Discriminatory and valuing communication behaviors in cardiology encounters

OBJECTIVE

Many have found racial differences in clinician-patient communication using validated codebooks that represent effective communication. No codebooks used for examining racial differences, however, have included patient input. In this paper, we describe creating codebook with Black patient advocates to determine if we could reliably code discriminatory/valuing communication and assess racial differences in these behaviors.

METHODS

We created a codebook for discriminatory/valuing communication behaviors with the input of Black patient advocates. We used the codebook to analyze data from 101 audio recorded encounters between White cardiologists and Black and White patients. We examined the differences in the prevalence of behaviors in cardiology encounters.

RESULTS

In comparison to White patients, cardiologists made fewer tailoring statements to their Black patients (68% vs. 49%, p = 0.07). Coders found 4 instances of stereotyping behaviors and only Black patients (p = 0.12). We found no significant associations between any of the other outcomes and patient race. Black patients had a lower incidence of tailoring statements (p = 0.13), lower incidence of interrupting statements (p = 0.16), and higher rushed global score (p = 0.14).

CONCLUSION AND PRACTICE IMPLICATIONS

We found that coders can reliably identify discriminatory/valuing behaviors in cardiology encounters. Future work should apply these codes to other datasets to assess their validity and generalizability.

Race differences in patient trust and distrust from audio-recorded cardiology encounters

OBJECTIVE

Many have reported racial disparities in self-reported trust in clinicians but have not directly assessed expressions of trust and distrust in physician-patient encounters. We created a codebook to examine racial differences in patient trust and distrust through audio-recorded cardiologist-patient interactions.

METHODS

We analyzed data from a randomized controlled trial of audio-recorded outpatient cardiology encounters (50 White and 51 Black patients). We created a codebook for trust and distrust that was applied to recordings between White cardiologists and White and Black patients. We assessed differences in trust, distrust, and guardedness while adjusting for patient age, sex, and first appointment with the cardiologist.

RESULTS

Compared to White patients, Black patients had significantly lower expressions of trust ([IRR] [95 % CI]: 0.59 [0.41, 0.84]) and a significantly lower mean guarded/open score ([β] [95 % CI] -0.38 [-0.71, -0.04]). There was no statistically significant association between race and odds of at least one distrustful expression (OR [95 % CI] 1.36 [0.37, 4.94]).

CONCLUSION AND PRACTICE IMPLICATIONS

We found that coders can reliably identify patient expressions of trust and distrust rather than relying on problematic self-reported measures. Results suggest that White clinicians can improve their communication with Black patients to increase expressions of trust.

Residential Structural Racism and Prevalence of Chronic Health Conditions

Importance

Studies elucidating determinants of residential neighborhood-level health inequities are needed.

Objective

To quantify associations of structural racism indicators with neighborhood prevalence of chronic kidney disease (CKD), diabetes, and hypertension.

Design, Setting, and Participants

This cross-sectional study used public data (2012-2018) and deidentified electronic health records (2017-2018) to describe the burden of structural racism and the prevalence of CKD, diabetes, and hypertension in 150 residential neighborhoods in Durham County, North Carolina, from US census block groups and quantified their associations using bayesian models accounting for spatial correlations and residents' age. Data were analyzed from January 2021 to May 2023.

Exposures

Global (neighborhood percentage of White residents, economic-racial segregation, and area deprivation) and discrete (neighborhood child care centers, bus stops, tree cover, reported violent crime, impervious areas, evictions, election participation, income, poverty, education, unemployment, health insurance coverage, and police shootings) indicators of structural racism.

Main Outcomes and Measures

Outcomes of interest were neighborhood prevalence of CKD, diabetes, and hypertension.

Results

A total of 150 neighborhoods with a median (IQR) of 1708 (1109-2489) residents; median (IQR) of 2% (0%-6%) Asian residents, 30% (16%-56%) Black residents, 10% (4%-20%) Hispanic or Latino residents, 0% (0%-1%) Indigenous residents, and 44% (18%-70%) White residents; and median (IQR) residential income of $54 531 ($37 729.25-$78 895.25) were included in analyses. In models evaluating global indicators, greater burden of structural racism was associated with greater prevalence of CKD, diabetes, and hypertension (eg, per 1-SD decrease in neighborhood White population percentage: CKD prevalence ratio [PR], 1.27; 95% highest density interval [HDI], 1.18-1.35; diabetes PR, 1.43; 95% HDI, 1.37-1.52; hypertension PR, 1.19; 95% HDI, 1.14-1.25). Similarly in models evaluating discrete indicators, greater burden of structural racism was associated with greater neighborhood prevalence of CKD, diabetes, and hypertension (eg, per 1-SD increase in reported violent crime: CKD PR, 1.15; 95% HDI, 1.07-1.23; diabetes PR, 1.20; 95% HDI, 1.13-1.28; hypertension PR, 1.08; 95% HDI, 1.02-1.14).

Conclusions and Relevance

This cross-sectional study found several global and discrete structural racism indicators associated with increased prevalence of health conditions in residential neighborhoods. Although inferences from this cross-sectional and ecological study warrant caution, they may help guide the development of future community health interventions.

Association of Age and Gender With Concerns About Live Donor Kidney Transplantation Among Black Individuals

Black individuals are less likely to receive live donor kidney transplantation (LDKT) compared to others. This may be partly related to their concerns about LDKT, which can vary based on age and gender. We conducted a cross-sectional, secondary analysis of the baseline enrollment data from the Talking about Living Kidney Donation Support trial, which studied the effectiveness of social workers and financial interventions on activation towards LDKT among 300 Black individuals from a deceased donor waiting list. We assessed concerns regarding the LDKT process, including their potential need for postoperative social support, future reproductive potential, recipient and donor money matters, recipient and donor safety, and interpersonal concerns. Answers ranged from 0 ("not at all concerned") to 10 ("extremely concerned"). We described and compared participants' concerns both overall and stratified by age (≥45 years old vs <45 years old) and self-reported gender ("male" versus "female"). The participants' top concerns were donor safety (median [IQR] score 10 [5-10]), recipient safety (5 [0-10]), money matters (5 [0-9]), and guilt/indebtedness (5 [0-9]). Younger females had statistically significantly higher odds of being concerned about future reproductive potential (odds ratio [OR] 3.77, 95% CI 2.77, 4.77), and older males had statistically higher mean concern about postoperative social support (OR 1.79, 95% CI 0.19, 3.38). Interventions to improve rates of LDKT among Black individuals should include education and counseling about the safety of LDKT for both recipients and donors, reproductive counseling for female LDKT candidates of childbearing age, and addressing older males' needs for increased social support.

Conjugation of HIV-1 envelope to hepatitis B surface antigen alters vaccine responses in rhesus macaques

An effective HIV-1 vaccine remains a critical unmet need for ending the AIDS epidemic. Vaccine trials conducted to date have suggested the need to increase the durability and functionality of vaccine-elicited antibodies to improve efficacy. We hypothesized that a conjugate vaccine based on the learned response to immunization with hepatitis B virus could be utilized to expand T cell help and improve antibody production against HIV-1. To test this, we developed an innovative conjugate vaccine regimen that used a modified vaccinia virus Ankara (MVA) co-expressing HIV-1 envelope (Env) and the hepatitis B virus surface antigen (HBsAg) as a prime, followed by two Env-HBsAg conjugate protein boosts. We compared the immunogenicity of this conjugate regimen to matched HIV-1 Env-only vaccines in two groups of 5 juvenile rhesus macaques previously immunized with hepatitis B vaccines in infancy. We found expansion of both HIV-1 and HBsAg-specific circulating T follicular helper cells and elevated serum levels of CXCL13, a marker for germinal center activity, after boosting with HBsAg-Env conjugate antigens in comparison to Env alone. The conjugate vaccine elicited higher levels of antibodies binding to select HIV Env antigens, but we did not observe significant improvement in antibody functionality, durability, maturation, or B cell clonal expansion. These data suggests that conjugate vaccination can engage both HIV-1 Env and HBsAg specific T cell help and modify antibody responses at early time points, but more research is needed to understand how to leverage this strategy to improve the durability and efficacy of next-generation HIV vaccines.

Racial Differences in Over-the-Counter Non-steroidal Anti-inflammatory Drug Use Among Individuals at Risk of Adverse Cardiovascular Events

PURPOSE

Black Americans are disproportionately affected by adverse cardiovascular events (ACEs). Over-the-counter (OTC) non-steroidal anti-inflammatory drugs (NSAIDs) confer increased risk for ACEs, yet racial differences in the use of these products remain understudied. This study sought to determine racial differences in OTC NSAID and high-potency powdered NSAID (HPP-NSAID) use.

