Measurement of glycated hemoglobin and glycated albumin in umbilical cord: evaluation of the glycemic control indicators in neonates

Correlation between hyperglycemia and glycated albumin with retinopathy of prematurity

To determine the association between hyperglycemia, glycated albumin (GlyA) and retinopathy of prematurity (ROP). Prospective study of all infants under ROP screening from March 2017 to July 2019. All demographic, clinical and laboratory data were collected. Glucose was measured at birth and every 8 h for the first week and serum GlyA was evaluated at birth, 1st, 2nd and 4th weeks after birth. Reference range for GlyA was obtained. Univariate logistic regression was used to examine risk factors for ROP followed by multivariate regression. A total of 152 infants were included in the study. Median gestational age was 30 weeks and median birth weight 1240 g. Thirty-three infants (21.7%) had ROP. Hyperglycemia was present in 24 (72.7%) infants diagnosed with any ROP versus 6 (0.05%) in those without ROP. Median GlyA at birth, 1st, 2nd and 4th and respective reference ranges were 8.50% (6.00-12.65), 8.20% (5.32-11.67), 8.00% (5.32-10.00) and 7.90% (5.30-9.00) respectively. After multivariate logistic regression, hyperglycemia but not GlyA, remained a significant risk factor for ROP overpowering the other recognized risk factors (Exp (B) 28.062, 95% CI for Exp(B) 7.881-99.924 p < 0.001). In our cohort, hyperglycemia but not GlyA, remained a significant risk factor for ROP overpowering the other recognized risk factors.

Development of filter paper hemoglobin A1c assay applicable to newborn screening

PURPOSE

Gestational diabetes influences risk for future metabolic disease including type 2 diabetes. Hemoglobin A1c (HbA1c) measurement assesses hemoglobin A glycosylation, and could theoretically be used as a test to estimate gestational glucose exposure. HbA1c assay on dried blood spots (DBS) is needed before potential application to statewide newborn screening (NBS) population studies. The study aimed to establish a reliable method to measure HbA1c on NBS DBS specimens. De-identified blood was used to generate trials to evaluate stability of HbA1c in DBS, optimal elution time, and stability of eluted blood.

RESULTS

Analysis of DBS stability HbA1c measurements from 3 to 6days after collection overestimated HbA1c values by a bias factor between 0.83 and 0.87. Sixty minutes of elution time produced maximal reproducibility and minimal bias of results. Within assay standard deviation: 0.058; average bias: -0.02%. Stability of eluted blood did not vary significantly between days 0-2 after DBS elution.

CONCLUSIONS

Measurement of HbA1c levels on DBS from human blood is feasible. Results suggest new method using DBS to measure HbA1c level with the following characteristics: optimal time for sample analysis 3-6days after collection, elution time of 60min and eluted blood analysis within 2days of elution. Measurement of neonatal HbA1c could provide insight regarding the infant's in utero exposure to glucose.

Glycation of fetal hemoglobin reflects hyperglycemia exposure in utero

OBJECTIVE

The lifetime risk of metabolic diseases in offspring of women with gestational diabetes mellitus (GDM) depends, at least in part, on the impact of glycemic fetal programming. To quantify this impact, we have developed and validated a unique mass spectrometry method to measure the percentage of glycated hemoglobin in cord blood.

RESEARCH DESIGN AND METHODS

This case-control study includes 37 GDM women and 30 pregnant women with normal glucose tolerance (NGT).

RESULTS

Glycation of the α-chain (Glα) was higher in neonates from GDM (2.32 vs. 2.20%, P < 0.01). Glα strongly correlated with maternal A1C measured at delivery in the overall cohort (r = 0.67, P < 0.0001) as well as in each group (GDM: r = 0.66, P < 0.0001; NGT: r = 0.50, P = 0.01).

CONCLUSIONS

Thus, Glα may reflect hyperglycemic exposure during the last weeks of fetal development. Future studies will confirm Glα is a predictive biomarker of prenatally programmed lifetime metabolic health and disease.

Glycemic control indicators in patients with neonatal diabetes mellitus

Neonatal diabetes mellitus (NDM) is a type of diabetes mellitus caused by genetic abnormality which develops in insulin dependent state within 6 mo after birth. HbA1c is widely used in clinical practice for diabetes mellitus as the gold standard glycemic control indicator; however, fetal hemoglobin (HbF) is the main hemoglobin in neonates and so HbA1c cannot be used as a glycemic control indicator in NDM. Glycated albumin (GA), another glycemic control indicator, is not affected by HbF. We reported that GA can be used as a glycemic control indicator in NDM. However, it was later found that because of increased metabolism of albumin, GA shows an apparently lower level in relation to plasma glucose in NDM; measures to solve this problem were needed. In this review, we outlined the most recent findings concerning glycemic control indicators in neonates or NDM.

Evaluation of glycated hemoglobin and fetal hemoglobin-adjusted HbA1c measurements in infants

BACKGROUND

As the presence of fetal hemoglobin (HbF) affects the accuracy of hemoglobin A1c (HbA1c) analysis methods, HbA1c measurement may not be a good indicator for patients with neonatal diabetes mellitus, whereas glycated albumin (GA) may be a good indicator.

