Socioeconomic factors and racial disparities in kidney disease outcomes

Proton pump inhibitors and chronic kidney disease risk: a comparative study with histamine-2 receptor antagonists

This observational study explored the association between proton pump inhibitor (PPI) and histamine-2 receptor antagonist (H2RA) use and the risk of chronic kidney disease (CKD). Using the National Health Insurance Service-National Sample Cohort (NHIS-NSC) and six-hospital electronic health record (EHR) databases, CKD incidence was analyzed among PPI and H2RA users. Propensity score matching was used to balance baseline characteristics, with 1,869 subjects each in the PPI and H2RA groups from the NHIS-NSC, and 5,967 in EHR databases. CKD incidence was similar for both groups (5.72/1000 person-years vs. 7.57/1000 person-years; HR = 0.68; 95% CI, 0.35-1.30). A meta-analysis of the EHR databases showed no significant increased CKD risk associated with PPI use (HR = 1.03, 95% CI: 0.87-1.23). These results suggest PPI use may not increase CKD risk compared to H2RA use, but the potential role of PPI-induced CKD needs further research. Clinicians should consider this when prescribing long-term PPI therapy.

Food Insecurity and Chronic Kidney Disease: Considerations for Practitioners

The coronavirus disease 2019 pandemic has exacerbated existing health disparities related to food security status. Emerging literature suggests individuals with Chronic Kidney Disease (CKD) who are also food insecure have a greater likelihood of disease progression compared to food secure individuals. However, the complex relationship between CKD and food insecurity (FI) is understudied relative to other chronic conditions. The purpose of this practical application article is to summarize the recent literature on the social-economic, nutritional, to care through which FI may negatively impact health outcomes in individuals with CKD. While several studies have reported on the cross-sectional prevalence of FI among persons with CKD, literature is lacking about the severity and duration of exposure to FI on CKD outcomes. Future research is needed to better understand how FI impairs CKD care, nutritional and structural barriers that impact disease prevention and disease progression, and effective strategies to support patients.

Racial Differences and Contributory Cardiovascular and Non-Cardiovascular Risk Factors Towards Chronic Kidney Disease Progression

Background

The prevalence of advanced chronic kidney disease (CKD) is higher in Black than in White Americans. We evaluated CKD progression in Black and White participants and the contribution of biological risk factors. We included the study of lung function (measured by forced vital capacity [FVC]), which is part of the emerging notion of interorgan cross-talk with the kidneys to racial differences in CKD progression.

Methods

This longitudinal study included 2175 Black and 2207 White adult Coronary Artery Risk Development in Young Adults (CARDIA) participants. Estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (UACR) were measured at study year 10 (age 27-41y) and every five years for 20 years. The outcome was CKD progression through no CKD, low, moderate, high, or very high-risk categories based on eGFR and UACR in combination. The association between race and CKD progression as well as the contribution of risk factors to racial differences were assessed in multivariable-adjusted Cox models.

Results

Black participants had higher CKD transition probabilities than White participants and more prevalent risk factors during the 20-year period studied. Hazard ratios for CKD transition for Black (vs White participants) were 1.38 from No CKD into ≥ low risk, 2.25 from ≤ low risk into ≥ moderate risk, and 4.49 from ≤ moderate risk into ≥ high risk. Racial differences in CKD progression from No CKD into ≥ low risk were primarily explained by FVC (54.8%), hypertension (30.9%), and obesity (20.8%). In contrast, racial differences were less explained in more severe transitions.

Conclusion

Black participants had a higher risk of CKD progression, and this discrepancy may be partly explained by FVC and conventional risk factors.

Diagnosis of Chronic Kidney Disease and Assessing Glomerular Filtration Rate

Chronic kidney disease (CKD) is a silent progressive disease. It is diagnosed by assessing filtration and markers of kidney damage such as albuminuria. The diagnosis of CKD should include not only assessing the glomerular filtration rate (GFR) and albuminuria but also the cause. The CKD care plan should include documentation of the trajectory and prognosis. The use of a combination of serum cystatin C and creatinine concentration offers a more accurate estimation of GFR. Social determinants of health are important to address as part of the diagnosis because they contribute to CKD disparities.

Dietary Patterns, Apolipoprotein L1 Risk Genotypes, and CKD Outcomes Among Black Adults in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Cohort Study

Rationale & Objective

Dietary factors may impact inflammation and interferon production, which could influence phenotypic expression of Apolipoprotein1 (APOL1) genotypes. We investigated whether associations of dietary patterns with kidney outcomes differed by APOL1 genotypes.

Study Design

Prospective cohort.

Settings & Participants

5,640 Black participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS).

Exposures

Five dietary patterns derived from food frequency questionnaires: Convenience foods, Southern, Sweets and Fats, Plant-based, and Alcohol/Salads.

Outcomes

Incident chronic kidney disease (CKD), CKD progression, and kidney failure. Incident CKD was defined as a change in estimated glomerular filtration rate (eGFR) to <60 mL/min/1.73 m2 accompanied by a ≥25% decline from baseline eGFR or development of kidney failure among those with baseline eGFR ≥60 mL/1.73 m2 body surface area. CKD progression was defined as a composite of 40% reduction in eGFR from baseline or development of kidney failure in the subset of participants who had serum creatinine levels at baseline and completed a second in-home visit/follow-up visit.

Analytical Approach

We examined associations of dietary pattern quartiles with incident CKD (n=4,188), CKD progression (n=5,640), and kidney failure (n=5,640). We tested for statistical interaction between dietary patterns and APOL1 genotypes for CKD outcomes and explored stratified analyses by APOL1 genotypes.

Results

Among 5,640 Black REGARDS participants, mean age was 64 years (standard deviation = 9), 35% were male, and 682 (12.1%) had high-risk APOL1 genotypes. Highest versus lowest quartiles (Q4 vs Q1) of Southern dietary pattern were associated with higher adjusted odds of CKD progression (OR, 1.28; 95% CI, 1.01-1.63) but not incident CKD (OR, 0.92; 95% CI, 0.74-1.14) or kidney failure (HR, 1.48; 95% CI, 0.90-2.44). No other dietary patterns showed significant associations with CKD. There were no statistically significant interactions between APOL1 genotypes and dietary patterns. Stratified analysis showed no consistent associations across genotypes, although Q3 and Q4 versus Q1 of Plant-based and Southern patterns were associated with lower odds of CKD progression among APOL1 high- but not low-risk genotypes.

Limitations

Included overlapping dietary patterns based on a single time point and multiple testing.

Conclusions

In Black REGARDS participants, Southern dietary pattern was associated with increased risk of CKD progression. Analyses stratified by APOL1 genotypes suggest associations may differ by genetic background, but these findings require confirmation in other cohorts.

Flattening the Playing Field for Treatment of Diabetic Kidney Disease

Diabetic kidney disease (DKD) remains a major health care issue and is beset with significant racial and ethnic disparities in regard to its incidence, progression, and complication rate. An individual's health is influenced strongly by an array of societal-level factors commonly called the social determinants of health. Among these, DKD is influenced highly by structured resources and opportunities, as well as an individual's socioeconomic status, health insurance status, access to care, education, health literacy, nutrition, green space exposure, level of trust in the medical community, and more. Health equity is considered a state in which everyone has a fair and just opportunity to attain his or her highest level of health. Conversely, health inequities are a consequence of a structured discriminatory system of inequitable allocation of social determinants of health. When this discriminatory system is race-based it is referred to as structural racism, which eventually leads to racial and ethnic health disparities. The further downstream sequela of structural racism, consciously or unconsciously, impacts health systems, providers, and patients, and can lead to disparities in DKD development, progression, and complications. In this article, we explore potential interventions at the societal, health system, and provider levels that can help flatten the playing field and reduce racial and ethnic disparities in DKD.

Impact of Social Determinants of Health in Spine Surgery

PURPOSE OF REVIEW

Social determinants of health (SDH) are factors that affect patient health outcomes outside the hospital. SDH are "conditions in the environments where people are born, live, learn, work, play, worship, and age that affect a wide range of health, functioning, and quality-of-life outcomes and risks." Current literature has shown SDH affecting patient reported outcomes in various specialties; however, there is a dearth in research relating spine surgery with SDH. The aim of this review article is to identify connections between SDH and post-operative outcomes in spine surgery. These are important, yet understudied predictors that can impact health outcomes and affect health equity.

