More and more, we are seeing that ethnicity and genetic background can play a role in how patients react to specific treatments. When it comes to determining the best treatment for certain diseases, we are becoming more aware of the fact that some treatments work better or worse for patients with certain genetic and ethnic backgrounds. In a recent study of adults with type 2 diabetes, those of black Caribbean ethnicity who are prescribed insulin are at increased risk for hypoglycemia as are those of black Caribbean, black African or Bangladeshi ethnicity who are prescribed a sulfonylurea, compared with adults of white British ethnicity, according to findings published in Diabetic Medicine. Additionally, researchers found a lower risk for hypoglycemia among adults with type 2 who are of Indian and Bangladeshi ethnicity when taking insulin vs. sulfonylurea in comparison with other populations. We are just beginning to look at ethnicity and genetic backgrounds before we determine the best treatments for the individual patient, called “personalized medical treatment.” A current study used data from electronic health records of 19,771 adults with type 2 diabetes who were patients at 128 general practices. The patients were prescribed insulin or a sulfonylurea 6 months before January 2013 (mean age, 66.2 years; 46.5% women). The study spanned from 2013 to 2015. Study participants were divided into two cohorts based on whether they were prescribed insulin (n = 7,269) or sulfonylurea (n = 12,502). Nine ethnic groups were examined, with those of white British ethnicity (17.3%) used as reference for comparison: Bangladeshi (26%), Indian (10.8%), black Caribbean (9.7%), black African (8.5%), other white (7%), Pakistani (6.7%), other South Asian (3.8%), other black ethnicities (3.5%) and the rest “other” or not recorded. Among the insulin cohort, hypoglycemic incident rates were highest for adults of black Caribbean ethnicity compared with adults with white British ethnicity. Adults of Bangladeshi ethnicity had the lowest incidence rate of any of the nine ethnicities in the study.

Among the sulfonylurea cohort, adults of black Caribbean, black African, Indian, and other South Asian ethnicities were at a higher risk for hypoglycemia than those of white British ethnicity. “The higher risk of hypoglycemia found among black African/Caribbean ethnic groups may be partly explained by relatively intensive glycemia targets in these ethnic groups. Black African/Caribbean and South Asian ethnic groups tend to have higher HbA1c levels at a given blood glucose than their white European counterparts,” the researchers wrote. “Consequently, these individuals may be at greater risk of hypoglycemia than white European populations when lowering HbA1c to national and international glycemic targets.”  The researchers also found that insulin use by adults of Indian and Bangladeshi ethnicity had a decreased hypoglycemic risk compared with sulfonylurea risk.

Medical researchers are now paying increasing attention to findings of racial or ethnic differences in quality and access to care, health outcomes, risk factors, genetic markers, and therapeutic response. However, this attention has been met with growing controversy and debate. Society’s history of discrimination, racism, and eugenics, and continued disparities in access and quality of care make this a particularly sensitive issue and an important one for the future of research.

Diabetes Care 2003 Jul; 26(7): 2189-2193.https://doi.org/10.2337/diacare.26.7.2189