METHODS AND MATERIALS

This retrospective analysis examined participants at risk of ACEs (defined as those with self-reported hypertension, diabetes, heart disease, or smoking history ≥ 20 years) from the North Carolina Colon Cancer Study, a population-based case-control study. We used multivariable logistic regression models to assess the independent associations of race with any OTC NSAID use, HPP-NSAID use, and regular use of these products.

RESULTS

Of the 1286 participants, 585 (45%) reported Black race and 701 (55%) reported non-Black race. Overall, 665 (52%) reported any OTC NSAID use and 204 (16%) reported HPP-NSAID use. Compared to non-Black individuals, Black individuals were more likely to report both any OTC NSAID use (57% versus 48%) and HPP-NSAID use (22% versus 11%). In multivariable analyses, Black (versus non-Black) race was independently associated with higher odds of both NSAID use (OR 1.4, 95% CI (1.1, 1.8)) and HPP-NSAID use (OR 1.8 (1.3, 2.5)).

CONCLUSIONS

Black individuals at risk of ACEs had higher odds of any OTC NSAID and HPP-NSAID use than non-Black individuals, after controlling for pain and socio-economic status. Further research is necessary to identify potential mechanisms driving this increased use.

Effect of intratrial mean 25(OH)D concentration on diabetes risk, by race and weight: an ancillary analysis in the D2d study

BACKGROUND

Higher serum 25-hydroxyvitamin D [25(OH)D] is associated with lower type 2 diabetes risk. 25(OH)D varies due to skin pigmentation and weight.

OBJECTIVES

This analysis aims to determine whether the effect of vitamin D differs among people of color and those with overweight/obesity (who have higher diabetes risk) compared with individuals who are White or have normal weight.

METHODS

The D2d study is a randomized clinical trial in people with prediabetes that tested the effects of daily vitamin D3 4000 IU vs. placebo on diabetes risk (median followup 2.5 y). We compared baseline and intratrial mean 25(OH)D concentrations, defined as the mean of all available annual 25(OH)D values, among groups defined by self-reported race and body mass index (BMI). We used Cox proportional hazards models to assess the associations between intratrial mean 25(OH)D and diabetes risk by race- and BMI-based groups.

RESULTS

Asian (n=130), Black (n=616), and White (n=1616) participants were included. Both baseline and intratrial mean 25(OH)D concentrations differed significantly by race groups (both P < 0.001) and were lower in Asian and Black vs. White participants, and in those with higher vs. lower BMI adjusted for race (both P < 0.001). Compared with those with lower concentrations, Black and White participants with intratrial mean 25(OH)D ≥ 40 ng/mL had significantly reduced diabetes risk [HR (95% CI): Black: 0.51 (0.29, 0.92); White: 0.42 (0.30, 0.60)] and with a similar reduction in diabetes risk among Asian participants: 0.39 (0.14, 1.11). Compared with those with lower concentrations, participants with baseline BMI < 40 kg/m2 who achieved intratrial mean 25(OH)D concentrations ≥ 40 ng/mL had a significantly reduced diabetes risk. There was no statistically significant interaction between intratrial 25(OH)D and race or between intratrial 25(OH)D and BMI on diabetes risk.

CONCLUSIONS

Among people with prediabetes, particularly for Black and White race groups and those with BMI < 40 kg/m2, the optimal 25(OH)D concentration may be ≥ 40 ng/mL to optimize diabetes-prevention efforts. This trial was registered at clinicaltrials.gov as NCT01942694.

Abstract P452: The Associations Between Potassium Levels, Arterial Stiffness, and Cardiovascular Disease Risk in the Jackson Heart Study

Background: Low-normal serum potassium (K) and low dietary K intake are more prevalent in Black than White individuals and are potentially modifiable risk factors for cardiovascular disease (CVD), hypertension, and diabetes, conditions that disproportionately affect Black adults. Arterial stiffness predicts the development of CVD. We sought to determine the associations of K measures with arterial stiffness and incident CVD.

Methods: We used data from participants of the Jackson Heart Study who were free of CVD at baseline. We used multivariable linear regression to assess the associations of serum K and dietary K intake with two measures of arterial stiffness: peripheral pulse pressure (PP) and carotid-femoral PWV (CFPWV) - the gold standard. Additionally, we analyzed associations of K measures with incident CVD using multivariable Cox proportional hazard models.

Results: Of 4467 participants included in our analyses, 1218 had low-normal serum K (K ≤ 4.0 mmol/L) at baseline, and 407 participants had a CVD event over a median of 13.7 years of follow-up. In minimally-adjusted models, there were significant inverse associations of serum K with PP and CFPWV. The association between serum K and CFPWV persisted after multivariable adjustment (Table). In multivariable models with serum K categorized into quintiles, those with serum K > 4.4 mmol/L had significantly lower CFPWV. There were no significant associations between dietary K and outcomes of arterial stiffness. There were no significant associations between either measure of K and incident CVD.

Conclusions: In this cohort of Black adults, higher serum K was significantly associated with reduced arterial stiffness.

Association of Perceived Neighborhood Health With Hypertension Self-care

Importance

Hypertension self-management is recommended for optimal blood pressure (BP) control, but self-identified residential contextual factors that hinder hypertension self-care are understudied.

Objective

To quantify perceived neighborhood health and hypertension self-care and assess interactions with the area deprivation index (ADI) and healthy food availability at home.

Design, Setting, and Participants

A cross-sectional study was conducted in Baltimore, Maryland, including primary care adults enrolled in the Achieving Blood Pressure Control Together trial between September 1, 2013, and June 30, 2014. Participants were Black and had at least 2 BP readings greater than or equal to 140/90 mm Hg in the 6 months before enrollment. Analyses were conducted from August 5, 2021, to January 28, 2022.

Exposures

Participants' perceived neighborhood health, defined as the mean standardized score across 4 subdomains of aesthetic quality, walkability, safety, and violence, with a higher score signifying better neighborhood health.

Main Outcomes and Measures

Hypertension self-care behavior and self-efficacy. Multivariable generalized linear models were fit regressing each outcome on perceived neighborhood health (higher scores on each domain signify better perceived neighborhood health), adjusted for confounders, and interaction terms between neighborhood health and potential modifiers (ADI [higher percentiles correspond to more deprivation] and healthy food availability [higher scores indicate greater availability]) of the primary association were included.

Results

Among 159 participants (median [IQR] age, 57 [49-64] years; mean [SD] age, 57 (11) years; 117 women [74%]), median (IQR) hypertension self-care behavior was 50 (45-56) and self-efficacy was 64 (57-72). Better perceived neighborhood health was associated with greater hypertension self-care behavior (β, 2.48; 95% CI, 0.63-4.33) and self-efficacy (β, 4.42; 95% CI, 2.25-6.59); these associations persisted for all neighborhood health subdomains except aesthetic quality. There were no statistically significant interactions between perceived neighborhood health or its subdomains with ADI on self-care behavior (P = .74 for interaction) or self-efficacy (P = .85 for interaction). However, better perceived neighborhood aesthetic quality had associations with greater self-care behavior specifically at higher healthy food availability at home scores: β at -1 SD, -0.29; 95% CI, -2.89 to 2.30 vs β at 1 SD, 2.97; 95% CI, 0.46-5.47; P = .09 for interaction). Likewise, associations of perceived worse neighborhood violence with lower self-care behavior were attenuated at higher healthy food availability at home scores (β for -1 SD, 3.69; 95% CI, 1.31-6.08 vs β for 1 SD, 0.01; 95% CI, -2.53 to 2.54; P = .04 for interaction).

Conclusions and Relevance

In this cross-sectional study, better perceived neighborhood health was associated with greater hypertension self-care among Black individuals with hypertension, particularly among those with greater in-home food availability. Thus, optimizing hypertension self-management may require multifaceted interventions targeting both the patients' perceived contextual neighborhood barriers to self-care and availability of healthy food resources in the home.

Decisional Conflict About Kidney Failure Treatment Modalities Among Adults With Advanced CKD

Rationale & Objective

Choosing from multiple kidney failure treatment modalities can create decisional conflict, but little is known about this experience before decision implementation. We explored decisional conflict about treatment for kidney failure and its associated patient characteristics in the context of advanced chronic kidney disease (CKD).

Study Design

Cross-sectional study.

Setting & Participants

Adults (N = 427) who had advanced CKD, received nephrology care in Pennsylvania-based clinics, and had no history of dialysis or transplantation.

Predictors

Participants' sociodemographic, physical health, nephrology care/knowledge, and psychosocial characteristics.