RECENT FINDINGS

Few studies have shown associations between SDH pillars (environment, race, healthcare, economic, and education) and spine surgery outcomes. The most notable relationships demonstrate increased disability, return to work time, and pain with lower income, education, environmental locations, healthcare status and/or provider. Despite these findings, there remains a significant lack of understanding between SDH and spine surgery. Our manuscript reviews the available literature comparing SDH with various spine conditions and surgeries. We organized our findings into the following narrative themes: 1) education, 2) geography, 3) race, 4) healthcare access, and 5) economics.

Health Disparities in Kidney Failure Among Patients With Autosomal Dominant Polycystic Kidney Disease: A Cross-Sectional Study

Rationale & Objective

Understanding potential differences in patterns of kidney failure among patients with autosomal dominant polycystic kidney disease (ADPKD) may provide insights into improving disease management. We sought to characterize patients with ADPKD and kidney failure across different race/ethnicities.

Study Design

Cross-sectional study.

Setting & Participants

Kaiser Permanente Southern California members diagnosed with ADPKD between January1, 2002, and December 31, 2018.

Exposure

ADPKD.

Outcome

Kidney failure, dialysis, or receipt of kidney transplant.

Analytical Approach

Differences in characteristics by race/ethnicity were assessed using analysis of variance F test and χ² test. To compare the range and distribution of the average age at onset of kidney failure by race/ethnicity and sex, we used box plots and confidence intervals. Multivariable logistic regression was used to estimate OR for kidney transplant.

Results

Among 3,677 ADPKD patients, 1,027 (27.3%) had kidney failure. The kidney failure cohort was comprised of Black (n=138; 30.7%), White (n=496; 30.6%), Hispanic (n=306; 24.7%), and Asian (n=87; 23.6%) patients. Hispanic patients had the youngest mean age of kidney failure onset (50 years) compared to Black (56 years) and White (57 years) patients. Black (44.2%; OR, 0.72) and Hispanic (49.7%; OR, 0.65) patients had lower rates of kidney transplantation compared to White (53.8%) patients. Preemptive kidney transplantations occurred in 15.0% of patients.

Limitations

Retrospective study design and possible misclassification of ADPKD cases. Kidney function calculations were based on equations incorporating race, potentially overestimating kidney function in African Americans. The study was conducted within a single, integrated health care system in 1 geographic region and may not be generalizable to all ADPKD patients.

Conclusions

Among a large diverse ADPKD population, we observed racial/ethnic differences in rates of kidney failure, age of kidney failure onset, and rates of kidney transplantation. Our real-world ADPKD cohort provides insight into racial/ethnic variation in clinical features of disease and potential disparities in care, which may affect ADPKD outcomes.

Black-White Inequities in Kidney Disease Mortality Across the 30 Most Populous US Cities

OBJECTIVES

To examine city-level kidney disease mortality rates and Black:White racial inequities for the USA and its largest cities, and to determine if these measures changed over the past decade.

METHODS

We used National Vital Statistics System mortality data and American Community Survey population estimates to calculate age-standardized kidney disease mortality rates for the non-Hispanic Black (Black), non-Hispanic White (White), and total populations for the USA and the 30 most populous US cities. We examined two time points, 2008-2013 (T1) and 2014-2018 (T2), and assessed changes in rates and inequities over time. Racial inequities were measured with Black:White mortality rate ratios and rate differences.

RESULTS

Kidney disease mortality rates varied from 2.5 (per 100,000) in San Diego to 24.6 in Houston at T2. The Black kidney disease mortality rate was higher than the White rate in the USA and all cities studied at both time points. In T2, the Black mortality rate ranged from 7.9 in New York to 45.4 in Charlotte, while the White mortality rate ranged from 2.0 in San Diego to 18.6 in Indianapolis. At T2, the Black:White rate ratio ranged from 1.79 (95% CI 1.62-1.99) in Philadelphia to 5.25 (95% CI 3.40-8.10) in Washington, DC, compared to the US rate ratio of 2.28 (95% CI 2.25-2.30). Between T1 and T2, only one city (Nashville) saw a significant decrease in the Black:White mortality gap.

CONCLUSIONS

The largest US cities experience widely varying kidney disease mortality rates and widespread racial inequities. These local data on racial inequities in kidney disease mortality can be used by city leaders and health stakeholders to increase awareness, guide the allocation of limited resources, monitor trends over time, and support targeted population health strategies.

Type 2 diabetes mellitus in sub-Saharan Africa: challenges and opportunities

Type 2 diabetes mellitus (T2DM), which was once thought to be rare in sub-Saharan Africa (SSA), is now well established in this region. The SSA region is undergoing a rapid but variable epidemiological transition fuelled by the pace of urbanization, with disease burden profiles shifting from communicable diseases to non-communicable diseases (NCDs). Information on the epidemiology of T2DM has increased, but wide variations in study methods, diagnostic biomarkers and criteria hamper analytical comparison, and data from high-quality studies are limited. The prevalence of T2DM is still low in some rural populations but moderate or high rates are reported in many countries/regions, with evidence for an increase in some. In addition, the proportion of undiagnosed T2DM is still high. The prevalence of T2DM is highest in African people living in urban areas, and the gradient between African people living in urban areas and people in the African diaspora is rapidly fading. However, data from longitudinal studies are lacking and there is limited information on chronic complications and the genetics of T2DM. The large unmet needs for T2DM care call for greater investment of resources into health systems to manage NCDs in SSA. Proposed health-system paradigms are being developed in some countries/regions. However, national NCD programmes need to be adequately funded and coordinated to stem the tide of T2DM and its complications.

Chronic kidney disease biomarkers and mortality among older adults: A comparison study of survey samples in China and the United States

OBJECTIVES

Among older adults in China and the US, we aimed to compare the biomarkers of chronic-kidney-diseases (CKD), factors associated with CKD, and the correlation between CKD and mortality.

SETTING

China and the US.

STUDY DESIGN

Cross-sectional and prospective cohorts.

PARTICIPANTS

We included 2019 participants aged 65 and above from the Chinese Longitudinal Healthy Longevity Study (CLHLS) in 2012, and 2177 from US National Health and Nutrition Examination Survey (NHANES) in 2011-2014.

OUTCOMES

Urinary albumin, urinary creatinine, albumin creatinine ratio (ACR), serum creatinine, blood urea nitrogen, plasma albumin, uric acid, and estimated glomerular filtration rate (eGFR). CKD (ACR ≥ 30 mg/g or eGFR< 60 ml/min/1.73m2) and mortality.

ANALYTICAL APPROACH

Logistic regression and Cox proportional hazard models. Covariates included age, sex, race, education, income, marital status, health condition, smoking and drinking status, physical activity and body mass index.

RESULTS

Chinese participants had lower levels of urinary albumin, ACR, and uric acid than the US (mean: 25.0 vs 76.4 mg/L, 41.7 vs 85.0 mg/g, 292.9 vs 341.3 μmol/L). In the fully-adjusted model, CKD was associated with the risk of mortality only in the US group (hazard ratio [HR], 95% CI: 2.179, 1.561-3.041 in NHANES, 1.091, 0.940-1.266 in CLHLS). Compared to eGFR≥90, eGFR ranged 30-44 ml/min/1.73m2 was only associated with mortality in the US population (HR, 95% CI: 2.249, 1.141-4.430), but not in the Chinese population (HR, 95% CI: 1.408, 0.884-2.241).

CONCLUSIONS

The elderly participants in the US sample had worse CKD-related biomarker levels than in China sample, and the association between CKD and mortality was also stronger among the US older adults. This may be due to the biological differences, or co-morbid conditions.

Racial and Socioeconomic Disparities in CKD in the Context of Universal Health Care Provided by the Military Health System

Rationale & Objective

Health-impeding social determinants of health—including reduced access to care—contribute to racial and socioeconomic disparities in chronic kidney disease (CKD). The Military Health System (MHS) provides an opportunity to assess a large, diverse population for CKD disparities in the context of universal health care.

Study Design

Cross-sectional study.

Setting & Participants

MHS beneficiaries aged 18 to 64 years receiving care between October 1, 2015, and September 30, 2018.

Predictors

Race, sponsor’s rank (a proxy for socioeconomic status and social class), median household income by sponsor’s zip code, and marital status.

