Does raising the glucose challenge test threshold impact birthweight in Asian gravidas?

Ethnic differences in the impact of gestational diabetes on macrosomia

BACKGROUND

Previous studies reported an ethnic disparity in gestational diabetes mellitus-associated birth outcomes, with some suggesting that macrosomia increases to a lesser extent in groups at high risk, the opposite of the pattern observed by others. Our aim was to evaluate ethnic variation in the impact of gestational diabetes mellitus (GDM).

METHODS

A case-control study evaluating pregnancy outcomes was conducted in women with and without GDM from five ethnic groups. Data on GDM were collected between January 2004 and July 2017. Women giving birth between May 2013 and July 2017 in whom pre-existing diabetes had been ruled out served as controls. A multivariate logistic regression analysis was performed to determine factors independently associated with macrosomia.

RESULTS

Overall, 852 GDM women and 3,803 controls were included. In Caucasian and East-Asian women excessive gestational weight gain (OR 2.273, 95% CI 1.364-3.788 and OR 3.776, 95% CI 0.958-14.886) was an independent predictor of macrosomia. In Latin-American and Moroccan women, obesity (OR 1.774, 95% CI 1.219-2.581 and OR 1.656, 95% CI 1.054-2.601), GDM (OR 2.440; 95% CI 1.048-5.679 and OR 3.249, 95% CI 1.269-8.321) and gestational weight gain but only for Latin-American women (OR 2.365, 95% CI 1.039-5.384) were associated with macrosomia. In South-Central Asian women, only GDM was associated with macrosomia (OR 3.701, 95% CI 1.437-9.532).

CONCLUSIONS

GDM is an independent predictor of macrosomia in Latin-American, South-Central Asian and Moroccan women but not in Caucasian or East-Asian women in whom other factors play a more important role.

Genetic risk factors associated with gestational diabetes in a multi-ethnic population

AIMS

Genome-wide association studies have shown an increased risk of type-2-diabetes (T2DM) in patients who carry single nucleotide polymorphisms in several genes. We investigated whether the same gene loci confer a risk for gestational diabetes mellitus (GDM) in women from Hawaii, and in particular, Pacific Islander and Filipino populations.

METHODS

Blood was collected from 291 women with GDM and 734 matched non-diabetic controls (Pacific Islanders: 71 GDM, 197 non-diabetic controls; Filipinos: 162 GDM, 395 controls; Japanese: 58 GDM, 142 controls). Maternal DNA was used to genotype and show allele frequencies of 25 different SNPs mapped to 18 different loci.

RESULTS

After adjusting for age, BMI, parity and gravidity by multivariable logistic regression, several SNPs showed significant associations with GDM and were ethnicity specific. In particular, SNPs rs1113132 (EXT2), rs1111875 (HHEX), rs2237892 (KCNQ1), rs2237895 (KCNQ1), rs10830963 (MTNR1B) and rs13266634 (SLC30A8) showed significant associations with GDM in Filipinos. For Japanese, SNPs rs4402960 (IGFBP2) and rs2237892 (KCNQ1) were significantly associated with GDM. For Pacific Islanders, SNPs rs10830963 (MTNR1B) and rs13266634 (SLC30A8) showed significant associations with GDM. Individually, none of the SNPs showed a consistent association with GDM across all three investigated ethnicities.

CONCLUSION

Several SNPs associated with T2DM are found to confer increased risk for GDM in a multiethnic cohort in Hawaii.

Gestational diabetes and macrosomia by race/ethnicity in Hawaii

Background

Gestational diabetes (GDM) has been shown to have long-term sequelae for both the mother and infant. Women with GDM are at increased risk of macrosomia, which predisposes the infant to birth injuries. Previous studies noted increased rates of GDM in Asian and Pacific Islander (API) women; however, the rate of macrosomia in API women with GDM is unclear. The objective of this study was to examine the relationship between ethnicity, gestational diabetes (GDM), and macrosomia in Hawaii.

Methods

A retrospective cohort study was performed using Hawaii Pregnancy Risk Assessment Monitoring System (PRAMS) data. Data from 2009–2011, linked with selected items from birth certificates, were used to examine GDM and macrosomia by ethnicity. SAS-callable SUDAAN 10.0 was used to generate odds ratios, point estimates and standard errors.

Results

Data from 4735 respondents were weighted to represent all pregnancies resulting in live births in Hawaii from 2009–2011. The overall prevalence of GDM in Hawaii was 10.9%. The highest prevalence of GDM was in Filipina (13.1%) and Hawaiian/Pacific Islander (12.1%) women. The lowest prevalence was in white women (7.4%). Hawaiian/Pacific Islander, Filipina, and other Asian women all had an increased risk of GDM compared to white women using bivariate analysis. Adjusting for obesity, age, maternal nativity, and smoking, Asian Pacific Islander (API) women, which includes Hawaiian/Pacific Islander, Filipina, and other Asian women, had a 50% increased odds of having GDM compared to white women when compared using multivariate analysis. Among women with GDM, the highest prevalence of macrosomia was in white women (14.5%) while the lowest was in Filipina (5.3%) women.

Conclusions

API women in Hawaii have increased rates of GDM compared to white women. Paradoxically, this elevated GDM risk in API women is not associated with an increased rate of macrosomia. This suggests the relationship between GDM and macrosomia is more complex in this population.