One of the Largest Studies Ever Conducted of Gestational Diabetes in Pregnant Women Less Than 3 Percent African American & Zero Hispanic Women

3.22.22

By Son of Inequity

This New England Journal of Medicine study titled “A Pragmatic, Randomized Clinical Trial of Gestational Diabetes Screening,” is billed as the largest study to date intended to determine the best of two common methods to diagnose Gestational Diabetes Mellitus (GDM) in pregnant women. All told, the Kaiser Permanente researchers who conducted the research included 23,792 pregnant women at two Kaiser Permanente hospitals in Portland OR and Honolulu, HI.

In addition to the age, weight and Medicare status of these women, the researchers documented the ethnicities of the participants with the number of patients (percentage) in each the two study cohorts:

 

Recruiting less than 3 percent of the total with African American women and no Hispanic women is notable because of the staggering negative impact these two communities face from GDM. Hispanic women are the most likely in the U.S. to be diagnosed with the dangerous condition and African American women are the most likely to suffer long-term complications from it.

In a 2001 study of pregnant women tested for GDM at a Detroit MI medical center, the prevalence of the disease was 5.4% among Hispanic women and 3.9% among African American women. While the rate of GDM was elevated in African American women compared to White women, Hispanic women were at the greatest risk. After adjusting for other risk factors, Hispanic women were 2.5 times more likely than African Americans to develop GDM, the researchers concluded. The 2001 study included 552 black women and 653 Hispanic women who were tested at a large Detroit health system.

The Detroit study confirmed that many well-defined risk factors were predictive of GDM, including family history of diabetes, age of the mother, weight, BMI and excessive weight gain during pregnancy (1).

A 2019 study of the prevalence of hyperglycemia in women diagnosed with GDM concluded: “Non-Hispanic black women had 63% higher risk and Hispanic women and `other’ racial/ethnic women had more than double the risk for diabetes compared with non-Hispanic white women.” (2)

Since obesity is a risk factor of GDM, virtually excluding African American women from this study is inexplicable considering the elevated rate of obesity among African Americans in general, who have a 51% greater prevalence of obesity than White Americans, according to a 2009 report by the Centers for Disease Control and Prevention (3).

In a huge 2001 study conducted by Kaiser Permanente—the very same health system that neglected African American and Hispanic women in the GDM study—researchers concluded that pregnant African American women who develop GDM have a 52 percent increased risk of developing diabetes after childbirth than White women also were diagnosed with GDM during pregnancy. In fact, African American women had the highest risk of developing diabetes following GDM than any other racial group. The 2001 study included 77,666 women who gave birth from 1995 to 2009 (4).

The 2011 review article “Why Do Black Americans Have Higher Prevalence of Hypertension? An Enigma Still Unsolved” published by the Journal Hypertension, details how obesity, hypertension, familial history and other risk factors strongly associated with GDM are elevated in African Americans.

So why were Hispanic and African American expecting mothers so underrepresented in this Kaiser NEJM study?

It’s possible that the researchers were unconcerned about race and ethnicity because they believed the method used to screen for GDM, the basic blood glucose test, shows no variation due to race or ethnicity. It’s also likely that it was difficult to recruit African American and Hispanic women at the two Kaiser study sites of Portland and Honolulu, where very few Hispanics and African Americans reside.

In any event, neglecting to enroll from the two American populations that suffer the most from GDM was extremely short sighted. Kaiser is the largest managed care organization in the U.S., with approximately 12 million members in its healthcare plan, nearly 40 hospitals and more than 700 medical offices in California, Washington, Oregon, Colorado, Hawaii, Maryland, Virginia, Georgia and Washington DC. With this kind of reach, recruiting minority women at great risk of GDM should have been easy.

References:

  1. J Am Med Womens Assoc, Fall 2001;56(4):181-7, 196; Obesity and gestational diabetes among African American women and Latinas in Detroit: implications for disparities in women’s health.
  2. Bower JK, Butler BN, Bose-Brill S, Kue J, Wassel CL. Racial/Ethnic Differences in Diabetes Screening and Hyperglycemia Among US Women After Gestational Diabetes. Prev. Chronic Dis. 2019;16:190144.
  3. Centers for Disease Control and Prevention (CDC). Differences in prevalence of obesity among black, white, and Hispanic adults – United States, 2006–2008. MMWR. 2009; 58:740–744.
  4. African American women with gestational diabetes face high long-term diabetes risk, ScienceDaily, Oct. 20, 2011.