Association of socioeconomic status and CKD among African Americans: the Jackson Heart Study

Social determinants of health and dialysis modality selection in patients with advanced chronic kidney disease: A retrospective cohort study

BACKGROUND

Social determinants of health are non-medical factors that impact health. For patients with chronic kidney disease (CKD) progressing to kidney failure, the influence of social determinants of health on dialysis modality selection (haemodialysis vs. peritoneal dialysis (PD)) is incompletely understood.

METHODS

Retrospective cohort study of 981 consecutive patients with advanced CKD referred to the Ottawa Hospital Multi-Care Kidney Clinic (Canada) who progressed to dialysis from 2010 to 2021. Multivariable logistic regression was used to measure odds ratios (OR) for the associations between social determinants of health (education, employment, marital status and residence) and modality of dialysis initiation.

RESULTS

The mean age and estimated glomerular filtration rate were 64 and 18 mL/min/1.73 m2, respectively. Not having a high school degree was associated with lower odds of initiating dialysis via PD compared to having a college degree (29% vs. 48%, OR 0.55 (95% confidence interval (CI) 0.34-0.88)). Unemployment was associated with lower odds of initiating dialysis via PD compared to active employment (38% vs. 62%, OR 0.40 (95% CI 0.27-0.60)). Being single was associated with lower odds of initiating dialysis via PD compared to being married (35% vs. 48%, adjusted OR 0.52 (95% CI 0.39-0.70)). Living alone at home was associated with lower odds of initiating dialysis via PD compared to living at home with family (33% vs. 47%, adjusted OR 0.55 (95% CI 0.39-0.78)).

CONCLUSIONS

Social determinants of health including education, employment, marital status and residence are associated with dialysis modality selection. Addressing these 'upstream' social factors may allow for more equitable outcomes during the transition from advanced CKD to kidney failure.

Show Me CKDintercept Initiative: A Collective Impact Approach to Improve Population Health in Missouri

Ninety percent of people with chronic kidney disease (CKD) remain undiagnosed, most people at risk do not receive guideline-concordant testing, and disparities of care and outcomes exist across all stages of the disease. To improve CKD diagnosis and management across primary care, the National Kidney Foundation launched a collective impact (CI) initiative known as Show Me CKDintercept. The initiative was implemented in Missouri, USA from January 2021 to June 2022, using a data strategy, stakeholder engagement and relationship mapping, learning in action working groups (LAWG), and a virtual leadership summit. The Reach, Effectiveness, Adoption, Implementation, and Maintenance framework was used to evaluate success. The initiative united 159 stakeholders from 81 organizations (Reach) to create an urgency for change and engage new CKD champions (Effectiveness). The adoption resulted in 53% of participants committed to advancing the roadmap (Adoption). Short-term results reported success in laying a foundation for CI across Missouri. The long-term success of the CI initiative in addressing the public health burden of kidney disease remains to be determined. The project reported the potential use of a CI initiative to build leadership consensus to drive measurable public health improvements nationwide.

Medical Nutrition Therapy for Chronic Kidney Disease: Low Access and Utilization

CKD affects approximately half of US adults aged 65 years and older and accounts for almost 1 out of every 4 dollars of total Medicare fee-for-service spending. Efforts to prevent or slow CKD progression are urgently needed to reduce the incidence of kidney failure and reduce health care expenditures. Current CKD care guidelines recommend medical nutrition therapy (MNT), a personalized, evidence-based application of the Nutrition Care Process (assessment, intervention, diagnosis, and monitoring and evaluation) provided by registered dietitian nutritionists (RDNs) to help slow CKD progression, improve quality of life, and delay kidney failure. MNT is covered by Medicare Part B and most private insurances with no cost sharing. Despite recommendations that patients with CKD receive MNT and insurance coverage for MNT, utilization remains low. This article demonstrates low utilization of MNT and inadequate numbers of RDNs and RDNs who are board certified in renal nutrition relative to the estimated number of Medicare eligible adults with self-reported diagnosed CKD by state, with noted disparities across states. We discuss interventions to increase MNT utilization, such as improving MNT reimbursement, augmenting accessibility of RDNs via telenutrition services and increasing health care provider promotion of MNT and referral to MNT to optimize CKD outcomes.

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.

