SGLT5 is the renal transporter for 1,5-anhydroglucitol, a major player in two rare forms of neutropenia

Neutropenia and neutrophil dysfunction in glycogen storage disease type 1b (GSD1b) and severe congenital neutropenia type 4 (SCN4), associated with deficiencies of the glucose-6-phosphate transporter (G6PT/SLC37A4) and the phosphatase G6PC3, respectively, are the result of the accumulation of 1,5-anhydroglucitol-6-phosphate in neutrophils. This is an inhibitor of hexokinase made from 1,5-anhydroglucitol (1,5-AG), an abundant polyol in blood. 1,5-AG is presumed to be reabsorbed in the kidney by a sodium-dependent-transporter of uncertain identity, possibly SGLT4/SLC5A9 or SGLT5/SLC5A10. Lowering blood 1,5-AG with an SGLT2-inhibitor greatly improved neutrophil counts and function in G6PC3-deficient and GSD1b patients. Yet, this effect is most likely mediated indirectly, through the inhibition of the renal 1,5-AG transporter by glucose, when its concentration rises in the renal tubule following inhibition of SGLT2. To identify the 1,5-AG transporter, both human and mouse SGLT4 and SGLT5 were expressed in HEK293T cells and transport measurements were performed with radiolabelled compounds. We found that SGLT5 is a better carrier for 1,5-AG than for mannose, while the opposite is true for human SGLT4. Heterozygous variants in SGLT5, associated with a low level of blood 1,5-AG in humans cause a 50-100% reduction in 1,5-AG transport activity tested in model cell lines, indicating that SGLT5 is the predominant kidney 1,5-AG transporter. These and other findings led to the conclusion that (1) SGLT5 is the main renal transporter of 1,5-AG; (2) frequent heterozygous mutations (allelic frequency > 1%) in SGLT5 lower blood 1,5-AG, favourably influencing neutropenia in G6PC3 or G6PT deficiency; (3) the effect of SGLT2-inhibitors on blood 1,5-AG level is largely indirect; (4) specific SGLT5-inhibitors would be more efficient to treat these neutropenias than SGLT2-inhibitors.

Understanding the role of SGLT2 inhibitors in glycogen storage disease type Ib: the experience of one UK centre

BACKGROUND

Glycogen storage disease type Ib (GSD Ib) is a severe disorder of carbohydrate metabolism due to bi-allelic variants in SLC37A4. It is associated with neutropaenia and neutrophil dysfunction, which has recently been attributed to the accumulation of 1,5-anhydroglucitol-6-phosphate (1,5AG6P) within neutrophils. Treatment with sodium-glucose co-transporter-2 (SGLT2) inhibitors, such as empagliflozin, is a novel therapy that reduces 1,5-anhydroglucitol (1,5AG) in plasma.

RESULTS

We report our experience in treating 8 paediatric GSD Ib patients with empagliflozin with a cumulative treatment time greater than 12 years. Treatment with a median dose of 5 mg (0.22 mg/kg height weight) of empagliflozin resulted in improvement in bowel health, growth, and laboratory parameters. Plasma 1,5AG levels reduced by a median of 78%. Baseline 1,5AG levels in our cohort were higher than in adult patients with GSD Ib. Hypoglycaemia on empagliflozin treatment occurred in 50% of our cohort.

CONCLUSION

We report the largest single centre cohort of GSD Ib patients treated with empagliflozin to date. Treatment with SGLT2 inhibitors is a novel and favourable treatment option for neutropaenia and neutrophil dysfunction in GSD Ib. We suggest a low starting dose of empagliflozin with careful titration due to the risk of hypoglycaemia. The interpretation of 1,5AG levels and their role in treatment monitoring is yet to be established, and requires ongoing research.

[Research on consistency of different measurement methods for saliva 1,5-anhydroglucitol]

