low 1,5-AG. This determination was unaffected by the use of anti-diabetic medication. Limiting HbA1c from 7.0% (52 mmol/mol) to 8.4% (68 mmol/mol) did not change this tendency. The maximum sum of sensitivity and specificity for patients with an HbA1c improvement of more than 0.7% was obtained with a 1,5-AG cutoff level of 7.65 µg/mL.

Conclusion

The use of SGLT2 inhibitors in patients with T2DM, 1,5-AG was identified as the most reliable indicator for predicting HbA1c reduction.

Vitreous humor endogenous compounds analysis for post-mortem forensic investigation

The chemical and biochemical analysis of bodily fluids after death is an important thanatochemical approach to assess the cause and time since death. Vitreous humor (VH) has been used as a biofluid for forensic purposes since the 1960s. Due to its established relevance in toxicology, a literature review highlighting the use of VH with an emphasis on endogenous compounds has not yet been undertaken. VH is a chemically complex aqueous solution of carbohydrates, proteins, electrolytes and other small molecules present in living organisms; this biofluid is useful tool for its isolated environment, preserved from bacterial contamination, decomposition, autolysis, and metabolic reactions. The post-mortem analysis of VH provides an important tool for the estimation of the post-mortem interval (PMI), which can be helpful in determining the cause of death. Consequently, the present review evaluates the recent chemical and biochemical advances with particular importance on the endogenous compounds present at the time of death and their modification over time, which are valuable for the PMI prediction and to identify the cause of death.

Association between 1,5-Anhydroglucitol and Acute C Peptide Response to Arginine among Patients with Type 2 Diabetes

OBJECTIVE

The aim of this study was to explore the association of 1,5-anhydroglucitol with acute C peptide response (ACPR) to arginine among patients with type 2 diabetes.

METHODS

Patients with type 2 diabetes were enrolled from the Department of Endocrinology and Metabolism, Shanghai Sixth People's Hospital. ACPR was assessed using arginine stimulation test. Decreased β-cell function was defined as ACPR < 2.1. Multivariable logistic regression models were used to demonstrate the association between 1,5-anhydroglucitol and decreased β-cell function.

RESULTS

Finally, 623 patients with type 2 diabetes were enrolled into the analysis. Multivariable-adjusted odds ratios for decreased β-cell function across quartiles of 1,5-anhydroglucitol were 1.00, 0.47 (95% confidence interval (CI) 0.23-0.99), 0.41 (95% CI 0.20-0.84), and 0.27 (95% CI 0.13-0.57) (P _trend = 0.042), respectively. When 1,5-anhydroglucitol was considered as a continuous variable after logarithm, the corresponding odds ratio was 0.40 (95% CI 0.23-0.71).

CONCLUSIONS

We demonstrated a dose-response linear association between 1,5-anhydroglucitol and ACPR. 1,5-Anhydroglucitol was likely to be associated with β-cell function. Further analysis with large sample size and prospective study design is warranted to validate our findings.

Metabolomics Identifies a Biomarker Revealing In Vivo Loss of Functional β-Cell Mass Before Diabetes Onset

Identification of individuals with decreased functional β-cell mass is essential for the prevention of diabetes. However, in vivo detection of early asymptomatic β-cell defect remains unsuccessful. Metabolomics has emerged as a powerful tool in providing readouts of early disease states before clinical manifestation. We aimed at identifying novel plasma biomarkers for loss of functional β-cell mass in the asymptomatic prediabetes stage. Nontargeted and targeted metabolomics were applied in both lean β-Phb2^-/- (β-cell-specific prohibitin-2 knockout) mice and obese db/db (leptin receptor mutant) mice, two distinct mouse models requiring neither chemical nor dietary treatments to induce spontaneous decline of functional β-cell mass promoting progressive diabetes development. Nontargeted metabolomics on β-Phb2^-/- mice identified 48 and 82 significantly affected metabolites in liver and plasma, respectively. Machine learning analysis pointed to deoxyhexose sugars consistently reduced at the asymptomatic prediabetes stage, including in db/db mice, showing strong correlation with the gradual loss of β-cells. Further targeted metabolomics by gas chromatography-mass spectrometry uncovered the identity of the deoxyhexose, with 1,5-anhydroglucitol displaying the most substantial changes. In conclusion, this study identified 1,5-anhydroglucitol as associated with the loss of functional β-cell mass and uncovered metabolic similarities between liver and plasma, providing insights into the systemic effects caused by early decline in β-cells.

