Is there a role for glycated albumin in the diagnosis of gestational diabetes mellitus?

Circulating glycated albumin levels and gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) is characterized by glucose intolerance that is first diagnosed during pregnancy, making it the most common complication associated with this period. Early detection and targeted treatment of GDM can minimize foetal exposure to maternal hyperglycaemia and subsequently reduce the associated adverse pregnancy outcomes. Previous studies have inconsistently suggested that the level of glycated albumin (GA) might predict GDM.

AIM

To review and synthesize existing evidence to evaluate the relationship between GA levels and the development of GDM.

METHODS

We sought to compare GA levels between GDM and control groups in this meta-analysis by systematically searching the Web of Science, PubMed, Cochrane Library, and Embase databases for articles published up to June 2023. The analysis utilized the weighted mean difference (WMD) as the primary metric. The data were meticulously extracted, and the quality of the included studies was assessed. Additionally, we conducted a subgroup analysis based on study region and sample size. We assessed heterogeneity using I² statistics and evaluated publication bias through funnel plots. Additionally, trim-and-fill analysis was employed to detect and address any potential publication bias.

RESULTS

The meta-analysis included a total of 11 studies involving 5477 participants, comprising 1900 patients with GDM and 3577 control individuals. The synthesized results revealed a notable correlation between elevated GA levels and increased susceptibility to GDM. The calculated WMD was 0.42, with a 95% confidence interval (95%CI) ranging from 0.11 to 0.74, yielding a P value less than 0.001. Concerning specific GA levels, the mean GA level in the GDM group was 12.6, while for the control group, it was lower, at 11.6. This discrepancy underscores the potential of GA as a biomarker for assessing GDM risk. Moreover, we explored the levels of glycated haemoglobin (HbA1c) in both cohorts. The WMD for HbA1c was 0.19, with a 95%CI ranging from 0.15 to 0.22 and a P value less than 0.001. This observation suggested that both GA and HbA1c levels were elevated in individuals in the GDM group compared to those in the control group.

CONCLUSION

Our meta-analysis revealed a substantial correlation between elevated GA levels and increased GDM risk. Furthermore, our findings revealed elevated levels of HbA1c in GDM patients, emphasizing the significance of monitoring both GA and HbA1c levels for early GDM detection and effective management.

Fetal pancreas size and maternal serum biomarkers glycated albumin and insulin-regulated aminopeptidase provide no potential for early prediction of gestational diabetes mellitus

PURPOSE

We aimed to determine the predictive values of fetal pancreas size and maternal serum biomarkers glycated albumin (GA) and insulin-regulated aminopeptidase (IRAP) for gestational diabetes mellitus (GDM).

MATERIALS AND METHODS

In this prospective observational study including 109 pregnant women, the fetal pancreas size and maternal serum biomarkers GA and IRAP were measured at the gestational age of 20-22 weeks and later at the gestational age of 24-28 weeks, in 19 participants of them, GDM was confirmed with the 75-g oral glucose tolerance test (OGTT) and the fetal pancreas size was measured in all the participants again.

RESULTS

The median fetal pancreas sizes were significantly higher in women with or without GDM when measured at the 24-28 weeks of pregnancy compared to those at the 20-22 weeks of pregnancy (p < 0.05). At both of the 20-22 and 24-28 weeks of pregnancy, the median values of fetal pancreas sizes in the women with or without GDM were found comparable (p > 0.05). There were no significant differences between pregnant women with or without GDM regarding maternal serum biomarkers GA and IRAP (p > 0.05). Multivariate logistic regression analysis revealed no meaningful association of study parameters with the development of GDM.

CONCLUSION

The fetal pancreas size and maternal serum biomarkers GA and IRAP provide no potential for early prediction of GDM at the 20-22 weeks of gestation. Further studies, including serial measurement of these parameters during the second and third trimesters of GDM pregnancies, may clarify their role in the antenatal care of women with GDM.

