[Relationship between serum 1, 5-anhydroglucitol level and insulin resistance, microvascular complications in type 2 diabetes mellitus].

Objective: To explore the relationship between serum 1, 5-dehydratoglucitol (1, 5-AG) level and insulin resistance, microvascular complications in patients with type 2 diabetes mellitus (T2DM). Methods: The clinical data of 836 patients with T2DM admitted to the Changsha Central Hospital Affiliated to University of South China from May to December 2023 were retrospectively and cross-sectionally analyzed. Serum 1, 5-AG levels were detected by pyranose oxidase method. According to the microvascular complications (diabetic peripheral neuropathy, diabetic nephropathy, diabetic retinopathy), the patients were divided into simple group (no microvascular complications, n=490), complication group 1 (1 microvascular complications, n=217), and complication group 2 (2 or more microvascular complications, n=129). The relationship between serum 1, 5-AG level and the related indicators of insulin resistance in T2DM patients were explored by Spearman correlation analysis, and the influencing factors of microvascular complications in T2DM patients were explored by multiple ordered logistic regression analysis. Results: The levels of FBG(fasting blood glucose) [(7.37±0.56) mmol/L], FINS(fasting insulin) [(11.34±1.86) mU/L] and HOMA-IR(homeostatic model assessment of insulin resistance) (0.96±0.31) in simple group were lower than those in complication group 1 [(8.37±1.02) mmol/L, (16.26±2.32) mU/L, (1.32±0.41)], complication group 2 [(10.25±2.13) mmol/L, (18.53±2.67) mU/L, (1.54±0.44)], and FBG, FINS and HOMA-IR in complication group 1 were lower than those in complication group 2, and the differences were statistically significant (F=537.470, 791.690, 136.340, P<0.001). Serum 1, 5-AG level in simple group [77.16 (16.30, 128.07) µg/ml] was higher than that in complication group 1 [51.05 (14.67, 63.18) µg/ml] and complication group 2 [30.42 (12.53, 47.26) µg/ml], and the serum level of 1, 5-AG in complication group 1 was higher than that in complication group 2, and the difference was statistically significant (H=210.020, P<0.001). The results of Spearman correlation analysis showed that serum 1, 5-AG level was negatively correlated with FBG, FINS and HOMA-IR in T2DM patients (r=-0.431, -0.372, -0.546, P<0.001). The results of multiple ordered logistic regression analysis showed that Longer duration of diabetes (OR=2.261, 95%CI: 1.564-3.269), increased HbA1c (OR=2.040, 95%CI: 1.456-2.858), and increased HOMA-IR (OR=2.158, 95%CI: 1.484-3.137) and decreased 1, 5-AG (OR=2.512, 95%CI: 1.691-3.732) were independent risk factors for microvascular complications in T2DM patients (P<0.05). The results of ROC curve analysis showed that the area under the curve of serum 1, 5-AG in the identification of one microvascular complication was 0.763 (95%CI: 0.731-0.795), and the area under the curve of serum 1, 5-AG in the identification of two or more microvascular complications was 0.730 (95%CI: 0.692-0.767). Conclusion: Serum 1, 5-AG level is negatively correlated with insulin resistance in T2DM patients. Low serum 1, 5-AG level may be an independent risk factor for microvascular complications in T2DM patients.

HbA1c combined with glycated albumin or 1,5-anhydroglucitol improves the efficiency of diabetes screening in a Chinese population.

AIMS: This study aimed to evaluate the ability of HbA1c combined with glycated albumin (GA) or 1,5-anhydroglucitol (1,5-AG) to detect diabetes in residents of Jiangsu, China. METHODS: The oral glucose tolerance test (OGTT) was performed on 2184 people in Jiangsu. HbA1c , GA, 1,5-AG and other serum biochemical parameters were measured. Receiver operating characteristic curves were plotted to determine the optimal thresholds of HbA1c , GA and 1,5-AG according to the Youden index. RESULTS: (1) The optimal thresholds of HbA1c , GA and 1,5-AG for the screening of diabetes were ≥45 mmol/mol (6.3%), ≥13.0% and ≤23.0 µg/ml, respectively. (2) The sensitivities of HbA1c combined with GA and 1,5-AG were both 85%, higher than that of HbA1c (70%, p < 0.001). CONCLUSIONS: This study is suitable for cases where plasma glucose is unavailable. Among the residents of Jiangsu, HbA1c combined with GA or 1,5-AG can improve the sensitivity of diabetes screening, reduce the miss rate and save the use of OGTT. GA and 1,5-AG are superior in individuals with mild glucose metabolism disorder. GA enhances the detection of diabetes in the nonobese, and 1,5-AG enhances the detection in those with hyperuricaemia.