Outcomes

Participants' results on the Sure of myself; Understand information; Risk-benefit ratio; Encouragement (SURE) screening test for decisional conflict (no decisional conflict vs decisional conflict).

Analytical Approach

We used multivariable logistic regression to quantify associations between aforementioned participant characteristics and decisional conflict. We repeated analyses among a subgroup of participants at highest risk of kidney failure within 2 years.

Results

Most (76%) participants reported treatment-related decisional conflict. Participant characteristics associated with lower odds of decisional conflict included complete satisfaction with patient-kidney team treatment discussions (OR, 0.16; 95% CI, 0.03-0.88; P = 0.04), attendance of treatment education classes (OR, 0.38; 95% CI, 0.16-0.90; P = 0.03), and greater treatment-related decision self-efficacy (OR, 0.97; 95% CI, 0.94-0.99; P < 0.01). Sensitivity analyses showed a similarly high prevalence of decisional conflict (73%) and again demonstrated associations of class attendance (OR, 0.26; 95% CI, 0.07-0.96; P = 0.04) and decision self-efficacy (OR, 0.95; 95% CI, 0.91-0.99; P = 0.03) with decisional conflict.

Limitations

Single-health system study.

Conclusions

Decisional conflict was highly prevalent regardless of CKD progression risk. Findings suggest efforts to reduce decisional conflict should focus on minimizing the mismatch between clinical practice guidelines and patient-reported engagement in treatment preparation, facilitating patient-kidney team treatment discussions, and developing treatment education programs and decision support interventions that incorporate decision self-efficacy-enhancing strategies.

Kinetics of pneumococcal antibodies among HIV-exposed, uninfected infants in Botswana

BACKGROUND

Streptococcus pneumoniae is a leading cause of severe infections among children. Despite vaccination, HIV-exposed, uninfected (HEU) children have a higher incidence of invasive pneumococcal disease than HIV-unexposed, uninfected (HUU) children. We sought to compare the immunogenicity of 13-valent pneumococcal conjugate vaccine (PCV-13) in HEU and HUU infants.

METHODS

We conducted a prospective cohort study of 134 mother-infant dyads in Botswana. Infants received PCV-13 doses at 2, 3, and 4 months through routine clinical care. We measured IgG antibodies specific to vaccine serotypes in sera collected from infants at 0, 5, and 12 months of age. We calculated the proportion of infants with protective IgG levels (≥0.35 µg/mL) to specific pneumococcal serotypes.

RESULTS

At birth, fewer than half of infants had protective IgG levels to serotypes 1 (38%), 3 (46%), 4 (33%), 5 (23%), 6B (40%), 7F (44%), 9 V (44%), and 23F (46%). Compared to HUU infants (n = 97), HEU infants (n = 37) had lower antibody concentrations at birth to serotypes 5 (p = 0.046) and 19A (p = 0.008) after adjustment for maternal age and infant birth weight. More than 80% of HEU and HUU infants developed protective antibody levels to each of the 13 vaccine serotypes following PCV-13 vaccination. Median concentrations of antibodies to pneumococcal serotypes declined by 55-93% between 5 and 12 months of age, with fewer than half of infants having protective antibody levels to serotypes 1 (47%), 3 (28%), 9 V (44%), 18C (24%), and 23F (49%) at 12 months of age.

CONCLUSIONS

Both HEU and HUU infants developed protective antibody responses to PCV-13 administered in a 3 + 0 schedule. However, antibody concentrations to many pneumococcal serotypes waned substantially by 12 months of age, suggesting that a PCV-13 booster dose in the second year of life may be needed to maintain protective pneumococcal antibody levels in older infants and young children.

Bioavailability of phosphorus and kidney function in the Jackson Heart Study

BACKGROUND

High phosphorus (P) exposure may have negative effects on kidney function. Nutrient databases provide total P, but bioavailability varies by source.

OBJECTIVES

We aimed to assess natural, added, and bioavailable P intake, and to relate these to estimated glomerular filtration rate (eGFR) in the Jackson Heart Study (JHS).

METHODS

A total of 3962 African-American participants of the JHS, aged 21-84 y, with urine albumin:creatinine ratio < 30 mg/g, and eGFR ≥ 60 mL · min-1 · 1.73 m-2, and without self-reported kidney disease, were included. Diet was assessed by FFQ. We assigned P in foods as naturally occurring or added, and weighted intake by P bioavailability, based on published literature. Relations between P variables and eGFR were assessed using multivariable regression.

RESULTS

Mean ± SE intakes were 1178 ± 6.7 mg and 1168 ± 5.0 mg for total P, 296 ± 2.8 mg and 291 ± 2.1 mg for bioavailable added P, and 444 ± 2.9 mg and 443 ± 2.2 mg for bioavailable natural P, in participants with eGFR = 60-89 and ≥90 mL · min-1 · 1.73 m-2, respectively. Major sources of total P included fish, milk, beef, eggs, cheese, and poultry; and of added P, fish, beef, processed meat, soft drinks, and poultry. After adjustment for confounders, P intakes, including total (β ± SE: -0.32 ± 0.15; P = 0.03), added (β ± SE: -0.73 ± 0.27; P = 0.01), bioavailable total (β ± SE: -0.62 ± 0.23; P = 0.01), and bioavailable added (β ± SE: -0.77 ± 0.29; P = 0.01), were significantly associated with lower eGFR. However, neither total nor bioavailable P from natural sources were associated with eGFR.

CONCLUSIONS

Added, but not natural, P was negatively associated with kidney function, raising concern about P additives in the food supply. Further studies are needed to improve estimation of dietary P exposure and to clarify the role of added P as a risk factor for kidney disease.

Race, Income, and Medical Care Spending Patterns in High-Risk Primary Care Patients: Results From the STOP-DKD (Simultaneous Risk Factor Control Using Telehealth to Slow Progression of Diabetic Kidney Disease) Study

Rationale & Objective

Little is known about how socioeconomic status (SES) relates to the prioritization of medical care spending over personal expenditures in individuals with multiple comorbid conditions, and whether this relationship differs between Blacks and non-Blacks. We aimed to explore the relationship between SES, race, and medical spending among individuals with multiple comorbid conditions.

Study Design

Cross-sectional evaluation of baseline data from a randomized controlled trial.

Setting & Participants

The STOP-DKD (Simultaneous Risk Factor Control Using Telehealth to Slow Progression of Diabetic Kidney Disease) study is a completed randomized controlled trial of Duke University primary care patients with diabetes, hypertension, and chronic kidney disease. Participants underwent survey assessments inclusive of measures of socio-demographics and medication adherence.

Predictors

Race (Black or non-Black) and socioeconomic status (income, education, and employment).

Outcomes

The primary outcomes were based on 4 questions related to spending, asking about reduced spending on basic/leisure needs or using savings to pay for medical care. Participants were also asked if they skipped medications to make them last longer.

Analytical Approach

Multivariable logistic regression stratified by race and adjusted for age, sex, and household chaos was used to determine the independent effects of SES components on spending.

Results

Of 263 STOP-DKD participants, 144 (55%) were Black. Compared with non-Blacks, Black participants had lower incomes with similar levels of education and employment but were more likely to reduce spending on basic needs (29.2% vs 13.5%), leisure activities (35.4% vs 20.2%), and to skip medications (31.3% vs 15.1%), all P < 0.05. After multivariable adjustment, Black race was associated with increased odds of reduced basic spending (OR, 2.29; 95% CI, 1.14-4.60), reduced leisure spending (OR, 1.94; 95% CI, 1.05-3.58), and skipping medications (OR, 2.12; 95% CI, 1.12-4.04).

Limitations

This study was conducted at a single site in Durham, North Carolina, and nearly exclusively included insured patients. Further, the impact of the number of comorbid conditions, medication costs, or copayments was not assessed.

Conclusions

In primary care patients with multiple chronic diseases, Black patients are more likely to reduce spending on basic needs and leisure activities to afford their medical care than non-Black patients of equivalent SES.

ClinicalTrials.gov Identifier

NCT01829256

Psychosocial determinants of cardiovascular events among black Americans with chronic kidney disease or associated risk factors in the Jackson heart study

Background

Individuals with chronic kidney disease (CKD), hypertension (HTN), or diabetes mellitus (DM) are at increased risk for cardiovascular disease (CVD). The extent to which psychosocial factors are associated with increased CVD risk within these individuals is unclear. Black individuals experience a high degree of psychosocial stressors due to socioeconomic factors, environment, racism, and discrimination. We examined the association between psychosocial factors and risk of CVD events among Black men and women with CKD and CKD risk factors in the Jackson Heart Study.