CLINICAL TRIALS

NCT05392231.

Protein glycation in diabetes mellitus

Diabetes mellitus is the ninth leading cause of mortality worldwide. It is a complex disease that manifests as chronic hyperglycemia. Glucose exposure causes biochemical changes at the proteome level as reflected in accumulation of glycated proteins. A prominent example is hemoglobin A1c (HbA1c), a glycated protein widely accepted as a diabetic indicator. Another emerging biomarker is glycated albumin which has demonstrated utility in situations where HbA1c cannot be used. Other proteins undergo glycation as well thus impacting cellular function, transport and immune response. Accordingly, these glycated counterparts may serve as predictors for diabetic complications and thus warrant further inquiry. Fortunately, modern proteomics has provided unique analytic capability to enable improved and more comprehensive exploration of glycating agents and glycated proteins. This review broadly covers topics from epidemiology of diabetes to modern analytical tools such as mass spectrometry to facilitate a better understanding of diabetes pathophysiology. This serves as an attempt to connect clinically relevant questions with findings of recent proteomic studies to suggest future avenues of diabetes research.

Performance of glycated albumin as a biomarker of hyperglycemia in pregnancy: Results from the National Health and Nutrition Examination Survey 1999-2004

AIM

We sought to evaluate the performance of glycated albumin (GA) as a measure of hyperglycemia in pregnant women.

METHODS

We used data from 555 pregnant women aged 20-40 years who participated in NHANES 1999-2004 and did not report a pre-pregnancy diagnosis of diabetes. We used Pearson's correlations and evaluated the area under the curve (AUC) for GA to detect elevated concentrations of random glucose, HbA1c, or fasting glucose (subset). We compared results to 1607 nonpregnant women aged 20-40 without diabetes.

RESULTS

In pregnant women, 1.9 % had HbA1c ≥ 39 mmol/mol (≥5.7 %), 9.1 % had random glucose ≥ 5.3 mmol/L (≥95 mg/dL), and 10.7 % had fasting glucose ≥ 5.3 mmol/L. In pregnancy, GA was poorly correlated with HbA1c (r = 0.08) and random glucose (r = 0.17). BMI was positively associated with HbA1c (r = 0.33) and random glucose (r = 0.25) but was inversely associated with GA (r = -0.27). GA had poor discrimination for detecting hyperglycemia in pregnant women, defined as HbA1c ≥ 39 mmol/mol (AUC = 0.634) or random glucose ≥ 5.3 mmol/L (AUC = 0.628). Similar patterns were observed among nonpregnant women.

CONCLUSIONS

GA is not a sensitive test to screen for hyperglycemia in pregnancy. GA was inversely associated with adiposity in pregnant women without diabetes. Pregnancy-related weight gain may complicate interpretation of repeated GA measurements.

Hyperglycemia First Detected in Pregnancy in South Africa: Facts, Gaps, and Opportunities

This review contextualizes hyperglycemia in pregnancy from a South-African perspective. It aims to create awareness of the importance of hyperglycemia in pregnancy in low-middle-income countries. We address unanswered questions to guide future research on sub-Saharan African women with hyperglycemia first detected in pregnancy (HFDP). South African women of childbearing age have the highest prevalence of obesity in sub-Saharan Africa. They are predisposed to Type 2 diabetes (T2DM), the leading cause of death in South African women. T2DM remains undiagnosed in many African countries, with two-thirds of people living with diabetes unaware. With the South African health policy's increased focus on improving antenatal care, women often gain access to screening for non-communicable diseases for the first time in pregnancy. While screening practices and diagnostic criteria for gestational diabetes mellitus (GDM) differ amongst geographical areas in South Africa (SA), hyperglycemia of varying degrees is often first detected in pregnancy. This is often erroneously ascribed to GDM, irrespective of the degree of hyperglycemia and not overt diabetes. T2DM and GDM convey a graded increased risk for the mother and fetus during and after pregnancy, with cardiometabolic risk accumulating across the lifespan. Resource limitations and high patient burden have hampered the opportunity to implement accessible preventative care in young women at increased risk of developing T2DM in the broader public health system in SA. All women with HFDP, including those with true GDM, should be followed and undergo glucose assessment postpartum. In SA, studies conducted early postpartum have noted persistent hyperglycemia in a third of women after GDM. Interpregnancy care is advantageous and may attain a favourable metabolic legacy in these young women, but the yield of return following delivery is suboptimal. We review the current best evidence regarding HFDP and contextualize the applicability in SA and other African or low-middle-income countries. The review identifies gaps and shares pragmatic solutions regarding clinical factors that may improve awareness, identification, diagnosis, and management of women with HFDP.

