Stress Reactivity as a Contributor to Racial and Socioeconomic Disparities: Rationale and Baseline Results From the Richmond Stress and Sugar Study.

OBJECTIVE:There are pronounced racial and socioeconomic disparities in type 2 diabetes. Although "stress" as a general phenomenon is hypothesized to contribute to these disparities, few studies have objective measures of stress reactivity in diverse samples to test hypotheses about purported mechanisms. This study describes the rationale and baseline characteristics of a cohort designed to address the question: how does stress contribute to disparities in diabetes risk? METHODS:The Richmond Stress and Sugar Study recruited 125 adults at elevated risk of type 2 diabetes using a two-by-two sampling frame wherein non-Hispanic whites and African Americans (AAs) were each recruited from neighborhoods of higher and lower socioeconomic status (SES). Stress reactivity was assessed using the Trier Social Stress Test (TSST) and salivary cortisol. Analyses of variance and multilevel modeling were used to examine how stress reactivity varied both within and across race and neighborhood SES. RESULTS:The mean (SD) age was 57.4 (7.3) years, 49% were female, 54% were AA or another racial/ethnic minority, and mean hemoglobin A1c level was in the prediabetes range (5.8%; range, 5.50%-5.93%). Living in a lower-SES neighborhood was associated with 16% (95% confidence interval [CI] = -0.04 to 34) higher pre-TSST cortisol, 8.4% (95% CI = -14 to -3) shallower increase in response to the TSST, and 1% (95% CI = 0.3 to 1.7) steeper decline post-TSST than living in the higher neighborhood SES. Post-TSST cortisol decline was 3% greater among AA compared with non-Hispanic whites. Race-by-SES interaction terms were generally small and nonsignificant. CONCLUSIONS:SES is associated with stress reactivity among adults at high risk of diabetes.