Methods and Results

We identified 1919 participants with prevalent CKD or CKD risk factors at baseline. We used rotated principal component analysis - a form of unsupervised machine learning that may identify constructs not intuitively identified by a person - to describe five groups of psychosocial components (including negative moods, religiosity, discrimination, negative outlooks, and negative coping resources) based on a battery of questionnaires. Multiple imputation by chained equation (MICE) was used to impute missing covariate data. Cox models were used to quantify the association between psychosocial components and incident CVD, defined as a fatal coronary heart disease event, myocardial infarction, cardiac procedure (angiography or revascularization procedure), or stroke. Of the 929 participants in the analysis, 67% were female, 28% were current/former smokers with mean age of 56 years and mean BMI of 33 kg/m². Over a median follow-up of 8 years, 6% had an incident CVD event. In multivariable models, each standard deviation (SD) increase in the religiosity component was associated with an increased hazard for CVD event (hazard ratio [HR] = 1.52, 95% CI: 1.09–2.13).

Conclusions

Religiosity was associated with CVD among participants with prevalent CKD or CKD risk factors. Studies to better understand the mechanisms of this relationship are needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02594-6.

Disparities in Discussions about Kidney Replacement Therapy in CKD Care

Participants who identified as female and Black reported more thorough discussions of dialysis than transplant.Participants with low incomes and education reported more thorough discussions of dialysis than transplant.

Transplant social worker and donor financial assistance to increase living donor kidney transplants among African Americans: The TALKS Study, a randomized comparative effectiveness trial

Lack of donors hinders living donor kidney transplantation (LDKT) for African Americans. We studied the effectiveness of a transplant social worker intervention (TALK SWI) alone or paired with living donor financial assistance to activate African Americans' potential living kidney donors. African Americans (N = 300) on the transplant waiting list were randomly assigned to usual care; TALK SWI; or TALK SWI plus Living Donor Financial Assistance. We quantified differences in live kidney donor activation (composite rate of live donor inquiries, completed new live donor evaluations, or live kidney donation) after 12 months. Participants' mean age was 52 years, 56% were male, and 43% had annual household income less than $40,000. Most previously pursued LDKT. Participants were highly satisfied with TALK social workers, but they rarely utilized Financial Assistance. After 12 months, few (n = 39, 13%) participants had a new donor activation event (35 [12%] new donor inquiries; 17 [6%] new donor evaluations; 4 [1%] LDKT). There were no group differences in donor activation events (subdistribution hazard ratio [95% CI]: 1.09 [0.51-2.30] for TALK SWI and 0.92 [0.42-2.02] for TALK SWI plus Financial Assistance compared to Usual Care, p = 91). Alternative interventions to increase LDKT for African Americans on the waiting list may be needed. Trial registration: ClinicalTrials.gov (NCT02369354).

African Americans' discussions about living-donor kidney transplants with family or friends: Who, what, and why not?

BACKGROUND

Although discussions with family or friends can improve access to living-donor kidney transplantation (LDKT), they remain an understudied step in the LDKT process.

METHODS

Among 300 African American transplant candidates, we examined how sociodemographic, clinical, LDKT-related, and psychosocial characteristics related to the occurrence of LDKT discussions with family or friends. We also analyzed the relation between discussion occurrence and donor activation on transplant candidates' behalves (at least one donor inquiry or completed donor evaluation in the medical record). We assessed associations of discussion characteristics (context, content, and perceptions) with donor activation among discussants, and we identified discussion barriers among non-discussants.

RESULTS

Most candidates (90%) had discussed LDKT. Only family functioning was statistically significantly associated with discussion occurrence. Specifically, family dysfunction was associated with 62% lower odds of discussion than family function. Family functioning, discussion occurrence, and different discussion characteristics were statistically significantly related to donor activation. The most prevalent discussion barrier was never having thought about discussing LDKT.

CONCLUSIONS

Family functioning affected the likelihood of discussing LDKT, and family functioning, discussion occurrence, and discussion characteristics were associated with donor activation. Advancing understanding of how family functioning and LDKT discussions affect progression to LDKT may benefit interventions to increase LDKT.

Preliminary evidence of effects of potassium chloride on a metabolomic path to diabetes and cardiovascular disease

INTRODUCTION

Low potassium intake can affect cardiovascular disease (CVD) risk and cardiometabolic risk factors.

OBJECTIVE

We hypothesize that potassium chloride (KCl) supplementation can improve cardiovascular risk metabolomic profile.

METHODS

In this secondary analysis of a pilot randomized clinical trial (RCT) of 26 participants with prediabetes randomized to KCl or placebo, we performed targeted mass-spectrometry-based metabolomic profiling on baseline and 12-week (end-of-study) plasma samples. Principal component analysis (PCA) was used to reduce the many correlated metabolites into fewer, independent factors that retain most of the information in the original data.

RESULTS

Those taking KCl had significant reductions (corresponding to lower cardiovascular risk) in the branched-chain amino acids (BCAA) factor (P = 0.004) and in valine levels (P = 0.02); and non-significant reductions in short-chain acylcarnitines (SCA) factor (P = 0.11).

CONCLUSIONS

KCl supplementation may improve circulating BCAA levels, which may reflect improvements in overall cardiometabolic risk profile.

CLINICAL TRIALS REGISTRY

Clinicaltrials.gov identifier: NCT02236598; https://clinicaltrials.gov/ct2/show/NCT02236598.

Life Course Socioeconomic Status, Allostatic Load, and Kidney Health in Black Americans

BACKGROUND AND OBJECTIVES

Low socioeconomic status confers unfavorable health, but the degree and mechanisms by which life course socioeconomic status affects kidney health is unclear.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We examined the association between cumulative lifetime socioeconomic status and CKD in black Americans in the Jackson Heart Study. We used conditional process analysis to evaluate allostatic load as a potential mediator of this relation. Cumulative lifetime socioeconomic status was an age-standardized z-score, which has 1-SD units by definition, and derived from self-reported childhood socioeconomic status, education, and income at baseline. Allostatic load encompassed 11 baseline biomarkers subsuming neuroendocrine, metabolic, autonomic, and immune physiologic systems. CKD outcomes included prevalent CKD at baseline and eGFR decline and incident CKD over follow-up.

RESULTS

Among 3421 participants at baseline (mean age 55 years [SD 13]; 63% female), cumulative lifetime socioeconomic status ranged from -3.3 to 2.3, and 673 (20%) had prevalent CKD. After multivariable adjustment, lower cumulative lifetime socioeconomic status was associated with greater prevalence of CKD both directly (odds ratio [OR], 1.18; 95% confidence interval [95% CI], 1.04 to 1.33 per 1 SD and OR, 1.45; 95% CI, 1.15 to 1.83 in lowest versus highest tertile) and via higher allostatic load (OR, 1.09; 95% CI, 1.06 to 1.12 per 1 SD and OR, 1.17; 95% CI, 1.11 to 1.24 in lowest versus highest tertile). After a median follow-up of 8 years (interquartile range, 7-8 years), mean annual eGFR decline was 1 ml/min per 1.73 m² (SD 2), and 254 out of 2043 (12%) participants developed incident CKD. Lower cumulative lifetime socioeconomic status was only indirectly associated with greater CKD incidence (OR, 1.04; 95% CI, 1.01 to 1.07 per 1 SD and OR, 1.08; 95% CI, 1.02 to 1.14 in lowest versus highest tertile) and modestly faster annual eGFR decline, in milliliters per minute (OR, 0.01; 95% CI, 0.00 to 0.02 per 1 SD and OR, 0.02; 95% CI, 0.00 to 0.04 in lowest versus highest tertile), via higher baseline allostatic load.

CONCLUSIONS

Lower cumulative lifetime socioeconomic status was substantially associated with CKD prevalence but modestly with CKD incidence and eGFR decline via baseline allostatic load.

Associations of perceived information adequacy and knowledge with pursuit of live donor kidney transplants and living donor inquiries among African American transplant candidates

We studied associations between perceived adequacy of live donor kidney transplant (LDKT) information or knowledge with pursuit of LDKT or receipt of live donor inquiries among 300 African American kidney transplant candidates. Participants reported via questionnaire how informed or knowledgeable they felt regarding LDKT. Participants also reported their pursuit of LDKT, categorized as "low" (no discussion with family or friends about LDKT and no identified donor), "intermediate" (discussed LDKT with family but no identified donor) or "high" (discussed LDKT with family and identified a potential donor). We reviewed participants' electronic health records to identify potential donors' transplant center inquiries on participants' behalves. A minority of participants reported they felt "very" or "extremely" well informed about LDKT (39%) or had "a great deal" of LDKT knowledge (38%). Participants perceiving themselves as "very" or "extremely" (vs "not" or "slightly") well informed about LDKT had statistically significantly greater odds of intermediate or high (vs low) pursuit of LDKT (odds ratio [95% confidence interval] 2.71 [1.02-7.17]). Perceived LDKT knowledge was not associated with pursuit of LDKT. Neither perceived information adequacy nor knowledge was associated with living donor inquiries. Efforts to better understand the role of education in the pursuit of LDKT among African American transplant candidates are needed.