Glycated albumin in pregnancy: LC-MS/MS-based reference interval in healthy, nulliparous Scandinavian women and its diagnostic accuracy in gestational diabetes mellitus

Glycated albumin (GA) may be a useful biomarker of glycemia in pregnancy. The aim of this study was to establish the reference interval (RI) for GA, analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), in healthy, nulliparous pregnant women. In addition, we assessed the accuracy of GA and glycated hemoglobin A1c (HbA1c) in the diagnosis of gestational diabetes mellitus (GDM). Finally, we explored the prevalence of GDM in healthy nulliparas, comparing three diagnostic guidelines (WHO-1999, WHO-2013 and the Norwegian guideline). The study was carried out at Stavanger University Hospital, Norway, and included a study population of 147 pregnant nulliparous women. An oral glucose tolerance test (OGTT) was performed and used as the gold standard for GDM diagnosis. Blood samples for analysis of GA and HbA1c were collected at pregnancy week 24-28. A nonparametric approach was chosen for RI calculation, and receiver operating characteristic (ROC) curves were used to evaluate the diagnostic performance of GA and HbA1c. The established RI for GA in 121 pregnant women was 7.1-11.6%. The area under the ROC curves (AUCs) were 0.531 (GA) and 0.627 (HbA1c). According to the WHO-1999, WHO-2013 and the Norwegian guideline, respectively, 24 (16%), 36 (24%) and 21 (14%) women were diagnosed with GDM. Only nine women (6%) fulfilled the GDM-criteria of all guidelines. In conclusion, we established the first LC-MS/MS-based RI for GA in pregnant women. At pregnancy weeks 24-28, neither GA nor HbA1c discriminated between those with and without GDM. Different women were diagnosed with GDM using the three guidelines.

Preliminary reference intervals of Glycated Albumin in healthy Caucasian pregnant women

BACKGROUND AND AIMS

Glycated albumin (GA) could represent a useful biomarker in pregnant women for diagnosing and monitoring gestational diabetes mellitus (GDM). The establishment of reference intervals (RI) is mandatory before assessing its clinical usefulness. The RIs of GA in healthy pregnant women are not well defined. The aim of the current study was to establish the RI in a cohort consisting of Caucasian pregnant women without overt diabetes mellitus or gestational diabetes mellitus.

METHODS

The study included 183 healthy pregnant women. GA was measured on plasma by an enzymatic method (quantILab Glycated Albumin, IL Werfen, Germany). The RI was calculated by the non-parametric and robust methods.

RESULTS

The RI of GA in the whole population was 10.16% (90%CI 9.60-10.70) and 15.44% (90%CI 14.90-16.90). GA levels decreased during pregnancy, with lower levels in the third trimester: 10.11 (90%CI 9.48-10.79) and 15.72 (90%CI 15.15-16.27) in the first trimester, 10.49 (90%CI 10.05-10.96) and 15.49 (90%CI 15.05-15.92) in the second trimester, 9.84 (90%CI 9.50-10.22) and 14.57 (90%CI 14.11-15.01) in the third trimester. Finally, a weak negative correlation was found between GA levels and body mass index.

CONCLUSION

This is the first study establishing the RIs of GA in Caucasian healthy pregnant women.