Racial And Socioeconomic Disparities In End-Stage Renal Disease In The U.S.
Yes, race and socioeconomic status in end-stage renal disease are highly correlated, particularly among African Americans. Those two have a strong association with kidney disease.
Author:Suleman ShahReviewer:Han JuAug 10, 20241.6K Shares120.7K Views
This review discusses the role of race and socioeconomic status in end-stage renal diseaseand explains racial disparities in the said disease.
Advanced chronic kidney disease (CKD) and, to a much greater extent, end-stage renal disease (ESRD) are two of the most striking examples of healthdisparities.
Across different races and ethnicities and socioeconomic status, both advanced CKD and ESRD are marked by:
- inequalities in the incidence and prevalence
- risk factors
- disease treatment
In the United States, the burden of advanced CKD disproportionately affects African Americans/blacks despite similar rates among racial/ethnic groups in early stages of CKD.
The incidence of ESRD is 3.4 times higher in blacks compared with whites.
The high incidence of ESRD among blacks has been attributed to the high prevalence of major CKD risk factors, including:
- hypertension
- diabetes
- obesity
- genetic predisposition
- low socioeconomic status
- inequities in access to and quality of CKD care
Race and socioeconomic status are strongly correlated in the U.S., and certain racial/ethnic minorities are more likely to be classified as having low socioeconomic status.
Income (or poverty status) is one of the most commonly used metrics to ascertain socioeconomic status.
In 2011, 27.6% of blacks lived below the U.S. federal poverty level compared with 9.8% of non-Hispanic whites.
Other measures of socioeconomic status commonly used in research include:
- education attained
- occupation
However, it is important to recognize the complexity of measuring an individual’s socioeconomic status, and none of these metrics may be sufficient to fully capture it.
Community-level socioeconomic status factors have also been used in research, such as:
- neighborhood poverty
- residential segregation
These factors may be equally or more important social determinants of health, especially in African Americans, than individual-level factors, such as income.
Low socioeconomic status individuals/families tend to cluster, creating areas of high poverty density.
Poverty density directly impacts the community resources available to an individual.
As opposed to someone with higher income who is living in a poverty dense area, an individual with a low income living in or in close proximity to higher socioeconomic status neighborhoods may still have access to:
- better schools
- healthy foods
- sanitary housing conditions
- safe parks for recreation
- quality health care
It is also conceivable that individual-level socioeconomic status factors may be modified by community-level socioeconomic status factors.
Low socioeconomic status is independently associated with ESRD incidence.
Socioeconomic status may influence ESRD risk through a number of mechanisms.
Individuals living in poverty have a high burden of acute and chronic social and psychosocial stressors, which may, in turn:
- lead to unhealthy behaviors
- impact their ability to access health information or services
Individuals living in poverty are also more likely to be exposed to toxins or pollutants from their physical environment.
Additionally, the negative health consequences of being persistently disadvantaged may be cumulative.
The aim of this review was to discuss racial and socioeconomic disparities in end-stage renal disease in the U.S.
Race And ESRD
Blacks have a disproportionately high burden of chronic kidney disease (CKD) in the United States.
Racial disparities in access to care and quality of care in advanced CKD and treated end-stage renal disease (ESRD) have also been well documented.
Blacks are less likely than whites to receive pre-ESRD care and are more likely to be referred late for nephrology care, both of which are associated with worse survival.
Blacks are also less likely to utilize home dialysis therapies and have significantly lower rates of kidney transplantation.
Furthermore, blacks with ESRD are more likely to:
- start hemodialysis without an arteriovenous fistula
- have untreated and higher intact parathyroid hormone levels
- receive inadequate dialysis
Note:All indices associated with poorer outcomes.
Despite the higher rates of progression to ESRD and inequalities in care, blacks with treated ESRD have a paradoxically better survival when compared with whites - a robust observation as elucidated by numerous studies. The reason for this survival paradox is not well understood.
Biological theories include:
- a more favorable nutritional and/or inflammatory profile
- resilience to inflammationin blacks
- differential sensitivity to dialysis dose
Otherspostulate that improved access to health care afforded by the U.S. Centers for Medicare and Medicaid Services (CMS) ESRD insurance coverage program may confer a survival benefit to black patients, who are more likely to be uninsured prior to dialysis initiation
This provision of health insurance coverage improves access to care and medication as well as facilitates nutrition and social work counseling, which may have been previously lacking in these patients.