Objective: To evaluate the consistency of different measurement methods of saliva 1,5-anhydroglucitol (1,5-AG) in different glucose metabolism populations. Methods: From January 2018 to June 2019, 175 healthy volunteers (21-65 years, 58 males and 117 females) with normal glucose tolerance (NGT) and 80 diabetic patients (18-70 years, 44 males and 36 females) were enrolled in Shanghai Jiao Tong University Affiliated Sixth People's Hospital. Saliva was collected by saliva collection tube, and 1,5-AG was measured using both enzymatic and mass spectrometry methods. Serum 1,5-AG was determined by enzymatic method. Results: In NGT subjects, both serum and saliva 1,5-AG levels detected by enzymatic method were positively correlated with the saliva 1,5-AG levels detected by liquid chromatography-mass spectrometry (r=0.247 and 0.523, respectively, both P<0.05). However, there was no significant correlation between saliva and serum 1,5-AG levels detected by enzymatic method (r=-0.074, P=0.333). In diabetic patients, both serum and saliva 1,5-AG levels detected by enzymatic method were positively correlated with the saliva 1,5-AG levels detected by gas chromatography-mass spectrometry (r=0.284 and 0.423, respectively, both P<0.05). However, there was no significant correlation between saliva and serum 1,5-AG levels detected by enzymatic method (r=-0.079, P=0.487). Conclusions: Both serum and saliva 1,5-AG levels detected by enzymatic method have a good consistency with saliva 1,5-AG levels detected by mass spectrometry method. The saliva and serum 1,5-AG levels detected by enzymatic method are not well correlated, and thus the enzymatic detection of saliva 1,5-AG needs further improvement in clinical practice.

Hypothesis: A Novel Neuroprotective Role for Glucose-6-phosphatase (G6PC3) in Brain-To Maintain Energy-Dependent Functions Including Cognitive Processes

The isoform of glucose-6-phosphatase in liver, G6PC1, has a major role in whole-body glucose homeostasis, whereas G6PC3 is widely distributed among organs but has poorly-understood functions. A recent, elegant analysis of neutrophil dysfunction in G6PC3-deficient patients revealed G6PC3 is a neutrophil metabolite repair enzyme that hydrolyzes 1,5-anhydroglucitol-6-phosphate, a toxic metabolite derived from a glucose analog present in food. These patients exhibit a spectrum of phenotypic characteristics and some have learning disabilities, revealing a potential linkage between cognitive processes and G6PC3 activity. Previously-debated and discounted functions for brain G6PC3 include causing an ATP-consuming futile cycle that interferes with metabolic brain imaging assays and a nutritional role involving astrocyte-neuron glucose-lactate trafficking. Detailed analysis of the anhydroglucitol literature reveals that it competes with glucose for transport into brain, is present in human cerebrospinal fluid, and is phosphorylated by hexokinase. Anhydroglucitol-6-phosphate is present in rodent brain and other organs where its accumulation can inhibit hexokinase by competition with ATP. Calculated hexokinase inhibition indicates that energetics of brain and erythrocytes would be more adversely affected by anhydroglucitol-6-phosphate accumulation than heart. These findings strongly support the paradigm-shifting hypothesis that brain G6PC3 removes a toxic metabolite, thereby maintaining brain glucose metabolism- and ATP-dependent functions, including cognitive processes.

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 A_1c (HbA_1c) and 1,5-AG levels were measured before coronary angiography. Fasting urinary 8-iso-prostaglandin F_2α (8-iso-PGF_2α) 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 HbA_1c 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 HbA_1c (0.587, P = 0.087). Levels of 1,5-AG were significantly correlated with urinary 8-iso-prostaglandin F_2α 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.

1,5-Anhydroglucitol × glycated hemoglobin A1c/100 as a potential biomarker for islet β-cell function among patients with type 2 diabetes

AIMS

This study aimed to explore the level of and changes in the 1,5-anhydroglucitol × glycated hemoglobin A_1c/100 (AH index, AHI) associated with different glucose metabolism statuses and to evaluate the islet function and insulin sensitivity of patients with type 2 diabetes (T2DM) with different AHI levels.

METHODS

Of the 3562 subjects enrolled in this study, 1697 had T2DM. The disposition index (DI) was the product of islet secretion function and insulin sensitivity-related indexes.

RESULTS

The mean AHI level was 1.0 (0.7-1.3) in the general population, while the mean AHI level in the T2DM group was 0.8 (0.5-1.2), which was significantly lower than that in the impaired glucose regulation and normal glucose tolerance group (both 1.2 (0.9-1.5), both P < 0.01). We further divided patients with T2DM into four subgroups according to the quartile of AHI. The results showed that with the increase in AHI level, the homeostasis model assessment of insulin resistance (HOMA-IR) decreased, while HOMA-β, insulin generation index, insulin sensitivity index, and DI increased (all P_{for trend} < 0.01). Multivariate logistic regression showed that the odds ratios for a low DI for increasing levels of AHI were 1.00, 0.22 (0.16-0.29), 0.16 (0.11-0.22), and 0.09 (0.06-0.13), showing a decreasing trend (P_{for trend} < 0.05).

