Racial and Ethnic Differences in Age at Diabetes Diagnosis—A Call for Action

In the November issue of JAMA Internal Medicine, Wangetal¹ conducted a cross-sectional analysis of pooled National Health and Nutrition Examination Survey data from 2011 to 2018 to examine racial and ethnic differences in a geat diagnosis of type 2 diabetes. They found that the mean (95% CI) age at diagnosis for Mexican American adults (44.9 [43.4–46.4] years) and non-Hispanic Black adults (47.2[46.1–48.4] years) was significantly younger than that for non-Hispanic White individuals (51.8 [50.8–52.9] years). Asian American individuals’ mean (95% CI) age at onset (50.5 [48.4–52.6] years) was not significantly different from that of non-Hispanic White individuals. The authors¹ suggest that younger age at diagnosis—and correspondingly longer diabetes duration over the life span-may be a contributing factor to racial and ethnic disparities in diabetes-related morbidity and mortality.²

These findings have implications for both the treatment and prevention of type 2 diabetes. More than one-third of Mexican American adults (35.0%) and one-quarter of non-Hispanic Black adults (25.1%) were diagnosed with diabetes before age 40 years (compared with only 14.4% for non-Hispanic White adults).¹ For these younger adults, age-based and racial and ethnic differences in glycemic control are apparent within a year of the diabetes diagnosis.³ Individuals with younger-on set type 2 diabetes are less likely to achieve key disease management targets, including weight loss, increased exercise, and improved blood glucose levels, suggesting that current type 2 diabetes care and self-management strategies for this population are inadequate.^3,4 Health system and community based resources that better accommodate younger individuals’ distinct needs (eg, more work and family responsibilities, less familiarity with health care system) may help promote healthy behavior changes associated with better glycemic and cardiovascular risk factor control among those with type 2 diabetes and delay or prevent onset among younger adults.

It is important to note that the National Health and Nutrition Examination Survey combines all Asian American subpopulations into a single group, likely masking significant within-group differences in age at diagnosis. Thus, although Wang et al1 found no significant difference in age at type 2 diabetes diagnosis between Asian American and non-Hispanic White adults, they were unable to look for heterogeneity in Asian American subpopulations. Data from the California Health Interview Survey,⁵ for example, show that some Asian American subpopulations, including South Asian, Vietnamese, Filipino, and Korean adults, had a younger average age at diabetes diagnosis than non-Hispanic White individuals, while Japanese and Chinese respondents did not. Similarly, the lack of granularity regarding the Latinx population (only findings for Mexican American adults were reported) may also obscure potential differences within this large, diverse population. Prior work⁶ has demonstrated differences in the prevalence of type 2 diabetes between Latinx subpopulations and suggests that groupings that separate by country of origin and/or immigration history may capture the present heterogeneity more appropriately.

Greater efforts are needed to ensure equitable screening and prevention efforts and to adapt current type 2 diabetes care approaches to meet the needs of younger adults, most of whom belong to vulnerable racial and ethnic minority groups. Recognizing and addressing the changing demographic landscape of the type 2 diabetes epidemic is a critical step toward narrowing disparities in morbidity and mortality.