Outcome

CKD prevalence, defined by International Classification of Diseases, Tenth Revision codes and/or a validated, laboratory value-based electronic phenotype.

Analytical Approach

Multivariable logistic regression compared CKD prevalence by predictors, controlling separately for confounders (age, sex, active-duty status, sponsor’s service branch, and depression) and mediators (hypertension, diabetes, HIV, and body mass index).

Results

Of 3,330,893 beneficiaries, 105,504 (3.2%) had CKD. In confounder-adjusted models, the CKD prevalence was higher in Black versus White beneficiaries (OR, 1.67; 95% CI, 1.64-1.70), but lower in single versus married beneficiaries (OR, 0.77; 95% CI, 0.76-0.79). The prevalence of CKD was increased among those with a lower military rank and among those with a lower median household income in a nearly dose-response fashion (P < 0.0001). Associations were attenuated when further adjusting for suspected mediators.

Limitations

The cross-sectional design prevents causal inferences. We may have underestimated the CKD prevalence, given a lack of data for laboratory tests conducted outside the MHS and the use of a specific CKD definition. The transient nature of the MHS population may limit the accuracy of zip code–level median household income data.

Conclusions

Racial and socioeconomic CKD disparities exist in the MHS despite universal health care coverage. The existence of CKD disparities by rank and median household income suggests that social risks may contribute to both racial and socioeconomic disparities despite access to universal health care coverage.

Structural Inequities and Barriers to Accessing Kidney Healthcare Services in the United States: A Focus on Uninsured and Undocumented Children and Young Adults

The population of children living in poverty and lacking healthcare insurance has increased in the United States of America in the last decade. Several factors have been responsible for this trend including illegal immigration, socioeconomic deprivation, young age, racial segregation, environmental degradation, and discriminatory housing policies. These systemic barriers have contributed to the exclusion of families from essential healthcare services. They are also contributory to the development of chronic illnesses (such as dialysis-dependent kidney disease) that are debilitating and frequently require considerable therapeutic resources. This unfortunate scenario creates a never-ending vicious cycle of poverty and diseases in a segment of society. For pediatric nephrologists, the challenges of caring for uninsured children with chronic kidney disease are all too familiar. Federally funded healthcare programs do not cover this patient population, leaving them the option of seeking care in emergency healthcare settings. Presentation with a critical illness often necessitates urgent placement of vascular catheters and the choice of acute hemodialysis. Adverse social environment influences the need for protracted chronic hemodialysis and a delay in kidney transplantation. Consequently, there is greater comorbidity, recurrent hospitalization, and a higher mortality rate. New policies should address the deficit in health insurance coverage while promoting social programs that will remove structural barriers to health care resources for undocumented children and young adults.

Global Epidemiology of End-Stage Kidney Disease and Disparities in Kidney Replacement Therapy

BACKGROUND

The global epidemiology of end-stage kidney disease (ESKD) reflects each nation's unique genetic, environmental, lifestyle, and sociodemographic characteristics. The response to ESKD, particularly regarding kidney replacement therapy (KRT), depends on local disease burden, culture, and socioeconomics. Here, we explore geographic variation and global trends in ESKD incidence and prevalence and examine variations in KRT modality, practice patterns, and mortality. We conclude with a discussion on disparities in access to KRT and strategies to reduce ESKD global burden and to improve access to treatment in low- and middle-income countries (LMICs).

SUMMARY

From 2003 to 2016, incidence rates of treated ESKD were relatively stable in many higher income countries but rose substantially predominantly in East and Southeast Asia. The prevalence of treated ESKD has increased worldwide, likely due to improving ESKD survival, population demographic shifts, higher prevalence of ESKD risk factors, and increasing KRT access in countries with growing economies. Unadjusted 5-year survival of ESKD patients on KRT was 41% in the USA, 48% in Europe, and 60% in Japan. Dialysis is the predominant KRT in most countries, with hemodialysis being the most common modality. Variations in dialysis practice patterns account for some of the differences in survival outcomes globally. Worldwide, there is a greater prevalence of KRT at higher income levels, and the number of people who die prematurely because of lack of KRT access is estimated at up to 3 times higher than the number who receive treatment. Key Messages: Many people worldwide in need of KRT as a life-sustaining treatment do not receive it, mostly in LMICs where health care resources are severely limited. This large treatment gap demands a focus on population-based prevention strategies and development of affordable and cost-effective KRT. Achieving global equity in KRT access will require concerted efforts in advocating effective public policy, health care delivery, workforce capacity, education, research, and support from the government, private sector, nongovernmental, and professional organizations.

The cumulative impact of social determinants of health factors on mortality in adults with diabetes and chronic kidney disease

BACKGROUND

A growing body of evidence supports the potential role of social determinants of health on health outcomes. However, few studies have examined the cumulative effect of social determinants of health on health outcomes in adults with chronic kidney disease (CKD) with or without diabetes. This study examined the cumulative impact of social determinants of health on mortality in U.S. adults with CKD and diabetes.

METHODS

We analyzed data from National Health and Nutrition Examination Surveys (2005-2014) for 1376 adults age 20 and older (representing 7,579,967 U.S. adults) with CKD and diabetes. The primary outcome was all-cause mortality. CKD was based on estimated glomerular filtration rate and albuminuria. Diabetes was based on self-report or Hemoglobin A1c of ≥6.5%. Social determinants of health measures included family income to poverty ratio level, depression based on PHQ-9 score and food insecurity based on Food Security Survey Module. A dichotomous social determinant measure (absence vs presence of ≥1 adverse social determinants) and a cumulative social determinant score ranging from 0 to 3 was constructed based on all three measures. Cox proportional models were used to estimate the association between social determinants of health factors and mortality while controlling for covariates.

RESULTS

Cumulative and dichotomous social determinants of health score were significantly associated with mortality after adjusting for demographics, lifestyle variables, glycemic control and comorbidities (HR = 1.41, 95%CI 1.18-1.68 and HR = 1.41, 95%CI 1.08-1.84, respectively). When investigating social determinants of health variables separately, after adjusting for covariates, depression (HR = 1.52, 95%CI 1.10-1.83) was significantly and independently associated with mortality, however, poverty and food insecurity were not statistically significant.

CONCLUSIONS

Specific social determinants of health factors such as depression increase mortality in adults with chronic kidney disease and diabetes. Our findings suggest that interventions are needed to address adverse determinants of health in this population.

Survival of the Fittest: Addressing the Disparities in the Burden of Chronic Kidney Disease

The prevalence of chronic kidney disease (CKD) is increasingly becoming recognized as a global health concern as well as a critical determinant of poor health outcomes. Decreased access to health care and low socioeconomic status (SES) worsen the adverse effects of biologic or genetic predisposition to CKD. All the studies used were retrieved using the PubMed database. The literature suggests that in developing and developed countries, lower SES is inversely proportional to CKD. It shows an inconsistent relationship between CKD and race; that is, there may or may not be a relationship between these two variables. In the United States (US), the prevalence of the early stages of CKD is similar across different racial/ethnic groups. However, the preponderance of end-stage renal disease (ESRD) is higher for minorities than their non-Hispanic white counterparts.

Further investigation is required to understand the role of racial disparities and CKD as well as to understand the significant difference seen in the incidence when progressing from CKD to ESRD. It is necessary to recognize how lower SES and racial/ethnic disparity may result in the impediment of appropriate disease management. A possible approach is the use of the biopsychosocial model, which integrates biological, individual, and neighborhood factors. A practical method of providing appropriate care to these populations will require economically feasible prevention strategies as well as extending the scope of dialysis by the implementation of cheaper alternatives.

Association of Socioeconomic Status and Comorbidities with Racial Disparities during Kidney Transplant Evaluation

BACKGROUND AND OBJECTIVES

Black patients referred for kidney transplantation have surpassed many obstacles but likely face continued racial disparities before transplant. The mechanisms that underlie these disparities are unclear. We determined the contributions of socioeconomic status (SES) and comorbidities as mediators to disparities in listing and transplant.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We studied a cohort (n=1452 black; n=1561 white) of patients with kidney failure who were referred for and started the transplant process (2009-2018). We estimated the direct and indirect effects of SES (self-reported income, education, and employment) and medical comorbidities (self-reported and chart-abstracted) as mediators of racial disparities in listing using Cox proportional hazards analysis with inverse odds ratio weighting. Among the 983 black and 1085 white candidates actively listed, we estimated the direct and indirect effects of SES and comorbidities as mediators of racial disparities on receipt of transplant using Poisson regression with inverse odds ratio weighting.