Primary Care Providers' Acceptance of Pharmacists' Recommendations to Support Optimal Medication Management for Patients with Diabetic Kidney Disease

BACKGROUND

Patients with diabetic kidney disease (DKD) often struggle with blood pressure control. In team-based models of care, pharmacists and primary care providers (PCPs) play important roles in supporting patients' blood pressure management.

OBJECTIVE

To describe whether PCPs' acceptance of pharmacists' recommendations impacts systolic blood pressure (SBP) at 36 months.

DESIGN

An observational analysis of a subset of participants randomized to the intervention arm of the Simultaneous risk factor control using Telehealth to slOw Progression of Diabetic Kidney Disease (STOP-DKD) study.

PARTICIPANTS

STOP-DKD participants for whom (1) the pharmacist made at least one recommendation to the PCP; (2) there were available data regarding the PCP's corresponding action; and (3) there were SBP measurements at baseline and 36 months.

INTERVENTION

Participants received monthly telephone calls with a pharmacist addressing health behaviors and medication management. Pharmacists made medication-related recommendations to PCPs.

MAIN MEASURES

We fit an unadjusted generalized linear mixed model to assess the association between the number of pharmacists' recommendations for DKD and blood pressure management and PCPs' acceptance of such recommendations. We used a linear regression model to evaluate the association between PCP acceptance and SBP at 36 months, adjusted for baseline SBP.

KEY RESULTS

Pharmacists made 176 treatment recommendations (among 59 participants), of which 107 (61%) were accepted by PCPs. SBP significantly declined by an average of 10.5 mmHg (p < 0.01) among 47 of 59 participants who had valid measurements at baseline and 36 months. There was a significant association between the number of pharmacist recommendations and the odds of PCP acceptance (OR 1.19; 95%CI 1.00, 1.42; p < 0.05), but no association between the number of accepted recommendations and SBP.

CONCLUSIONS

Pharmacists provided actionable medication-related recommendations. We identified a significant decline in SBP at 36 months, but this reduction was not associated with recommendation acceptance.

TRIAL REGISTRATION

NCT01829256.

Hypertension Self-management in Socially Disadvantaged African Americans: the Achieving Blood Pressure Control Together (ACT) Randomized Comparative Effectiveness Trial

BACKGROUND

Effective hypertension self-management interventions are needed for socially disadvantaged African Americans, who have poorer blood pressure (BP) control compared to others.

OBJECTIVE

We studied the incremental effectiveness of contextually adapted hypertension self-management interventions among socially disadvantaged African Americans.

DESIGN

Randomized comparative effectiveness trial.

PARTICIPANTS

One hundred fifty-nine African Americans at an urban primary care clinic.

INTERVENTIONS

Participants were randomly assigned to receive (1) a community health worker ("CHW") intervention, including the provision of a home BP monitor; (2) the CHW plus additional training in shared decision-making skills ("DoMyPART"); or (3) the CHW plus additional training in self-management problem-solving ("Problem Solving").

MAIN MEASURES

We assessed group differences in BP control (systolic BP (SBP) < 140 mm Hg and diastolic BP (DBP) < 90 mmHg), over 12 months using generalized linear mixed models. We also assessed changes in SBP and DBP and participants' BP self-monitoring frequency, clinic visit patient-centeredness (i.e., extent of patient-physician discussions focused on patient emotional and psychosocial concerns), hypertension self-management behaviors, and self-efficacy.

KEY RESULTS

BP control improved in all groups from baseline (36%) to 12 months (52%) with significant declines in SBP (estimated mean [95% CI] - 9.1 [- 15.1, - 3.1], - 7.4 [- 13.4, - 1.4], and - 11.3 [- 17.2, - 5.3] mmHg) and DBP (- 4.8 [- 8.3, - 1.3], - 4.0 [- 7.5, - 0.5], and - 5.4 [- 8.8, - 1.9] mmHg) for CHW, DoMyPART, and Problem Solving, respectively). There were no group differences in BP outcomes, BP self-monitor use, or clinic visit patient-centeredness. The Problem Solving group had higher odds of high hypertension self-care behaviors (OR [95% CI] 18.7 [4.0, 87.3]) and self-efficacy scores (OR [95% CI] 4.7 [1.5, 14.9]) at 12 months compared to baseline, while other groups did not. Compared to DoMyPART, the Problem Solving group had higher odds of high hypertension self-care behaviors (OR [95% CI] 5.7 [1.3, 25.5]) at 12 months.

CONCLUSION

A context-adapted CHW intervention was correlated with improvements in BP control among socially disadvantaged African Americans. However, it is not clear whether improvements were the result of this intervention. Neither the addition of shared decision-making nor problem-solving self-management training to the CHW intervention further improved BP control.

TRIAL REGISTRY

ClinicalTrials.gov Identifier: NCT01902719.

DASH Diet and Blood Pressure Among Black Americans With and Without CKD: The Jackson Heart Study

BACKGROUND

The Dietary Approaches to Stop Hypertension (DASH) diet lowers blood pressure (BP) more effectively in blacks compared to other US racial subgroups. Considering chronic kidney disease (CKD) raises BP through complex mechanisms, DASH may affect BP differently among blacks with and without CKD. We compared the association of DASH accordance to BP and prevalent hypertension among blacks with and without CKD.

METHODS

Our study involved 3,135 black Americans enrolled in the Jackson Heart Study (2000-2004) with diet and office BP data. Using linear models adjusted for demographics, health behaviors, and clinical factors, we determined the association of a modified DASH score (excluding sodium intake, ranging from 0 to 8 with increasing DASH accordance) with BP. We performed tests for interaction between DASH score and CKD status.

RESULTS

Among participants (mean age: 55 years; hypertension: 60%; CKD: 19%), the median DASH score was similar among participants with and without CKD (1.0 [interquartile range (IQR): 0.5-2] and 1.0 [IQR: 0.5-1.5]). CKD status modified the association of the DASH score with systolic BP (SBP) and diastolic BP (DBP; P interactions were 0.06 and <0.01). Among participants without CKD, SBP and DBP were not associated with the DASH score (-0.4 [95% confidence interval: -1.0, 0.1] mm Hg and -0.1 [-0.4, 0.2] mm Hg per one unit higher DASH score). Among participants with CKD, one unit higher DASH score was associated with lower SBP by 1.6 (0.5, 2.6) mm Hg and lower DBP by 0.9 (0.3, 1.5) mm Hg.

CONCLUSIONS

Despite low DASH scores overall, better DASH accordance was associated with lower BP among Black Americans with CKD.

Obesity and synergistic risk factors for chronic kidney disease in African American adults: the Jackson Heart Study

Background

African Americans are at high risk for chronic kidney disease (CKD). Obesity may increase the risk for CKD by exacerbating features of the metabolic syndrome and promoting glomerular hyperfiltration. Whether other factors also affecting these pathways may amplify or mitigate obesity-CKD associations has not been investigated.

Methods

We studied interactions between obesity and these candidate factors in 2043 African Americans without baseline kidney disease enrolled in the Jackson Heart Study. We quantified obesity as body mass index (BMI), sex-normalized waist circumference and visceral adipose volume measured by abdominal computed tomography at an interim study visit. Interactions were hypothesized with (i) metabolic risk factors (dietary quality and physical activity, both quantified by concordance with American Heart Association guidelines) and (ii) factors exacerbating or mitigating hyperfiltration (dietary protein intake, APOL1 risk status and use of renin-angiotensin system blocking medications). Using multivariable regression, we evaluated associations between obesity measures and incident CKD over the follow-up period, as well as interactions with metabolic and hyperfiltration factors.

Results

Assessed after a median of 8 years (range 6-11 years), baseline BMI and waist circumference were not associated with incident CKD. Higher visceral adipose volume was independently associated with incident CKD (P = 0.008) in a nonlinear fashion, but this effect was limited to those with lower dietary quality (P = 0.001; P-interaction = 0.04). In additional interaction models, higher waist circumference was associated with greater risk of incident CKD among those with the low-risk APOL1 genotype (P = 0.04) but not those with a high-risk genotype (P-interaction = 0.02). Other proposed factors did not modify obesity-CKD associations. Conclusions. Higher risks associated with metabolically active visceral adipose volume and interactions with dietary quality suggest that metabolic factors may be key determinants of obesity-associated CKD risk. Interactions between obesity and APOL1 genotype should be considered in studies of African Americans.