CONCLUSION

The AHI could reflect the variation in glycemic disorder and the function of islet β cells. The lower the AHI, the worse the glycemic disorder, as well as the islet β-cell function.

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.

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.

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.

Serum 1,5-anhydroglucitol levels slightly increase rather than decrease after a glucose load in subjects with different glucose tolerance status

AIMS

Previous studies showed that serum 1,5-anhydroglucitol (1,5-AG) levels are significantly reduced in patients with diabetes mellitus (DM). However, it remains unclear how 1,5-AG levels acutely change in response to a glucose load. This study explored acute changes in 1,5-AG levels after a glucose load and the related influencing factors in individuals with differing degrees of glucose tolerance.

METHODS

A total of 681 participants (353 without DM and 328 with DM) without a prior history of DM were enrolled. All participants underwent an oral glucose tolerance test. Fasting and postload (30, 60, 120, and 180 min) levels of plasma glucose, serum 1,5-AG, and insulin were measured.

RESULTS

In all participant groups, serum 1,5-AG levels were slightly elevated after a glucose load and reached peak values at 120 min after loading (all P < 0.05). Regression analysis showed that body weight was negatively associated with the difference between peak and baseline 1,5-AG levels (Δ1,5-AG, standardized β = -0.119, P < 0.01). A strong and positive association between 1,5-AG₀ and Δ1,5-AG was also found independent of other confounding factors (standardized β = 0.376, P < 0.01). The ratio of the Δ1,5-AG to the 1,5-AG₀ was higher in DM patients (7.3% [3.4-11.5%]) than in those without DM (6.2% [3.6-9.2%]).

CONCLUSIONS

In contrast to the established decline in 1,5-AG levels with long-term hyperglycemia, the present study showed that serum 1,5-AG levels slightly increased by 6-7% after a glucose load. Further studies in different 1,5-AG transport models are needed to investigate the relevant metabolic pathways.

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.

Glycemic control and variability in association with body mass index and body composition over 18months in youth with type 1 diabetes

AIMS

The impact of adiposity on glycemic control in type 1 diabetes patients has important implications for preventing complications. This study examined associations of glycemic outcomes with body mass index (BMI, kg/m(2)) and body composition in youth with type 1 diabetes.

METHODS

This is a secondary analysis of an 18-month randomized controlled dietary intervention trial (N=136, baseline age=12.3±2.5y, HbA1c=8.1±1.0% (65±11mmol/mol)). Measured height and weight every 3months were abstracted from medical records. Body composition was assessed by dual energy X-ray absorptiometry (DXA) at baseline, 12 and 18months. Glycated hemoglobin (HbA1c) and glycemic variability assessed by masked 3-day continuous blood glucose monitoring (CGM) were obtained every 3months. 1,5-Anhydroglucitol (1,5-AG) was assessed every 6months. Adjusted random effects models for repeated measures estimated associations of time-varying BMI and body composition with time-varying glycemic outcomes.

RESULTS

There was no treatment effect on glycemic outcomes. HbA1c was not associated with BMI or body composition indicators. 1,5-AG was inversely associated with BMI and adiposity indicators (%fat, trunk fat mass and trunk %fat), adjusting for developmental covariates. Adiposity indicators were positively associated with %glucose >180mg/dL and >126mg/dL when adjusting for developmental covariates, and %glucose >126mg/dL when additionally adjusting for diabetes-related covariates. Fewer consistent relationships were observed for 3-day mean glucose and %glucose <70.2mg/dL. BMI and body composition variables were not associated with standard deviation of glycemic values or mean amplitude of glycemic excursions.

CONCLUSIONS

The role of greater BMI and adiposity in diabetes management in youth with type 1 diabetes may relate specifically to increased hyperglycemic excursions.

1,5-Anhydro-D-Glucitol Could Reflect Hypoglycemia Risk in Patients with Type 2 Diabetes Receiving Insulin Therapy

BACKGROUND

The identification of a marker for hypoglycemia could help patients achieve strict glucose control with a lower risk of hypoglycemia. 1,5-Anhydro-D-glucitol (1,5-AG) reflects postprandial hyperglycemia in patients with well-controlled diabetes, which contributes to glycemic variability. Because glycemic variability is related to hypoglycemia, we aimed to evaluate the value of 1,5-AG as a marker of hypoglycemia.

