Sleep Apnea and Incident Stroke in a National Cohort of Black and White Adults

BACKGROUND AND OBJECTIVES

Racial/ethnic differences have been documented in the relationship between obstructive sleep apnea (OSA) and stroke incidence, yet racial differences in OSA symptoms or treatment and their relationship with stroke incidence are underexplored and may contribute to stroke disparities. We comprehensively examined OSA symptoms and their relationships to stroke incidence by race/ethnicity.

METHODS

Data were collected from the REasons for Geographic and Racial Differences in Stroke (REGARDS) study, a population-based cohort of Black and White individuals in the United States. Participants free from a stroke diagnosis at baseline were included. Participants self-reported the following: (1) snoring; (2) daytime sleepiness; (3) provider-diagnosed sleep apnea (PDSA); and (4) treatment for PDSA using positive airway pressure (PAP). OSA risk was categorized as high or low based on the Berlin Sleep Questionnaire. Incident stroke was defined as first occurrence of stroke over an average of 12 (SD 3.9) years of follow-up. We report the relationships between snoring, OSA risk, PDSA, PAP therapy use, and incident stroke by race/ethnicity using Cox proportional hazards models after adjusting for demographic and socioeconomic factors and stroke risk factors.

RESULTS

Among the 22,192 participants (mean age [SD] 64.2[9.1] years), 38.1% identified as Black. Overall, snoring was not associated with incident stroke (hazard ratio [HR] 0.98, 95% CI 0.85-1.13). However, among White individuals but not Black individuals, high OSA risk and PDSA were associated with incident stroke (HR 1.22, 95% CI 1.01-1.47; HR 1.33, 95% CI 1.04-1.70, respectively). PAP therapy use among those with PDSA (compared with non-PDSA) was associated with incident stroke in White individuals (HR 1.38, 95% CI 1.05-1.80). PAP therapy use among those with PDSA (compared with those with PDSA without PAP therapy use) was associated with reduced risk of incident stroke in Black (HR 0.39, 95% CI 0.17-0.91) but not White (HR 0.63, 95% CI 0.37-1.10) individuals.

DISCUSSION

White individuals with high OSA risk and those with PDSA with or without PAP therapy use were at increased incident stroke risk, whereas Black individuals reporting PDSA and PAP had reduced incident stroke risk relative to those not using PAP. Future research is needed to understand the mechanisms underlying racial differences in OSA and stroke such as differences in assessment modes and treatment.

Cytokines, C-Reactive Protein, and Risk of Incident Hypertension in the REGARDS Study

BACKGROUND

Hypertension is a highly prevalent cardiovascular disease risk factor that may be related to inflammation. Whether adverse levels of specific inflammatory cytokines relate to hypertension is unknown. The present study sought to determine whether higher levels of IL (interleukin)-1β, IL-6, TNF (tumor necrosis factor)-α, IFN (interferon)-γ, IL-17A, and CRP (C-reactive protein) are associated with a greater risk of incident hypertension.

METHODS

The REGARDS study (Reasons for Geographic and Racial Difference in Stroke) is a prospective cohort study that recruited 30 239 community-dwelling Black and White adults from the contiguous United States in 2003 to 2007 (visit 1), with follow-up 9 years later in 2013 to 2016 (visit 2). We included participants without prevalent hypertension who attended follow-up 9 years later and had available laboratory measures and covariates of interest. Poisson regression estimated the risk ratio of incident hypertension by level of inflammatory biomarkers.

RESULTS

Among 1866 included participants (mean [SD] aged of 62 [8] years, 25% Black participants, 55% women), 36% developed hypertension. In fully adjusted models comparing the third to first tertile of each biomarker, there was a greater risk of incident hypertension for higher IL-1β among White (1.24 [95% CI, 1.01-1.53]) but not Black participants (1.01 [95% CI, 0.83-1.23]) and higher TNF-α (1.20 [95% CI, 1.02-1.41]) and IFN-γ (1.22 [95% CI, 1.04-1.42]) among all participants. There was no increased risk with IL-6, IL-17A, or CRP.

CONCLUSIONS

Higher levels of IL-1β, TNF-α, and IFN-γ, representing distinct inflammatory pathways, are elevated in advance of hypertension development. Whether modifying these cytokines will reduce incident hypertension is unknown.

Interleukin-6, Diabetes, and Metabolic Syndrome in a Biracial Cohort: The Reasons for Geographic and Racial Differences in Stroke Cohort

OBJECTIVE

Black Americans have a greater risk of type 2 diabetes than White Americans. The proinflammatory cytokine interleukin-6 (IL-6) is implicated in diabetes pathogenesis, and IL-6 levels are higher in Black individuals. This study investigated associations of IL-6 with incident diabetes and metabolic syndrome in a biracial cohort.

RESEARCH DESIGN AND METHODS

The Reasons for Geographic and Racial Differences in Stroke (REGARDS) study enrolled 30,239 Black and White adults age ≥45 years in 2003-2007, with a follow-up ∼9.5 years later. Baseline plasma IL-6 was measured in 3,399 participants at risk of incident diabetes and 1,871 at risk of metabolic syndrome. Relative risk (RR) by IL-6 was estimated with modified Poisson regression for both groups.

RESULTS

Incident diabetes occurred in 14% and metabolic syndrome in 20%; both rates rose across IL-6 quartiles. There was a three-way interaction of IL-6, race, and central adiposity for incident diabetes (P = 8 × 10-5). In Black participants with and without central adiposity, RRs were 2.02 (95% CI 1.00-4.07) and 1.66 (1.00-2.75) for the fourth compared with first IL-6 quartile, respectively. The corresponding RRs were 1.73 (0.92-3.26) and 2.34 (1.17-4.66) in White participants. The pattern was similar for IL-6 and metabolic syndrome.

CONCLUSIONS

Although IL-6 was higher in Black than in White participants and those with central adiposity, the association of IL-6 with diabetes risk was statistically significant only among White participants without central adiposity. The association with metabolic syndrome risk was similarly stronger in low-risk groups. The results support the concept of interventions to lower inflammation in diabetes prevention, but to reduce race disparities, better biomarkers are needed.

Neighborhood Disadvantage and Risk of Heart Failure: The Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study

BACKGROUND

Heart failure (HF) affects >6 million US adults, with recent increases in HF hospitalizations. We aimed to investigate the association between neighborhood disadvantage and incident HF events and potential differences by diabetes status.

METHODS

We included 23 645 participants from the REGARDS study (Reasons for Geographic and Racial Differences in Stroke), a prospective cohort of Black and White adults aged ≥45 years living in the continental United States (baseline 2005-2007). Neighborhood disadvantage was assessed using a Z score of 6 census tract variables (2000 US Census) and categorized as quartiles. Incident HF hospitalizations or HF-related deaths through 2017 were adjudicated. Multivariable-adjusted Cox regression was used to examine the association between neighborhood disadvantage and incident HF. Heterogeneity by diabetes was assessed using an interaction term.

RESULTS

The mean age was 64.4 years, 39.5% were Black adults, 54.9% females, and 18.8% had diabetes. During a median follow-up of 10.7 years, there were 1125 incident HF events with an incidence rate of 3.3 (quartile 1), 4.7 (quartile 2), 5.2 (quartile 3), and 6.0 (quartile 4) per 1000 person-years. Compared to adults living in the most advantaged neighborhoods (quartile 1), those living in neighborhoods in quartiles 2, 3, and 4 (most disadvantaged) had 1.30 (95% CI, 1.06-1.60), 1.36 (95% CI, 1.11-1.66), and 1.45 (95% CI, 1.18-1.79) times greater hazard of incident HF even after accounting for known confounders. This association did not significantly differ by diabetes status (interaction P=0.59). For adults with diabetes, the adjusted incident HF hazards comparing those in quartile 4 versus quartile 1 was 1.34 (95% CI, 0.92-1.96), and it was 1.50 (95% CI, 1.16-1.94) for adults without diabetes.

CONCLUSIONS

In this large contemporaneous prospective cohort, neighborhood disadvantage was associated with an increased risk of incident HF events. This increase in HF risk did not differ by diabetes status. Addressing social, economic, and structural factors at the neighborhood level may impact HF prevention.

Stroke Severity, Caregiver Feedback, and Cognition in the REGARDS-CARES Study

Objective

Cognitive impairment after stroke is common, present up to 60% of survivors. Stroke severity, indicated by both volume and location, is the most consequential predictor of cognitive impairment, with severe strokes predicting higher chances of cognitive impairment. The current investigation examines the associations of two stroke severity ratings and a caregiver-report of post-stroke functioning with longitudinal cognitive outcomes.

Methods

The analysis was conducted on 157 caregivers and stroke survivor dyads who participated in the Caring for Adults Recovering from the Effects of Stroke (CARES) project, an ancillary study of the REasons for Geographic and Racial Differences in Stroke (REGARDS) national cohort study. Glasgow Outcome Scale (GOS) and modified Rankin Scale (mRS) collected at hospitalization discharge were included as two primary predictors of cognitive impairment. The number of caregiver-reported problems and impairments at nine months following stroke were included as a third predictor. Cognition was assessed using a biennial telephone battery, incorporating multiple cognitive assessments to assess learning, memory, and executive functioning. Longitudinal cognitive scores were analyzed up to five years post-stroke, controlling for baseline (pre-stroke) cognitive scores and demographic variables of each stroke survivor collected at CARES baseline.

Results

Separate mixed models showed significant main effects of GOS (b=0.3280, p=0.0009), mRS (b=-0.2119, p=0.0002), and caregiver-reported impairments (b=-0.0671, p<0.0001) on longitudinal cognitive scores. In a combined model including all three predictors, only caregiver-reported problems significantly predicted cognitive outcomes (b=-0.0480, p<0.0001).

Impact

These findings underscore the importance of incorporating caregivers feedback in understanding cognitive consequences of stroke.