Irbesartan treatment does not influence plasma levels of the dicarbonyls methylglyoxal, glyoxal and 3-deoxyglucosone in participants with type 2 diabetes and microalbuminuria: An IRMA2 sub-study.

AIM: Angiotensin receptor blockers (ARBs) reduce vascular complications in diabetes independently of blood pressure. Experimental studies suggested that ARBs may restore the detoxifying enzyme glyoxalase 1, thereby lowering dicarbonyls such as methylglyoxal. Human data on the effects of ARBs on plasma dicarbonyl levels are lacking. We investigated, in individuals with type 2 diabetes, whether irbesartan lowered plasma levels of the dicarbonyls methylglyoxal, glyoxal, 3-deoxyglucosone and their derived advanced glycation end products (AGEs), and increased d-lactate, reflecting greater methylglyoxal flux. METHODS: We analysed a subset of the Irbesartan in Patients with T2D and Microalbuminuria (IRMA2) study. We measured plasma dicarbonyls methylglyoxal, glyoxal and 3-deoxyglucosone, free AGEs and d-lactate using ultra-performance liquid chromatography tandem mass-spectrometry (UPLC-MS/MS) in the treatment arm receiving 300 mg irbesartan (n = 121) and a placebo group (n = 101) at baseline and after 1 and 2 years. Effect of treatment was analysed with repeated measurements ANOVA. RESULTS: There was a slight, but significant difference in baseline median methylglyoxal levels [placebo 1119 (907-1509) nmol/l vs. irbesartan 300 mg 1053 (820-1427) nmol/l], but no significant changes were observed in any of the plasma dicarbonyls over time in either group and there was no effect of irbesartan treatment on plasma free AGEs or d-lactate levels at either 1 or 2 years. CONCLUSION: Irbesartan treatment does not change plasma levels of the dicarbonyls methylglyoxal, glyoxal and 3-deoxyglucosone, free AGEs or d-lactate in type 2 diabetes. This indicates that increased dicarbonyls in type 2 diabetes are not targetable by ARBs, and other approaches to lower systemic dicarbonyls are needed in type 2 diabetes. (Clinical Trial Registry No: #NCT00317915).

Effect of 1,5-anhydroglucitol levels on culprit plaque rupture in diabetic patients with acute coronary syndrome.

BACKGROUND: Postprandial hyperglycemia was reported to play a key role in established risk factors of coronary artery diseases (CAD) and cardiovascular events. Serum 1,5-anhydroglucitol (1,5-AG) levels are known to be a clinical marker of short-term postprandial glucose (PPG) excursions. Low serum 1,5-AG levels have been associated with occurrence of CAD. However, the relationship between 1,5-AG levels and coronary plaque rupture has not been fully elucidated. The aim of this study was to evaluate 1,5-AG as a predictor of coronary plaque rupture in diabetic patients with acute coronary syndrome (ACS). METHODS: A total of 144 diabetic patients with ACS were included in this study. All patients underwent intravascular ultrasound examination, which revealed 49 patients with plaque rupture and 95 patients without plaque rupture in the culprit lesion. Fasting blood glucose (FBG), hemoglobin A1c (HbA1c) and 1,5-AG levels were measured before coronary angiography. Fasting urinary 8-iso-prostaglandin F2α (8-iso-PGF2α) level was measured and corrected by creatinine clearance. RESULTS: Patients with ruptured plaque had significantly lower serum 1,5-AG levels, longer duration of diabetes, higher HbA1c and FBG levels than patients without ruptured plaque in our study population. In multivariate analysis, low 1,5-AG levels were an independent predictor of plaque rupture (odds ratio 3.421; P = 0.005) in diabetic patients with ACS. The area under the receiver-operating characteristic curve for 1,5-AG (0.658, P = 0.002) to predict plaque rupture was superior to that for HbA1c (0.587, P = 0.087). Levels of 1,5-AG were significantly correlated with urinary 8-iso-prostaglandin F2α levels (r = - 0.234, P = 0.005). CONCLUSIONS: Serum 1,5-AG may identify high risk for coronary plaque rupture in diabetic patients with ACS, which suggests PPG excursions are related to the pathogenesis of plaque rupture in diabetes.

Impact of serum 1,5-anhydro-D-glucitol level on the prediction of severe coronary artery calcification: an intravascular ultrasound study.