Polyherbal dietary supplementation for prediabetic adults: study protocol for a randomized controlled trial

Background

Prediabetes describes a state of hyperglycemia outside of normal limits that does not meet the criteria for diabetes diagnosis, is generally symptomless, and affects an estimated 38% of adults in the United States. Prediabetes typically precedes the diagnosis of type 2 diabetes, which accounts for increased morbidity and mortality. Although the use of dietary and herbal supplements is popular worldwide, and a variety of single herbal medicines have been examined for glycemic management, the potential of increasingly common polyherbal formulations to return glycemic parameters to normal ranges among adults with prediabetes remains largely unexplored. The purpose of this study is to evaluate the efficacy of a commercially available, polyherbal dietary supplement on glycemic and lipid parameters in prediabetic individuals.

Methods

In this multi-site, double-blinded, randomized controlled clinical trial, 40 participants with prediabetes will be randomized to either a daily oral polyherbal dietary supplement (GlucoSupreme™ Herbal; Designs for Health®, Suffield, CT, USA; containing cinnamon bark (Cinnamomum cassia), banaba leaf (Lagerstroemia speciosa standardized to 1% corosolic acid), kudzu root (Pueraria lobata standardized to 40% isoflavones), fenugreek seed (Trigonella foenum-graceum standardized to 60% saponins), gymnema leaf (Gymnema sylvestre standardized to 25% gymnemic acid), American ginseng root (Panax quinquefolius standardized to 5% ginsenosides), and berberine HCl derived from bark (Berberis aristata)) or placebo for 12 weeks. Short-, medium-, and comparatively long-term markers of glycemic control (blood glucose and fasting insulin, fructosamine, and glycated hemoglobin/A1c, respectively), and other glycemic parameters (GlycoMark, β-cell function, and insulin sensitivity/resistance) will be obtained. Lipid profile (total cholesterol, LDL, HDL, and triglycerides), inflammation (hs-CRP), progression to type 2 diabetes mellitus, as well as safety indices (ALT, AST) will be obtained. An intention-to-treat analysis will be used to assess changes in study outcomes.

Discussion

Treatment options for adults with prediabetes are currently limited. This study aims to evaluate the safety and efficacy of a commercially available dietary supplement in the popular, but as yet insufficiently studied, category of polyherbal formulas for the management of glycemic parameters and other biomarkers associated with prediabetes.

Trial registration

ClinicalTrials.gov, ID: NCT03388762. Retrospectively registered on 4 January 2018.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-3032-6) contains supplementary material, which is available to authorized users.

Glucose Peaks and the Risk of Dementia and 20-Year Cognitive Decline

OBJECTIVE

Hemoglobin A_1c (HbA_1c), a measure of average blood glucose level, is associated with the risk of dementia and cognitive impairment. However, the role of glycemic variability or glucose excursions in this association is unclear. We examined the association of glucose peaks in midlife, as determined by the measurement of 1,5-anhydroglucitol (1,5-AG) level, with the risk of dementia and 20-year cognitive decline.

RESEARCH DESIGN AND METHODS

Nearly 13,000 participants from the Atherosclerosis Risk in Communities (ARIC) study were examined. Dementia was ascertained from surveillance, neuropsychological testing, telephone calls with participants or their proxies, or death certificate dementia codes. Cognitive function was assessed using three neuropsychological tests at three visits over 20 years and was summarized as z scores. We used Cox and linear mixed-effects models. 1,5-AG level was dichotomized at 10 μg/mL and examined within clinical categories of HbA_1c.

RESULTS

Over a median time of 21 years, dementia developed in 1,105 participants. Among persons with diabetes, each 5 μg/mL decrease in 1,5-AG increased the estimated risk of dementia by 16% (hazard ratio 1.16, P = 0.032). For cognitive decline among participants with diabetes and HbA_1c <7% (53 mmol/mol), those with glucose peaks had a 0.19 greater z score decline over 20 years (P = 0.162) compared with those without peaks. Among participants with diabetes and HbA_1c ≥7% (53 mmol/mol), those with glucose peaks had a 0.38 greater z score decline compared with persons without glucose peaks (P < 0.001). We found no significant associations in persons without diabetes.