Race-specific associations: inflammatory mediators and chronic low back pain

ABSTRACT

Chronic low back pain (cLBP) is a global health crisis that disproportionately burdens non-Hispanic Black (NHB) individuals, compared with those who identify as non-Hispanic White (NHW). Despite the growing personal and societal impact of cLBP, its biological underpinnings remain poorly understood. To elucidate the biological factors that underlie the racial disparities in cLBP, this study sought to determine whether inflammatory mediators associated with pain interference (PI), pain at rest (PAR), and movement-evoked pain (MEP) differ as a function of racial identity. Blood samples were collected from 156 individuals with cLBP (n = 98 NHB participants, n = 58 NHW participants). Enzyme-linked immunosorbent assay and multiplex assays were used to quantify concentrations of proinflammatory (fibrinogen, C-reactive protein [CRP], serum amyloid A, tumor necrosis factor α [TNF-α], and interleukin [IL]-1α, IL-1β, and IL-6) and anti-inflammatory markers (IL-4 and IL-13). Spearman rho correlations were used to assess associations among markers of inflammation and PI, PAR, and MEP using the Brief Pain Inventory-Short Form. Analyses revealed that for NHW patients, CRP, serum amyloid A, and IL-6 were positively associated with cLBP outcomes and IL-4 was inversely associated with PAR and MEP. However, for NHB patients, only IL-1α was positively associated with PAR. Our findings suggest that, while there are associations between inflammation and cLBP outcomes, the biomarkers that underlie the inflammation could very well differ as a function of racialized minority group. However, more research with racially inclusive samples is needed to elucidate the mechanisms that may contribute to racial disparities in cLBP.

Life-Space Mobility: Normative Values From a National Cohort of U.S. Older Adults

BACKGROUND

Life-space mobility, which measures the distance, frequency, and independence achieved as individuals move through their community, is one of the most important contributors to healthy aging. The University of Alabama at Birmingham Life-Space Assessment (LSA) is the most commonly used measure of life-space mobility in older adults, yet U.S. national norms for LSA have not previously been reported. This study reports such norms based on age and sex among community-dwelling older adults.

METHODS

A cross-sectional analysis using data from the national REasons for Geographic and Racial Disparities in Stroke cohort study. LSA data were available for 10 118 Black and White participants over age 50, which were grouped by age (in 5-year increments) and sex, weighted for the U.S. national population. Correlations were calculated between LSA and measures of functional and cognitive impairment and physical performance.

RESULTS

The weighted mean LSA ranged from 102.9 for 50-54-year-old males to 69.5 for males aged 85 and older, and from 102.1 for 50-54-year-old females to 60.1 for females aged 85 and older. LSA was strongly correlated with measures of timed walking, activities of daily living, cognition, depressive symptoms, and quality of life (all p < .001).

CONCLUSIONS

We report U.S. national norms for LSA among community-dwelling Black and White older adults. These norms can serve as a reference tool for determining if clinical and research samples have greater or lesser life-space mobility than typical older adults in the United States for their age and sex.

Plasma proenkephalin A and incident chronic kidney disease and albuminuria in the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort

BACKGROUND

Plasma proenkephalin A (PENK-A) is a precursor of active enkephalins. Higher blood concentrations have been associated with estimated glomerular filtration rate (eGFR) decline in European populations. Due to the significant disparity in incident chronic kidney disease (CKD) between White and Black people, we evaluated the association of PENK-A with incident CKD and other kidney outcomes among a biracial cohort in the U.S.

METHODS

In a nested cohort of 4,400 participants among the REasons for Geographic And Racial Differences in Stroke, we determined the association between baseline PENK-A concentration and incident CKD using the creatinine-cystatin C CKD-EPI 2021 equation without race coefficient, significant eGFR decline, and incident albuminuria between baseline and a follow-up visit 9.4 years later. We tested for race and sex interactions. We used inverse probability sampling weights to account for the sampling design.

RESULTS

At baseline, mean (SD) age was 64 (8) years, 49% were women, and 52% were Black participants. 8.5% developed CKD, 21% experienced ≥ 30% decline in eGFR and 18% developed albuminuria. There was no association between PENK-A and incident CKD and no difference by race or sex. However, higher PENK-A was associated with increased odds of progressive eGFR decline (OR: 1.12; 95% CI 1.00, 1.25). Higher PENK-A concentration was strongly associated with incident albuminuria among patients without diabetes mellitus (OR: 1.29; 95% CI 1.09, 1.53).

CONCLUSION

While PENK-A was not associated with incident CKD, its associations with progression of CKD and incident albuminuria, among patients without diabetes, suggest that it might be a useful tool in the evaluation of kidney disease among White and Black patients.

Application of marginalized zero-inflated models when mediators have excess zeroes

Mediation analysis has become increasingly popular over the last decade as researchers are interested in assessing mechanistic pathways for intervention. Although available methods have increased, there are still limited options for mediation analysis with zero-inflated count variables where the distribution of response has a "cluster" of data at the zero value (i.e. distribution of number of cigarettes smoked per day, where nonsmokers cluster at zero cigarettes). The currently available methods do not obtain unbiased population average effects of mediation effects. In this paper, we propose an extension of the counterfactual approach to mediation with direct and indirect effects to scenarios where the mediator is a count variable with excess zeroes by utilizing the Marginalized Zero-Inflated Poisson Model (MZIP) for the mediator model. We derive direct and indirect effects for continuous, binary, and count outcomes, as well as adapt to allow mediator-exposure interactions. Our proposed work allows straightforward calculation of direct and indirect effects for the overall population mean values of the mediator, for scenarios in which researchers are interested in generalizing direct and indirect effects to the population. We apply this novel methodology to an application observing how alcohol consumption may explain sex differences in cholesterol and assess model performance via a simulation study comparing the proposed MZIP mediator framework to existing methods for marginal mediator effects.

Age and sex differences in the association between neighborhood socioeconomic environment and incident diabetes: Results from the diabetes location, environmental attributes and disparities (LEAD) network

Objective

Worse neighborhood socioeconomic environment (NSEE) may contribute to an increased risk of type 2 diabetes (T2D). We examined whether the relationship between NSEE and T2D differs by sex and age in three study populations.

Research design and methods

We conducted a harmonized analysis using data from three independent longitudinal study samples in the US: 1) the Veteran Administration Diabetes Risk (VADR) cohort, 2) the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort, and 3) a case-control study of Geisinger electronic health records in Pennsylvania. We measured NSEE with a z-score sum of six census tract indicators within strata of community type (higher density urban, lower density urban, suburban/small town, and rural). Community type-stratified models evaluated the likelihood of new diagnoses of T2D in each study sample using restricted cubic splines and quartiles of NSEE.

Results

Across study samples, worse NSEE was associated with higher risk of T2D. We observed significant effect modification by sex and age, though evidence of effect modification varied by site and community type. Largely, stronger associations between worse NSEE and diabetes risk were found among women relative to men and among those less than age 45 in the VADR cohort. Similar modification by age group results were observed in the Geisinger sample in small town/suburban communities only and similar modification by sex was observed in REGARDS in lower density urban communities.

Conclusions

The impact of NSEE on T2D risk may differ for males and females and by age group within different community types.

Promoting transportation safety in adolescence: the drivingly randomized controlled trial

BACKGROUND

The impact of young drivers' motor vehicle crashes (MVC) is substantial, with young drivers constituting only 14% of the US population, but contributing to 30% of all fatal and nonfatal injuries due to MVCs and 35% ($25 billion) of the all medical and lost productivity costs. The current best-practice policy approach, Graduated Driver Licensing (GDL) programs, are effective primarily by delaying licensure and restricting crash opportunity. There is a critical need for interventions that target families to complement GDL. Consequently, we will determine if a comprehensive parent-teen intervention, the Drivingly Program, reduces teens' risk for a police-reported MVC in the first 12 months of licensure. Drivingly is based on strong preliminary data and targets multiple risk and protective factors by delivering intervention content to teens, and their parents, at the learner and early independent licensing phases.

METHODS

Eligible participants are aged 16-17.33 years of age, have a learner's permit in Pennsylvania, have practiced no more than 10 h, and have at least one parent/caregiver supervising. Participants are recruited from the general community and through the Children's Hospital of Philadelphia's Recruitment Enhancement Core. Teen-parent dyads are randomized 1:1 to Drivingly or usual practice control group. Drivingly participants receive access to an online curriculum which has 16 lessons for parents and 13 for teens and an online logbook; website usage is tracked. Parents receive two, brief, psychoeducational sessions with a trained health coach and teens receive an on-road driving intervention and feedback session after 4.5 months in the study and access to DriverZed, the AAA Foundation's online hazard training program. Teens complete surveys at baseline, 3 months post-baseline, at licensure, 3months post-licensure, 6 months post-licensure, and 12 months post-licensure. Parents complete surveys at baseline, 3 months post-baseline, and at teen licensure. The primary end-point is police-reported MVCs within the first 12 months of licensure; crash data are provided by the Pennsylvania Department of Transportation.

DISCUSSION

Most evaluations of teen driver safety programs have significant methodological limitations including lack of random assignment, insufficient statistical power, and reliance on self-reported MVCs instead of police reports. Results will identify pragmatic and sustainable solutions for MVC prevention in adolescence.

TRIAL REGISTRATION

ClinicalTrials.gov # NCT03639753.

Neighborhood Factors, Individual Stressors, and Cardiovascular Health Among Black and White Adults in the US: The Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study

Importance

Chronic stress has been posited to contribute to racial disparities in cardiovascular health. Investigation of whether neighborhood- and individual-level stressors mediate this disparity is needed.

Objective

To examine whether racial differences in ideal cardiovascular health (ICH) are attenuated by experiences with neighborhood- and individual-level stressors within a racially and geographically diverse population sample.

Design, Setting, and Participants

This cross-sectional study examined data from 7720 participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study who completed the second in-home visit (2013-2016). The REGARDS study is a population-based, longitudinal study of 30 239 non-Hispanic Black and non-Hispanic White adults aged 45 years or older at baseline (2003-2007). Data for the present study were analyzed from June to July 2021 and in March 2022.

Exposures

Neighborhood physical environment (eg, excessive noise, violence; scored from 7-28, with higher scores indicating more problems), neighborhood safety (scored as very safe, safe, or not safe), neighborhood social cohesion (eg, shared values; scored from 5-25, with higher scores indicating higher cohesion), perceived stress (eg, coping; scored from 0-16, with higher scores indicating greater perceived stress), and the experience of discrimination (yes or no).