RESULTS

Within the first year, 876 (60%) black and 1028 (66%) white patients were waitlisted. The relative risk of listing for black compared with white patients was 0.76 (95% confidence interval [95% CI], 0.69 to 0.83); after adjustment for SES and comorbidity, the relative risk was 0.90 (95% CI, 0.83 to 0.97). The proportion of the racial disparity in listing was explained by SES by 36% (95% CI, 26% to 57%), comorbidity by 44% (95% CI, 35% to 61%), and SES with comorbidity by 58% (95% CI, 44% to 85%). There were 409 (42%) black and 496 (45%) white listed candidates transplanted, with a median duration of follow-up of 3.9 (interquartile range, 1.2-7.1) and 2.8 (interquartile range, 0.8-6.3) years, respectively. The incidence rate ratio for black versus white candidates was 0.87 (95% CI, 0.79 to 0.96); SES and comorbidity did not explain the racial disparity.

CONCLUSIONS

SES and comorbidity partially mediated racial disparities in listing but not for transplant.

Racial and Sex Disparities in Catheter Use and Dialysis Access in the United States Medicare Population

BACKGROUND

Despite efforts to increase arteriovenous fistula and graft use, 80% of patients in the United States start hemodialysis on a central venous catheter (CVC).

METHODS

To better understand in incident hemodialysis patients how sex and race/ethnicity are associated with time on a central venous catheter and transition to an arteriovenous fistula and graft, our observational cohort study analyzed US Renal Data System data for patients with incident ESKD aged ≥66 years who started hemodialysis on a CVC in July 2010 through 2013.

RESULTS

At 1 year, 32.7% of 74,194 patients transitioned to an arteriovenous fistula, 10.8% transitioned to an arteriovenous graft, 32.1% stayed on a CVC, and 24.5% died. Women spent a significantly longer time on a CVC than men. Compared with white patients, patients who were black, Hispanic, or of another racial/ethnicity minority spent significantly more days on a CVC. In competing risk regression, women were significantly less likely than men to transition to a fistula and more likely to transition to a graft. Compared with white patients, blacks were significantly less likely to transition to a fistula but more likely to transition to a graft, Hispanics were significantly more likely to transition to a fistula, and other races/ethnicities were significantly more likely to transition to either a fistula or a graft.

CONCLUSIONS

Female patients spend a longer time on a CVC and are less likely to transition to permanent access. Compared with white patients, minorities also spend longer time on a CVC, but are more likely to eventually transition to permanent access. Strategies to speed transition to permanent access should target groups that currently lag in this area.

Glyphosate exposures and kidney injury biomarkers in infants and young children

The goal of this study was to assess biomarkers of exposure to glyphosate and assess potential associations with renal function in children. Glyphosate is used ubiquitously in agriculture worldwide. While previous studies have indicated that glyphosate may have nephrotoxic effects, few have examined potential effects on kidney function in children. We leveraged three cohorts across different phases of child development and measured urinary levels of glyphosate. We evaluated associations of glyphosate with three biomarkers of kidney injury: albuminuria (ACR), neutrophil gelatinase-associated lipocalin (NGAL), and kidney injury marker 1 (KIM-1). Multivariable regression analyses examined associations of glyphosate with kidney injury biomarkers controlling for covariates. We identified glyphosate in 11.1% of the total participants. The herbicide was detected more frequently in the neonate population (30%). Multivariable regression models failed to identify significant associations of log-transformed glyphosate with any of the kidney injury biomarkers, controlling for covariates age, sex, and maternal education. While we confirm detectability of glyphosate in children's urine at various ages and stages of life, there is no evidence in this study for renal injury in children exposed to low levels of glyphosate. Further studies of larger sample size are indicated to better understand putative deleterious effects of the herbicide after different levels of exposure.

Awareness and Discussions About Chronic Kidney Disease Among African-Americans with Chronic Kidney Disease and Hypertension: a Mixed Methods Study

BACKGROUND

Routine primary care visits provide an educational opportunity for African-Americans with chronic kidney disease (CKD) and CKD risk factors such as hypertension. The nature of patient-physician discussions about CKD and their impact on CKD awareness in this population have not been well explored.

OBJECTIVE

To characterize patient CKD awareness and discussions about CKD between patients and primary care physicians (PCPs).

DESIGN

Mixed methods study.

PATIENTS

African-American patients with uncontrolled hypertension (≥ 140/90 mmHg) and CKD (albuminuria or eGFR < 60 ml/min/1.73 m2) recruited from an urban primary care clinic.

MAIN MEASURES

We assessed patient CKD awareness with questionnaires and audio-recorded patients-PCP discussions during a routine visit. We characterized discussions and used multivariate regression analysis to identify independent patient and visit predictors of CKD awareness or CKD discussions.

RESULTS

Among 48 African-American patients with uncontrolled hypertension and CKD, 29% were aware of their CKD. After adjustment, CKD awareness was associated with moderate-severe CKD (stages 3-4) (vs. mild CKD [stages 1-2]) (prevalence ratio [PR] 2.82; 95% CI 1.18-6.78) and inversely associated with diabetes (vs. without diabetes) (PR 0.28; 95% CI 0.10-0.75). CKD discussions occurred in 30 (63%) visits; most focused on laboratory assessment (n = 23, 77%) or risk factor management to delay CKD progression (n = 19, 63%). CKD discussions were associated with moderate-severe CKD (vs. mild CKD) (PR 1.57; 95% CI 1.04-2.36) and diabetes (vs. without diabetes) (PR 1.42; 95% CI 1.09-1.85), and inversely associated with uncontrolled hypertension (vs. controlled) (PR 0.58; 95% CI 0.92-0.89). In subgroup analysis, follow-up CKD awareness did not change by presence or absence of CKD discussion (10.5% vs. 7.7%, p = 0.8).

CONCLUSIONS

In patients at risk of CKD progression, few were aware of CKD, and CKD discussions were not associated with CKD awareness. More resources may be needed to enhance the clarity of clinical messages regarding CKD and its significance for patients' health.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01902719.

Neighborhood Poverty and Sex Differences in Live Donor Kidney Transplant Outcomes in the United States

BACKGROUND

Neighborhood poverty has been associated with worse outcomes after live donor kidney transplantation (LDKT), and prior work suggests that women with kidney disease may be more susceptible to the negative influence of poverty than men. As such, our goal was to examine whether poverty differentially affects women in influencing LDKT outcomes.

METHODS

Using data from the Scientific Registry of Transplant Recipients and US Census, we performed multivariable Cox regression to compare outcomes among 18 955 women and 30 887 men who received a first LDKT in 2005-2014 with follow-up through December 31, 2016.

RESULTS

Women living in poor (adjusted hazard ratio [aHR], 1.30; 95% confidence interval [CI], 1.13-1.50) and middle-income (aHR, 1.26; 95% CI, 1.14-1.40) neighborhoods had higher risk of graft loss than men, but there were no differences in wealthy areas (aHR, 1.07; 95% CI, 0.88-1.29). Women living in wealthy (aHR, 0.71; 95% CI, 0.59-0.87) and middle-income (aHR, 0.82; 95% CI, 0.74-0.92) neighborhoods incurred a survival advantage over men, but there were no statistically significant differences in mortality in poor areas (aHR, 0.85; 95% CI, 0.72-1.01).

CONCLUSIONS

Given our findings that poverty is more strongly associated with graft loss in women, targeted efforts are needed to specifically address mechanisms driving these disparities in LDKT outcomes.

Kidney Disease in African American Children: Biological and Nonbiological Disparities

Pediatric-onset chronic kidney disease (CKD) is as relevant to adults as it is to children. Congenital anomalies of the kidney and urinary tract may have a significant impact on health from birth or during childhood or may not manifest until adulthood. Many acquired kidney diseases start to appear in late childhood and adolescence. The propensity for more rapid progression of CKD to end-stage kidney disease in adults of African ancestry, as well as disparities in access to kidney transplantation and allograft longevity, have been well documented for decades. Similar disparate patterns are seen in children, and we now know that there are a range of biological and nonbiological risk factors for the development and progression of CKD in people of African descent that are pertinent to CKD in children. In some cases, it is unclear whether there are effective potential interventions, whereas in other situations, there are opportunities to improve outcomes.

