Glycated albumin may be used as preliminary test for gestational diabetes mellitus, suggests study

The babies of women with GDM may be premature, growth-restricted, or large-for-date. They may suddenly die in utero or have birth injuries from shoulder dystocia and instrumental delivery. These babies may be admitted into the special care baby unit for hyperglycemia, hypoglycemia, hyperbilirubinemia, electrolyte imbalance, necrotizing enterocolitis, intra-ventricular hemorrhage, or respiratory distress syndrome.

The morbidities associated with GDM can be significantly reduced if the women are diagnosed with GDM early and appropriate treatment is instituted. The Oral glucose tolerance test is the gold standard for GDM screening in pregnant women. The OGTT requires a stable carbohydrate diet for about three days and an overnight fast of at least eight hours. The OGTT is also affected by medications, acute illness, exercise, and stress. Most women do not meet these pre-analytical conditions before they are screened for GDM using the OGTT. The OGTT procedure requires drinking a glucose solution that may cause nausea and vomiting and also requires multiple sample collections. Therefore, the OGTT procedure is cumbersome.

Glycated albumin is formed when albumin undergoes a nonenzymatic glycation reaction with blood sugar. Unlike OGTT which can be affected by fasting and type of food, glycated albumin is not affected by fasting or type of carbohydrate intake. The half-life of glycated albumin is about 20 days, therefore can be used to assess glycemic control for up to three weeks with a single sample collection irrespective of fasting or type of food eaten by the woman. Glycated albumin concentration in plasma is not affected by iron deficiency anemia, sickle cell disease, and sickle cell disease traits, however, it can be affected by disease conditions that affect albumin metabolism, age, and body mass index. Glycated albumin is also affected by ethnicity and race. Black Americans have higher glycated albumin levels than Caucasians.

The study involved 200 pregnant women attending the antenatal clinic at the University of Port Harcourt Teaching Hospital. The diagnosis of gestational diabetes mellitus was made using the World Health Organization 2013 diagnostic criteria. The test characteristics of glycated albumin were determined using the area under the curve of the receiver operator characteristic curve, sensitivity, specificity, positive predictive value, and negative predictive value.

The prevalence of gestational diabetes mellitus was 9.0%. The area under the receiver operator characteristic curve for glycated albumin was 0.8 (95% CI 0.7-0.9; p=0.0001). The sensitivity and specificity of glycated albumin were 83.3% and 86.8% respectively. The positive predictive value was 38.5% and the negative predictive value was 98.1%.

The prevalence of GDM in this study is 9.0% which is higher than the values reported in a systematic review and meta-analysis of other studies in Africa. Glycated albumin measured between 24 to 28 weeks of gestation at a diagnostic cut-off value of 19% has a sensitivity of 83.3%, a specificity of 86.8%, a positive predictive value of 38.5%, and a negative predictive value of 98.1%. Therefore, can be used as a preliminary test in determining who will be screened for GDM using OGTT.

Source: Woruka et al. / Indian Journal of Obstetrics and Gynecology Research 2024;11(2):281–286

https://doi.org/10.18231/j.ijogr.2024.054