No abstract

The Collaborative Cohort of Cohorts for COVID-19 Research (C4R) is a national prospective study of adults comprising 14 established United States (US) prospective cohort studies. Starting as early as 1971, C4R cohorts have collected data on clinical and subclinical diseases and their risk factors, including behavior, cognition, biomarkers, and social determinants of health. C4R links this pre-COVID phenotyping to information on SARS-CoV-2 infection and acute and post-acute COVID-related illness. C4R is largely population-based, has an age range of 18–108 years, and reflects the racial, ethnic, socioeconomic, and geographic diversity of the US. C4R ascertains SARS-CoV-2 infection and COVID-19 illness using standardized questionnaires, ascertainment of COVID-related hospitalizations and deaths, and a SARS-CoV-2 serosurvey via dried blood spots. Master protocols leverage existing robust retention rates for telephone and in-person examinations, and high-quality events surveillance. Extensive pre-pandemic data minimize referral, survival, and recall bias. Data are harmonized with research-quality phenotyping unmatched by clinical and survey-based studies; these will be pooled and shared widely to expedite collaboration and scientific findings. This resource will allow evaluation of risk and resilience factors for COVID-19 severity and outcomes, including post-acute sequelae, and assessment of the social and behavioral impact of the pandemic on long-term trajectories of health.

Purpose We previously described the magnitude of rural‐urban differences in the prevalence of stroke risk factors and stroke mortality. In this report, we sought to extend the understanding of rural‐urban differences in the prevalence of stroke risk factors by using an enhanced definition of rural‐urban status and assessing the impact of neighborhood socioeconomic status (nSES) on risk factor differences. Methods This analysis included 28,242 participants without a history of stroke from the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort. Participants were categorized into the 6‐level ordinal National Center for Health Statistics Urban‐Rural Classification Scheme. The prevalence of stroke risk factors (hypertension, diabetes, smoking, atrial fibrillation, left ventricular hypertrophy, and heart disease) was assessed across the rural‐urban scale with adjustment for demographic characteristics and further adjustment for nSES score. Findings Hypertension, diabetes, and heart disease were more prevalent in rural than urban regions. Higher odds were observed for these risk factors in the most rural compared to the most urban areas (odds ratios [95% CI]: 1.25 [1.11‐1.42] for hypertension, 1.15 [0.99‐1.33] for diabetes, and 1.19 [1.02‐1.39] for heart disease). Adjustment for nSES score partially attenuated the odds of hypertension and heart disease with rurality, completely attenuated the odds of diabetes, and unmasked an association of current smoking. Conclusions Some of the higher stroke mortality in rural areas may be due to the higher burden of stroke risk factors in rural areas. Lower nSES contributed most notably to rural‐urban differences for diabetes and smoking.

In the United States, causes of racial differences in stroke and its risk factors remain only partly understood, and there is a long-standing disparity in stroke incidence and mortality impacting Black Americans. Only half of the excess risk of stroke in the United States Black population is explained by traditional risk factors, suggesting potential effects of other factors including genetic and biological characteristics. Here, we nonsystematically reviewed candidate laboratory biomarkers for stroke and their relationships to racial disparities in stroke. Current evidence indicates that IL-6 (interleukin-6), a proinflammatory cytokine, mediates racial disparities in stroke through its association with traditional risk factors. Only one reviewed biomarker, Lp(a) (lipoprotein[a]), is a race-specific risk factor for stroke. Lp(a) is highly genetically determined and levels are substantially higher in Black than White people; clinical and pharmaceutical ramifications for stroke prevention remain uncertain. Other studied stroke risk biomarkers did not explain racial differences in stroke. More research on Lp(a) and other biological and genetic risk factors is needed to understand and mitigate racial disparities in stroke.

The Collaborative Cohort of Cohorts for COVID-19 Research (C4R) is a national prospective study of adults at risk for coronavirus disease 2019 (COVID-19) comprising 14 established United States (US) prospective cohort studies. For decades, C4R cohorts have collected extensive data on clinical and subclinical diseases and their risk factors, including behavior, cognition, biomarkers, and social determinants of health. C4R will link this pre-COVID phenotyping to information on SARS-CoV-2 infection and acute and post-acute COVID-related illness. C4R is largely population-based, has an age range of 18-108 years, and broadly reflects the racial, ethnic, socioeconomic, and geographic diversity of the US. C4R is ascertaining severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and COVID-19 illness using standardized questionnaires, ascertainment of COVID-related hospitalizations and deaths, and a SARS-CoV-2 serosurvey via dried blood spots. Master protocols leverage existing robust retention rates for telephone and in-person examinations, and high-quality events surveillance. Extensive pre-pandemic data minimize referral, survival, and recall bias. Data are being harmonized with research-quality phenotyping unmatched by clinical and survey-based studies; these will be pooled and shared widely to expedite collaboration and scientific findings. This unique resource will allow evaluation of risk and resilience factors for COVID-19 severity and outcomes, including post-acute sequelae, and assessment of the social and behavioral impact of the pandemic on long-term trajectories of health and aging.