CONCLUSIONS

Among participants with diabetes, glucose peaks are a risk factor for cognitive decline and dementia. Targeting glucose peaks, in addition to average glycemia, may be an important avenue for prevention.

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.

Value of serum 1,5-anhydroglucitol measurements in childhood obesity in the continuum of diabetes

PURPOSE

The prevalence of type 2 diabetes mellitus (T2DM) and obesity are currently increasing. Accordingly, the concept of "preventing diabetes" in high-risk groups has become more important in diabetic care, but the use of glycated hemoglobin (HbA1c) as a measure has limitations in this field. The aim of this study was to investigate the utility of 1,5-anhydroglucitol (1,5-AG) in assessing prediabetes status in obese children.

METHODS

The medical records of 74 subjects aged 6-19 years (of which 27 were overweight/obese and 47 had diabetes) who had 1,5-AG data were reviewed retrospectively. We compared 1,5-AG with HbA1c using the Pearson correlation test to assess the clinical utility of 1,5-AG.

RESULTS

1,5-AG levels were higher (31.1±10.1 µg/mL vs. 7.4±7.3 µg/mL) and HbA1c levels were lower (5.5%±0.3% vs. 8.9%±2.7%) in the overweight/obese group than in the diabetics group. The range of 1,5-AG levels in obese children was wide (16.8-59.3 µg/mL), and did not have significance with HbA1c. A negative correlation between 1,5-AG and HbA1c was significant in the entire subject (r=-0.822, P<0.001), and also in the HbA1c range of 5.5% to 8% (r=-0.736, P<0.001).

CONCLUSION

1,5-AG is a valuable index in the HbA1c range of 5.5%-8% and it might be considered an early glycemic control index in insulin-resistant obese children with an HbA1c level above 5.5%. Moreover, the 1,5-AG level assessment should be presented as a supplementary tool for better compliance, as well as being an improvement in diabetes management for the short-term glucose control in relatively well-controlled diabetes patients with an HbA1c level below 8%.

Effect of postprandial hyperglycaemia on coronary flow reserve in patients with impaired glucose tolerance and type 2 diabetes mellitus

BACKGROUND

This study investigated whether postprandial hyperglycaemia has an adverse effect on coronary microvascular function and left ventricular diastolic function.

METHODS

In all, 28 patients with type 2 diabetes mellitus with no significant stenosis in left anterior descending artery were enrolled. In all subjects, plasma 1,5-anhydroglucitol was measured, and coronary flow reserve in the left anterior descending artery was evaluated using a Doppler wire. Membrane type-1 matrix metalloproteinase expression on circulating peripheral blood mononuclear cells was measured by flow cytometry. Correlation analyses were performed for coronary flow reserve and 1,5-anhydroglucitol, other coronary risk factors, membrane type-1 matrix metalloproteinase and E/e'.

RESULTS

Strong correlations were found only between 1,5-anhydroglucitol and coronary flow reserve and membrane type-1 matrix metalloproteinase. On multiple regression analysis, 1,5-anhydroglucitol remained an independent predictor of coronary flow reserve (β = 0.38, p = 0.048).

CONCLUSION

Postprandial hyperglycaemia appears to have an adverse effect on coronary microvascular function, suggesting that improvement of postprandial hyperglycaemia may contribute to the improvement of coronary microvascular dysfunction.

Rational diagnoses of diabetes: the comparison of 1,5-anhydroglucitol with other glycemic markers

Diabetes mellitus (DM) is a frequently encountered disease with important morbidity and mortality. The aim of this study is to document the importance of 1,5-anhydroglucitol (1,5-AG) for the diagnosis of prediabetes and DM, as well as to compare the 1,5-AG with other glycemic markers in order to understand which one is the better diagnostic tool. Between April 2012 and December 2012, 128 participants enrolled in the study. Participants were split into five groups that are IFG, IGT, IFG+IGT, diabetic and control groups by their OGTT results. The diagnostic value of markers was compared by ROC (receiver operating characteristic) method. The mean serum 1,5-AG levels in the diabetic group (33.38 nmol/ml) were lower than, IFG (59.83 nmol/ml), IGT (54.44 nmol/ml), IFG+IGT (51.98 nmol/ml) and control groups (73.24 nmol/ml). When analyzed in the total study population serum 1,5-AG levels did not differ by gender significantly. When analyzed in the total study population, 1,5-AG correlates inversely with age significantly (p = 0.036). In subgroup analysis, in the control group, serum 1,5-AG level was also inversely correlated with age (p = 0.087). The best marker for the diagnosis of prediabetes and DM was fasting plasma glucose (FPG). 1,5-AG was not found to be effective for the diagnosis of DM. This study, contributes to our knowledge of the efficiency and cut-off values of 1,5-AG for the diagnosis of prediabetes and DM. In future, there is a need for larger studies with more standardized and commonly used measurement methods for 1,5-AG, in order to evaluate the efficiency of 1,5-AG for the diagnosis of prediabetes and DM.