Revisiting racial differences in ESRD due to ADPKD in the United States

Introduction

Autosomal dominant polycystic kidney disease (ADPKD) affects all races. Whether the progression of ADPKD varies by race remains unclear.

Methods

In this retrospective cohort study from 2004 to 2013 non-Hispanic blacks and non-Hispanic whites of all ages classified in the US Renal Data System (USRDS) with incident ESRD from ADPKD (n = 23,647), hypertension/large vessel disease (n = 296,352), or diabetes mellitus (n = 451,760) were stratified into five-year age categories ranging from < 40 to > 75 (e.g., < 40, 40–44, 45–49, …, 75+). The Cochran-Mantel-Haenszel test was used to determine the association of race and incidence of ESRD from ADPKD, diabetes, or hypertension. The difference in the proportions of ESRD in non-Hispanic black and non-Hispanic white patients at each age categorical bin was compared by two-sample proportion test. The age of ESRD onset between non-Hispanic black and non-Hispanic white patients at each year was compared using two-sample t-test with unequal variance.

Results

1.068% of non-Hispanic blacks and 2.778% of non-Hispanic whites had ESRD attributed to ADPKD. Non-Hispanic blacks were less likely than non-Hispanic whites to have ESRD attributed to ADPKD (odds ratio (OR) (95% CI) = 0.38 (0.36–0.39), p <  0.0001). Using US Census data as the denominator to adjust for population differences non-Hispanic blacks were still slightly under-represented (OR (95% CI) 0.94 (0.91–0.96), p = 0.004). However, non-Hispanic blacks with ADPKD had a younger age of ESRD (54.4 years ±13) than non-Hispanic whites (55.9 years ±12.8) (p <  0.0001). For those < 40 years old, more non-Hispanic blacks had incident ESRD from ADPKD than non-Hispanic whites (9.49% vs. 7.68%, difference (95% CI) = 1.81% (0.87–2.84%), p <  0.001) for the combined years examined.

Conclusions

As previously shown, we find the incidence of ESRD from ADPKD in non-Hispanic blacks is lower than in non-Hispanic whites. Among the younger ADPKD population (age < 40), however, more non-Hispanic blacks initiated dialysis than non-Hispanic whites. Non-Hispanic blacks with ADPKD initiated dialysis younger than non-Hispanic whites. A potential implication of these findings may be that black race should be considered an additional risk factor for progression in ADPKD.

2019 World Kidney Day Editorial - burden, access, and disparities in kidney disease

Kidney disease is a global public health problem, affecting over 750 million persons worldwide. The burden of kidney disease varies substantially across the world, as does its detection and treatment. In many settings, rates of kidney disease and the provision of its care are defined by socio-economic, cultural, and political factors leading to significant disparities. World Kidney Day 2019 offers an opportunity to raise awareness of kidney disease and highlight disparities in its burden and current state of global capacity for prevention and management. Here, we highlight that many countries still lack access to basic diagnostics, a trained nephrology workforce, universal access to primary health care, and renal replacement therapies. We point to the need for strengthening basic infrastructure for kidney care services for early detection and management of acute kidney injury and chronic kidney disease across all countries and advocate for more pragmatic approaches to providing renal replacement therapies. Achieving universal health coverage worldwide by 2030 is one of the World Health Organization's Sustainable Development Goals. While universal health coverage may not include all elements of kidney care in all countries, understanding what is feasible and important for a country or region with a focus on reducing the burden and consequences of kidney disease would be an important step towards achieving kidney health equity.

The National Kidney Foundation of Illinois KidneyMobile: a mobile resource for community based screenings of chronic kidney disease and its risk factors

BACKGROUND

Early detection and treatment of chronic kidney disease (CKD) and its risk factors improves outcomes; however, many high-risk individuals lack access to healthcare. The National Kidney Foundation of Illinois (NKFI) developed the KidneyMobile (KM) to conduct community-based screenings, provide disease education, and facilitate follow-up appointments for diabetes, hypertension, and CKD.

METHODS

Cross-sectional design. Adults > = 18 years of age participated in NKFI KM screenings across Illinois between 2005 and 2011. Sociodemographic and medical history were self-reported using structured interviews; laboratory data and blood pressure were assessed using standard procedures.

RESULTS

Among 20,770 participants, mean age was 53.5 years, 68% were female, 49% were African-American or Hispanic, 21% primarily spoke Spanish, and at least 27% lacked health insurance. Seventy-eight percent of participants with elevated blood pressure (≥ 140/90 mmHg) were aware of having hypertension, 93% of participants with abnormal blood glucose (fasting glucose > 126 mg/dl or a random glucose of > 200 mg/dL) were aware of having diabetes, and 19% of participants with albuminuria (> 30 mg/gm) were aware of having CKD. In participants reporting hypertension, 47% had blood pressure ≥ 140/90 mmHg, and in those reporting diabetes, 56% had blood glucose ≥ 130 mg/dl (fasting) or ≥ 180 mg/dl (random). Among 4937 participants with abnormal screening findings that participated in follow-up interviews, 69% reported having further medical evaluation.

CONCLUSIONS

A high-risk disadvantaged population is being reached by the NKFI KidneyMobile and connected with healthcare services. A significant proportion of participants were newly informed of having abnormal results suggestive of diabetes, hypertension, and/or CKD or that their diabetes and hypertension were inadequately controlled.

The Effect of Socioeconomic Factors on Outcomes of Distal Radius Fractures: A Systematic Review

BACKGROUND

Socioeconomic factors are known to affect outcomes for both medical and surgical conditions. The purpose of this systematic review was to assess the current evidence regarding the effect of socioeconomic factors such as income, geographic location, educational level, and occupation on clinical outcomes after distal radius fractures.

METHODS

A systematic search strategy was performed to identify studies commenting on the effect of socioeconomic factors on clinical outcomes following open or closed distal radius fracture repair. Abstract and full-text screening was performed by 2 independent reviewers, and articles were evaluated by Structured Effectiveness Quality Evaluation Scale (SEQES). Treatment outcomes of interest included, but were not limited to, pain, function, range of motion, and grip strength.

RESULTS

There were 1745 studies that met our inclusion and exclusion criteria for abstract screening. Of these, 48 studies met our inclusion criteria for full-text screening and 20 studies met our criteria for quality analysis with the SEQES score. There were 3 studies of high quality, 16 of moderate quality, and 1 of low quality. Meta-analyses were not possible due to the variability in outcomes of interest across papers.

CONCLUSIONS

Patient factors indicative of socioeconomic status are relevant predictors of functional outcome after distal radius fractures. There is currently limited evidence in this area of research, and further examination should be considered to improve outcomes from a patient and system standpoint.

Goal-Striving Stress Is Associated with Chronic Kidney Disease Among Participants in the Jackson Heart Study

OBJECTIVE

Research that assesses the relationship between psychosocial factors and chronic kidney disease (CKD) among African Americans (AAs) is limited. Using the Jackson Heart Study (JHS) cohort data, we investigated the association of goal-striving stress (GSS)-the stress experienced from not reaching goals-with prevalent CKD among AAs.

DESIGN

This was a cross-sectional analysis of JHS exam 1 data that assessed the relationship between GSS and CKD.

SETTING AND PARTICIPANTS

We utilized a sample from the JHS (n = 4967), an AA sample of women and men, 35-84 years old from the Jackson, MS metro area.

MAIN OUTCOME MEASURES

The baseline relationship between GSS levels (low, moderate, and high) and CKD (eGFR < 60 mL/min/1.73m²) was evaluated using a logistic regression model to estimate odds ratios (OR) on a 95% confidence interval (CI). The final model was adjusted for sex, age, socioeconomic status, health behaviors, risk factors, and total stress.

RESULTS

After full adjustment, the odds of prevalent CKD increased by 52% (OR 1.52; 95% CI 1.04, 2.24) for those reporting high (versus low) GSS.

CONCLUSIONS

Deficiencies between goal aspiration and achievement were associated with prevalent CKD. Potential interventions might consider the impact GSS contributes to prevalent CKD.

Race/Ethnicity, Dietary Acid Load, and Risk of End-Stage Renal Disease among US Adults with Chronic Kidney Disease

BACKGROUND

Dietary acid load (DAL) contributes to the risk of CKD and CKD progression. We sought to determine the relation of DAL to racial/ethnic differences in the risk of end-stage renal disease (ESRD) among persons with CKD.

