Bengaluru, Karnataka: Findings from recent study stress on the need to revise cut-off values of blood sugar for the diagnosis of gestational diabetes (GD) in the Indian population. According to the study, published in the ADA journal Diabetes. The researchers have found that even with lower blood sugar cut off values compared to the international classification system, Indian pregnant women are at a higher risk of adverse birth outcomes.
At present The NICE & Australian guidelines recommend a risk based screening with 75gm 2 hour OGTT with fasting blood sugar ≥126 mg/dL & Postprandil blood sugar 2hr ≥ 140 mg/ dL taken as diagnostic for Gestational diabetes mellitus.
The prevalence of high blood sugar in pregnancy increases rapidly with age and is highest in women over the age of 45.
About 5 million pregnant women are affected by gestational diabetes mellitus (GDM) in India which is associated with multiple adverse pregnancy outcomes. Exposure to intrauterine high blood sugar increases the risk of obesity and diabetes in infants. Indian phenotype tends to deposit excess central fat, which is linked to insulin resistance. Giridhara R. Babu from Bangalore, India, and colleagues aimed to determine the effect of varying blood sugar concentrations in predicting adverse maternal and infant outcomes in participants of a birth cohort in India.
For the purpose, the researchers examined a prospective cohort of pregnant women in public hospitals of Bengaluru. A 2-hour 75g Oral glucose Tolerance Test (OGTT) was conducted in 1847 pregnant women between 24 to 36 weeks. Women in children were then followed up at delivery and recorded skinfold thickness of babies at biceps, triceps, and subscapular region. 240 robust Poisson models were fitted to estimate the risk of the sum of skinfold thickness (SSFT) infants and caesarian section delivery with the FBS and PPBS. With one-unit increase beginning from Fasting blood sugar≥87 up to 92 mg/dL and Postprandil blood sugar ≥134 up to 153 mg/dL were tested with the sum of skinfold Thickness (SSST) and Cesarean section delivery.
Key findings of the study include:
10.65% of 1847 infants had SSFT above 90th percentile, and 46.91% of the women underwent caesarian section.
The results indicate that FBS≥87 mg/dL and PPBS of ≥134mg/dl was associated with risk of increased SSST in infants [adjusted RR 1.70] and caesarian section delivery [Adjusted RR 1.19] after adjusting for age, parity, socioeconomic status, height and adiposity in mothers.
"The pregnant women in India are at a higher risk of adverse birth outcomes with lower blood sugar cut-off values, compared to the international classification systems. These findings offer insights to revise the cut off points based on contextual settings in LMIC countries," concluded the authors.
The study, "Is It Time for Country-Specific Glucose Cut-Off Values for Diagnosing Gestational Diabetes Mellitus in the Indian Population?," is published in the journal Diabetes.
DOI: https://doi.org/10.2337/db20-169-LB