Maternal racial and ethnic disparities in glycemic threshold for pharmacotherapy initiation for gestational diabetes

To compare the glycemic threshold for pharmacotherapy initiation in women with gestational diabetes (GDM) based on maternal race/ethnicity.

A retrospective cohort study of women with GDM who received pharmacotherapy during pregnancy, in addition to diet and exercise, between 2015 and 2019 in a university center. The primary outcome was percent of elevated capillary blood glucoses (CBGs) prior to pharmacotherapy initiation. This was compared between four maternal racial and ethnic groups: non-Hispanic white (NHW), non-Hispanic black (NHB), Hispanic and other race and ethnicity group that included Asian, American Indian and Alaskan Native. Univariable and multivariable analyses were done to estimate whether there was an independent association between maternal race and ethnicity and the percent of elevated CBGs prior to pharmacotherapy initiation.

A total of 440 women met inclusion criteria. In univariable analysis, NHB women, Hispanic, and women of other race and ethnicity had higher percent of elevated CBGs prior to pharmacotherapy initiation, compared to NHW women (45.5 ± 22.5% for NHW, 65.2 ± 25.4% for NHB, 58.3 ± 21.7% for Hispanic and 51.6 ± 26.8% for other race and ethnicity, respectively, p < .001). After the adjustment for maternal demographic and clinical factors, maternal race and ethnicity remained to be significantly associated with timing of pharmacotherapy initiation, with women of racial and ethnic minority having a higher percent of elevated CBGs prior to pharmacotherapy initiation (adjusted linear regression coefficient 18.1, 95% CI 11.3-25.0 for NHB, adjusted linear regression coefficient 13.2, 95% CI 5.0-21.4 for Hispanic, and adjusted linear regression coefficient 9.8, 95% CI 2.6-16.9 for women of other race and ethnicity).

A significant variation was identified in glycemic threshold for pharmacotherapy initiation in women with GDM across different maternal racial and ethnic groups with minority women starting pharmacotherapy at higher percent of elevated CBGs.