Main Outcomes and Measures

Ideal cardiovascular health (ICH), measured as a composite of 4 health behaviors (cigarette smoking, diet, physical activity, body mass index) and 3 health factors (blood pressure, cholesterol, and glucose levels).

Results

The sample included 7720 participants (mean [SD] age, 71.9 [8.3] years; 4390 women [56.9%]; 2074 Black participants [26.9%]; and 5646 White participants [73.1%]). Black participants compared with White participants reported higher perceived stress (mean [SD] score, 3.2 [2.8] vs 2.8 [2.7]) and more often reported discrimination (77.0% vs 24.0%). Black participants also reported poorer neighborhood physical environment (mean [SD] score, 11.2 [3.8] vs 9.8 [2.9]) and social cohesion (mean [SD] score, 15.5 [2.0] vs 15.7 [1.9]) and more often reported their neighborhoods were unsafe (54.7% vs 24.3%). The odds of having a high total ICH score (ie, closer to ideal) were lower for Black adults compared with White adults, both overall (adjusted odds ratio [AOR], 0.53; 95% CI, 0.45-0.61) and by gender (men: AOR, 0.73 [95% CI, 0.57-0.93]; women: AOR, 0.45 [95% CI, 0.37-0.54]). In mediation analyses, the racial disparity in total ICH score was attenuated by neighborhood physical environment (5.14%), neighborhood safety (6.27%), neighborhood social cohesion (1.41%), and discrimination (11.01%). In stratified analyses, the factors that most attenuated the racial disparity in total ICH scores were neighborhood safety among men (12.32%) and discrimination among women (14.37%). Perceived stress did not attenuate the racial disparity in total ICH scores.

Conclusions and Relevance

In this cross-sectional study of Black and White US adults aged 45 years and older, neighborhood-level factors, including safety and physical and social environments, and individual-level factors, including discrimination, attenuated racial disparities in cardiovascular health. Interventional approaches to improve ICH that separately target neighborhood context and discrimination by gender and race are warranted.

Acetylglutamine Differentially Associated with First-Time Versus Recurrent Stroke

Approximately one-quarter of strokes occur in individuals with prior stroke. Despite the advancement in secondary stroke prevention, the long-term risk of recurrent stroke has remained unchanged. The objective of this study was to identify metabolite risk markers that are associated with recurrent stroke. We performed targeted metabolomic profiling of 162 metabolites by liquid chromatography-tandem mass spectrometry in baseline plasma in a stroke case-cohort study nested within the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, an observational cohort study of 30,239 individuals aged 45 and older enrolled in 2003-2007. Weighted Cox proportional hazard models were used to identify metabolites that had a differential effect on first-time versus recurrent stroke using an interaction term between metabolite and prior stroke at baseline (yes or no). The study included 1391 incident stroke cases identified during 7.1 ± 4.5 years of follow-up and 1050 participants in the random cohort sample. Among 162 metabolites, 13 candidates had a metabolite-by-prior stroke interaction at a p-value <0.05, with one metabolite, acetylglutamine, surpassing the Bonferroni adjusted p-value threshold (p for interaction = 5.78 × 10-5). In an adjusted model that included traditional stroke risk factors, acetylglutamine was associated with recurrent stroke (HR = 2.27 per SD increment, 95% CI = 1.60-3.20, p = 3.52 × 10-6) but not with first-time stroke (HR = 0.96 per SD increment, 95% CI = 0.87-1.06, p = 0.44). Acetylglutamine was associated with recurrent stroke but not first-time stroke, independent of traditional stroke risk factors. Future studies are warranted to elucidate the pathogenesis of acetylglutamine and recurrent stroke risk.

Childhood Residential Mobility and Mental and Physical Health in Later Life: Findings From the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study

The study objective was to investigate the effects of childhood residential mobility on older adult physical and mental health. In REasons for Geographic and Racial Differences in Stroke (REGARDS) Study, we used linear regression models to investigate if number of moves during childhood predicted mental and physical health (SF-12 MCS, PCS), adjusting for demographic covariates, childhood socioeconomic status (SES), childhood social support, and adverse childhood experiences (ACEs). We investigated interaction by age, race, childhood SES, and ACEs. People who moved more during childhood had poorer MCS scores, β = -0.10, SE = 0.05, p = 0.03, and poorer PCS scores, β = -0.25, SE = 0.06, p < 0.0001. Effects of moves on PCS were worse for Black people compared to White people (p = 0.06), those with low childhood SES compared to high childhood SES (p = 0.02), and high ACEs compared to low ACEs (p = 0.01). As family instability accompanying residential mobility, family poverty, and adversity disproportionately affect health, Black people may be especially disadvantaged.

Gut microbiota-associated metabolites and risk of ischemic stroke in REGARDS

Several metabolite markers are independently associated with incident ischemic stroke. However, prior studies have not accounted for intercorrelated metabolite networks. We used exploratory factor analysis (EFA) to determine if metabolite factors were associated with incident ischemic stroke. Metabolites (n = 162) were measured in a case-control cohort nested in the REasons for Geographic and Racial Differences in Stroke (REGARDS) study, which included 1,075 ischemic stroke cases and 968 random cohort participants. Cox models were adjusted for age, gender, race, and age-race interaction (base model) and further adjusted for the Framingham stroke risk factors (fully adjusted model). EFA identified fifteen metabolite factors, each representing a well-defined metabolic pathway. Of these, factor 3, a gut microbiome metabolism factor, was associated with an increased risk of stroke in the base (hazard ratio per one-unit standard deviation, HR = 1.23; 95%CI = 1.15-1.31; P = 1.98 × 10-10) and fully adjusted models (HR = 1.13; 95%CI = 1.06-1.21; P = 4.49 × 10-4). The highest tertile had a 45% increased risk relative to the lowest (HR = 1.45; 95%CI = 1.25-1.70; P = 2.24 × 10-6). Factor 3 was also associated with the Southern diet pattern, a dietary pattern previously linked to increased stroke risk in REGARDS (β = 0.11; 95%CI = 0.03-0.18; P = 8.75 × 10-3). These findings highlight the role of diet and gut microbial metabolism in relation to incident ischemic stroke.

Risk Factors for Incident CKD in Black and White Americans: The REGARDS Study

RATIONALE & OBJECTIVE

Little information exists on the incidence of and risk factors for chronic kidney disease (CKD) in contemporary US cohorts and whether risk factors differ by race, sex, or region in the United States.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

4,198 Black and 7,799 White participants aged at least 45 years, recruited from 2003 through 2007 across the continental United States, with baseline estimated glomerular filtration rate (eGFR)>60mL/min/1.73m2 and eGFR assessed again approximately 9 years later.

EXPOSURES

Age, sex, race (Black or White), region ("stroke belt" or other), education, income, systolic blood pressure, body mass index, diabetes, coronary heart disease, hyperlipidemia, smoking, and albuminuria.

OUTCOMES

(1) eGFR change and (2) incident CKD defined as eGFR<60mL/min/1.73m2 and≥40% decrease from baseline or kidney failure.

ANALYTICAL APPROACH

Linear regression and modified Poisson regression were used to determine the association of risk factors with eGFR change and incident CKD overall and stratified by race, sex, and region.

RESULTS

Mean age of participants was 63±8 (SD) years, 54% were female, and 35% were Black. After 9.4±1.0 years of follow-up, CKD developed in 9%. In an age-, sex-, and race-adjusted model, Black race (β =-0.13; P<0.001) was associated with higher risk of eGFR change, but this was attenuated in the fully adjusted model (β=0.02; P=0.5). Stroke belt residence was independently associated with eGFR change (β =-0.10; P<0.001) and incident CKD (relative risk, 1.14 [95% CI, 1.01-1.30]). Albuminuria was more strongly associated with eGFR change (β of-0.26 vs-0.17; P=0.01 for interaction) in Black compared with White participants. Results were similar for incident CKD.

LIMITATIONS

Persons of Hispanic ethnicity were excluded; unknown duration and/or severity of risk factors.

CONCLUSIONS

Established CKD risk factors accounted for higher risk of incident CKD in Black versus White individuals. Albuminuria was a stronger risk factor for eGFR decrease and incident CKD in Black compared with White individuals. Living in the US stroke belt is a novel risk factor for CKD.

Longitudinal associations of anticholinergic medications on cognition and possible mitigating role of physical activity

BACKGROUND

Many older adults take at least one prescription medication with anticholinergic (ACH) activity, which can impact the central nervous system and can lead to cognitive decline and impairment especially in an aging population susceptible to cognitive changes. We examined this relationship between ACH burden and cognitive function in middle-aged and older adults. We further determined if increased activity levels mitigated the relationships between ACH burden and cognition.

METHODS

Data from The Reasons for Geographic and Racial Differences in Stroke project were used. We included 20,575 adults aged ≥45 years with longitudinal cognitive testing. The anticholinergic cognitive burden (ACB) scale was used to assess for ACH use and overall burden. Cognitive data included an overall composite score, a memory, and verbal fluency composites. Mixed effects models were conducted to determine if cognitive function worsened over time for participants with higher ACB (>3) scores. The full model adjusted for age, sex, race, education, diabetes, hypertension, cardiovascular disease, congestive heart failure, and dyslipidemia, self-reported physical activity (PA) and depressive symptoms.

RESULTS

A significant relationship between ACH burden and composite cognitive scores was found (p = <0.001), with those with higher ACB showing more rapid cognitive decline over time. There was an effect of age for participants with higher ACB (>3) scores and ACB as a continuous variable. Baseline PA level was associated with less cognitive decline over time and this effect was greater in older cohorts.

CONCLUSIONS

We observed an effect of ACHs on cognition in adults ≥45 years old that worsened with age. ACH users showed more cognitive effects, whereas PA emerged as a possible mitigating factor.

Association of Circulating Metabolites With Racial Disparities in Hypertension and Stroke in the REGARDS Study

BACKGROUND AND OBJECTIVES

In the United States, the risk of stroke is greater among Black compared with that among White individuals. However, the reasons for the difference in stroke incidence are not fully elucidated. We aimed to identify metabolites that account for higher prevalent hypertension and incident ischemic stroke among Black adults.