1,5-anhydroglucitol is associated with early-phase insulin secretion in chinese patients with newly diagnosed type 2 diabetes mellitus

BACKGROUND

The goal of the present study was to explore the correlations of 1,5-anhydroglucitol (l,5-AG), glycated hemoglobin (HbA1c), and glycated albumin (GA) with insulin sensitivity and secretion.

SUBJECTS AND METHODS

In total, 302 patients with newly diagnosed type 2 diabetes mellitus (166 men, 136 women) were enrolled in this study. The homeostasis model assessment for insulin resistance (HOMA-IR) and homeostasis model assessment for β-cell function (HOMA-β) were calculated to determine the basal insulin sensitivity and secretion. The insulinogenic index (IGI) was used to evaluate early-phase insulin secretion. 1,5-AG and GA were assayed via the enzymatic method, and HbA1c was detected by high-pressure liquid chromatography.

RESULTS

Among all 302 subjects, the serum 1,5-AG level was 13.1±7.2 μg/mL, and the HbA1c and GA levels [median (interquartile range)] were 6.7% (6.2-7.3%) and 17.7% (16.0-19.5%), respectively. Increased 1,5-AG quartiles were accompanied by trends toward a decreased HOMA-IR and an increased HOMA-β and IGI (for all trends, P<0.001). 1,5-AG was negatively associated with HOMA-IR (r=-0.200, P<0.001) and positively associated with HOMA-β and IGI (r=0.210 and 0.413, respectively; both P<0.001). 1,5-AG was independently related to HOMA-IR and HOMA-β and exhibited an independent positive association with IGI (standardized β=0.242, P<0.001). Additionally, both HbA1c and GA were independently correlated with HOMA-IR and HOMA-β.

CONCLUSIONS

1,5-AG is not only correlated with basal insulin sensitivity and secretion, but also closely associated with early-phase insulin secretion in Chinese patients with newly diagnosed type 2 diabetes mellitus.

1,5-anhydroglucitol as a useful marker for assessing short-term glycemic excursions in type 1 diabetes

BACKGROUND

Type 1 diabetes is associated with more severe glycemic variability and more frequent hypoglycemia than type 2 diabetes. Glycemic variability is associated with poor glycemic control and diabetic complications. In this study, we demonstrate the clinical usefulness of serum 1,5-anhydroglucitol (1,5-AG) for assessing changes in glycemic excursion in type 1 diabetes.

METHODS

Seventeen patients with type 1 diabetes were enrolled in this study. A continuous glucose monitoring system (CGMS) was applied twice at a 2-week interval to evaluate changes in glycemic variability. The changes in serum glycemic assays, including 1,5-AG, glycated albumin and hemoglobin A1c (HbA1c), were also evaluated.

RESULTS

Most subjects showed severe glycemic excursions, including hypoglycemia and hyperglycemia. The change in 1,5-AG level was significantly correlated with changes in the glycemic excursion indices of the standard deviation (SD), mean amplitude of glucose excursion (MAGE), lability index, mean postmeal maximum glucose, and area under the curve for glucose above 180 mg/dL (r=-0.576, -0.613, -0.600, -0.630, and -0.500, respectively; all P<0.05). Changes in glycated albumin were correlated with changes in SD and MAGE (r=0.495 and 0.517, respectively; all P<0.05). However, changes in HbA1c were not correlated with any changes in the CGMS variables.

CONCLUSION

1,5-AG may be a useful marker for the assessment of short-term changes in glycemic variability. Furthermore, 1,5-AG may have clinical implications for the evaluation and treatment of glycemic excursions in type 1 diabetes.