METHODS

Among 1,123 non-Hispanic black (NHB) and non-Hispanic white (NHW) National Health and Nutrition Examination Survey III participants with estimated glomerular filtration rate 15-59 mL/min/1.73 m2, DAL was estimated using the Remer and Manz net acid excretion (NAEes) formula and 24-h dietary recall. ESRD events were ascertained via linkage with Medicare. A competing risk model (accounting for death) was used to estimate the hazard ratio (HR) for treated ESRD, comparing NHBs with NHWs, adjusting for demographic, clinical and nutritional factors (body surface area, total caloric intake, serum bicarbonate, protein intake), and NAEes. Additionally, whether the relation of NAEes with ESRD risk varied by race/ethnicity was tested.

RESULTS

At baseline, NHBs had greater NAEes (50.9 vs. 44.2 mEq/day) than NHWs. It was found that 22% developed ESRD over a median of 7.5 years. The unadjusted HR comparing NHBs to NHWs was 3.35 (95% CI 2.51-4.48) and adjusted HR (for factors above) was 1.68 (95% CI 1.18-2.38). A stronger association of NAE with risk of ESRD was observed among NHBs (adjusted HR per mEq/day increase in NAE 1.21, 95% CI 1.12-1.31) than that among NHWs (HR 1.08, 95% CI 0.96-1.20), p interaction for race/ethnicity × NAEes = 0.004.

CONCLUSIONS

Among US adults with CKD, the association of DAL with progression to ESRD is stronger among NHBs than NHWs. DAL is worthy of further investigation for its contribution to kidney outcomes across race/ethnic groups.

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.

Perceived Discrimination and Longitudinal Change in Kidney Function Among Urban Adults

OBJECTIVE

Perceived discrimination has been associated with psychosocial distress and adverse health outcomes. We examined associations of perceived discrimination measures with changes in kidney function in a prospective cohort study, the Healthy Aging in Neighborhoods of Diversity across the Life Span.

METHODS

Our study included 1620 participants with preserved baseline kidney function (estimated glomerular filtration rate [eGFR] ≥ 60 mL/min/1.73 m) (662 whites and 958 African Americans, aged 30-64 years). Self-reported perceived racial discrimination and perceived gender discrimination (PGD) and a general measure of experience of discrimination (EOD) ("medium versus low," "high versus low") were examined in relation to baseline, follow-up, and annual rate of change in eGFR using multiple mixed-effects regression (γbase, γrate) and ordinary least square models (γfollow).

RESULTS

Perceived gender discrimination "high versus low PGD" was associated with a lower baseline eGFR in all models (γbase = -3.51 (1.34), p = .009 for total sample). Among white women, high EOD was associated with lower baseline eGFR, an effect that was strengthened in the full model (γbase = -5.86 [2.52], p = .020). Overall, "high versus low" PGD was associated with lower follow-up eGFR (γfollow = -3.03 [1.45], p = .036). Among African American women, both perceived racial discrimination and PGD were linked to lower follow-up kidney function, an effect that was attenuated with covariate adjustment, indicating mediation through health-related, psychosocial, and lifestyle factors. In contrast, EOD was not linked to follow-up eGFR in any of the sex by race groups.

CONCLUSIONS

Perceived racial and gender discrimination are associated with lower kidney function assessed by glomerular filtration rate and the strength of associations differ by sex and race groups. Perceived discrimination deserves further investigation as a psychosocial risk factors for kidney disease.

Race and Breast Cancer Reconstruction: Is There a Health Care Disparity?

BACKGROUND

Racial disparity continues to be a well-documented problem afflicting contemporary health care. Because the breast is a symbol of femininity, breast reconstruction is critical to mitigating the psychosocial stigma of a breast cancer diagnosis. Whether different races have equitable access to breast reconstruction remains unknown.

METHODS

Two thousand five hundred thirty-three women underwent first-time autologous versus implant-based reconstruction following mastectomy. Information regarding age, smoking, diabetes, obesity, provider, race, pathologic stage, health insurance type, charge to insurance, and socioeconomic status was recorded. Established statistics compared group medians and proportions. A backward-stepwise multivariate logistic regression model identified independent predictors of breast reconstruction type.

RESULTS

Compared with whites, African Americans were more likely to be underinsured (p < 0.01), face a lesser charge for reconstruction (p < 0.01), smoke (p < 0.01), have diabetes (p < 0.01), suffer from obesity (p < 0.01), live in a zip code with a lower median household income (p < 0.01), and undergo autologous-based reconstruction (p = 0.01). On multivariate analysis, only African American race (OR, 2.23; p < 0.01), charge to insurance (OR, 1.00; p < 0.01), and provider (OR, 0.96; p < 0.01) independently predicted type of breast reconstruction, whereas age (OR, 1.02; p = 0.06) and diabetes (OR, 0.48; p = 0.08) did not.

CONCLUSIONS

African American race remains the most clinically significant predictor of autologous breast reconstruction, even after controlling for age, obesity, pathologic stage, health insurance type, charge to patient, socioeconomic status, smoking, and diabetes. Future research may address whether this disparity stems from patient preferences or more profound sociocultural and economic forces, including discrimination.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Food Insecurity, CKD, and Subsequent ESRD in US Adults

BACKGROUND

Poor access to food among low-income adults has been recognized as a risk factor for chronic kidney disease (CKD), but there are no data for the impact of food insecurity on progression to end-stage renal disease (ESRD). We hypothesized that food insecurity would be independently associated with risk for ESRD among persons with and without earlier stages of CKD.

STUDY DESIGN

Longitudinal cohort study.

SETTING & PARTICIPANTS

2,320 adults (aged ≥ 20 years) with CKD and 10,448 adults with no CKD enrolled in NHANES III (1988-1994) with household income ≤ 400% of the federal poverty level linked to the Medicare ESRD Registry for a median follow-up of 12 years.

PREDICTOR

Food insecurity, defined as an affirmative response to the food-insecurity screening question.

OUTCOME

Development of ESRD.

MEASUREMENTS

Demographics, income, diabetes, hypertension, estimated glomerular filtration rate, and albuminuria. Dietary acid load was estimated from 24-hour dietary recall. We used a Fine-Gray competing-risk model to estimate the relative hazard (RH) for ESRD associated with food insecurity after adjusting for covariates.

RESULTS

4.5% of adults with CKD were food insecure. Food-insecure individuals were more likely to be younger and have diabetes (29.9%), hypertension (73.9%), or albuminuria (90.4%) as compared with their counterparts (P<0.05). Median dietary acid load in the food-secure versus food-insecure group was 51.2 mEq/d versus 55.6 mEq/d, respectively (P=0.05). Food-insecure adults were more likely to develop ESRD (RH, 1.38; 95% CI, 1.08-3.10) compared with food-secure adults after adjustment for demographics, income, diabetes, hypertension, estimated glomerular filtration rate, and albuminuria. In the non-CKD group, 5.7% were food insecure. We did not find a significant association between food insecurity and ESRD (RH, 0.77; 95% CI, 0.40-1.49).

LIMITATIONS

Use of single 24-hour diet recall; lack of laboratory follow-up data and measure of changes in food insecurity over time; follow-up of cohort ended 10 years ago.

CONCLUSIONS

Among adults with CKD, food insecurity was independently associated with a higher likelihood of developing ESRD. Innovative approaches to address food insecurity should be tested for their impact on CKD outcomes.

Social Determinants of Racial Disparities in CKD

Significant disparities in CKD rates and outcomes exist between black and white Americans. Health disparities are defined as health differences that adversely affect disadvantaged populations, on the basis of one or more health outcomes. CKD is the complex result of genetic and environmental factors, reflecting the balance of nature and nurture. Social determinants of health have an important role as environmental components, especially for black populations, who are disproportionately disadvantaged. Understanding the social determinants of health and appreciating the underlying differences associated with meaningful clinical outcomes may help nephrologists treat all their patients with CKD in an optimal manner. Altering the social determinants of health, although difficult, may embody important policy and research efforts, with the ultimate goal of improving outcomes for patients with kidney diseases, and minimizing the disparities between groups.