METHODS

We used a stroke case cohort nested within the REasons for Geographic and Racial Differences in Stroke (REGARDS) study. Targeted metabolomic profiling of 162 plasma metabolites was performed by liquid chromatography-tandem mass spectrometry. We identified metabolites that were associated with prevalent hypertension and incident ischemic stroke and mediated the relationship between hypertension and ischemic stroke by weighted logistic regression, Cox proportional hazard model, and inverse odds ratio weighting mediation analysis.

RESULTS

Incident ischemic stroke cases adjudicated through April 1, 2019 (n = 1,075) were included in the study. The random cohort sample was derived from the full cohort using stratified sampling (n = 968). Among 162 metabolites, gluconic acid was associated with prevalent hypertension in Black adults (odds ratio [OR] 1.86, 95% CI 1.39-2.47, p = 2.58 × 10-5) but not in White adults (OR 1.00, 95% CI 0.80-1.24, p = 0.97; p for interaction = 4.57 × 10-4). Gluconic acid also demonstrated an association with incident ischemic stroke among Black participants (hazard ratio [HR] 1.53, 95% CI 1.28-1.81, p = 1.76 × 10-6) but not White participants (HR 1.16, 95% CI 1.00-1.34, p = 0.057; p for interaction = 0.019). In mediation analysis, gluconic acid mediated 25.4% (95% CI 4.1%-46.8%, p = 0.02) of the association between prevalent hypertension and incident ischemic stroke among Black individuals. Specific socioeconomic factors were linked to elevated gluconic acid level among Black adults in multivariable analysis, including a Southern dietary pattern (β = 0.18, 95% CI 0.08-0.28, p < 0.001), lower educational attainment (β = 0.45, 95% CI 0.19-0.72, p = 0.001), and a lack of exercise (β = 0.26, 95% CI 0.01-0.51, p = 0.045).

DISCUSSION

Gluconic acid is associated with prevalent hypertension and incident ischemic stroke and mediates the relationship between hypertension and ischemic stroke in Black but not White adults. Gluconic acid is a biomarker that is associated with social determinants of health including a Southern diet, low educational attainment, and low physical activity.

Comparison of Intimate Partner Violence and Correlates at Urgent Care Clinics and an Emergency Department in a Rural Population

This paper describes the prevalence of and factors associated with intimate partner violence (IPV) in the urgent care setting and an academic emergency department in Appalachia. A questionnaire assessing social support, mental and physical health status, substance use, and intimate partner violence was administered to 236 women seeking care in an academic emergency department or two affiliated urgent care clinics. Data collected were compared to IPV screening data from medical records. Separate logistic regression models were fit to estimate the association between sociodemographic and health-related factors and lifetime physical and sexual intimate partner violence, adjusted for the clinical setting. Of the 236 participating women, 63 were seen in the emergency department and 173 were seen in an urgent care clinic. Emergency department patients were significantly more likely to report lifetime threatened physical, physical, or sexual abuse. Based on medical records, over 20% of participants had not been screened for IPV by clinical staff during their healthcare visit. Of those that were screened, none disclosed IPV, despite a substantial proportion reporting IPV on the survey. Although survey reports of IPV were lower in the urgent care clinics, this remains an important location to introduce screenings and resources.

Mediation of an association between neighborhood socioeconomic environment and type 2 diabetes through the leisure-time physical activity environment in an analysis of three independent samples

INTRODUCTION

Inequitable access to leisure-time physical activity (LTPA) resources may explain geographic disparities in type 2 diabetes (T2D). We evaluated whether the neighborhood socioeconomic environment (NSEE) affects T2D through the LTPA environment.

RESEARCH DESIGN AND METHODS

We conducted analyses in three study samples: the national Veterans Administration Diabetes Risk (VADR) cohort comprising electronic health records (EHR) of 4.1 million T2D-free veterans, the national prospective cohort REasons for Geographic and Racial Differences in Stroke (REGARDS) (11 208 T2D free), and a case-control study of Geisinger EHR in Pennsylvania (15 888 T2D cases). New-onset T2D was defined using diagnoses, laboratory and medication data. We harmonized neighborhood-level variables, including exposure, confounders, and effect modifiers. We measured NSEE with a summary index of six census tract indicators. The LTPA environment was measured by physical activity (PA) facility (gyms and other commercial facilities) density within street network buffers and population-weighted distance to parks. We estimated natural direct and indirect effects for each mediator stratified by community type.

RESULTS

The magnitudes of the indirect effects were generally small, and the direction of the indirect effects differed by community type and study sample. The most consistent findings were for mediation via PA facility density in rural communities, where we observed positive indirect effects (differences in T2D incidence rates (95% CI) comparing the highest versus lowest quartiles of NSEE, multiplied by 100) of 1.53 (0.25, 3.05) in REGARDS and 0.0066 (0.0038, 0.0099) in VADR. No mediation was evident in Geisinger.

CONCLUSIONS

PA facility density and distance to parks did not substantially mediate the relation between NSEE and T2D. Our heterogeneous results suggest that approaches to reduce T2D through changes to the LTPA environment require local tailoring.

Abstract MP57: Coagulation Factor IX and Incident Diabetes Risk: The REasons for Geographic and Racial Differences in Stroke (REGARDS) Study

Introduction: A prothrombotic state is implicated in the vascular complications of type 2 diabetes (DM), and such complications disproportionately affect Black compared to White adults. However, it is not known if this is due to DM or whether coagulation factor levels are related to DM incidence. Higher coagulation factor IX (FIX) was related to increased risk of CHD and stroke among Black but not White participants in the REGARDS cohort. We hypothesized higher FIX antigen would be associated with incident DM risk, with stronger relationships in Black versus White adults.

Methods: REGARDS enrolled 30,239 Black and White adults from across the contiguous US from 2003-2006 with a second in-home visit from 2013-2016. The Biomarkers as MEDiators of Racial Disparities in Risk Factors (BioMedioR) nested cohort study included 4,400 participants who completed both visits, balanced on race and sex. Modified Poisson regression models estimated the RR of incident DM per 1-SD increment log FIX. We tested for a FIX-by-race interaction a priori due to differential associations of FIX with CHD and stroke by race in REGARDS.

Results: Among 3,381 participants without baseline DM (mean age 63 years, 44% Black race, 51% women), 456 (13.5%) developed incident DM over 9.5-years. Adjusting for age, sex, and race, there was a significant difference in the association of FIX with DM by race (p-interaction<0.01). As shown in the Figure, adjusted for age and sex (Model 1), the RR (95% CI) for incident DM was 1.19 (1.05, 1.34) for Black adults and 1.49 (1.23, 1.81) for White adults. Adjusting for clinical risk factors (Model 2) fully attenuated this association for Black adults, and further adjusting for behavioral factors (Model 3) fully attenuated this association for Black and White adults.

Conclusions: Higher FIX levels were associated with incident DM risk. Relationships between FIX and incident DM were stronger for White than Black adults. The FIX-DM association may be due to adverse clinical and behavioral risk factors.

D-dimer and the risk of hypertension: The REasons for Geographic And Racial Differences in Stroke Cohort Study

Background

Reasons for increased risk of hypertension in Black compared with White people are only partly understood. D-dimer, a thrombo-inflammatory marker higher in Black individuals, is also higher in people with hypertension. However, the impact of D-dimer on racial disparities in risk of incident hypertension has not been studied.

Objectives

To assess whether D-dimer is associated with the risk of incident hypertension, whether the association between D-dimer and the risk of incident hypertension differs by race, and whether the biology reflected by D-dimer explains racial disparities in the risk of incident hypertension.

Methods

This study included 1867 participants in the REasons for Geographic And Racial Differences in Stroke cohort study without baseline hypertension and with a second visit 9.4 years after baseline. Risk ratios of incident hypertension by baseline D-dimer level were estimated, a D-dimer-by-race interaction was tested, and the mediating effect of D-dimer (which represents underlying biological processes) on the association of race and hypertension risk was assessed.

Results

The risk of incident hypertension was 47% higher in persons in the top quartile than in those in the bottom quartile of D-dimer (risk ratio [RR]: 1.47; 95% CI: 1.23-1.76). The association was partly attenuated after adjusting for sociodemographic and adiposity-related risk factors (RR: 1.22; 95% CI: 1.02-1.47). The association of D-dimer and hypertension did not differ by race, and D-dimer did not attenuate the racial difference in the risk of incident hypertension.

Conclusion

D-dimer concentration reflects pathophysiology related to the development of hypertension. Specific mechanisms require further study and may involve adiposity.

Racial Differences in 25-Hydroxy Vitamin D and Self-Reported Pain Severity in a Sample of Individuals Living with Non-Specific Chronic Low Back Pain

Introduction

Considerable evidence suggests that there are significant ethnic/racial differences in the experience of pain among individuals suffering from chronic musculoskeletal conditions. Additionally, low levels of vitamin D have been associated with pain severity. Further, vitamin D deficiency is more prevalent in Non-Hispanic Black (NHB) individuals compared to Non-Hispanic Whites (NHW).

Objective

The aim of this study was to investigate the associations among race, pain severity, and serum levels of vitamin D in a sample of patients with chronic low back pain (cLBP).

Methods

All study participants (n = 155) self-identified their race/ethnicity as either NHB or NHW. Blood samples were collected to assess circulating levels of serum 25- hydroxy vitamin D. Vitamin D levels were categorized as optimal (≥20 ng/mL), insufficient (12-19 ng/mL) or deficient (<12 ng/mL). Participants then self-reported their pain severity using the Brief Pain Inventory - Short Form.

Results

Results showed that a greater proportion of NHB versus NHW participants were categorized as Vitamin D deficient (χ 2 (2, N = 155) = 16.79, p < 0.001). An analysis of covariance (ANCOVA) revealed that NHBs reported significantly greater pain severity relative to NHWs (F(1150) = 6.45) p = 0.012. Further, self-reported pain severity significantly differed according to Vitamin D clinical categories (F(2150) = 4.19, p = 0.013). Participants with deficient vitamin D reported significantly greater pain severity in comparison to participants with optimal vitamin D (F(1101) = 7.28, p = 0.008).

Conclusion

The findings suggest that Vitamin D deficiency may be linked to greater pain severity in a sample of individuals with cLBP, especially for those who identify as NHB.