Association of urinary RBP4 with insulin resistance, inflammation, and microalbuminuria

OBJECTIVE

Serum concentrations of retinol-binding protein 4 (RBP4) are elevated in type 2 diabetes and associated with the severity of insulin resistance; however, there are few data about the relationship between urinary RBP4 levels and metabolic parameters. We assessed urinary RBP4 as a new biomarker by establishing its relationship with clinical parameters associated with insulin resistance and urinary albumin excretion.

DESIGN AND METHODS

We measured RBP4 in the serum and urine of 689 subjects with diverse glucose tolerance status. We also evaluated the relationship between urinary RBP4 and cardiometabolic risk factors, including insulin resistance, high-sensitivity C-reactive protein (hsCRP), arterial stiffness, and microalbuminuria.

RESULTS

Urinary RBP4 levels were higher in insulin-resistant subjects with prediabetes or type 2 diabetes than in subjects with normal glucose tolerance (NGT) (type 2 diabetes>prediabetes>NGT; all P<0.001). Urinary RBP4 correlated strongly with homeostasis model assessments of insulin resistance (HOMA-IR), fasting glucose, triglycerides, blood pressure, hsCRP, arterial stiffness, estimated glomerular filtration rate, and urinary albumin-to-creatinine ratio (all P<0.01). HOMA-IR and arterial stiffness were found to be independent determinants of urinary RBP4 concentration. Furthermore, urinary RBP4 was highly predictive of microalbuminuria (odds ratio 2.6, 95% CI 1.6-4.2), even after adjustment for other metabolic parameters. The area under the ROC curve for urinary RBP4 to detect the presence of microalbuminuria was 0.80±0.02 (95% CI 0.76-0.84) and the cut-off value was 157.01 μg/gCr.

CONCLUSIONS

Urinary RBP4 concentrations were elevated in patients with dysregulation of glucose metabolism and were related to various cardiometabolic risk factors including insulin resistance, inflammation, and microalbuminuria.

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.

Urinary adiponectin concentration is positively associated with micro- and macro-vascular complications

BACKGROUND

A relationship between plasma adiponectin level and a number of metabolic conditions, including insulin resistance, obesity, and type 2 diabetes, has been reported. This study aimed to assess whether urinary adiponectin concentration is correlated with vascular complications.

METHODS

The study comprised 708 subjects who enrolled in the Seoul Metro City Diabetes Prevention Program and were carefully monitored from September 2008 to December 2008. Levels of urinary adiponectin were measured using an enzyme linked immunosorbent assay (ELISA) kit (AdipoGen, Korea). Urinary albumin excretion was assessed by the ratio of urinary albumin to creatinine (A/C ratio). Participants were divided into three groups based on tertiles of urinary adiponectin concentration, and we investigated whether urinary adiponectin levels are associated with microalbuminuria and pulse wave velocity.

RESULTS

Urinary adiponectin concentrations were significantly higher in subjects with microalbuminuria than subjects with normoalbuminuria (P < 0.001). Urinary adiponectin concentration was positively correlated with age, fasting plasma glucose level, HbA1C level, triglyceride level, HOMA-IR, systolic/diastolic blood pressure, and urinary A/C ratio (all P < 0.05). Subjects in the highest tertile of urinary adiponectin concentration had an increased likelihood of microalbuminuria than those in the lowest tertile (Odds ratio (OR), 6.437; 95% confidence interval (CI), 4.202 to 9.862; P < 0.001). After adjusting for age, sex, and estimated creatinine clearance rate (eCcr), the OR remained significant (OR, 5.607; 95% CI, 3.562 to 8.828; P < 0.001). Backward multiple linear regression analysis revealed urinary adiponectin concentration to be a significant determinant of mean brachial-ankle pulse wave velocity (baPWV).

CONCLUSIONS

An increased urinary adiponectin concentration is significantly associated with microalbuminuria and increased mean baPWV. These results suggest that urinary adiponectin may play an important role as a biomarker for vascular dysfunction.

High urinary ACE2 concentrations are associated with severity of glucose intolerance and microalbuminuria

OBJECTIVE

Angiotensin-converting enzyme 2 (ACE2) plays an important role in glucose metabolism and renal function. However, the relationship between ACE2 and hyperglycemia or microalbuminuria has not been established in humans. We investigated whether urinary ACE2 levels are associated with abnormal glucose homeostasis and urinary albumin excretion.