OBJECTIVE

To investigate whether total glycated hemoglobin (GHb) or HbF-adjusted HbA1c (adj-HbA1c) can act as a glycemic control marker in infants.

SUBJECTS AND METHODS

Plasma glucose (PG), GA, HbF, GHb measured using the affinity method, and HbA1c measured using the latex-immunoturbidimetry (LA) or the high-performance liquid chromatography (HPLC) methods were determined in 26 full-term newborn infants aged 4-234 d. Adj-HbA1c was calculated as HbA1c/(total Hb - HbF).

RESULTS

GHb, adj-HbA1c measured using the LA and the HPLC methods were 4.8 ± 0.5%, 4.5 ± 0.5%, and 4.7 ± 0.6%, respectively. GA was most positively correlated with PG (r = 0.696, p < 0.0001). GHb was positively correlated with both PG (r = 0.479, p = 0.013) and GA (r = 0.727, p < 0.0001). Adj-HbA1c measured using the LA method was positively correlated with GA (r = 0.465, p = 0.017), but not PG (r = 0.304, p = 0.132). Adj-HbA1c measured using the HPLC method was correlated with neither PG (r = -0.077, p = 0.710) nor GA (r = 0.360, p = 0.071).

CONCLUSIONS

GHb measured using the affinity method may be a useful glycemic control marker in infants. Although adj-HbA1c measured using the LA method was correlated with GA, it may not be a practical measure because it was not correlated with PG and determining HbF levels using HPLC method can be troublesome. Adj-HbA1c measured using the HPLC method should not be used as a glycemic marker in infants.

Glycated albumin is lower in infants than in adults and correlated with both age and serum albumin

BACKGROUND

Glycated albumin (GA) reflects glycemic control in patients with neonatal diabetes mellitus (NDM). However, GA in NDM patients is apparently low in relation to glycemia.

OBJECTIVE

To establish the reference intervals for GA in healthy infants.

SUBJECTS AND METHODS

Fifty-eight healthy, full-term newborn infants were used to define the GA reference values and to investigate its relationship to plasma glucose (PG) and serum albumin. The infants were categorized into three groups according to age: group A, 5 (4-6) median (range) d: n = 18; group B, 33 (30-38) d: n = 19; and group C, 181 (50-352) d: n = 21. We also studied 212 non-diabetic adults [group D, 53 (28-78) yr old] and the 5 NDM patients previously reported for GA comparisons.

RESULTS

In the infants, GA was strongly positively correlated with logarithmic transformation of age [log (age)] (p = 0.831, p < 0.0001). The GA in groups A, B, C, and D were 7.3 ± 1.0%, 8.6 ± 1.1%, 10.9 ± 0.8%, and 14.0 ± 1.1%, respectively. The GA was more strongly positively correlated with serum albumin (r = 0.768, p < 0.0001) than with PG (r = 0.596, p < 0.0001). When GA levels were compared with the age-dependent reference values, GA in the transient NDM patient was normalized although GA in the four permanent NDM patients decreased but remained high after insulin therapy.

CONCLUSIONS

This study showed that the reference range for GA in infants is lower than that of adults and increases with age, with which we confirmed that GA in the NDM patients reflected the clinical course. Consequently, GA in NDM patients should be compared with the age-based reference values to assess the accurate glycemic status.

Glycated albumin but not HbA1c reflects glycaemic control in patients with neonatal diabetes mellitus

AIMS/HYPOTHESIS

It is difficult to use HbA(1c) as an indicator of glycaemic control in patients with neonatal diabetes mellitus (NDM) because of high levels of fetal haemoglobin (HbF) remaining in the blood. In this study, glycated albumin (GA), which is not affected by HbF, and HbA(1c) were compared to evaluate whether they reflect glycaemic control in patients with NDM.

METHODS

This study included five patients with NDM. Age at diagnosis was 38 ± 20 days. Insulin therapy was started in all patients, and levels of GA, HbA(1c) and HbF were measured monthly for 6 months. One-month average preprandial plasma glucose (aPPG) was calculated using self-monitoring of blood glucose.

RESULTS

Plasma glucose and GA were elevated (29.7 ± 13.1 mmol/l [n = 5] and 33.3 ± 6.9% [n = 3], respectively) but HbA(1c) was within normal limits (5.4 ± 2.6% [35.5 ± 4.9 mmol/mol]; n = 4) at diagnosis. With diabetes treatment, aPPG (r = -0.565, p = 0.002), GA (r = -0.552, p = 0.003) and HbF (r = -0.855, p < 0.0001) decreased with age, whereas HbA(1c) increased (r = 0.449, p = 0.004). GA was strongly positively correlated with aPPG (r = 0.784, p < 0.0001), while HbA(1c) showed no correlation with aPPG (r = 0.221, p = 0.257) and was significantly inversely correlated with HbF (r = -0.539, p = 0.004).

CONCLUSIONS/INTERPRETATION

GA is a useful indicator of glycaemic control in patients with NDM, whereas HbA(1c) is influenced by age-related changes in HbF and does not accurately reflect glycaemic control.