Racial, Ethnic Disparities Associated with Earlier Onset of Diabetes

Sadiya S. Khan, MD, MSc

Disparities by race and ethnicity in diabetes complications may be due to earlier age at diabetes onset, which is linked to a greater risk of cardiovascular complications and death.

Investigators in a recent study observed the mean age of diabetes diagnosis was 4 - 7 years earlier among non-Hispanic Black and Mexican American adults, in comparison to non-Hispanic White adults.

The team, led by Sadiya S. Khan, MD, MSc, Division of Cardiology, Northwestern University Feinberg School of Medicine, noted this may contribute to observed disparities in diabetes-related microvascular and macrovascular complications and premature mortality.

Methods

A cross-sectional study was performed to pool data from 2-year cycles of the National Health and Nutrition Examination Survey. A total of 4 cycles were included from January 2011 - December 2018.

The team noted the 2011 - 2012 survey was the first to include self-reported Asian individuals, so it was used as the first study in the analysis.

For inclusion criteria, the team included all adults aged ≥20 years with a self-reported history of diabetes and age of diagnosis. In addition, self-reported race/ethnicity was assessed as a social construct for investigators to identify health disparities.

Investigators determined the mean age at diagnosis of overall diabetes and by race and ethnicity, using t tests and quantile regression.

Further, exclusions in the analysis included adults with a likely diagnosis of type 1 diabetes, from self-report of diagnosis before age 30 and those on insulin monotherapy.

Results

A total of 3022 participants who reported diabetes were included in the study. Data show the patient population included 1586 men and 1436 women, with 946 non-Hispanic White participants and a mean age of 61.1 years.

Khan and colleagues found the overall mean age at diabetes diagnosis was 49.9 years (95% CI, 49.2 - 50.7 years).

In comparison to non-Hispanic White adults (mean 51.8 years; 95% CI, 50.8 - 52.9 years), data show Mexican Americans (mean 47.2 years; 95% CI, 46.1 - 48.4 years) and non-Hispanic adults (mean 44.9 years; 95% CI, 43.4 - 46.4 years; P < .001) reported a significantly younger mean age at diagnosis.

However, non-Hispanic Asian adults did not report a younger mean age (mean 50.5 years; 95% CI, 48.4 - 52.6 years).

Further, investigators found the weighted proportion of adults with a diabetes diagnosis before age 40 years to be greater among Mexican American adults (35.0%) and non-Hispanic Black adults (25.1%), in comparison to non-Hispanic White adults (14.4%), all P ≤ .001.

Commentary

In an invited commentary accompanying the study, Anjali Gopalan, MD, MS, Division of Research, Kaiser Permanente Northern California, discussed implications for treatment and prevention of diabetes in both age-based and racial and ethnic populations.

“Individuals with younger-onset 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,” they wrote.

Further, the commentary noted the inability in the study data to search for heterogeneity in Asian American subpopulations as all are combined into a single group, as well as lack of granularity in the Latinx population obscuring potential differences in the diverse population.

“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,” Gopalan said.

The research letter, “Age at Diagnosis of Diabetes by Race and Ethnicity in the United States From 2011 to 2018,” was published online in JAMA Internal Medicine.