METHODS

We developed an ELISA for quantifying ACE2 in urine. The ELISA was used to measure urinary ACE2 levels in 621 subjects with: normal glucose tolerance (NGT; n=77); impaired fasting glucose (IFG) or impaired glucose tolerance (IGT) (n=132); and type 2 diabetes mellitus (T2DM, n=412). Insulin resistance was assessed by homeostasis model assessment for insulin resistance (HOMA-IR) index and urinary albumin excretion by urine albumin-to-creatinine ratio (ACR). Other biochemical and anthropometric parameters were measured.

RESULTS

Urinary ACE2 levels were significantly higher in insulin-resistant subjects with IFG, IGT, and T2DM than in the NGT group (P<0.001). Urinary ACE2 concentrations appeared to correlate with HOMA-IR, fasting blood glucose, triglyceride, high-sensitivity C-reactive protein, serum creatinine, urinary ACR, and systolic blood pressure (all P<0.05). After adjustment for impaired renal function and other metabolic parameters, urinary ACE2 concentration was still associated with a higher risk for T2DM (OR 1.80, 95% CI 1.05-3.08, P=0.02). In addition, urinary ACE2 levels were highly predictive of microalbuminuria after adjusting for clinical risk factors (OR 2.68, 95% CI 1.55-4.64, P<0.001).

CONCLUSION

Our data suggest that the urinary ACE2 level is closely associated with T2DM and is an independent risk factor for microalbuminuria.

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.

Serum 1,5-anhydroglucitol is associated with diabetic retinopathy in Type 2 diabetes

AIMS

To determine whether there is a relationship between 1,5-anhydroglucitol (1,5-AG), a marker of postprandial hyperglycaemia and glycaemic variability, and the presence of diabetic retinopathy and albuminuria in patients with Type 2 diabetes.

METHODS

Five hundred and sixty-seven patients with Type 2 diabetes (serum creatinine < 133 μmol/l), who were enrolled in the Seoul Metro-City Diabetes Prevention Program (SMC-DPP), were cross-sectionally assessed by multivariate logistic regression analysis.

RESULTS

After controlling for age, sex, binary HbA(1c) levels, duration of diabetes, triglyceride, systolic blood pressure, smoking status, history of hypertension and dyslipidaemia, and the use of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker medication, the odds ratios (95% CI) of diabetic retinopathy were 2.86 (1.12-7.25) for the first (lowest) quartile of 1,5-anhydroglucitol, 2.87 (1.25-6.61) for the second quartile and 0.88 (0.35-2.22) for the third quartile compared with the fourth quartile (P for trend = 0.010). Conversely, the associations between 1,5-anhydroglucitol and clinical albuminuria were non-significant after adjustment. Subjects with low 1,5-anhydroglucitol (< 10.0 μg/ml) were more likely to experience diabetic retinopathy than those with high 1,5-anhydroglucitol (≥ 10.0 μg/ml) under moderate glucose control (HbA(1c) < 8%, 64 mmol/mol) and there were no significant differences in the prevalence of diabetic retinopathy between the subgroup with HbA(1c) < 8% (64 mmol/mol) and low 1,5-anhydroglucitol and the subgroup with HbA(1c) ≥ 8% (64 mmol/mol).

CONCLUSIONS

1,5-Anhydroglucitol levels show close associations with diabetic retinopathy, especially among patients under moderate glucose control, but not with albuminuria. These results suggest that 1,5-anhydroglucitol might be a complementary marker for targeting higher risk group.

Increased 1,5-anhydroglucitol predicts glycemic remission in patients with newly diagnosed type 2 diabetes treated with short-term intensive insulin therapy

BACKGROUND

Short-term intensive insulin therapy has been shown to induce long-term glycemic remission in patients with newly diagnosed type 2 diabetes. However, predictors of remission are still uncertain. This study was conducted to evaluate whether changes of 1,5-anhydroglucitol (1,5AG) and fructosamine (FA) could be a predictor of remission.