Geographic Variation and US County Characteristics Associated With Rapid Kidney Function Decline

Introduction

Geographic variation in the prevalence of chronic kidney disease and incidence of end-stage renal disease has been previously reported. However, the geographic epidemiology of rapid estimated glomerular filtration rate (eGFR) decline has not been examined.

Methods

We built a longitudinal cohort of 2,107,570 US veterans to characterize the spatial epidemiology of and examine the associations between US county characteristics and rapid eGFR decline.

Results

There were 169,029 (8.02%) with rapid eGFR decline (defined as eGFR slope < –5 ml/min per 1.73 m²/year). The prevalence of rapid eGFR decline adjusted for age, race, gender, diabetes, and hypertension varied by county from 4.10%–6.72% in the lowest prevalence quintile to 8.41%–22.04% in the highest prevalence quintile (P for heterogeneity < 0.001). Examination of adjusted prevalence showed substantial geographic variation in those with and without diabetes and those with and without hypertension (P for heterogeneity < 0.001). Cohort participants had higher odds of rapid eGFR decline when living in counties with unfavorable characteristics in domains including health outcomes (odds ratio [OR] = 1.15; confidence interval [CI] = 1.09–1.22), health behaviors (OR = 1.08; CI = 1.03–1.13), clinical care (OR = 1.11; CI = 1.06–1.16), socioeconomic conditions (OR = 1.15; CI = 1.09–1.22), and physical environment (OR = 1.15; CI = 1.01–1.20); living in counties with high percentage of minorities and immigrants was associated with rapid eGFR decline (OR = 1.25; CI = 1.20–1.31). Spatial analyses suggest the presence of cluster of counties with high prevalence of rapid eGFR decline.

Discussion

Our findings show substantial geographic variation in rapid eGFR decline among US veterans; the variation persists in analyses stratified by diabetes and hypertension status; results show associations between US county characteristics in domains capturing health, socioeconomic, environmental, and diversity conditions, and rapid eGFR decline.

Are There Clinical Implications of Racial Differences in HbA1c? A Difference, to Be a Difference, Must Make a Difference

Studies that have compared HbA1c levels by race have consistently demonstrated higher HbA1c levels in African Americans than in whites. These racial differences in HbA1c have not been explained by measured differences in glycemia, sociodemographic factors, clinical factors, access to care, or quality of care. Recently, a number of nonglycemic factors and several genetic polymorphisms that operate through nonglycemic mechanisms have been associated with HbA1c Their distributions across racial groups and their impact on hemoglobin glycation need to be systematically explored. Thus, on the basis of evidence for racial differences in HbA1c, current clinical guidelines from the American Diabetes Association state: "It is important to take…race/ethnicity…into consideration when using the A1C to diagnose diabetes." However, it is not clear from the guidelines how this recommendation might be actualized. So, the critical question is not whether racial differences in HbA1c exist between African Americans and whites; the important question is whether the observed differences in HbA1c level are clinically meaningful. Therefore, given the current controversy, we provide a Point-Counterpoint debate on this issue. In the preceding point narrative, Dr. Herman provides his argument that the failure to acknowledge that HbA1c might be a biased measure of average glycemia and an unwillingness to rigorously investigate this hypothesis will slow scientific progress and has the potential to do great harm. In the counterpoint narrative below, Dr. Selvin argues that there is no compelling evidence for racial differences in the validity of HbA1c as a measure of hyperglycemia and that race is a poor surrogate for differences in underlying causes of disease risk.-William T. CefaluEditor in Chief, Diabetes Care.

Advancing a Comprehensive Approach to the Study of Lower Urinary Tract Symptoms

PURPOSE

Lower urinary tract symptoms are common in the United States population, leading to significant economic, quality of life and public health issues. The burden will increase as the population ages, and risk factors for lower urinary tract symptoms, including diabetes and obesity, remain highly prevalent. Improving clinical management and establishing the knowledge base to prevent lower urinary tract symptoms will require a comprehensive research approach that examines factors beyond the lower urinary tract. While the study of extra-lower urinary tract factors has increased recently, current urological research does not systematically account for the broad set of potential contributing factors spanning biological, behavioral, psychological/executive function and sociocultural factors. A comprehensive assessment of potential contributors to risk, treatment response and progression is necessary to reduce the burden of this condition in the United States.

MATERIALS AND METHODS

We considered challenges to continuing the predominantly lower urinary tract dysfunction centric approach that has dominated previous research of lower urinary tract symptoms.

RESULTS

We developed a new, comprehensive framework for urology research that includes a broader set of potential factors contributing to lower urinary tract symptoms. This framework aims to broaden research to consider a comprehensive set of potential contributing factors and to engage a broad range of researchers in the investigation of as many extra-lower urinary tract factors as possible, with the goal of improving clinical care and prevention.

CONCLUSIONS

We propose a new framework for future urology research, which should help to reduce the medical and economic burden of lower urinary tract symptoms in the United States population.

Genomics in CKD: Is This the Path Forward?

Recent advances in genomics and sequencing technology have led to a better understanding of genetic risk in CKD. Genetics could account in part for racial differences in treatment response for medications including antihypertensives and immunosuppressive medications due to its correlation with ancestry. However, there is still a substantial lag between generation of this knowledge and its adoption in routine clinical care. This review summarizes the recent advances in genomics and CKD, discusses potential reasons for its underutilization, and highlights potential avenues for application of genomic information to improve clinical care and outcomes in this particularly vulnerable population.

CKD as a Model for Improving Chronic Disease Care through Electronic Health Records

Electronic health records have the potential to improve the care of patients with chronic medical conditions. CKD provides a unique opportunity to show this potential: the disease is common in the United States, there is significant room to improve CKD detection and management, CKD and its related conditions are defined primarily by objective laboratory data, CKD care requires collaboration by a diverse team of health care professionals, and improved access to CKD-related data would enable identification of a group of patients at high risk for multiple adverse outcomes. However, to realize the potential for improvement in CKD-related care, electronic health records will need to provide optimal functionality for providers and patients and interoperability across multiple health care settings. The goal of the National Kidney Disease Education Program Health Information Technology Working Group is to enable and support the widespread interoperability of data related to kidney health among health care software applications to optimize CKD detection and management. Over the course of the last 2 years, group members met to identify general strategies for using electronic health records to improve care for patients with CKD. This paper discusses these strategies and provides general goals for appropriate incorporation of CKD-related data into electronic health records and corresponding design features that may facilitate (1) optimal care of individual patients with CKD through improved access to clinical information and decision support, (2) clinical quality improvement through enhanced population management capabilities, (3) CKD surveillance to improve public health through wider availability of population-level CKD data, and (4) research to improve CKD management practices through efficiencies in study recruitment and data collection. Although these strategies may be most effectively applied in the setting of CKD, because it is primarily defined by laboratory abnormalities and therefore, an ideal computable electronic health record phenotype, they may also apply to other chronic diseases.

Apolipoprotein L1, income and early kidney damage

BACKGROUND

The degree to which genetic or environmental factors are associated with early kidney damage among African Americans (AAs) is unknown.

METHODS

Among 462 AAs in the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study, we examined the cross-sectional association between apolipoprotein L1 (APOL1) risk variants and income with: 1) mildly reduced eGFR (<75 mL/min/1.73 m(2), creatinine-cystatin C equation) and 2) elevated urine albumin-to-creatinine ratio (ACR) (≥17 in men and ≥25 mg/g in women). High risk APOL1 status was defined by 2 copies of high-risk variants; low risk if 0 or 1 copy. Income groups were dichotomized as < $14,000/year (lowest income group) or ≥ $14,000/year. Logistic regression models were adjusted for age, sex, and % European ancestry.

RESULTS

Overall, participants' mean age was 47 years and 16% (n = 73) had high risk APOL1 status. Mean eGFR was 99 mL/min/1.73 m(2). Mildly reduced eGFR was prevalent among 11% (n = 51). The lowest income group had higher adjusted odds (aOR) of mildly reduced eGFR than the higher income group (aOR 1.8, 95% CI 1.2-2.7). High-risk APOL1 was not significantly associated with reduced eGFR (aOR 1.5, 95% CI 0.9-2.5). Among 301 participants with ACR data, 7% (n = 21) had elevated ACR. Compared to low-risk, persons with high-risk APOL1 had higher odds of elevated ACR (aOR 3.8, 95% CI 2.0-7.3). Income was not significantly associated with elevated ACR (aOR 1.8, 95% CI 0.7-4.5). There were no significant interactions between APOL1 and income.