Persistence of Depressive Symptoms and Risk of Incident Cardiovascular Disease With and Without Diabetes: Results from the REGARDS Study

BACKGROUND

Baseline depressive symptoms are associated with subsequent adverse cardiovascular (CV) events in subjects with and without diabetes but the impact of persistent symptoms vs. improvement remains controversial.

OBJECTIVE

Examine long-term changes in depressive symptoms in individuals with and without diabetes and the associated risk for adverse CV events.

DESIGN

REGARDS is a prospective cohort study of CV risk factors in 30,000 participants aged 45 years and older.

PARTICIPANTS

N = 16,368 (16.5% with diabetes mellitus) who remained in the cohort an average of 11.1 years later and who had complete data.

MAIN MEASURES

Depressive symptoms were measured using the 4-item Centers for Epidemiologic Study of Depression (CES-D) questionnaire at baseline and again at a mean follow-up of 5.07 (SD = 1.66) years. Adjudicated incident stroke, coronary heart disease (CHD), CV mortality, and a composite outcome were assessed in a subsequent follow-up period of 6.1 (SD = 2.6) years.

METHODS

The association of changes in depressive symptoms (CES-D scores) across 5 years with incident CV events was assessed using Cox proportional hazards modeling.

KEY RESULTS

Compared to participants with no depressive symptoms at either time point, participants without diabetes but with persistently elevated depressive symptoms at both baseline and follow-up demonstrated a significantly increased risk of incident stroke (HR (95% CI) = 1.84 (1.03, 3.30)), a pattern which was substantially more prevalent in blacks (HR (95% CI) = 2.64 (1.48, 4.72)) compared to whites (HR (95% CI) = 1.06 (0.50, 2.25)) and in those not taking anti-depressants (HR (95% CI) = 2.01 (1.21, 3.35)) in fully adjusted models.

CONCLUSIONS

The persistence of depressive symptoms across 5 years of follow-up in participants without diabetes identifies individuals at increased risk for incident stroke. This was particularly evident in black participants and among those not taking anti-depressants.

Differences in the Association of Select Dietary Measures With Risk of Incident Type 2 Diabetes

OBJECTIVE

To evaluate associations between a broad range of approaches to classifying diet and incident type 2 diabetes in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study.

RESEARCH DESIGN AND METHODS

This study included 8,750 Black and White adults without diabetes at baseline. Diabetes was defined according to fasting glucose ≥70 mmol/L, random glucose ≥111 mmol/L, or use of diabetes medications. The exposures were diet scores for Mediterranean and Dietary Approaches to Stop Hypertension (DASH) diets and Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND), dietary inflammatory index (DII), dietary inflammation score (DIS), and empirical dietary patterns (plant-based and Southern) determined using data collected with use of the Block98 food-frequency questionnaire. Modified Poisson regression was used to assess association of dietary measures with risk of incident type 2 diabetes, with models adjusted for total energy intake, demographics, lifestyle factors, and waist circumference.

RESULTS

There were 1,026 cases of incident type 2 diabetes during follow-up (11.7%). Adherence to the Southern dietary pattern was most strongly associated with risk of incident type 2 diabetes after adjustment for demographics and lifestyle (quintile [Q]5 vs. lowest Q1: risk ratio [RR] 1.95; 95% CI 1.57, 2.41). Of the diet scores, DIS (Q5 vs. Q1 RR 1.41) and MIND (Q1 vs. Q5 RR 1.33), demonstrated anti-inflammatory diets, had strongest associations with lower diabetes incidence.

CONCLUSIONS

We found associations of several dietary approaches with incident type 2 diabetes. Investigation into mechanisms driving the association with the Southern dietary pattern is warranted. Further research into use of DIS, DII, and MIND diet score should be considered for dietary recommendations for diabetes prevention.

The Area Deprivation Index Corresponds Effectively With Other Measures of Objective Socioeconomic Status in Adults With Chronic Low Back Pain

Background and Purpose: How the Area Deprivation Index (ADI) performs compared to other measures of socioeconomic status (SES) is unknown. The study purpose is to compare the ADI and other measures of SES in their ability to predict pain severity/interference. Methods: Four measures of SES were compared-ADI, income, education, and subjective social status (SSS). Results: Pain severity/interference correlated positively with ADI (r = .396/r = .33), and negatively with income (r = -.507/r = -.428) and education (r = -.271/r = -.102). Criterion scores of the pain severity model suggest income performs best (AIC = 428.29/BIC = 436.22), followed by ADI (AIC = 437.24/BIC = 445.17), with education performing least well (AIC = 446.35/BIC = 454.29). Similar results were seen for the pain interference model. Conclusions: Neighborhood-level factors warrant consideration along with individual-level factors when attempting to understand the impact of SES on chronic low back pain.

Dietary Inflammatory Index (DII) is Associated with Movement-Evoked Pain Severity in Adults with Chronic Low Back Pain: Sociodemographic Differences

Chronic low back pain (CLBP) is one of the leading causes of pain and disability in adults in the United States and disproportionately burdens non-Hispanic Black (NHB) individuals and females. Approximately 90% of CLBP cases are of unknown cause, and it is imperative that potential causes be explored. It has been reported that diet quality can influence pain state via diet-induced inflammation. The present study assessed the relationship between Dietary Inflammatory Index (DII) and movement evoked-pain severity in people with CLBP and investigated whether race/sex moderated the relationship between DII and movement-evoked pain. Results revealed no significant differences in DII scores between males and females, or between NHB and non-Hispanic White (NHW) participants. Participant sex significantly modified the relationship between DII and movement-evoked pain severity (P = .0155), such that movement-evoked pain severity was significantly impacted by DII scores in females, but not males. Participant race did not significantly moderate the DII - movement-evoked pain severity relationship. These results suggest that diet-induced inflammation may impact the CLBP experiences of females to a greater degree than males. Further research is needed to determine whether dietary interventions that reduce inflammation improve CLBP outcomes and whether these interventions may be differentially-beneficial based on sex. PERSPECTIVE: This article highlights the impact of diet-induced inflammation in a community-based sample as a whole, as well as stratified in various sociodemographic groups. This work expands our understanding of the influence of diet on pain experience and suggests that modifications to diet may be efficacious treatments for reducing chronic pain.

Trends in diagnosed hypertension prevalence by geographic region for older adults with and without diagnosed diabetes, 2005-2017

Given that the prevalence of hypertension increases with age and is more common among adults with diabetes than those without diabetes, the objective of this study was to examine trends in hypertension prevalence by geographic region among older adults with and without diabetes. Among older adults with diabetes, hypertension prevalence generally increased from 2005 to 2017 across all regions, although the annual percent change was lower from 2011 to 2017 than 2005-2011 for all regions.

Evaluation of associations between estimates of particulate matter exposure and new onset type 2 diabetes in the REGARDS cohort

BACKGROUND

Studies of PM_2.5 and type 2 diabetes employ differing methods for exposure assignment, which could explain inconsistencies in this growing literature. We hypothesized associations between PM_2.5 and new onset type 2 diabetes would differ by PM_2.5 exposure data source, duration, and community type.

METHODS

We identified participants of the US-based REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort who were free of diabetes at baseline (2003-2007); were geocoded at their residence; and had follow-up diabetes information. We assigned PM_2.5 exposure estimates to participants for periods of 1 year prior to baseline using three data sources, and 2 years prior to baseline for two of these data sources. We evaluated adjusted odds of new onset diabetes per 5 µg/m³ increases in PM_2.5 using generalized estimating equations with a binomial distribution and logit link, stratified by community type.

RESULTS

Among 11,208 participants, 1,409 (12.6%) had diabetes at follow-up. We observed no associations between PM_2.5 and diabetes in higher and lower density urban communities, but within suburban/small town and rural communities, increases of 5 µg/m³ PM_2.5 for 2 years (Downscaler model) were associated with diabetes (OR [95% CI] = 1.65 [1.09, 2.51], 1.56 [1.03, 2.36], respectively). Associations were consistent in direction and magnitude for all three PM_2.5 sources evaluated.

SIGNIFICANCE

1- and 2-year durations of PM_2.5 exposure estimates were associated with higher odds of incident diabetes in suburban/small town and rural communities, regardless of exposure data source. Associations within urban communities might be obfuscated by place-based confounding.

Spike-and-slab least absolute shrinkage and selection operator generalized additive models and scalable algorithms for high-dimensional data analysis

There are proposals that extend the classical generalized additive models (GAMs) to accommodate high-dimensional data ( p ≫ n $$ p\gg n $$ ) using group sparse regularization. However, the sparse regularization may induce excess shrinkage when estimating smooth functions, damaging predictive performance. Moreover, most of these GAMs consider an "all-in-all-out" approach for functional selection, rendering them difficult to answer if nonlinear effects are necessary. While some Bayesian models can address these shortcomings, using Markov chain Monte Carlo algorithms for model fitting creates a new challenge, scalability. Hence, we propose Bayesian hierarchical generalized additive models as a solution: we consider the smoothing penalty for proper shrinkage of curve interpolation via reparameterization. A novel two-part spike-and-slab LASSO prior for smooth functions is developed to address the sparsity of signals while providing extra flexibility to select the linear or nonlinear components of smooth functions. A scalable and deterministic algorithm, EM-Coordinate Descent, is implemented in an open-source R package BHAM. Simulation studies and metabolomics data analyses demonstrate improved predictive and computational performance against state-of-the-art models. Functional selection performance suggests trade-offs exist regarding the effect hierarchy assumption.

Nucleosides Associated With Incident Ischemic Stroke in the REGARDS and JHS Cohorts

BACKGROUND AND OBJECTIVES

Both genetic and environmental factors contribute to stroke risk. We sought to identify novel metabolites associated with incident stroke in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort and determine whether they reflected genetic or environmental variation.

METHODS

This was a stroke case-cohort observational study nested in REGARDS. Cases were defined as incident stroke and metabolomic profiles were compared to a randomly selected control cohort. In baseline plasma samples, 162 metabolites were measured using liquid chromatography-tandem mass spectrometry. Cox proportional hazards models were adjusted for age, sex, race, and age by race in the base model. Fully adjusted models included traditional stroke risk factors. Mediation analyses conducted for these stroke risk factors used the metabolite as mediator. Genome-wide associations with the leading candidate metabolites were calculated using array data. Replication analyses in the Jackson Heart Study (JHS) were conducted using random effects meta-analysis.