SUBJECTS AND METHODS

Newly diagnosed drug-naive patients with type 2 diabetes (n = 64) were enrolled. After baseline assessments, continuous subcutaneous insulin infusion (CSII) was administered in all patients until euglycemia was achieved and maintained for another 2 weeks. Patients were subsequently followed monthly for 3 months. 1,5AG and FA were measured before and after therapy and at 1-month follow-up.

RESULTS

After CSII, A1C and FA decreased from baseline, whereas 1,5AG increased. 1,5AG was higher at 1-month follow-up (11.5 ± 4.1 vs. 6.7 ± 2.8 mg/L, P<0.001), whereas FA was lower (273.1 ± 56.1 vs. 316.2 ± 39.3 μmol/L, P = 0.021) in the remission group. Stepwise logistic regression analysis showed that 1,5AG at 1-month follow-up rather than FA was an independent predictor of remission after adjusting for other confounders (odds ratio 1.56, 95% confidence interval [CI] 1.15-2.12, P = 0.004). The area under the curve of the receiver operating characteristic curve analysis was 0.85 (95% CI 0.75-0.96, P<0.001). The optimal cutoff point for 1,5AG at 1-month follow-up was 8.9 mg/L (specificity, 83.3%; sensitivity, 78.6%).

CONCLUSIONS

Improvement of 1,5AG predicts maintenance of glycemic remission after intensive insulin therapy in patients with newly diagnosed type 2 diabetes.

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

OBJECTIVE

To assess the relationship between 1,5-anhydroglucitol (AG) levels, which are a marker of glycemic control, and stages of chronic kidney disease (CKD).

RESEARCH DESIGN AND METHODS

This was a cross-sectional study with 269 subjects with type 2 diabetes who were divided into four groups based on estimated glomerular filtration rate (eGFR) using Modification of Diet in Renal Disease (eGFR(MDRD)) formula: 57 in control, 111 in CKD stages 1-2, 78 in stage 3, and 23 in stages 4-5.

RESULTS

The study groups differed significantly with respect to 1,5-AG and fasting plasma glucose (FPG), age, duration of diabetes, blood pressure, HDL, and percentage of antihypertension or antidyslipidemia medication use. Stepwise multivariate regression analyses showed that 1,5-AG levels in the control group, the CKD stages 1-2 group, and the CKD stage 3 group could be explained by HbA(1c), age, duration of diabetes, FPG, and antihypertension medication. However, eGFR(MDRD) was the only independent determinant of 1,5-AG levels in CKD stages 4-5. Logarithmic transformed 1,5-AG values (ln[1,5-AG]) had significant inverse correlations with HbA(1c) and FPG levels for CKD stages 1-2 and CKD stage 3 (all P < 0.001). However, associations between ln(1,5-AG) and HbA(1c) or FPG were insignificant for CKD stages 4-5 (P = 0.274 and P = 0.080, respectively).

CONCLUSIONS

This study demonstrated that 1,5-AG levels do not appear to be influenced by mild or moderate renal dysfunction, suggesting it is a reliable glycemic marker in type 2 diabetes with CKD stages 1-3.

Racial differences in glycemic markers: a cross-sectional analysis of community-based data

BACKGROUND

Although differences between black and white persons in hemoglobin A(1c) (HbA(1c)) values are well established, recent studies suggest that this might not reflect differences in glycemia.

OBJECTIVE

To investigate racial disparities in glycemic markers, including those that reflect biological processes independent of hemoglobin glycation and erythrocyte turnover.

DESIGN

Cross-sectional.

SETTING

Community-based.

PARTICIPANTS

1376 nondiabetic and 343 diabetic adults in a substudy of the Atherosclerosis Risk in Communities Study.

MEASUREMENTS

Hemoglobin A(1c), fasting glucose, glycated albumin, fructosamine, and 1,5-anhydroglucitol levels.

RESULTS

Among persons with and without diabetes, black persons had significantly higher HbA(1c), glycated albumin, and fructosamine levels than white persons before and after adjustment for covariates and fasting glucose concentration. Serum 1,5-anhydroglucitol levels, which are reduced in the setting of hyperglycemia-induced glycosuria, were lower in black persons than in white persons, although this difference was statistically significant only in nondiabetic adults.

LIMITATION

The design was cross-sectional, a limited number of participants with a history of diabetes was included, and the study did not include integrated measures of circulating nonfasting glycemia.