BACKGROUND: A low 1,5-anhydro-D-glucitol (AG) blood level is considered a clinical marker of postprandial hyperglycemia. Previous studies reported that 1,5-AG levels were associated with vascular endothelial dysfunction and coronary artery disease (CAD). However, the association between 1,5-AG levels and coronary artery plaque in patients with CAD is unclear. METHODS: This study included 161 patients who underwent percutaneous coronary intervention for CAD. The culprit plaque characteristics and the extent of coronary calcification, which was measured by the angle of its arc, were assessed by preintervention intravascular ultrasound (IVUS). Patients with chronic kidney disease or glycosylated hemoglobin ≥ 7.0 were excluded. Patients were divided into 2 groups according to serum 1,5-AG levels (< 14.0 µg/mL vs. ≥ 14 µg/mL). RESULTS: The total atheroma volume and the presence of IVUS-attenuated plaque in the culprit lesions were similar between groups. Calcified plaques were frequently observed in the low 1,5-AG group (p = 0.06). Compared with the high 1,5-AG group, the low 1,5-AG group had significantly higher median maximum calcification (144° vs. 107°, p = 0.03) and more frequent calcified plaques with a maximum calcification angle of ≥ 180° (34.0% vs. 13.2%, p = 0.003). Multivariate logistic regression analysis showed that a low 1,5-AG level was a significant predictor of a greater calcification angle (> 180°) (OR 2.64, 95% CI 1.10-6.29, p = 0.03). CONCLUSIONS: Low 1,5-AG level, which indicated postprandial hyperglycemia, was associated with the severity of coronary artery calcification. Further studies are needed to clarify the effects of postprandial hyperglycemia on coronary artery calcification.

Response of 1,5-anhydroglucitol level to intensive glucose- and blood-pressure lowering interventions, and its associations with clinical outcomes in the ADVANCE trial.

AIMS: To evaluate 1,5-anhydroglucitol (1,5-AG) according to clinical outcomes and assess the effects of glucose- and blood pressure-lowering interventions on change in 1,5-AG levels in people with type 2 diabetes. METHODS: We measured 1,5-AG in 6826 stored samples at baseline and in a random subsample of 684 participants at the 1-year follow-up visit in the ADVANCE trial. We examined baseline 1,5-AG [< 39.7, 39.7-66.2, ≥ 66.2 µmol/L (<6, 6-10, ≥10 µg/mL)] and microvascular and macrovascular events and mortality using Cox regression models during 5 years of follow-up. Using an intention-to-treat approach, we examined 1-year change in 1,5-AG (mean and percent) in response to the glucose- and blood pressure-lowering interventions in the subsample. RESULTS: Low 1,5-AG level [<39.7 µmol/L vs ≥ 66.2 µmol/L (<6 µg/mL vs ≥10 µg/mL)] was associated with microvascular events (hazard ratio 1.28, 95% confidence interval 1.03-1.60) after adjustment for risk factors and baseline glycated haemoglobin (HbA1c); however, the associations for macrovascular events and mortality were not independent of HbA1c. The glucose-lowering intervention was associated with a significant 1-year increase in 1,5-AG (vs standard control) of 6.69 µmol/L (SE 2.52) [1.01 µg/mL (SE 0.38)], corresponding to an 8.26% (SE 0.10%) increase from baseline. We also observed an increase in 1,5-AG of similar magnitude in response to the blood pressure intervention independent of the glucose-lowering effect. CONCLUSIONS: Our results suggest that 1,5-AG is a marker of risk in adults with type 2 diabetes, but only for microvascular events independently of HbA1c. We found that 1,5-AG was improved (increased) in response to an intensive glucose-lowering intervention, although the independent effect of the blood pressure-lowering intervention on 1,5-AG suggests potential non-glycaemic influences.

Screening for cystic fibrosis-related diabetes and prediabetes: Evaluating 1,5-anhydroglucitol, fructosamine, glycated albumin, and hemoglobin A1c.

OBJECTIVE: Dysglycemia is prevalent in cystic fibrosis (CF) but screening with annual oral glucose tolerance tests (OGTT) can be burdensome. We investigated alternate glycemic markers-hemoglobin A1c (HbA1c), 1,5-anhydroglucitol (1,5AG), fructosamine (FA), and glycated albumin (GA)-as screening tests for CF-related diabetes (CFRD) and pre-diabetes (CFPD) in youth with CF as defined by the gold-standard OGTT 2-hour glucose (2hG). METHODS: Youth 10 to 18 years with CF had a 1,5AG, FA, GA, HbA1c, and 2-hour OGTT collected. Correlations between all glycemic markers and 2hG were evaluated. Area under the receiver operative characteristic (ROC-AUC) curves were generated. Optimal cut points for predicting CFPD (2hG ≥ 140 mg/dL) and CFRD (2hG ≥ 200 mg/dL) were determined. RESULTS: Fifty-eight youth with CF were included (2hG < 140, n = 16; CFPD, n = 33; CFRD, n = 9; 41% male, mean ± SD age 14.2 ± 3.6 years, BMI z-score 0.0 ± 0.8, % predicted forced expiratory volume in 1 second [FEV1] 89.9 ± 15.1, % predicted forced vital capacity [FVC] 103.2 ± 14.6). ROC-AUC's for all alternate markers were low for CFPD (0.52-0.67) and CFRD (0.56-0.61). At a cut point of 5.5%, HbA1c had 78% sensitivity (95% CI: 0.45-0.94) and 41% specificity (95% CI: 0.28-0.55) for identifying CFRD, correlating to a ROC-AUC of 0.61 (95% CI: 0.42-0.8). CONCLUSIONS: All alternate markers tested demonstrate poor diagnostic accuracy for identifying CFRD by 2hG.