RESULTS

There were 2,043 participants who were followed over an average period of 7.1 years, including 1,075 stroke cases and 968 random controls. Nine metabolites were associated with stroke in the base model, 8 of which were measured and remained significant in meta-analysis with JHS. In the fully adjusted model in REGARDS, guanosine (hazard ratio [HR] 1.34, 95% CI 1.18-1.53; p = 7.26 × 10^-6) and pseudouridine (HR 1.28, 95% CI 1.13-1.45; p = 1.03 × 10^-4) were associated with incident ischemic stroke following Bonferroni adjustment. Guanosine also partially mediated the relationship between hypertension and stroke (17.6%) and pseudouridine did not mediate any risk factor. Genome-wide association analysis identified loci rs34631560 and rs34631560 associated with pseudouridine, but these did not explain the association of pseudouridine with stroke.

DISCUSSION

Guanosine and pseudouridine are nucleosides associated with incident ischemic stroke independently of other risk factors. Genetic and mediation analyses suggest that environmental exposures rather than genetic variation link nucleoside levels to stroke risk.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that guanosine and pseudouridine are associated with incident stroke.

C-reactive Protein and Racial Differences in Type 2 Diabetes Incidence: The REGARDS Study

CONTEXT

Black adults experience more type 2 diabetes mellitus and higher inflammatory markers, including C-reactive protein (CRP), than White adults. Inflammatory markers are associated with risk of incident diabetes but the impact of inflammation on racial differences in incident diabetes is unknown.

OBJECTIVE

We assessed whether CRP mediated the Black-White incident diabetes disparity.

METHODS

The REasons for Geographic And Racial Differences in Stroke (REGARDS) study enrolled 30 239 US Black and White adults aged ≥45 years in 2003-2007 with a second visit approximately 10 years later. Among participants without baseline diabetes, adjusted sex- and race-stratified risk ratios for incident diabetes at the second visit by CRP level were calculated using modified Poisson regression. Inverse odds weighting estimated the percent mediation of the racial disparity by CRP.

RESULTS

Of 11 073 participants without baseline diabetes (33% Black, 67% White), 1389 (12.5%) developed diabetes. Black participants had higher CRP at baseline and greater incident diabetes than White participants. Relative to CRP < 3 mg/L, CRP ≥ 3 mg/L was associated with greater risk of diabetes in all race-sex strata. Black participants had higher risk of diabetes at CRP < 3 mg/L, but not at CRP ≥ 3 mg/L. In women, CRP mediated 10.0% of the racial difference in incident diabetes. This mediation was not seen in men.

CONCLUSION

Higher CRP is a risk factor for incident diabetes, but the excess burden of diabetes in Black adults was only seen in those with lower CRP, suggesting that inflammation is unlikely to be the main driver of this racial disparity.

Epigenome-wide DNA methylation profiling of conditioned pain modulation in individuals with non-specific chronic low back pain

BACKGROUND

The pathoanatomic cause of chronic low back pain (cLBP) cannot be identified for up to 90% of individuals. However, dysfunctional processing of endogenous nociceptive input, measured as conditioned pain modulation (CPM), has been associated with cLBP and may involve changes in neuronal gene expression. Epigenetic-induced changes such as DNA methylation (DNAm) have been associated with cLBP.

METHODS

In the present study, the relationship between CPM and DNAm changes in a sample of community-dwelling adults with nonspecific cLBP (n = 48) and pain-free controls (PFC; n = 50) was examined using reduced representation bisulfite sequencing. Gene ontology (GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were applied to identify key pathways involved in efficient versus deficient CPM.

RESULTS

Based on CPM efficiency, we identified 6006 and 18,305 differentially methylated CpG sites (DMCs) with q values < 0.01 among individuals with cLBP and PFCs, respectively. Most of the DMCs were hypomethylated and annotated to genes of relevance to pain, including OPRM1, ADRB2, CACNA2D3, GNA12, LPL, NAXD, and ASPHD1. In both cLBP and PFC groups, the DMCs annotated genes enriched many GO terms relevant to pain processing, including transcription regulation by RNA polymerase II, nervous system development, generation of neurons, neuron differentiation, and neurogenesis. Both groups also enriched the pathways involved in Rap1-signaling, cancer, and dopaminergic neurogenesis. However, MAPK-Ras signaling pathways were enriched in the cLBP, not the PFC group.

CONCLUSIONS

This is the first study to investigate the genome-scale DNA methylation profiles of CPM phenotype in adults with cLBP and PFCs. Based on CPM efficiency, fewer DMC enrichment pathways were unique to the cLBP than the PFCs group. Our results suggest that epigenetically induced modification of neuronal development/differentiation pathways may affect CPM efficiency, suggesting novel potential therapeutic targets for central sensitization. However, CPM efficiency and the experience of nonspecific cLBP may be independent. Further mechanistic studies are required to confirm the relationship between CPM, central sensitization, and nonspecific cLBP.

Pro-neurotensin/Neuromedin N and Hypertension Risk: A Prospective Study

BACKGROUND

Neurotensin, a neuropeptide with direct cardiac effects, has been associated with prospective risk of hypertension-related conditions through measurement of its precursor, pro-neurotensin/neuromedin N (pro-NT/NMN). Its association with incident hypertension has not been evaluated.

METHODS

From 2003 to 2007, the REasons for Geographic And Racial Differences in Stroke (REGARDS) study enrolled 30,239 Black or White adults age ≥45. Pro-NT/NMN was measured in 1,692 participants without baseline hypertension (self-reported antihypertensive use or blood pressure ≥140/90 mm Hg) who underwent follow-up assessment in 2013-2016. A sensitivity analysis was conducted using a lower threshold (≥130/80 mm Hg) to define hypertension. Three robust Poisson regression models were fitted to risk of incident hypertension, adding demographics, cardiometabolic risk factors, and dietary covariates.

RESULTS

Six hundred and fourteen participants developed hypertension over 9.4 years of follow-up. Pro-NT/NMN ranged from 14 to 1,246 pmol/l, with median [interquartile range] 154 [112, 206] pmol/l. Pro-NT/NMN was not associated with hypertension overall (fully adjusted incidence rate ratio per SD increment log pro-NT/NMN 1.03, 95% confidence interval 0.95-1.11). Results of sensitivity analysis did not differ substantially.

CONCLUSIONS

Baseline pro-NT/NMN was not associated with incident hypertension. This may be a result of neurotensin's long-term interactions with other molecular regulators of blood pressure, such as the renin-angiotensin-aldosterone system.

Plasma Pro-Enkephalin A and Ischemic Stroke Risk: The Reasons for Geographic and Racial Differences in Stroke Cohort

OBJECTIVES

The opioid neuropeptide pro-enkephalin A (PENK-A) may be a circulating marker of cardiovascular risk, with prior findings relevant to heart failure, kidney disease, and vascular dementia. Despite these findings, the association of PENK-A with ischemic stroke is unknown, so we examined this association in a prospective cohort study and analyzed differences by race and sex.

MATERIALS AND METHODS

The REasons for Geographic and Racial Differences in Stroke study (REGARDS) is a prospective cohort study of 30,239 Black and White adults. Plasma PENK-A was measured in 473 participants that developed first-time ischemic stroke over 5.9 years and 899 randomly selected participants. Cox models adjusted for demographics and stroke risk factors were used to calculate hazard ratios (HRs) of stroke by baseline PENK-A.

RESULTS

PENK-A was higher with increasing age, female sex, White race, lower body mass index, and antihypertensive medication use. Each SD higher increment of PENK-A was associated with an adjusted HR of 1.20 (95% CI 1.01-1.42) for stroke, with minimal confounding by stroke risk factors. Spline plots suggested a U-shaped relationship, particularly in White men, with an adjusted HR 3.88 (95% CI 1.94-7.77) for the 95^th versus 50^th percentile of PENK-A in White men.

CONCLUSIONS

Higher baseline plasma PENK-A was independently associated with future stroke risk in REGARDS. This association was most apparent among White men. There was little confounding by established stroke risk factors, suggesting a possible causal role in stroke etiology. Further research is needed to understand the role of endogenous opioids in stroke pathogenesis.

Biomarkers as MEDiators of racial disparities in risk factors (BioMedioR): Rationale, study design, and statistical considerations

PURPOSE

Relative to White adults, Black adults have a substantially higher prevalence of hypertension and diabetes, both key risk factors for stroke, cardiovascular disease, cognitive impairment, and dementia. Blood biomarkers have shown promise in identifying contributors to racial disparities in many chronic diseases.

METHODS

We outline the study design and related statistical considerations for a nested cohort study, the Biomarker Mediators of Racial Disparities in Risk Factors (BioMedioR) study, within the 30,239-person biracial REasons for Geographic And Racial Differences in Stroke (REGARDS) study (2003-present). Selected biomarkers will be assessed for contributions to racial disparities in risk factor development over median 9.4 years of follow-up, with initial focus on hypertension, and diabetes. Here we outline study design decisions and statistical considerations for the sampling of 4,400 BioMedioR participants.

RESULTS

The population for biomarker assessment was selected using a random sample study design balanced across race and sex to provide the optimal opportunity to describe association of biomarkers with the development of hypertension and diabetes. Descriptive characteristics of the BioMedioR sample and analytic plans are provided for this nested cohort study.

CONCLUSIONS

This nested biomarker study will examine pathways with the target to help explain racial differences in hypertension and diabetes incidence.

Feasibility and Acceptability of Guided Imagery to Sequentially Address Multiple Health Behaviors During Pregnancy

INTRODUCTION

Pregnancy presents health challenges related to well-being, physical activity, dietary regulation, and body image. There is evidence to support the use of guided imagery to address these concerns during pregnancy. The purpose of this study was to analyze the use and short-term outcomes of a multiple-behavior guided imagery intervention delivered through a mobile health (mHealth) application for pregnant women.

METHODS

A single-arm, 5-week feasibility trial was conducted, and participants were instructed to listen to an audio file every day for 35 days on an mHealth application. Measurements included ongoing assessments of the participants' use of the guided imagery audio files and pre- and post-test measures of depression, anxiety, stress, physical activity, food cravings, and body image. Postintervention qualitative interviews were conducted to assess whether participants would continue to use guided imagery.

