Experiences of In-Group and Out-Group Skin Tone Discrimination and Their Associations with Incident Cardiovascular Disease Among African American Adults in the Jackson Heart Study.

Background: African American adults face an elevated risk of cardiovascular disease (CVD) compared to other racial and/or ethnic groups in the USA. Although discrimination has been linked to this disparity, the relationship between skin tone discrimination and CVD incidence remains scarce. This study investigated the associations of in-group discrimination (from African American individuals) and out-group skin tone discrimination (from White individuals) with incident CVD and whether these associations differed by sex and optimism.

Methods: This study analyzed data from 3519 African American participants (aged 21-95 years) in the Jackson Heart Study from 2000 to 2016. Cox Proportional Hazards regression assessed associations between skin tone discrimination and CVD (including stroke and coronary heart disease (CHD)). Each CVD component, along with heart failure (HF), was also analyzed separately. Models adjusting for sociodemographic characteristics, health behaviors, and CVD risk factors estimated hazard ratios (HR) and 95% confidence intervals (CI). Interaction terms were included in the fully adjusted models to assess the moderating roles of sex and optimism.

Results: Over the 16-year follow-up, 8.0% of participants developed CVD, 3.9% developed stroke, 4.9% developed CHD, and 7.3% developed HF. Participants who reported that Black individuals treated them better than other Black individuals because of their skin tone had an increased risk of CVD (HR 1.33, 95% CI 0.95-1.83). Out-group skin tone discrimination, whether better or worse treatment, was associated with a higher incidence of CHD (HRs ranged from 1.23 to 1.43), although CIs were wide. These associations did not vary by sex. Optimism moderated the association between out-group skin tone discrimination and HF, such that those who reported worse treatment and had the highest level of optimism had the greatest risk of HF. Optimism did not moderate the associations between in-group skin tone discrimination and the CVD outcomes.

Conclusions: These findings highlight the differential impact of in-group and out-group skin tone discrimination on cardiovascular health. Better in-group treatment was marginally linked to a higher CVD risk, while out-group skin tone discrimination, whether better or worse treatment, marginally increased CHD risk. Skin tone discrimination may therefore be a unique risk factor for CVD for African American individuals.