The relationship between Pittsburgh Sleep Quality Index subscales and diabetes control

OBJECTIVES:

Data suggest that poor sleep quality as measured by the Pittsburgh Sleep Quality Index (PSQI) contributes to suboptimal diabetes control. How the subscales comprising the PSQI individually relate to diabetes control is poorly understood.

METHODS:

In order to explore how PSQI subscales relate to diabetes control, we analyzed baseline data from a trial of a telemedicine intervention for diabetes. We used multivariable modeling to examine: (1) the relationship between the global PSQI and hemoglobin A1c (HbA1c); (2) the relationships between the 7 PSQI subscales and HbA1c; and (3) medication nonadherence as a possible mediating factor.

RESULTS:

Global PSQI was not associated with HbA1c (n = 279). Only one PSQI subscale, sleep disturbances, was associated with HbA1c after covariate adjustment; HbA1c increased by 0.4 points for each additional sleep disturbances subscale point (95%CI 0.1 to 0.8). Although the sleep disturbances subscale was associated with medication nonadherence (OR 2.04, 95%CI 1.27 to 3.30), a mediation analysis indicated nonadherence does not mediate the sleep disturbances-HbA1c relationship.

DISCUSSION:

The sleep disturbances subscale may drive the previously observed relationship between PSQI and HbA1c. The mechanism for the relationship between sleep disturbances and HbA1c remains unclear, as does the impact on HbA1c of addressing sleep disturbances.

Association of functional and structural social support with chronic kidney disease among African Americans: the Jackson Heart Study

Background

There is limited evidence on the relationship between social support and renal outcomes in African Americans. We sought to determine the association of social support with prevalent chronic kidney disease (CKD) and kidney function decline in an African American cohort. We also examined whether age modifies the association between social support and kidney function decline.

Methods

We identified Jackson Heart Study (JHS) participants with baseline (Exam in 2000–2004) functional and structural social support data via the Interpersonal Support Evaluation List (ISEL) and social network size questions, respectively. With ISEL as our primary exposure variable, we performed multivariable regression models to evaluate the association between social support and prevalent CKD [estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m2 or urine albumin-creatinine ratio (ACR) ≥30 mg/g], eGFR decline, and rapid renal function decline (RRFD) (> 30% decrease in eGFR over approximately 10 years). All models were adjusted for baseline sociodemographics, diabetes, hypertension, smoking status, and body mass index; models for eGFR decline and RRFD were additionally adjusted for eGFR and ACR. In models for eGFR decline, we assessed for interaction between age and social support. For secondary analyses, we replaced ISEL with its individual domains (appraisal, belonging, self-esteem, and tangible) and social network size in separate models as exposure variables.

Results

Of 5301 JHS participants, 4015 (76%) completed the ISEL at baseline. 843 (21%) had low functional social support (ISEL score < 32). Participants with low (vs. higher) functional social support were more likely to have lower income (47% vs. 28%), be current or former tobacco users (39% vs. 30%), have diabetes (25% vs. 21%) or CKD (14% vs. 12%). After multivariable adjustment, neither ISEL or social network size were independently associated with prevalent CKD, eGFR decline, or RRFD. Of the ISEL domains, only higher self-esteem was associated with lower odds of prevalent CKD [OR 0.94 (95% CI 0.89–0.99)]. The associations between social support measures and eGFR decline were not modified by age.

Conclusions

In this African-American cohort, social support was not associated with prevalent CKD or kidney function decline. Further inquiry of self-esteem’s role in CKD self-management and renal outcomes is warranted.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1432-9) contains supplementary material, which is available to authorized users.

Modifiers of Plasma 25-Hydroxyvitamin D and Chronic Kidney Disease Outcomes in Black Americans: The Jackson Heart Study

BACKGROUND

25-hydroxyvitamin D [25(OH)D] is lower in black compared with white Americans but is not consistently associated with outcomes in this group, possibly due to genetic and other biological differences. We examined the association of plasma 25(OH)D and renal outcomes in black Americans with a focus on effect modifiers.

METHODS

We studied associations between baseline 25(OH)D with (i) annual rate of estimated glomerular filtration rate (eGFR) decline and (ii) incident chronic kidney disease (CKD) in the Jackson Heart Study, a prospective cohort of black Americans. Plasma 25(OH)D levels were corrected for monthly variation in sunlight exposure using the residual method. We used adjusted generalized linear models to evaluate outcomes and assessed potential effect modification by diabetes mellitus, vitamin D binding protein (DBP) genotype, obesity, dietary sodium intake, and use of renin-angiotensin-aldosterone system inhibitors.

RESULTS

Among 5164 participants with 25(OH)D available, plasma 25(OH)D was 14.5 ± 6.5 ng/mL (mean ± SD), and eGFR was 94.1 ± 22.0 mL/min/1.73 m2. Over a median of 8 years, eGFR decline was 1.3 ± 2.0 mL/min/1.73 m2 per year in 3228 participants with complete data, and 220 out of 1803 eligible participants developed incident CKD. Overall, 25(OH)D was not associated with eGFR decline in fully adjusted models. However, higher 25(OH)D was associated with slower eGFR decline among those with diabetes: each 5 ng/mL higher 25(OH)D was associated with a 0.27 mL/min/1.73 m2/y slower eGFR decline (95% CI, 0.13 to 0.41; P < 0.001). Higher 25(OH)D was not associated with incident CKD overall, but it was associated with lower odds of incident CKD among participants with the GG or GT genotype at rs7041 in the gene encoding DBP [OR, 0.69 per 5 ng/mL higher 25(OH)D; 95% CI, 0.51 to 0.93; P-interaction = 0.005]. Other interactions were not significant.

CONCLUSION

These findings support a potential benefit of higher 25(OH)D for kidney health in black Americans with diabetes or specific variants in DBP.

Evaluation of Allostatic Load as a Mediator of Sleep and Kidney Outcomes in Black Americans

Introduction

Poor sleep associates with adverse chronic kidney disease (CKD) outcomes yet the biological mechanisms underlying this relation remain unclear. One proposed mechanism is via allostatic load, a cumulative biologic measure of stress.

Methods

Using data from 5177 Jackson Heart Study participants with sleep measures available, we examined the association of self-reported sleep duration: very short, short, recommended, and long (≤5, 6, 7–8, or ≥9 hours per 24 hours, respectively) and sleep quality (high, moderate, low) with prevalent baseline CKD, and estimated glomerular filtration rate (eGFR) decline and incident CKD at follow-up. CKD was defined as eGFR <60 ml/min per 1.73 m² or urine albumin-to-creatinine ratio ≥30 mg/g. Models were adjusted for demographics, comorbidities, and kidney function. We further evaluated allostatic load (quantified at baseline using 11 biomarkers from neuroendocrine, metabolic, autonomic, and immune domains) as a mediator of these relations using a process analysis approach.

Results

Participants with very short sleep duration (vs. 7–8 hours) had greater odds of prevalent CKD (odds ratio [OR] 1.31, 95% confidence interval [CI] 1.03–1.66). Very short, short, or long sleep duration (vs. 7–8 hours) was not associated with kidney outcomes over a median follow-up of 8 years. Low sleep quality (vs. high) associated with greater odds of prevalent CKD (OR 1.26, 95% CI 1.00–1.60) and 0.18 ml/min per 1.73 m² (95% CI 0.00–0.36) faster eGFR decline per year. Allostatic load did not mediate the associations of sleep duration or sleep quality with kidney outcomes.

Conclusions

Very short sleep duration and low sleep quality were associated with adverse kidney outcomes in this all-black cohort, but allostatic load did not appear to mediate these associations.

Low use of routine medical care among African Americans with high CKD risk: the Jackson Heart Study

Background

Use of routine medical care (RMC) is advocated to address ethnic/racial disparities in chronic kidney disease (CKD) risks, but use is less frequent among African Americans. Factors associated with low RMC use among African Americans at risk of renal outcomes have not been well studied.

Methods

We examined sociodemographic, comorbidity, healthcare access, and psychosocial (discrimination, anger, stress, trust) factors associated with low RMC use in a cross-sectional study. Low RMC use was defined as lack of a physical exam within one year among participants with CKD (estimated glomerular filtration rate < 60 mL/min/1.73m² or urine albumin-to-creatinine ratio > 30 mg/g) or CKD risk factors (diabetes or hypertension). We used multivariable logistic regression to estimate the odds of low RMC use at baseline (2000–2004) for several risk factors.