METHODS

We enrolled 18 adults with type 2 diabetes mellitus (T2DM) receiving insulin therapy and assessed the occurrence of hypoglycemia within a 3-month period. We measured 1,5-AG level, performed a survey to score the severity of hypoglycemia, and applied a continuous glucose monitoring system (CGMS).

RESULTS

1,5-AG was significantly lower in the high hypoglycemia-score group compared to the low-score group. Additionally, the duration of insulin treatment was significantly longer in the high-score group. Subsequent analyses were adjusted by the duration of insulin treatment and mean blood glucose, which was closely associated with both 1,5-AG level and hypoglycemia risk. In adjusted correlation analyses, 1,5-AG was negatively correlated with hypoglycemia score, area under the curve at 80 mg/dL, and low blood glucose index during CGMS (P=0.068, P=0.033, and P=0.060, respectively).

CONCLUSION

1,5-AG level was negatively associated with hypoglycemia score determined by recall and with documented hypoglycemia after adjusting for mean glucose and duration of insulin treatment. As a result, this level could be a marker of the risk of hypoglycemia in patients with well-controlled T2DM receiving insulin therapy.

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: a new predictor of neonatal birth weight in diabetic pregnancies

OBJECTIVE

To determine whether 1,5-anhydroglucitol is predictive of neonatal birth weight.

STUDY DESIGN

A retrospective cohort study including 85 pregnancies complicated by diabetes (Type 1=37, Type 2=24, gestational=24). Women had simultaneous hemoglobin A1c and 1,5-anhydroglucitol measurements every 4-8 weeks throughout pregnancy until delivery. Neonatal birth weight was evaluated by standardized z-scores. Linear regression analysis was performed to determine an association of 1,5-anhydroglucitol with neonatal birth weight z-score.

RESULTS

Type 1 diabetic patients had the lowest mean 1,5-anhydroglucitol of 3.5mcg/mL (SD=1.6mcg/mL) and highest mean hemoglobin A1c of 6.5% (SD=0.74%) compared to gestational diabetic patients who had the highest mean 1,5-anhydroglucitol of 6.7mcg/mL (SD=3.8mcg/mL) and lowest mean hemoglobin A1c of 6.0% (SD=0.94%). Mean 1,5-anhydroglucitol values were significantly different between diabetes types (p<0.01). Mean neonatal birth weight was above population averages for all diabetes classifications, although mean birth weight z-scores did not differ significantly between diabetic types (p=0.38). Multivariate linear regression showed a negative association between log-transformed 1,5-anhydroglucitol and birth weight (coefficient -0.82, 95% CI -1.19, -0.46).

CONCLUSION

In pregnancies complicated by diabetes, low 1,5-anhydroglucitol was associated with increased neonatal birth weight. 1,5-Anhydroglucitol may be useful in the assessment of glycemic control in pregnancy in addition to A1c.

Serum uric acid in relation to serum 1,5-anhydroglucitol levels in patients with and without type 2 diabetes mellitus

OBJECTIVES

The aim of this study was to examine the relationship between serum levels of uric acid (UA) and 1,5-anhydroglucitol (1,5-AG) in elderly subjects (60 years or older; mean age, 73.0±7.2 years) with and without type 2 diabetes mellitus (DM).

METHODS

Subjects with DM (n=97) and without DM (n=360) were recruited from among our outpatients (estimated glomerular filtration rate≥45 mL min⁻¹ 1.73 m⁻², and urine protein equivalent to <1.0 g/L), and a cross-sectional study was performed with simple linear regression and stepwise multiple linear regression analyses.

RESULTS

The mean serum UA levels of men were significantly higher than those of women in both groups. The mean serum 1,5-AG levels of men were significantly higher than those of women in the non-DM group. There were positive correlations (indicated by Pearson's correlation coefficients) between serum UA levels and 1,5-anhydroglucitol levels in all patients and in both men and women. Simple linear regression and multiple linear regression analyses showed that the serum 1,5-AG levels were significantly and positively correlated with the serum UA level in both the non-DM group and the DM group. In the non-DM group, HbA1c levels, as well as 1,5-AG levels, were positively correlated with serum UA levels. Furthermore, the correlation between 1,5-AG and UA levels was stronger in subjects with DM than in subjects without DM.

CONCLUSIONS

These results suggest that the serum 1,5-AG level is an independent factor associated with serum UA levels in the nondiabetic state, as in DM.