RESULTS

Fifty-eight participants (mean age, 28.5 years) were enrolled from January to June of 2018. Cloud analytics data showed an average of 4.96 audio downloads per week with the Sleep and Relaxation file being the most widely used (mean weekly usage, 5.67) and reported favorite during follow-up interviews. Paired-sample t tests from pre- to post-test showed significant reductions in depression, anxiety, and stress, increased physical activity, and sedentary behavior along with some changes in body image.

DISCUSSION

Future scalable guided imagery interventions are justified to test for efficacy. Guided imagery may also be delivered in person by health care providers or by using widely available technologies.

Pro-Neurotensin/Neuromedin N and Risk of Incident Metabolic Syndrome and Diabetes Mellitus in the REGARDS Cohort

CONTEXT

The peptide neurotensin is implicated in insulin resistance, diabetes mellitus (DM), and cardiovascular disease.

OBJECTIVE

We studied the association of neurotensin's stable precursor, pro-neurotensin/neuromedin N (pro-NT/NMN) with incident metabolic syndrome (MetS) and DM.

METHODS

We included 3772 participants from the REasons for Geographic and Racial Differences in Stroke (REGARDS) study who completed the baseline exam (2003-2007), the follow-up exam (2013-2016), and had pro-NT/NMN measured by immunoassay. Weighted logistic regression models were fitted to incident DM, incident MetS, and each MetS component, separately, incorporating demographics, metabolic risk factors, homeostasis model of insulin resistance (HOMA-IR), and diet scores. Incident MetS was defined by 3 or more harmonized criteria at follow-up in those with fewer than 3 at baseline. Incident DM was defined by use of hypoglycemic drugs/insulin, fasting glucose 126 mg/dL or greater, or random glucose 200 mg/dL or greater in those without these at baseline.

RESULTS

Median (IQR) plasma pro-NT/NMN was 160 pmol/L (118-218 pmol/L). A total of 564 (of 2770 without baseline MetS) participants developed MetS, and 407 (of 3030 without baseline DM) developed DM. Per SD higher log-pro-NT/NMN, the demographic-adjusted odds ratio (OR) and 95% CI of incident MetS was 1.22 (1.11-1.35), 1.16 (1.00-1.35) for incident low high-density lipoprotein (HDL), and 1.25 (1.11-1.40) for incident dysglycemia. The association of pro-NT/NMN with MetS was attenuated in the model adding HOMA-IR (OR per SD log-pro-NT/NMN 1.14; 95% CI, 1.00-1.30). There was no association with incident DM (OR per SD log-pro-NT/NMN 1.06; 95% CI, 0.94-1.19).

CONCLUSION

Pro-NT/NMN was associated with MetS and 2 components, dysglycemia and low HDL, likely explained by insulin resistance.

C-Reactive Protein and Incident Hypertension in Black and White Americans in the REasons for Geographic And Racial Differences in Stroke (REGARDS) Cohort Study

BACKGROUND

More inflammation is associated with greater risk incident hypertension, and Black United States (US) adults have excess burden of hypertension. We investigated whether increased inflammation as quantified by higher C-reactive protein (CRP) explains the excess incidence in hypertension experienced by Black US adults.

METHODS

We included 6,548 Black and White REasons for Geographic and Racial Differences in Stroke (REGARDS) participants without hypertension at baseline (2003-2007) who attended a second visit (2013-2016). Sex-stratified risk ratios (RRs) for incident hypertension at the second exam in Black compared to White individuals were estimated using Poisson regression adjusted for groups of factors known to partially explain the Black-White differences in incident hypertension. We calculated the percent mediation by CRP of the racial difference in hypertension.

RESULTS

Baseline CRP was higher in Black participants. The Black-White RR for incident hypertension in the minimally adjusted model was 1.33 (95% confidence interval 1.22, 1.44) for males and 1.15 (1.04, 1.27) for females. CRP mediated 6.6% (95% confidence interval 2.7, 11.3%) of this association in females and 19.7% (9.8, 33.2%) in males. In females, CRP no longer mediated the Black-White RR in a model including waist circumference and body mass index, while in males the Black-White difference was fully attenuated in models including income, education and dietary patterns.

CONCLUSIONS

Elevated CRP attenuated a portion of the unadjusted excess risk of hypertension in Black adults, but this excess risk was attenuated when controlling for measures of obesity in females and diet and socioeconomic factors in males. Inflammation related to these risk factors might explain part of the Black-White disparity in hypertension.

Sleep and neighborhood socioeconomic status: a micro longitudinal study of chronic low-back pain and pain-free individuals

Individuals with chronic low back pain (cLBP) frequently report sleep disturbances. Living in a neighborhood characterized by low-socioeconomic status (SES) is associated with a variety of negative health outcomes, including poor sleep. Whether low-neighborhood SES exacerbates sleep disturbances of people with cLBP, relative to pain-free individuals, has not previously been observed. This study compared associations between neighborhood-level SES, pain-status (cLBP vs. pain-free), and daily sleep metrics in 117 adults (cLBP = 82, pain-free = 35). Neighborhood-level SES was gathered from Neighborhood Atlas, which provides a composite measurement of overall neighborhood deprivation (e.g. area deprivation index). Individuals completed home sleep monitoring for 7-consecutive days/nights. Neighborhood SES and pain-status were tested as predictors of actigraphic sleep variables (e.g., sleep efficiency). Analyses revealed neighborhood-level SES and neighborhood-level SES*pain-status interaction significantly impacted objective sleep quality. These findings provide initial support for the negative impact of low neighborhood-level SES and chronic pain on sleep quality.

Sex and Race Differences in the Risk of Ischemic Stroke Associated With Fasting Blood Glucose in REGARDS

OBJECTIVE

To investigate sex and race differences in the association between fasting blood glucose (FBG) and risk of ischemic stroke (IS).

METHODS

This prospective longitudinal cohort study included adults age ≥45 years at baseline in the Reasons for Geographic And Racial Differences in Stroke Study, followed for a median of 11.4 years. The exposure was baseline FBG (mg/dL); suspected IS events were ascertained by phone every 6 months and were physician-adjudicated. Cox proportional hazards were used to assess the adjusted sex/race-specific associations between FBG (by category and as a restricted cubic spline) and incident IS.

RESULTS

Of 20,338 participants, mean age was 64.5 (SD 9.3) years, 38.7% were Black, 55.4% were women, 16.2% were using diabetes medications, and 954 IS events occurred. Compared to FBG <100, FBG ≥150 was associated with 59% higher hazards of IS (95% confidence interval [CI] 1.21-2.08) and 61% higher hazards of IS among those on diabetes medications (95% CI 1.12-2.31). The association between FBG and IS varied by race/sex (hazard ratio, FBG ≥150 vs FBG <100: White women 2.05 [95% CI 1.23-3.42], Black women 1.71 [95% CI 1.10-2.66], Black men 1.24 [95% CI 0.75-2.06], White men 1.46 [95% CI 0.93-2.28], p _{FBG×race/sex} = 0.004). Analyses using FBG splines suggest that sex was the major contributor to differences by race/sex subgroups.

CONCLUSIONS

Sex differences in the strength and shape of the association between FBG and IS are likely driving the significant differences in the association between FBG and IS across race/sex subgroups. These findings should be explored further and may inform tailored stroke prevention guidelines.

N-Terminal Pro-B-Type Natriuretic Peptide and Longitudinal Risk of Hypertension

BACKGROUND

Hypertension is a common condition that increases risk for future cardiovascular disease. N-terminal B-type natriuretic peptide (NT-proBNP) is higher in individuals with hypertension, but studies of its association with hypertension risk have been mixed.

METHODS

The REasons for Geographic And Racial Differences in Stroke (REGARDS) study enrolled 30,239 U.S. Black or White adults aged ≥45 years from 2003 to 2007. A subcohort included 4,400 participants who completed a second assessment in 2013-2016. NT-proBNP was measured by immunoassay in 1,323 participants without baseline hypertension, defined as blood pressure ≥140/90 or self-reported antihypertensive prescriptions. Two robust Poisson regression models assessed hypertension risk, yielding incidence rate ratios (IRRs): Model 1 included behavioral and demographic covariates and Model 2 added risk factors. A sensitivity analysis using a less conservative definition of hypertension (blood pressure ≥130/80 or self-reported antihypertensive prescriptions) was conducted.

RESULTS

Four hundred and sixty-six participants developed hypertension after mean follow-up of 9.4 years. NT-proBNP was not associated with hypertension (Model 2 IRR per SD log NT-proBNP 1.01, 95% confidence interval 0.92-1.12), with no differences by sex, body mass index, age, or race. Similar findings were seen in lower-threshold sensitivity analysis.

CONCLUSIONS

NT-proBNP was not associated with incident hypertension in REGARDS; this did not differ by race or sex.

Perceived Injustice Helps Explain the Association Between Chronic Pain Stigma and Movement-Evoked Pain in Adults with Nonspecific Chronic Low Back Pain

OBJECTIVE

For most patients with chronic low back pain (cLBP), the cause is "nonspecific," meaning there is no clear association between pain and identifiable pathology of the spine or associated tissues. Laypersons and providers alike are less inclined to help, feel less sympathy, dislike patients more, suspect deception, and attribute lower pain severity to patients whose pain does not have an objective basis in tissue pathology. Because of these stigmatizing responses from others, patients with cLBP may feel that their pain is particularly unjust and unfair. These pain-related injustice perceptions may subsequently contribute to greater cLBP severity. The purpose of this study was to examine whether perceived injustice helps explain the relationship between chronic pain stigma and movement-evoked pain severity among individuals with cLBP.

METHODS

Participants included 105 patients with cLBP who completed questionnaires assessing chronic pain stigma and pain-related injustice perception, as well as a short physical performance battery for the assessment of movement-evoked pain and physical function.

RESULTS

Findings revealed that perceived injustice significantly mediated the association between chronic pain stigma and cLBP severity (indirect effect = 6.64, 95% confidence interval [CI] = 2.041 to 14.913) and physical function (indirect effect = -0.401, 95% CI = -1.029 to -0.052). Greater chronic pain stigma was associated with greater perceived injustice (P = 0.001), which in turn was associated with greater movement-evoked pain severity (P = 0.003).