Serum 1,5-Anhydroglucitol Concentration as a Biomarker for Type 1 Diabetes in Adults and Children.

BACKGROUND: Type 1 diabetes (T1D) is an autoimmune disease and the leading form of diabetes among young white people. 1,5-Anhydroglucitol (1,5-AG), a nontraditional biomarker of postprandial glycemic control (after 1 - 3 days to 2 weeks), may be useful in T1D screening. We studied serum 1,5-AG concentration as a potential biomarker for T1D screening and diagnosis in adults and children. METHODS: In this case-control study, adults (n = 121; age, 19 - 61 years) and children (n = 19; age, 8 - 14 years) with T1D were matched with healthy subjects (n = 242) according to gender and age. Serum 1,5-AG levels were measured enzymatically (GlycoMark Inc., NY, USA). RESULTS: Patients showed no symptoms of overt kidney disease, assessed by serum creatinine concentrations. The median (25th - 75th percentile) 1,5-AG concentrations for the control group compared with the T1D group were 155 (128 - 183) vs. 21 (14 - 34) µmol/L in adults and 190 (158 - 237) vs. 20 (12 - 30) µmol/L in children (p < 0.001 for both). Receiver operating characteristic curves showed that 1,5-AG cutoffs of ≤ 113 and ≤ 79 µmol/L for adult men and women, respectively, and ≤ 57 µmol/L for children of both genders had > 95% sensitivity and specificity for both groups. CONCLUSIONS: Our results suggest that serum 1,5-AG concentration may be useful as an adjunct measure of hyperglycemia for diagnosing T1D and has the potential to screen for T1D in high-risk subjects.

Methylglyoxal as a prognostic factor in patients with chronic kidney disease.

AIM: Advanced glycation end products and their precursors cause vascular damage through oxidative stress. We investigated the hypothesis that methylglyoxal (MG), 3-deoxyglucosone (3-DG) and pentosidine influence outcomes of chronic kidney disease (CKD) patients. METHODS: We conducted a 3 years prospective observational study involving 150 outpatients at CKD stages 3-5. At enrolment, MG, 3-DG and pentosidine plasma concentrations were measured; patients were divided into tertiles according to the concentration of each substance. The primary endpoint was death, a cardiovascular event or end-stage renal disease. Survival analysis was performed using the Cox regression model. RESULTS: The patients' mean age was 62 ± 12 years, 97 were men, and 20 had diabetic nephropathy. The mean estimated glomerular filtration rate was 25.0 ± 12.1 mL/min per 1.73 m2 , which negatively correlated with MG but not with 3-DG and pentosidine. Forty-eight patients reached the primary endpoint. Compared with the lowest MG tertile, the hazard ratio for the primary endpoint was 7.57 (95% confidence interval (CI): 1.71-33.54) in the middle tertile and 27.00 (CI: 6.46-112.82) in the highest tertile. When adjusted for characteristics at baseline, the corresponding hazard ratio decreased to 2.09 (CI: 0.37-11.96) and 6.13 (CI: 0.97-38.82), but MG tertile remained an independent risk factor for the primary endpoint. However, 3-DG and pentosidine were not related to the primary outcome. CONCLUSION: Methylglyoxal has a close clinical association with CKD. Higher MG concentrations may contribute renal function deterioration in CKD. In CKD patients, MG concentration might be useful when determining the prognosis.

Establishment of Community-Based Reference Intervals for Fructosamine, Glycated Albumin, and 1,5-Anhydroglucitol.