In a study published in 2011 by the Journal of the American Medical Association (JAMA), the authors, with Lauren M. Kucirka as lead author, challenged the robustness of this racial survival paradox by demonstrating that it was not present across all age strata.
In their study, 18 to 30-year-old dialysis patients had a nearly twofold increased risk of death compared with whites.
The authors postulated that this younger dialysis population in the U.S. might be particularly vulnerable to racial and socioeconomic disparities in CKD care and ESRD management, which may be offset by Medicare entitlement in the older adult population.
Race, SES, And ESRD Incidence
Both community-level (such as neighborhood poverty, residential segregation, and access to quality foods and health care) and individual-level (such as education, income, and health literacy) socioeconomic factors have been associated with:
- risk of chronic kidney disease (CKD)
- incidence of end-stage renal disease (ESRD)
- treatment of advanced CKD and ESRD
The authors of a study published in 1991 by the journal JAMA Internal Medicine(known as the Archives of Internal Medicineat the time of publication), with Dr. Jeffrey C. Whittle as lead author, made an ecological analysis of the Maryland Network 31 ESRD Regional Registry.
Dr. Whittle et al. demonstrated that the relative risk of hypertensive ESRD comparing African Americans with whites was attenuated from 5.6 to 4.5 (95% CI, 3.2 to 6.2) after accounting the following in their analysis:
- education
- hypertension
- severe hypertension
- diabetes
- population age
In their study published in 1991 by the journal JAMA Internal Medicine(formerly Archives of Internal Medicine), Dr. Thomas V. Perneger, Dr. Paul K. Whelton, and Dr. Michael J. Klag examined the role of of these two major factors in ESRD incidence:
a. Low socioeconomic status
- household annual income
- years of education
b. Limited access to care
- health insurance status
- number of missing teeth
- usual source of care
- use of preventative services
The authors did so in a case-control study of 716 patients with ESRD and 361 population controls (age 20-64) from:
- Maryland
- Virginia
- West Virginia
- Washington D.C.
They found that low socioeconomic status and limited access to health care were independently associated with ESRD risk, and adjusting for these factors partially reduced the odds of ESRD in blacks.
The proportion of ESRD incidence:
- black race - 46%
- low socioeconomic status - 53%
- poor access to care - 33%
In a study published in 2002 by the Journal of the American Society of Nephrology, the authors, with Michelle E. Tarver-Carr as lead author, reported that socioeconomic factors, including poverty status and education, accounted for 12% of the excess risk of ESRD experienced by African Americans.
They used National Health and Nutrition Examination Survey data from 1976 to 1980.
Similar findings have been demonstrated by other studies.
In a study published in 2008 by the Journal of the American Society of Nephrology, the authors, with Nataliya Volkova as lead author, extended these prior studies by assessing whether the socioeconomic status influence was different in Africans Americans and whites.
In a study of three south-eastern U.S. states, they showed that increasing neighborhood poverty was associated with increasing risk of ESRD for both African Americans and whites, but the effect was greatest for African Americans.
This may indicate that African Americans and whites have differential exposure to the negative health consequences of low socioeconomic status.
Low socioeconomic status may also potentiate differences in underlying biology between African Americans and whites.
The discovery of the association of apolipoprotein L1 (APOL1) risk variant status with hypertensive and HIV-related kidney disease suggests that a gene-environment interaction is very plausible.
Race, SES, And ESRD Survival
Few studies have examined the interaction of race and socioeconomic status in end-stage renal disease (ESRD) survival.
Earlier population-based studies in the U.S. found an association between low socioeconomic status and higher mortality and indicated that this relationship may be limited to blacks.
In a study published in 1990 by ASAIO Transactions(American Society for Artificial Internal Organs) and in a cohort of 20 to 59-year-old hemodialysis patients in Michigan between 1980 and 1987, the authors, with Dr. Friedrich K. Port as lead author, found a significant inverse relationship between the adjusted mortality risk for blacks and the average household income in their residential area.
However, the trend for whites was not significant.
Pushkal P. Garg, Marie Diener-West, and Neil R. Powe made a prospective cohort study of 3,165 incident ESRD patients in the early 1990s.
In their study published in 2001 by the journal Seminars in Nephrology, they confirmed the relation between income and ESRD mortality and showed that increasing neighborhood income was associated with better survival.
However, more recent studies have not indicated that African Americans of low socioeconomic status have worse survival on hemodialysis.