CONCLUSIONS

These results suggest that perceived injustice may be a means through which chronic pain stigma impacts nonspecific cLBP severity and physical function.

Temporal summation of mechanical pain prospectively predicts movement-evoked pain severity in adults with chronic low back pain

BACKGROUND

Biopsychosocial factors above and beyond pathoanatomical changes likely contribute to the severity of chronic low back pain. A pro-nociceptive endogenous pain modulatory balance (↓inhibition and ↑facilitation) may be an important contributor to chronic low back pain severity and physical function; however, additional research is needed to address this possibility. The objective of this study was to determine whether quantitative sensory tests of endogenous pain inhibition and facilitation prospectively predict movement-evoked pain and cLBP severity self-reported on a validated questionnaire.

METHODS

One hundred thirty-four individuals with chronic low back pain were enrolled in this two-session study. During the first study session, temporal summation of mechanical pain and conditioned pain modulation were assessed at the lumbar spine to determine endogenous pain facilitation and inhibition, respectively. One week later, participants returned for a second study session whereby they reported their pain severity and pain interference using the Brief Pain Inventory-Short Form. Movement-evoked pain and physical function capacity were assessed upon completion of the balance, walking, and transition from sit to stand tests of the Short Physical Performance Battery.

RESULTS

Temporal summation of mechanical pain, but not conditioned pain modulation, significantly and prospectively predicted greater movement-evoked pain and poorer physical function on the Short Physical Performance Battery. Neither temporal summation nor conditioned pain modulation were significantly related to self-reported pain severity or pain interference on the Brief Pain Inventory-Short Form.

CONCLUSIONS

Findings suggest that a pro-nociceptive pain modulatory balance characterized by enhanced pain facilitation may be an important driver of movement-evoked pain severity and poor physical function in individuals with chronic low back pain.

Does the Association Between Hemoglobin A1c and Risk of Cardiovascular Events Vary by Residential Segregation? The REasons for Geographic And Racial Differences in Stroke (REGARDS) Study

OBJECTIVE

To examine if the association between higher A1C and risk of cardiovascular disease (CVD) among adults with and without diabetes is modified by racial residential segregation.

RESEARCH DESIGN AND METHODS

The study used a case-cohort design, which included a random sample of 2,136 participants at baseline and 1,248 participants with incident CVD (i.e., stroke, coronary heart disease [CHD], and fatal CHD during 7-year follow-up) selected from 30,239 REasons for Geographic And Racial Differences in Stroke (REGARDS) study participants originally assessed between 2003 and 2007. The relationship of A1C with incident CVD, stratified by baseline diabetes status, was assessed using Cox proportional hazards models adjusting for demographics, CVD risk factors, and socioeconomic status. Effect modification by census tract-level residential segregation indices (dissimilarity, interaction, and isolation) was assessed using interaction terms.

RESULTS

The mean age of participants in the random sample was 64.2 years, with 44% African American, 59% female, and 19% with diabetes. In multivariable models, A1C was not associated with CVD risk among those without diabetes (hazard ratio [HR] per 1% [11 mmol/mol] increase, 0.94 [95% CI 0.76-1.16]). However, A1C was associated with an increased risk of CVD (HR per 1% increase, 1.23 [95% CI 1.08-1.40]) among those with diabetes. This A1C-CVD association was modified by the dissimilarity (P < 0.001) and interaction (P = 0.001) indices. The risk of CVD was increased at A1C levels between 7 and 9% (53-75 mmol/mol) for those in areas with higher residential segregation (i.e., lower interaction index). In race-stratified analyses, there was a more pronounced modifying effect of residential segregation among African American participants with diabetes.

CONCLUSIONS

Higher A1C was associated with increased CVD risk among individuals with diabetes, and this relationship was more pronounced at higher levels of residential segregation among African American adults. Additional research on how structural determinants like segregation may modify health effects is needed.

Sex Differences in Factors Contributing to the Racial Disparity in Diabetes Risk

INTRODUCTION

Diabetes incidence differs by race in the U.S., with a persistent reported Black-White disparity. However, the factors that contribute to this excess risk in middle-aged and older adults are unclear.

METHODS

This prospective cohort study included 7,171 Black and White adults aged ≥45 years without diabetes at baseline (2003‒2007) who completed a follow-up examination (2013‒2016). Modified Poisson regression was used to obtain sex-stratified RRs for diabetes. Mediation analyses using a change in β coefficient assessed individual and neighborhood factors that contribute to the racial disparity in diabetes incidence. Statistical analyses were conducted in 2018-2019.

RESULTS

The cumulative incidence of diabetes was higher for Black men (16.2%) and women (17.7%) than for White men (11.0%) and women (8.1%). Adjusting for age and prediabetes, diabetes risk was higher for Black women than for White women (RR=1.75, 95% CI=1.47, 2.07) and for Black men than for White men (RR=1.33, 95% CI=1.09, 1.64). The individual factors that attenuated the racial disparity the most were Southern dietary pattern (change in β=42.8%) and neighborhood socioeconomic environment (change in β=26.3%) among men and BMI (change in β=34.4%) and waist circumference (change in β=32.4%) among women. When including all factors collectively, the racial disparity in diabetes incidence was similar for men (RR=1.38, 95% CI=1.04, 1.83) and was attenuated for women (RR=1.41, 95% CI=1.11, 1.81).

CONCLUSIONS

The racial disparity in diabetes incidence remained after accounting for individual and neighborhood factors. Further investigation of additional factors underlying this racial disparity is needed to inform multilevel strategies for diabetes prevention.

Evaluating disparities in child occupant protection using a proportion-eliminated approach to mediation

OBJECTIVE

While there are clear racial/ethnic disparities in child restraint system (CRS) use, to date no studies have identified mediators that quantitatively explain the relationship between race and CRS use. Therefore, the objective of this study was to provide an example of how a proportion-eliminated approach to mediation may be particularly useful in understanding the complex relationship between race and CRS use.

METHODS

Sixty-two mothers with a child between 4-8 years old completed a survey and had their CRS use assessed by a Child Passenger Safety Technician using a structured assessment based on the 2018 American Academy of Pediatrics' Best Practice guidelines. Recruitment and data collection occurred in Birmingham, Alabama between June 2018 and January 2019. We used chi-squared tests, logistic regressions, and a proportion-eliminated approach to mediation to compare our variables of interest and to estimate the amount of the association between racial group membership and errors in restraint use that may be explained by sociodemographic, psychosocial, and parenting variables.

RESULTS

Before mediation, Nonwhite mothers in this sample had a 7.38 greater odds of having an error in CRS use than White mothers. Mediation analyses indicated that being married and self-reported seatbelt use explained 47% and 35% of the effect of race on CRS use errors, respectively.

CONCLUSION

A proportion-eliminated approach to mediation may be particularly useful in child passenger safety research aiming to inform the development of interventions tailored for racial minority populations.

Injuries on the Youth Soccer (Football) Field: Do Additional Referees Reduce Risk? Randomized Crossover Trial

OBJECTIVE

Youth soccer injury can be prevented through various means, but few studies consider the role of referees. Following previous research suggesting children take fewer risks when supervised intensely, this randomized crossover trial evaluated whether risky play and injuries decrease under supervision from three referees instead of one referee.

METHODS

Youth soccer clubs serving a metropolitan U.S. area participated. Boys' and girls' clubs at under age 10 (U10) and under age 11 (U11) levels were randomly assigned such that when the same clubs played each other twice in the same season, they played once with one referee and once with three referees. A total of 98 games were videotaped and subsequently coded to obtain four outcomes: collisions between players, aggressive fouls (involving physical player-to-player contact) called by the referee(s) on the field, aggressive fouls judged by trained coders, and injuries requiring adult attention or play stoppage.

RESULTS

Poisson mixed model results suggest players in the 98 games committed fewer aggressive fouls, as identified independently by referees (rate ratio [RR] 0.58; 95% confidence interval [CI] 0.35-0.96) and by researchers (RR 0.67; 95% CI 0.50-0.90), when there were three referees versus one referee. Collisions (RR 0.98; 95% CI 0.86-1.12) and injury rates (RR 1.15; 95% CI 0.60-2.19) were similar across conditions.

CONCLUSION

When the same youth soccer clubs played with three referees rather than one, they committed fewer aggressive fouls. More intense supervision created better rule adherence. Injury rates were unchanged with increased supervision. Results raise questions concerning whether financial investment in additional referees on youth soccer fields yields safety benefits.

Study protocol: developing and evaluating an interactive web platform to teach children hunting, shooting and firearms safety: a randomized controlled trial

BACKGROUND

Firearms injuries present a major pediatric public health challenge in the United States. This study protocol describes research to develop and then conduct a randomized clinical trial to evaluate ShootSafe, an interactive, engaging, educational website to teach children firearms safety. ShootSafe has three primary goals: (a) teach children basic knowledge and skills needed to hunt, shoot, and use firearms safely; (b) help children learn and hone critical cognitive skills of impulse control and hypothetical thinking needed to use firearms safely; and (c) alter children's perceptions about their own vulnerability and susceptibility to firearms-related injuries, the severity of those injuries, and their perceived norms about peer behavior surrounding firearms use. ShootSafe will accomplish these goals through a combination of interactive games plus short, impactful testimonial videos and short expert-led educational videos.

METHODS

Following website development, ShootSafe will be evaluated through a randomized controlled trial with 162 children ages 10-12, randomly assigning children to engage in ShootSafe or an active control website. Multiple self-report, computer-based, and behavioral measures will assess functioning at baseline, immediately following training, and at 4-month follow-up. Four sets of outcomes will be considered: firearms safety knowledge; cognitive skills in impulse control and hypothetical thinking; perceptions about firearms safety; and simulated behavior when handling, storing and transporting firearms. Training in both conditions will comprise two 45-min sessions.

DISCUSSION

If results are as hypothesized, ShootSafe offers potential as a theory-based program to teach children firearms safety in an accessible, engaging and educational manner. Translation into practice is highly feasible.

TRIAL REGISTRATION

The study protocol was registered on 11/10/20 at clinicaltrials.gov ( NCT04622943 ).