CONCLUSION

Differences between black and white persons in glycated albumin, fructosamine, and 1,5-anhydroglucitol levels parallel differences between these groups in HbA(1c) values. Racial differences in hemoglobin glycation and erythrocyte turnover cannot explain racial disparities in these serum markers. The possibility that black persons have systematically higher levels of nonfasting glycemia warrants further study.

PRIMARY FUNDING SOURCE

National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases.

Effect of initial combination therapy with sitagliptin, a dipeptidyl peptidase-4 inhibitor, and pioglitazone on glycemic control and measures of β-cell function in patients with type 2 diabetes

AIM/HYPOTHESIS

To assess the safety and efficacy of initial combination therapy with sitagliptin and pioglitazone compared with pioglitazone monotherapy in drug-naïve patients with type 2 diabetes.

METHODS

A total of 520 patients were randomised to initial combination therapy with sitagliptin 100 mg q.d. and pioglitazone 30 mg q.d. or pioglitazone 30 mg q.d. monotherapy for 24 weeks.

RESULTS

Initial combination therapy with sitagliptin and pioglitazone led to a mean reduction from baseline in A1C of -2.4% compared with -1.5% for pioglitazone monotherapy (p<0.001). Mean reductions from baseline were greater in patients with a baseline A1C≥10% (-3.0% with combination therapy vs. -2.1% with pioglitazone monotherapy) compared with patients with a baseline A1C<10% (-2.0% with combination therapy vs. -1.1% with pioglitazone monotherapy). Sixty percent of patients in the combination therapy group vs. 28% in the pioglitazone monotherapy group had an A1C of <7% at week 24 (p<0.001). Fasting plasma glucose decreased by -63.0 mg/dl (-3.5 mmol/l) in the combination therapy group compared with -40.2 mg/dl (-2.2 mmol/l) for pioglitazone monotherapy (p<0.001), and 2-h post meal glucose decreased by -113.6 mg/dl (-6.3 mmol/l) with combination therapy compared with -68.9 mg/dl (-3.8 mmol/l) for pioglitazone monotherapy (p<0.001). Measures related to β-cell function also improved significantly with combination therapy compared with pioglitazone monotherapy. Combination therapy was generally well-tolerated compared with pioglitazone monotherapy, with similar incidences of hypoglycemia (1.1% and 0.8%, respectively), gastrointestinal adverse events (5.7% and 6.9%, respectively), and oedema (2.7% and 3.5%, respectively).

CONCLUSION/INTERPRETATION

Initial combination therapy with sitagliptin and pioglitazone substantially improved glycemic control and was generally well-tolerated compared with pioglitazone monotherapy.

Correlation between baseline serum 1,5-anhydroglucitol levels and 2-hour post-challenge glucose levels during oral glucose tolerance tests

Since there is increasing evidence that postprandial hyperglycemia is a risk factor for the development of macrovascular complications, it is important to predict postprandial hyperglycemia in the early stages of glucose intolerance, and routine medical checkups provide a good opportunity to do so. The aim of this study was to evaluate the usability of 1,5-anhydroglucitol (1,5-AG) in routine medical checkups. The subjects were 77 Japanese men who participated in a routine medical checkup. First, we performed 75 g oral glucose tolerance tests (OGTTs), and examined the changes in glucose and 1,5-AG levels measured at 0, 30, 60, 90, 120, and 180 minutes (min). 1,5-AG levels did not significantly change until 90 min after the glucose load. Second, a linear regression analysis showed an inverse correlation between the 2-hour post-challenge glucose (2h-PG) and baseline 1,5-AG levels during the OGTT (P = 0.001, r(2) = 0.13), and the correlation was still significant after adjustment for age (2h-PG = 170 + 0.83 × (age in years) - 3.23 × (1,5-AG), P = 0.002, adjusted r(2) = 0.12). Finally, to investigate the test characteristics of 1,5-AG levels as a predictor of a 2h-PG level ≥200 mg/dL, we plotted a receiver operating characteristic (ROC) curve. The area under the ROC curve was 0.78, and the maximal sum of sensitivity and specificity (78% and 72%, respectively) was obtained at a 1,5-AG cutoff level of <14.2µg/mL. We conclude that 1,5-AG values may provide an ancillary predictor of 2h-PG of 75 g OGTTs in routine medical checkups.