BACKGROUND: There is growing interest in fructosamine, glycated albumin, and 1,5-anhydroglucitol (1,5-AG) as alternative measures of hyperglycemia, particularly for use in settings where traditional measures (glucose and HbA1c) are problematic or where intermediate (2-4 weeks) glycemic control is of interest. However, reference intervals for these alternative biomarkers are not established. METHODS: We measured fructosamine, glycated albumin, and 1,5-AG in a community-based sample of US black and white adults who participated in the Atherosclerosis Risk in Communities (ARIC) Study. We calculated reference intervals, evaluated demographic differences, and derived cutoffs aligned with current diagnostic cutpoints for HbA1c and fasting glucose. RESULTS: In a healthy reference population of 1799 individuals (mean age, 55 years; 51% women; 15% black), the 2.5 and 97.5 percentiles, respectively, were 194.8 and 258.0 µmol/L for fructosamine, 10.7% and 15.1% for glycated albumin, and 8.4 and 28.7 µg/mL for 1,5-AG. Distributions differed by race, sex, and body mass index. Equivalent concentrations of fructosamine and glycated albumin corresponding to an HbA1c of 6.5% (96.5 percentile) were 270.2 µmol/L and 15.6%, respectively. Equivalent concentrations of fructosamine and glycated albumin corresponding to a fasting glucose of 126 mg/dL (93.9 percentile) were 261.7 µmol/L and 15.0%, respectively. CONCLUSIONS: The reference intervals for these biomarkers should inform their clinical use. Diagnostic cutpoint equivalents for fructosamine and glycated albumin could be useful to identify persons with hyperglycemia in settings where fasting glucose or HbA1c are not available or where the interpretation of these traditional measures is problematic.

A decrease in serum 1,5-anhydroglucitol levels is associated with the presence of a first-degree family history of diabetes in a Chinese population with normal glucose tolerance.

AIM: This study aimed to investigate alterations in HbA1c , glycated albumin (GA) and 1,5-anhydroglucitol (1,5-AG) in Chinese first-degree relatives of individuals with diabetes (FDR) in pursuit of an index for early screening of glucose metabolism disturbance. METHODS: A total of 467 participants (age range: 20-78 years) with normal weight and normal glucose tolerance, as determined by a 75-g oral glucose tolerance test, were enrolled. HbA1c was measured using high-performance liquid chromatography. Serum GA and 1,5-AG levels were determined by enzymatic methods. Serum insulin levels were measured using an electrochemiluminescence immunoassay. RESULTS: The study population included 208 FDR and 259 non-FDR. Serum 1,5-AG levels were lower in FDR than that in non-FDR (20.4 ± 7.5 vs 23.8 ± 8.3 µg/ml, P < 0.001), but HbA1c and GA levels did not differ between them (P = 0.835 and 0.469, respectively). Logistic regression analysis revealed an independent relationship between a first-degree family history of diabetes and reduced serum 1,5-AG levels (odds ratio = 0.944, P < 0.001). Multiple regression analysis showed that a first-degree family history of diabetes (ß = -3.041, P < 0.001) and insulinogenic index (ß = 0.081, P = 0.001) were independently associated with serum 1,5-AG levels. CONCLUSION: In a Chinese population with normal glucose tolerance, serum 1,5-AG levels were lower among FDR, and serum 1,5-AG levels were independently associated with FDR status. For FDR, serum 1,5-AG levels were more sensitive than HbA1c or GA levels to early-phase abnormality in glucose metabolism.

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.

Serum Levels of 1,5-Anhydroglucitol and Risk of Incident End-Stage Renal Disease.

Glycemic excursions, independent of average glucose, have been implicated in the development of diabetic complications. It is unknown whether low levels of 1,5-anhydroglucitol (1,5-AG) are associated with advanced stages of kidney disease independent of kidney function and glycemia. In the Atherosclerosis Risk in Communities Study (n = 13,277 from 4 US communities), we used structural equation modeling to estimate the association between serum 1,5-AG levels and end-stage renal disease (ESRD) from baseline (1990-1992) through 2013 with adjustment for demographics, risk factors, a latent variable for glycemia (diabetes status, fasting glucose, glycated hemoglobin (HbA1c), fructosamine, glycated albumin), and a latent variable for kidney function (creatinine, cystatin C, ß2-microglobulin). After adjusting for demographics, risk factors, and the latent variable for kidney function, the linear spline terms representing 1,5-AG levels <6.0 µg/mL (incidence rate ratio (IRR) = 0.79, 95% confidence interval (CI): 0.70, 0.88) and 6.0-9.9 µg/mL (IRR = 0.80, 95% CI: 0.70, 0.92) were significantly associated with ESRD. After additionally adjusting for the latent variable for glycemia, low 1,5-AG levels (<6.0 µg/mL) were no longer significantly associated with ESRD (IRR = 0.92, 95% CI: 0.81, 1.05). In conclusion, low 1,5-AG levels are associated with higher risk of incident ESRD independent of baseline kidney function but not independent of glycemia.

