Skin tone – a marker of bias known as colorism – in relation to sleep health among African American women

People with darker-skin tone are more likely than their lighter-skin counterparts to have less access to health-promoting resources (e.g., economic security; quality housing; favorable neighborhood environment). These adverse conditions can affect sleep and result in poor health outcomes such as cardiovascular disease and depression. However, few studies have examined associations between skin tone and sleep disparities. To address this gap, we used cross-sectional (2010-2012) and longitudinal (until 2014-2018) data from the Study of Environment, Lifestyle and Fibroids cohort of 1674 Black women aged 23-35 years and residing in the Detroit, Michigan area. Skin tone was measured using a skin reflectance instrument and categorized as light [29.3-57.6] (25%), medium [57.7-72.4] (50%), and dark [72.5-106.1] (25%) brown. Self-reported sleep dimensions were dichotomized (yes vs. no): short sleep duration, non-restorative sleep, insomnia symptoms, and sleep apnea. Adjusting for age and educational attainment, we used Poisson regression with robust variance to estimate prevalence ratios (PRs) and 95% confidence intervals (CIs) and applied generalized estimating equations to log binomial models to determine risk ratios (RRs) and 95% CIs between skin tone and each sleep dimension, separately. Dark vs. light skin tone was associated with marginally higher prevalence and risk of short sleep (PR = 1.04 [95% CI:1.00-1.08]; RR = 1.07 [95% CI: 0.99-1.16]) and a lower prevalence of insomnia symptoms (PR = 0.95 [95% CI: 0.91-0.99]). Insomnia symptoms were more prevalent among women with light skin tone (21.1% vs. 17.7% [medium] and 15.6% [dark]). Our findings elucidate the critical importance and need to address the differential impact of historical ideologies, systems, policies, and practices on Black women, which can manifest health-damaging social phenomena like colorism.