Results

Among 3191 participants with CKD, diabetes, or hypertension, 2024 (63.4%) were ≥ 55 years of age, and 700 (21.9%) reported low RMC use. After multivariable adjustment, age < 55 years (OR 1.61 95% CI 1.31–1.98), male sex (OR 1.71; 1.41–2.07), <high school diploma (OR 1.31; 1.07–1.62), absence of hypertension (OR 1.74; 1.27–2.39) or diabetes (OR 1.34; 1.09–1.65), and tobacco use (OR 1.43; 1.18–1.72) were associated with low RMC use. Low trust in providers (OR 2.16; 1.42–3.27), high stress (OR 1.41; 1.09–1.82), high daily discrimination (OR 1.30; 1.01–1.67) and low burden of lifetime discrimination (OR 1.52; 1.18–1.94), were also associated with low RMC use.

Conclusions

High-risk African Americans who were younger, male, less-educated, and with low trust in providers were more likely to report low RMC use. Efforts to improve RMC use by targeting these populations could mitigate African Americans’ disparities in CKD risks.

Electronic supplementary material

The online version of this article (10.1186/s12882-018-1190-0) contains supplementary material, which is available to authorized users.

Trends in African Americans' Attitudes and Behaviors About Living Donor Kidney Transplantation

BACKGROUND

Due to marginal efforts to increase living donor kidney transplantation, it is unclear whether interventions to improve African Americans' interest and pursuit of living donation should be tailored to address patients' exposure to or familiarity with dialysis or transplant settings.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a cross-sectional secondary analysis of baseline data from 3 separate randomized clinical trials among African Americans with varying degrees of experience with dialysis or transplantation (predialysis, on dialysis but not on transplant list, and on transplant wait-list) settings.

METHODS

Interest in living donation was described using a 0 to 10 scale and pursuit of living donor kidney transplantation by achievement of at least 1 pursuant behavior. In multivariable logistic regression analyses, we assessed the association of knowledge, health literacy, and trust in health care with interest in or pursuit of living donation.

RESULTS

Interest among the 3 study cohorts was high (predialysis, 62.9%; dialysis, 67.4%; and transplant wait-list, 74.2%). The dialysis and transplant wait-list study cohorts pursued living donation more readily than those not on dialysis (73%, 92%, and 45%, respectively). Interest and pursuit were not statistically significantly associated with knowledge, health literacy, or the 3 factors reflecting medical mistrust.

CONCLUSION

Interest and pursuit of living donation were greater among study participants with greater exposure to dialysis or transplant settings. Efforts to promote patients' early interest and pursuit of living donor transplants may consider novel strategies to educate patients with less experience about the benefits of living donor kidney transplantation.

KCNJ11 variants and their effect on the association between serum potassium and diabetes risk in the Atherosclerosis Risk in Communities (ARIC) Study and Jackson Heart Study (JHS) cohorts

BACKGROUND

In the Atherosclerosis Risk in Communities (ARIC) Study and Jackson Heart Study (JHS) cohorts, serum potassium (K) is an independent predictor of diabetes risk, particularly among African-American participants. Experimental studies show that serum K levels affects insulin secretion. The KCNJ11 gene encodes for a K channel that regulates insulin secretion and whose function is affected by serum K levels. Variants in KCNJ11 are associated with increased diabetes risk. We hypothesized that there could be a gene-by-environment interaction between KCNJ11 variation and serum K on diabetes risk.

METHODS

Evaluating a combined cohort of ARIC and JHS participants, we sought to determine if KCNJ11 variants are risk factors for diabetes; and if KCNJ11 variants modify the association between serum K and diabetes risk. Among participants without diabetes at baseline, we performed multivariable logistic regression to determine the effect of serum K, KCNJ11 variants, and their interactions on the odds of incident diabetes mellitus over 8-9 years in the entire cohort and by race.

RESULTS

Of 11,812 participants, 3220 (27%) participants developed diabetes. 48% and 47% had 1 or 2 diabetes risk alleles of rs5215 and rs5219, respectively. Caucasians had higher proportions of these risk alleles compared to African Americans (60% vs 17% for rs5215 and 60% vs 13% for rs5219, p<0.01). Serum K was a significant independent predictor of incident diabetes. Neither rs5215 nor rs5219 was associated with incident diabetes. In multivariable models, we found no statistically significant interactions between race and either rs5215 or rs5219 (P-values 0.493 and 0.496, respectively); nor between serum K and either rs5215 or rs5219 on odds of incident diabetes (P-values 0.534 and 0.687, respectively).

CONCLUSION

In this cohort, rs5215 and rs5219 of KCNJ11 were not significant predictors of incident diabetes nor effect modifiers of the association between serum K and incident diabetes.

Functional interaction-based nonlinear models with application to multiplatform genomics data

Functional regression allows for a scalar response to be dependent on a functional predictor; however, not much work has been done when a scalar exposure that interacts with the functional covariate is introduced. In this paper, we present 2 functional regression models that account for this interaction and propose 2 novel estimation procedures for the parameters in these models. These estimation methods allow for a noisy and/or sparsely observed functional covariate and are easily extended to generalized exponential family responses. We compute standard errors of our estimators, which allows for further statistical inference and hypothesis testing. We compare the performance of the proposed estimators to each other and to one found in the literature via simulation and demonstrate our methods using a real data example.

Simultaneous Risk Factor Control Using Telehealth to slOw Progression of Diabetic Kidney Disease (STOP-DKD) study: Protocol and baseline characteristics of a randomized controlled trial

Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease (ESKD) in the United States. Multiple risk factors contribute to DKD development, yet few interventions target more than a single DKD risk factor at a time. This manuscript describes the study protocol, recruitment, and baseline participant characteristics for the Simultaneous Risk Factor Control Using Telehealth to slOw Progression of Diabetic Kidney Disease (STOP-DKD) study. The STOP-DKD study is a randomized controlled trial designed to evaluate the effectiveness of a multifactorial behavioral and medication management intervention to mitigate kidney function decline at 3 years compared to usual care. The intervention consists of up to 36 monthly educational modules delivered via telephone by a study pharmacist, home blood pressure monitoring, and medication management recommendations delivered electronically to primary care physicians. Patients seen at seven primary care clinics in North Carolina, with diabetes and [1] uncontrolled hypertension and [2] evidence of kidney dysfunction (albuminuria or reduced estimated glomerular filtration rate [eGFR]) were eligible to participate. Study recruitment completed in December 2014. Of the 281 participants randomized, mean age at baseline was 61.9; 52% were male, 56% were Black, and most were high school graduates (89%). Baseline co-morbidity was high- mean blood pressure was 134/76 mmHg, mean body mass index was 35.7 kg/m2, mean eGFR was 80.7 ml/min/1.73 m2, and mean glycated hemoglobin was 8.0%. Experiences of recruiting and implementing a comprehensive DKD program to individuals at high risk seen in the primary care setting are provided.

TRIAL REGISTRATION

NCT01829256.

A Powerful Test for SNP Effects on Multivariate Binary Outcomes using Kernel Machine Regression

Evaluating multiple binary outcomes is common in genetic studies of complex diseases. These outcomes are often correlated because they are collected from the same individual and they may share common marker effects. In this paper, we propose a procedure to test for effect of a SNP-set on multiple, possibly correlated, binary responses. We develop a score-based test using a nonparametric modeling framework that jointly models the global effect of the marker set. We account for the nonlinear effects and potentially complicated interaction between markers using reproducing kernels. Our testing procedure only requires estimation under the null hypothesis and we use multivariate generalized estimating equations (GEEs) to estimate the model components to account for the correlation among the outcomes. We evaluate finite sample performance of our test via simulation study and demonstrated our methods using the CATIE antibody study data and the CoLaus Study data.

Nondepressive Psychosocial Factors and CKD Outcomes in Black Americans

BACKGROUND AND OBJECTIVES

Established risk factors for CKD do not fully account for risk of CKD in black Americans. We studied the association of nondepressive psychosocial factors with risk of CKD in the Jackson Heart Study.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We used principal component analysis to identify underlying constructs from 12 psychosocial baseline variables (perceived daily, lifetime, and burden of lifetime discrimination; stress; anger in; anger out; hostility; pessimism; John Henryism; spirituality; perceived social status; and social support). Using multivariable models adjusted for demographics and comorbidity, we examined the association of psychosocial variables with baseline CKD prevalence, eGFR decline, and incident CKD during follow-up.