Low 1,5-anhydroglucitol levels are associated with long-term cardiac mortality in acute coronary syndrome patients with hemoglobin A1c levels less than 7.0.

BACKGROUND: Diabetes mellitus is considered an important risk factor for cardiovascular diseases. High hemoglobin A1c (HbA1c) levels, which indicate poor glycemic control, have been associated with occurrence of cardiovascular diseases. There are few parameters which can predict cardiovascular risk in patients with well-controlled diabetes. Low 1,5-anhydroglucitol (1,5-AG) levels are considered a clinical marker of postprandial hyperglycemia. We hypothesized that low 1,5-AG levels could predict long-term mortality in acute coronary syndrome (ACS) patients with relatively low HbA1c levels. METHODS: The present study followed a retrospective observational study design. We enrolled 388 consecutive patients with ACS admitted to the cardiac intensive care unit at the Juntendo University Hospital from January 2011 to December 2013. Levels of 1,5-AG were measured immediately before emergency coronary angiography. Patients with early stent thrombosis, no significant coronary artery stenosis, malignancy, liver cirrhosis, a history of gastrectomy, current steroid treatment, moderately to severely reduced kidney function (estimated glomerular filtration rate < 45 ml/min/1.73 m2; chronic kidney disease stage 3B, 4, and 5), HbA1c levels ≥ 7.0%, and those who received sodium glucose co-transporter 2 inhibitor therapy were excluded. RESULTS: During the 46.9-month mean follow-up period, nine patients (4.5%) died of cardiovascular disease. The 1,5-AG level was significantly lower in the cardiac death group compared with that in the survivor group (12.3 ± 5.3 vs. 19.2 ± 7.7 µg/ml, p < 0.01). Kaplan-Meier survival analysis showed that low 1,5-AG levels were associated with cardiac mortality (p = 0.02). Multivariable Cox regression analysis showed that 1,5-AG levels were an independent predictor of cardiac mortality (hazard ratio 0.76; 95% confidence interval 0.41-0.98; p = 0.03). CONCLUSION: Low 1,5-AG levels, which indicate postprandial hyperglycemia, predict long-term cardiac mortality even in ACS patients with HbA1c levels < 7.0%.

Effects of dietary carbohydrate on 1,5-anhydroglucitol in a population without diabetes: results from the OmniCarb trial.

AIMS: To determine the effects of dietary changes in amount and type of carbohydrate on 1,5-anhydroglucitol levels. METHODS: We conducted an ancillary study to a completed, randomized clinical trial in overweight and obese adults without diabetes (N=159). Using a crossover design, participants were fed each one of four diets in turn for 5 weeks, with 2-week washout periods inbetween. The four diets were: high glycaemic index (≥65) with high proportion of carbohydrate (58% kcal) (GC); low glycaemic index (GI≤45) with low proportion of carbohydrate (40% kcal) (gc); low glycaemic index with high proportion of carbohydrate (gC); and high glycaemic index with low proportion of carbohydrate (Gc). Plasma 1,5-anhydroglucitol levels were measured at baseline and after each feeding period. RESULTS: At baseline, participants had a mean age of 53 years (53% women, 52% non-Hispanic black, 50% obese). Their mean fasting glucose and 1,5-anhydroglucitol levels were 97 mg/dl (5.4 mmol/l) and 18.6 µg/mL (113.3 µmol/l), respectively. Compared with baseline, each of the four diets reduced 1,5-anhydroglucitol by a range of -2.4 to -3.7 µg/mL (-14.6 to -22.5 µmol/l); all P <0.001). Reducing either glycaemic index or proportion of carbohydrate lowered 1,5-anhydroglucitol levels. These effects were additive, such that reducing both glycaemic index and proportion of carbohydrates decreased 1,5-anhydroglucitol by -1.31 µg/mL [95% CI: -1.63, -0.99; P<0.001 or -8.0 (-9.9, -6.0) µmol/l]. Furthermore, these effects were confirmed in a subgroup of participants with 12-h glucose monitoring and no documented hyperglycaemia (fasting glucose <160 mg/dl or 8.9 mmol/l). CONCLUSIONS: Both type and amount of dietary carbohydrate affect 1,5-anhydroglucitol plasma concentrations in adults without diabetes. This finding contradicts the long-standing notion that 1,5-anhydroglucitol remains at constant concentrations in the blood in the absence of hyperglycaemic excursions. (Clinical trials registry number: NCT00051350).