CONCLUSIONS

Both genetic and socioeconomic factors may be important determinants of early kidney damage among AAs.

Environmental exposures, socioeconomics, disparities, and the kidneys

Kidney disease disproportionately affects racial and ethnic minority populations, the poor, and the socially disadvantaged. The excess risk of kidney disease among minority and disadvantaged populations can only be partially explained by an excess of diabetes, hypertension, and poor access to preventive care. Disparities in the environmental exposure to nephrotoxicants have been documented in minority and disadvantaged populations and may explain some of the excess risk of kidney disease. High-level environmental and occupational exposure to lead, cadmium, and mercury are known to cause specific nephropathies. However, there is growing evidence that low-level exposures to heavy metals may contribute to the development of CKD and its progression. In this article, we summarize the excess risk of environmental exposures among minority and disadvantaged populations. We also review the epidemiologic and clinical data linking low-level environmental exposure to lead, cadmium, and mercury to CKD and its progression. Finally, we briefly describe Mesoamerican nephropathy, an epidemic of CKD affecting young men in Central America, which may have occupational and environmental exposures contributing to its development.

Stress and the kidney

The prevalence of CKD has increased considerably over the past 2 decades. The rising rates of CKD have been attributed to known comorbidities such as diabetes, hypertension, and obesity; however, recent research has begun to explore the degree to which social, economic, and psychological factors have implications for the prevalence and progression of CKD, especially among high-risk populations such as African Americans. It has been suggested that stress can have implications for CKD, but this area of research has been largely unexplored. One contributing factor associated with the paucity of research on CKD is that many of the social, psychological, and environmental stressors cannot be recreated or simulated in a laboratory setting. Social science has established that stress can have implications for health, and we believe that stress is an important determinant of the development and progression of CKD. We draw heavily from the social scientific and social epidemiologic literature to present an intersectional conceptual frame specifying how stress can have implications for kidney disease, its progression, and its complications through multiple stressors and pathways.

Perceived barriers and facilitators of using dietary modification for CKD prevention among African Americans of low socioeconomic status: a qualitative study

Background

Factors influencing the use of dietary interventions for modification of CKD risk among African Americans have not been well-explored. We assessed perceived barriers and facilitators of CKD prevention through dietary modifications among African Americans with low socioeconomic status (SES) and at high risk for CKD.

Methods

We conducted a qualitative study involving three 90 minute focus groups of low SES (limited education, unemployed, uninsured, or income < $25,000/year) African American residents of Baltimore, Maryland (N = 17), who were aged 18-60 years, with no known history of CKD and (1) a family history of end stage renal disease and (2) self-reported diabetes, hypertension, cardiovascular disease, HIV or obesity. A trained moderator asked a series of 21 closed and open-ended questions. Group sessions were recorded, transcribed, and two independent investigators reviewed transcripts to identify common themes.

Results

Participants’ mean (SD) age was 39.8 (12.4) years. Most (59%) were female and earned < $5,000/year (71%). One quarter (24%) had self-reported diabetes and over half had hypertension (53%). Few (12%) perceived their CKD risk as high. Perceived barriers to CKD prevention through dietary change included the expense and unavailability of healthy foods, family member preferences, convenience of unhealthy foods, and inability to break lifelong habits. They identified vouchers for healthy foods, family-based interventions, nutritional counseling and group gatherings for persons interested in making dietary changes as acceptable facilitators of dietary CKD prevention efforts.

Conclusions

Low SES African Americans at high risk for CKD had limited perception of their risk but they identified multiple barriers and potential facilitators of CKD prevention via dietary modifications which can inform future studies and public health interventions.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2369-15-194) contains supplementary material, which is available to authorized users.

Disparities in the burden, outcomes, and care of chronic kidney disease

PURPOSE OF REVIEW

Racial, ethnic and socioeconomic disparities in chronic kidney disease (CKD) have been documented for decades, yet little progress has been made in mitigating them. Several recent studies offer new insights into the root causes of these disparities, point to areas in which future research is warranted, and identify opportunities for changes in policy and clinical practice.

RECENT FINDINGS

Recently published evidence suggests that geographic disparities in CKD prevalence exist and vary by race. CKD progression is more rapid for racial and ethnic minority groups compared with whites and may be largely, but not completely, explained by genetic factors. Stark socioeconomic disparities in outcomes for dialysis patients exist and vary by race, place of residence, and treatment facility. Disparities in access to living kidney donation may be driven primarily by the socioeconomic status of the donor as opposed to recipient factors.

SUMMARY

Recent studies highlight opportunities to eliminate disparities in CKD, including efforts to direct resources to areas and populations where disparities are most prevalent, efforts to understand how to best use emerging information on the contribution of genetic factors to disparities, and continued work to identify modifiable environmental, social, and behavioral factors for targeted interventions among high-risk populations.

Complement factor H gene associations with end-stage kidney disease in African Americans

BACKGROUND

Mutations in the complement factor H gene (CFH) region associate with renal-limited mesangial proliferative forms of glomerulonephritis including IgA nephropathy (IgAN), dense deposit disease (DDD) and C3 glomerulonephritis (C3GN). Lack of kidney biopsies could lead to under diagnosis of CFH-associated end-stage kidney disease (ESKD) in African Americans (AAs), with incorrect attribution to other causes. A prior genome-wide association study in AAs with non-diabetic ESKD implicated an intronic CFH single nucleotide polymorphism (SNP).

METHODS

Thirteen CFH SNPs (8 exonic, 2 synonymous, 2 3'UTR, and the previously associated intronic variant rs379489) were tested for association with common forms of non-diabetic and type 2 diabetes-associated (T2D) ESKD in 3770 AAs (1705 with non-diabetic ESKD, 1305 with T2D-ESKD, 760 controls). Most cases lacked kidney biopsies; those with known IgAN, DDD or C3GN were excluded.

RESULTS

Adjusting for age, gender, ancestry and apolipoprotein L1 gene risk variants, single SNP analyses detected 6 CFH SNPs (5 exonic and the intronic variant) as significantly associated with non-diabetic ESKD (P = 0.002-0.01), three of these SNPs were also associated with T2D-ESKD. Weighted CFH locus-wide Sequence Kernel Association Testing (SKAT) in non-diabetic ESKD (P = 0.00053) and T2D-ESKD (P = 0.047) confirmed significant evidence of association.

CONCLUSIONS

CFH was associated with commonly reported etiologies of ESKD in the AA population. These results suggest that a subset of cases with ESKD clinically ascribed to the effects of hypertension or glomerulosclerosis actually have CFH-related forms of mesangial proliferative glomerulonephritis. Genetic testing may prove useful to identify the causes of renal-limited kidney disease in patients with ESKD who lack renal biopsies.

Effect of food insecurity on chronic kidney disease in lower-income Americans

BACKGROUND

The relation of food insecurity (inability to acquire nutritionally adequate and safe foods) and chronic kidney disease (CKD) is unknown. We examined whether food insecurity is associated with prevalent CKD among lower-income individuals in both the general US adult population and an urban population.

METHODS

We conducted cross-sectional analyses of lower-income participants of the National Health and Nutrition Examination Survey (NHANES) 2003-2008 (n = 9,126) and the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study (n = 1,239). Food insecurity was defined based on questionnaires and CKD was defined by reduced estimated glomerular filtration rate or albuminuria; adjustment was performed with multivariable logistic regression.

RESULTS

In NHANES, the age-adjusted prevalence of CKD was 20.3, 17.6, and 15.7% for the high, marginal, and no food insecurity groups, respectively. Analyses adjusting for sociodemographics and smoking status revealed high food insecurity to be associated with greater odds of CKD only among participants with either diabetes (OR = 1.67, 95% CI: 1.14-2.45 comparing high to no food insecurity groups) or hypertension (OR = 1.37, 95% CI: 1.03-1.82). In HANDLS, the age-adjusted CKD prevalence was 5.9 and 4.6% for those with and without food insecurity, respectively (p = 0.33). Food insecurity was associated with a trend towards greater odds of CKD (OR = 1.46, 95% CI: 0.98-2.18) with no evidence of effect modification across diabetes, hypertension, or obesity subgroups.

CONCLUSION

Food insecurity may contribute to disparities in kidney disease, especially among persons with diabetes or hypertension, and is worthy of further study.