RESULTS

Of 3390 (64%) Jackson Heart Study participants with the required data, 656 (19%) had prevalent CKD. Those with CKD (versus no CKD) had lower perceived daily (mean [SD] score =7.6 [8.5] versus 9.7 [9.0]) and lifetime discrimination (2.5 [2.0] versus 3.1 [2.2]), lower perceived stress (4.2 [4.0] versus 5.2 [4.4]), higher hostility (12.1 [5.2] versus 11.5 [4.8]), higher John Henryism (30.0 [4.8] versus 29.7 [4.4]), and higher pessimism (2.3 [2.2] versus 2.0 [2.1]; all P<0.05). Principal component analysis identified three factors from the 12 psychosocial variables: factor 1, life stressors (perceived discrimination, stress); factor 2, moods (anger, hostility); and, factor 3, coping strategies (John Henryism, spirituality, social status, social support). After adjustments, factor 1 (life stressors) was negatively associated with prevalent CKD at baseline among women only: odds ratio, 0.76 (95% confidence interval, 0.65 to 0.89). After a median follow-up of 8 years, identified psychosocial factors were not significantly associated with eGFR decline (life stressors: β=0.08; 95% confidence interval, -0.02 to 0.17; moods: β=0.03; 95% confidence interval, -0.06 to 0.13; coping: β=-0.02; 95% confidence interval, -0.12 to 0.08) or incident CKD (life stressors: odds ratio, 1.07; 95% confidence interval, 0.88 to 1.29; moods: odds ratio, 1.02; 95% confidence interval, 0.84 to 1.24; coping: odds ratio, 0.91; 95% confidence interval, 0.75 to 1.11).

CONCLUSIONS

Greater life stressors were associated with lower prevalence of CKD at baseline in the Jackson Heart Study. However, psychosocial factors were not associated with risk of CKD over a median follow-up of 8 years.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2018_01_03_CJASNPodcast_18_2_L.mp3.

Effects of potassium supplements on glucose metabolism in African Americans with prediabetes: a pilot trial

Background: Low potassium has been identified both as a risk factor for type 2 diabetes and as a mediator of the racial disparity in diabetes risk. Low potassium could be a potentially modifiable risk factor, particularly for African Americans.Objective: We sought to determine the effects of potassium chloride (KCl) supplements, at a commonly prescribed dose, on measures of potassium and glucose metabolism.Design: Among African-American adults with prediabetes, we conducted a double-blinded pilot randomized controlled trial that compared the effects of 40 mEq K/d as KCl supplements with a matching placebo, taken for 3 mo, on measures of potassium and glucose metabolism, with measures collected from frequently sampled oral-glucose-tolerance tests (OGTTs).Results: Twenty-seven of 29 recruited participants completed the trial. Participants had high adherence to the study medication (92% by pill count). Participants in both groups gained weight, with an overall mean ± SD weight gain of 1.24 ± 2.03 kg. In comparison with participants who received placebo, urine potassium but not serum potassium increased significantly among participants randomly assigned to receive KCl (P = 0.005 and 0.258, respectively). At the end of the study, participants taking KCl had stable or improved fasting glucose, with a mean ± SD change in fasting glucose of -1.1 ± 8.4 mg/dL compared with an increase of 6.1 ± 7.6 mg/dL in those who received placebo (P = 0.03 for comparison between arms). There were no significant differences in glucose or insulin measures during the OGTT between the 2 groups, but there was a trend for improved insulin sensitivity in potassium-treated participants.Conclusions: In this pilot trial, KCl at a dose of 40 mEq/d did not increase serum potassium significantly. However, despite weight gain, KCl prevented worsening of fasting glucose. Further studies in larger sample sizes, as well as with interventions to increase serum potassium more than was achieved with our intervention, are indicated to definitively test this potentially safe and inexpensive approach to reducing diabetes risk. This trial was registered at clinicaltrials.gov as NCT02236598.

Serum potassium is a predictor of incident diabetes in African Americans with normal aldosterone: the Jackson Heart Study

BACKGROUND

Low-normal potassium is a risk factor for diabetes and may account for some of the racial disparity in diabetes risk. Aldosterone affects serum potassium and is associated with insulin resistance.

OBJECTIVES

We sought to confirm the association between potassium and incident diabetes in an African-American cohort, and to determine the effect of aldosterone on this association.

DESIGN

We studied participants from the Jackson Heart Study, an African-American adult cohort, who were without diabetes at baseline. With the use of logistic regression, we characterized the associations of serum, dietary, and urinary potassium with incident diabetes. In addition, we evaluated aldosterone as a potential effect modifier of these associations.

RESULTS

Of 2157 participants, 398 developed diabetes over 8 y. In a minimally adjusted model, serum potassium was a significant predictor of incident diabetes (OR: 0.83; 95% CI: 0.74, 0.92 per SD increment in serum potassium). In multivariable models, we found a significant interaction between serum potassium and aldosterone (P = 0.046). In stratified multivariable models, in those with normal aldosterone (<9 ng/dL, n = 1163), participants in the highest 2 potassium quartiles had significantly lower odds of incident diabetes than did those in the lowest potassium quartile [OR (95% CI): 0.61 (0.39, 0.97) and 0.54 (0.33, 0.90), respectively]. Among those with high-normal aldosterone (≥9 ng/dL, n = 202), we found no significant association between serum potassium and incident diabetes. In these stratified models, serum aldosterone was not a significant predictor of incident diabetes. We found no statistically significant associations between dietary or urinary potassium and incident diabetes.

CONCLUSIONS

In this African-American cohort, we found that aldosterone may modify the association between serum potassium and incident diabetes. In participants with normal aldosterone, high-normal serum potassium was associated with a lower risk of diabetes than was low-normal serum potassium. Additional studies are warranted to determine whether serum potassium is a modifiable risk factor that could be a target for diabetes prevention. This trial was registered at clinicaltrials.gov as NCT00415415.

Clinical and echocardiographic predictors of mortality in acute pulmonary embolism

PURPOSE

The aim of this study was to evaluate the utility of adding quantitative assessments of cardiac function from echocardiography to clinical factors in predicting the outcome of patients with acute pulmonary embolism (PE).

METHODS

Patients with a diagnosis of acute PE, based on a positive ventilation perfusion scan or computed tomography (CT) chest angiogram, were identified using the Duke University Hospital Database. Of these, 69 had echocardiograms within 24-48 h of the diagnosis that were suitable for offline analysis. Clinical features that were analyzed included age, gender, body mass index, vital signs and comorbidities. Echocardiographic parameters that were analyzed included left ventricular (LV) ejection fraction (EF), regional, free wall and global RV speckle-tracking strain, RV fraction area change (RVFAC), Tricuspid Annular Plane Systolic Excursion (TAPSE), pulmonary artery acceleration time (PAAT) and RV myocardial performance (Tei) index. Univariable and multivariable regression statistical analysis models were used.

RESULTS

Out of 69 patients with acute PE, the median age was 55 and 48 % were female. The median body mass index (BMI) was 27 kg/m². Twenty-nine percent of the cohort had a history of cancer, with a significant increase in cancer prevalence in non-survivors (57 % vs 29 %, p = 0.02). Clinical parameters including heart rate, respiratory rate, troponin T level, active malignancy, hypertension and COPD were higher among non-survivors when compared to survivors (p ≤ 0.05). Using univariable analysis, NYHA class III symptoms, hypoxemia on presentation, tachycardia, tachypnea, elevation in Troponin T, absence of hypertension, active malignancy and chronic obstructive pulmonary disease (COPD) were increased in non-survivors compared to survivors (p ≤ 0.05). In multivariable models, RV Tei Index, global and free (lateral) wall RVLS were found to be negatively associated with survival probability after adjusting for age, gender and systolic blood pressure (p ≤ 0.05).

CONCLUSION

The addition of echocardiographic assessment of RV function to clinical parameters improved the prediction of outcomes for patients with acute PE. Larger studies are needed to validate these findings.

Parametrically guided estimation in nonparametric varying coefficient models with quasi-likelihood

Varying coefficient models allow us to generalize standard linear regression models to incorporate complex covariate effects by modeling the regression coefficients as functions of another covariate. For nonparametric varying coefficients, we can borrow the idea of parametrically guided estimation to improve asymptotic bias. In this paper, we develop a guided estimation procedure for the nonparametric varying coefficient models. Asymptotic properties are established for the guided estimators and a method of bandwidth selection via bias-variance tradeoff is proposed. We compare the performance of the guided estimator with that of the unguided estimator via both simulation and real data examples.