Serum 1,5-Anhydroglucitol: Risk Factor of Acute Ischemic Stroke and Transient Ischemic Attack in Well-Controlled Diabetes.

BACKGROUND: Serum 1,5-anhydroglucitol (1,5-AG) levels are a measure that provides information on daily glycemic variations. We evaluated whether 1,5-AG could be a possible marker of acute ischemic stroke (AIS) or transient ischemic attacks (TIA) in patients with diabetes mellitus (DM). METHODS: We retrospectively reviewed electronic medical records of 5,294 AIS/TIA patients. Of the 5,294, 1,898 had diabetes and in 1,246, serum 1,5-AG levels were measured (group S). Group S was divided into 2 subgroups: hemoglobin A1c (HbA1c) <7% (S-low) and >7% (S-high). As controls, 394 outpatients with diabetes (group C) without AIS/TIA were likewise divided into subgroups, C-low and C-high according to HbA1c level. In each HbA1c subgroup, the association between serum 1,5-AG (≥14 vs. <14 µg/mL) and stroke was examined using multivariable logistic regression (MLR) with stepwise variable selection. In model 1, the OR and 95% CI was examined adjusted for age and gender. Known risk factors for stroke; hypertension, dyslipidemia, alcohol consumption, smoking, and estimated glomerular filtration rate were included in model 2. RESULTS: Overall, serum 1,5-AG levels were lower in group S than in group C. Serum 1,5-AG levels were low in subgroups S-high and C-high, showing no differences in mean values. However, mean serum 1,5-AG levels in S-low was statistically lower than that in C-low. MLR analysis showed that the OR for low (<14 µg/mL) 1,5-AG for stroke was statistically significant only in well-controlled diabetes (OR [95% CI] 2.19 [1.54-3.10]) in model 1 and (2.26 [1.56-3.28]) model 2. CONCLUSIONS: Low serum 1,5-AG levels could be a possible marker for AIS/TIA risk in patients with well-controlled DM.

Alternate glycemic markers reflect glycemic variability in continuous glucose monitoring in youth with prediabetes and type 2 diabetes.

OBJECTIVE: To determine whether the alternate glycemic markers, fructosamine (FA), glycated albumin (GA), and 1,5-anhydroglucitol (1,5AG), predict glycemic variability captured by continuous glucose monitoring (CGM) in obese youth with prediabetes and type 2 diabetes (T2D). STUDY DESIGN: Youth with BMI ≥85th%ile, 10-18 years, had collection of fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), FA, GA, and 1,5AG and 72 hours of CGM. Participants with HbA1c ≥5.7% were included. Relationships between glycemic markers and CGM variables were determined with Spearman correlation coefficients. Linear models were used to examine the association between alternate markers and CGM measures of glycemic variability-standard deviation (SD) and mean amplitude of glycemic excursions (MAGE)-after controlling for HbA1c. RESULTS: Total n = 56; Median (25th%ile, 75th%ile) age = 14.3 years (12.5, 15.9), 32% male, 64% Hispanic, 20% black, 13% white, HbA1c = 5.9% (5.8, 6.3), FA=211 mmol/L (200, 226), GA= 12% (11%, 12%), and 1,5AG = 22mcg/mL (19, 26). HbA1c correlated with average sensor glucose, AUC, SD, MAGE, and %time > 140 mg/dL. FA and GA correlated with average and peak sensor glucose, %time >140 and >200 mg/dL, and MAGE. GA also correlated with SD and AUC180. 1,5AG correlated with peak glucose, AUC180, SD, and MAGE. After adjusting for HbA1c, all 3 markers independently predicted MAGE; FA and GA independently predicted SD. CONCLUSIONS: Alternate glycemic markers predict glycemic variability as measured by CGM in youth with prediabetes and T2D. After adjusting for HbA1c, these alternate markers continued to predict components of glycemic variability detected by CGM.

The establishment of biological reference intervals of nontraditional glycemic markers in a Chinese population.

BACKGROUND: We established the reference intervals for glycated albumin (GA), fructosamine (FA), and 1,5-anhydroglucitol (1,5-AG) in a Chinese healthy population. METHODS: This study enrolled a total of 458 eligible reference individuals, consisted of 226 men and 232 women, aged from 20~79 years (median age 43 years), who attending routine healthy checks. We stratified the subjects according to gender (males and females) and age (20-39, 40-59, and 60-79 years), and combined statistical methods with Lahti algorithm, as well as appropriate clinical consideration, to judge whether partitioning for data was needed. RESULTS: Glycated albumin levels between males and females were statistically different (P<.001), but the absolute difference between the upper reference limits was only 0.31%, which was too small to be clinically relevant. GA levels across the three age groups were statistically different (P<.001), and Lahti algorithm suggested partitioning for 20-59 and 60-79 years, which reference intervals were 10.38%-13.89% and 10.23%-14.79%, respectively. 1,5-AG levels in males were significant higher than females (P<.001), and absolute difference was 51 µmol/L (8.5 µg/mL) in mean level. Thus, partitioning for gender was needed. Reference intervals for 1,5-AG were 107-367 µmol/L for males and 79-306 µmol/L for females. The absolute difference of the lower reference limits for FA was only 7 µmol/L between males and females. FA levels across the three age groups were not statistically different (P>.05). The reference interval for FA was 220-298 µmol/L. CONCLUSION: New reference intervals for nontraditional glycemic markers were established based on a Chinese population.