In a study published in 2009 by The American Journal of Medicine, the authors, with Eric L. Eisenstein as lead author, used Zip Code level median income to stratify patients into low, middle, and high income.
They found no difference in survival by income level, and black patients had better survival compared with whites across all income groups.
In a study published in 2007 by the journal Annals of Internal Medicine, the authors, with Dr. Rudolph A. Rodriguez as lead author, using the racial composition of Zip Codes as a marker of neighborhood socioeconomic status, also found no difference in survival for blacks compared with whites living in Zip Codes where ≥75% of residents were black.
In their study published in 2013 by the Journal of the American Society of Nephrology, Paul L. Kimmel, Chyng-Wen Fwu, and Paul W. Eggers, using race-specific Zip Code median income, demonstrated that the lowest income category was associated with worst survival for blacks and whites.
However, blacks maintained a survival advantage over whites when they adjusted for all income categories.
The authors also examined the race-survival association by the dissimilarity index, which measures the severity of residential segregation.
They demonstrated that blacks who were living in more racially segregated counties had a higher hazard of death while the risk of death for whites was unchanged.
This finding suggests that community-level socioeconomic status factors (e.g., neighborhood of residence and living conditions), may play a more important role in African Americans than individual-level factors (e.g., income).
It is, however, important to note that in these latter studies, the average age of the incident dialysis cohorts was 60 years or above, and none of these studies stratified by age group.
This could possibly mask the effects of socioeconomic status and access to care factors, which could be more racially disparate in a young adult dialysis cohort because of Medicare eligibility among older patients.
Conclusion
In summary, the interplay between race and socioeconomic status in end-stage renal disease risk and outcomes is complex and not well understood.
Socioeconomic factors, both community and individual level, are likely to contribute to racial disparities in end-stage renal disease risk through many different mechanisms.
Low socioeconomic status also appears to have a differential effect in African Americans compared with whites, possibly through a dose relationship (years of exposure) and/or by potentiating racial differences in biology.
Studies are needed to address whether there may be a cumulative effect on the chronically disadvantaged.
Future studies examining the role of socioeconomic status in end-stage renal disease risk and outcomes should also include children and young adults who may be particularly vulnerable to the negative health consequences of low socioeconomic status.
Moreover, studies should also include the pre-natal and perinatal periods, where exposure to psychosocial and physical factors may be particularly relevant.
Further research is also needed about race and socioeconomic status in end-stage renal disease to advance our understanding of gene-environment interactions in chronic kidney disease.
Suleman Shah
Author
Suleman Shah is a researcher and freelance writer. As a researcher, he has worked with MNS University of Agriculture, Multan (Pakistan) and Texas A & M University (USA). He regularly writes science articles and blogs for science news website immersse.com and open access publishers OA Publishing London and Scientific Times. He loves to keep himself updated on scientific developments and convert these developments into everyday language to update the readers about the developments in the scientific era. His primary research focus is Plant sciences, and he contributed to this field by publishing his research in scientific journals and presenting his work at many Conferences.
Shah graduated from the University of Agriculture Faisalabad (Pakistan) and started his professional carrier with Jaffer Agro Services and later with the Agriculture Department of the Government of Pakistan. His research interest compelled and attracted him to proceed with his carrier in Plant sciences research. So, he started his Ph.D. in Soil Science at MNS University of Agriculture Multan (Pakistan). Later, he started working as a visiting scholar with Texas A&M University (USA).
Shah’s experience with big Open Excess publishers like Springers, Frontiers, MDPI, etc., testified to his belief in Open Access as a barrier-removing mechanism between researchers and the readers of their research. Shah believes that Open Access is revolutionizing the publication process and benefitting research in all fields.
Han Ju
Reviewer
Hello! I'm Han Ju, the heart behind World Wide Journals. My life is a unique tapestry woven from the threads of news, spirituality, and science, enriched by melodies from my guitar. Raised amidst tales of the ancient and the arcane, I developed a keen eye for the stories that truly matter. Through my work, I seek to bridge the seen with the unseen, marrying the rigor of science with the depth of spirituality.
Each article at World Wide Journals is a piece of this ongoing quest, blending analysis with personal reflection. Whether exploring quantum frontiers or strumming chords under the stars, my aim is to inspire and provoke thought, inviting you into a world where every discovery is a note in the grand symphony of existence.
Welcome aboard this journey of insight and exploration, where curiosity leads and music guides.
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