Measurement of 1,5-anhydroglucitol in blood and saliva: from non-targeted metabolomics to biochemical assay.

BACKGROUND: Diabetes testing using saliva, rather than blood and urine, could facilitate diabetes screening in public spaces. We previously identified 1,5-anhydro-D-glucitol (1,5-AG) in saliva as a diabetes biomarker. The Glycomark™ assay kit is FDA approved for 1,5-AG measurement in blood. Here we evaluated its applicability for 1,5-AG quantification in saliva. METHODS: Using pooled saliva samples, we validated Glycomark™ assay use with a RX Daytona(+) clinical chemistry analyser. We then used this set-up to analyse 82 paired blood and saliva samples from a diabetes case-control study, for which broad mass spectrometry-based characterization of the blood and saliva metabolome was also available. Osmolality was measured to account for potential variability in saliva samples. RESULTS: The technical variability of the read-outs for the pooled saliva samples (CV = 2.05 %) was comparable to that obtained with manufacturer-provided blood surrogate quality controls (CV = 1.38-1.8 %). We found a high correlation between Glycomark assay and mass spectrometry measurements of serum 1,5-AG (r(2) = 0.902), showing reproducibility of the non-targeted metabolomics results. The significant correlation between the osmolality measurements performed at two independent platforms with the time interval of 2 years (r(2) = 0.887), also indicates the sample integrity. The assay read-out for saliva was not correlated with the mass spectrometry-based 1,5-AG saliva measurements. Comparison with the full saliva metabolome revealed a high correlation of the saliva assay read-outs with galactose. CONCLUSIONS: Glycomark™ assay read-outs for saliva were stable and replicable. However, the signal was dominated by galactose, which is biochemically similar to 1,5-AG and absent in blood. Adapting the 1,5-AG kit for saliva analysis will require enzymatic depletion of galactose. This should be feasible, since the assay already includes a similar step for glucose depletion from blood samples.

Low and exacerbated levels of 1,5-anhydroglucitol are associated with cardiovascular events in patients after first-time elective percutaneous coronary intervention.

BACKGROUND: Postprandial hyperglycemia plays an important role in the pathogenesis of coronary artery disease and cardiovascular events. Serum 1,5-anhydroglucitol (1,5-AG) levels are known to be a clinical marker of postprandial hyperglycemia. However, the impact of 1,5-AG level on cardiovascular events has not been fully investigated. METHODS: We enrolled 240 consecutive patients who had undergone first-time elective percutaneous coronary intervention (PCI) with follow-up angiography within 1 year. We excluded patients with a history of acute coronary syndrome, advanced chronic kidney disease (estimated glomerular filtration rate <30 mL/min/1.73 m2), or uncontrolled diabetes mellitus (HbA1c ≥7.0 %). Fasting blood glucose (FBS), HbA1c, and 1,5-AG levels were measured prior to PCI and at the time of follow-up angiography. Clinical events, including target lesion revascularization, target vessel revascularization, and revascularization of new lesions, were evaluated. RESULTS: Subjects were divided into two groups according to clinical outcomes: the Event (+) group (n = 40) and the Event (-) group (n = 200). No significant differences were observed, except for the number of diseased vessels and the prevalence of statin use, in baseline clinical characteristics between the two groups. Serum levels of 1,5-AG at follow-up were significantly lower in the Event (+) group than in the Event (-) group (P = 0.02). A significant reduction in 1,5-AG level from baseline to follow-up was observed in the Event (+) group compared with the Event (-) group (P = 0.04). The association between 1,5-AG levels at follow-up and clinical events remained significant after adjustment for independent variables, including FBS and HbA1c levels (P = 0.04). CONCLUSIONS: Low and exacerbated levels of 1,5-AG were associated with cardiovascular events in the present study, indicating that postprandial hyperglycemia is an important risk factor for adverse clinical events even in patients with HbA1c < 7.0 %, following first-time elective PCI.