Fluoxetine partially alleviates inflammation in the kidney of socially stressed male C57 BL/6 mice

Stress-related illnesses are linked to the onset and progression of renal diseases and depressive disorders. To investigate stress-induced changes in the renal transcriptome associated with the development of depressive behaviors, we generated here a chronic social defeat stress (CSDS) model of C57 BL/6 male mice and then performed RNA sequencing of the kidneys to obtain an inflammation-related transcriptome. Administration of the antidepressant drug fluoxetine (10 mg·kg-1 ·day-1 ) during CSDS induction could partially alleviate renal inflammation and reverse CSDS-induced depression-like behaviors. Moreover, fluoxetine also modulated gene expression of stress-related hormone receptors, including prolactin and melanin-concentrating hormone. These results suggest that CSDS can induce gene expression changes associated with inflammation in the kidney of C57 BL/6 male mice, and this inflammation can be treated effectively by fluoxetine.

Social determinants of health and the transition from advanced chronic kidney disease to kidney failure

BACKGROUND

The transition from chronic kidney disease (CKD) to kidney failure is a vulnerable time for patients, with suboptimal transitions associated with increased morbidity and mortality. Whether social determinants of health are associated with suboptimal transitions is not well understood.

METHODS

This retrospective cohort study included 1070 patients with advanced CKD who were referred to the Ottawa Hospital Multi-Care Kidney Clinic and developed kidney failure (dialysis or kidney transplantation) between 2010 and 2021. Social determinant information, including education level, employment status and marital status, was collected under routine clinic protocol. Outcomes surrounding suboptimal transition included inpatient (versus outpatient) dialysis starts, pre-emptive (versus delayed) access creation and pre-emptive kidney transplantation. We examined the association between social determinants of health and suboptimal transition outcomes using multivariable logistic regression.

RESULTS

The mean age and estimated glomerular filtration rate were 63 years and 18 ml/min/1.73 m2, respectively. Not having a high school degree was associated with higher odds for an inpatient dialysis start compared with having a college degree {odds ratio [OR] 1.71 [95% confidence interval (CI) 1.09-2.69]}. Unemployment was associated with higher odds for an inpatient dialysis start [OR 1.85 (95% CI 1.18-2.92)], lower odds for pre-emptive access creation [OR 0.53 (95% CI 0.34-0.82)] and lower odds for pre-emptive kidney transplantation [OR 0.48 (95% CI 0.24-0.96)] compared with active employment. Being single was associated with higher odds for an inpatient dialysis start [OR 1.44 (95% CI 1.07-1.93)] and lower odds for pre-emptive access creation [OR 0.67 (95% CI 0.50-0.89)] compared with being married.

CONCLUSIONS

Social determinants of health, including education, employment and marital status, are associated with suboptimal transitions from CKD to kidney failure.

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.

Self-rated health and the risk of incident chronic kidney disease: a community‐based Korean study

BACKGROUND

The relationship between self-rated health (SRH) and the development of incident chronic kidney disease (CKD) has not been explored in the general population.

METHODS

We reviewed the data of 7027 participants in the Ansung-Ansan cohort study. SRH was categorized as poor, fair, or good, and the outcome was the development of CKD, defined as the first event of an estimated glomerular filtration rate < 60 mL/min/1.73 m², at least twice during the follow-up period. Hazard ratios (HRs) and confidence intervals (CIs) were calculated using Cox proportional hazards regression analysis.

RESULTS

Over a mean follow-up duration of 11.9 years, 951 participants (13.5%) developed CKD. Compared with poor self-rated health, the HR (95% CI) of fair self-rated health for incident CKD development was 0.771 (0.657-0.905; P = 0.001), whereas that of good self-rated health was 0.795 (0.676-0.935; P = 0.006). However, the renal hazard of good self-rated health did not differ from that of fair self-rated health. In the fully adjusted model, the HR (95% CI) of poor self-rated health compared to non-poor self-rated health for incident CKD was 1.278 (1.114-1.465, P < 0.001). Old age, smoking, cardiovascular disease, diabetes, hypertension, impaired sleep, and high levels of C-reactive protein and white blood cell counts were associated with increased odds of poor self-rated health, whereas male sex, college graduate level of education, and alcohol consumption were associated with decreased odds of poor self-rated health.

CONCLUSION

Poor self-rated health is independently associated with CKD development. Therefore, the early detection of potential CKD patients through a brief questionnaire assessment may help control the incidence of CKD.

Unstable Housing and Kidney Disease: A Primer

Stable housing is essential for health. Over 580,000 Americans experienced homelessness during one night in 2020, and over 37 million households spend over 30% of their income on housing. Unstable housing has been associated with mortality, acute care utilization, communicable and non-communicable diseases, a higher risk of kidney disease, and kidney disease progression. In this review, we define various forms of unstable housing, provide an overview of the interaction between unstable housing and health, and discuss existing evidence associating housing and kidney disease. We provide historical context for unstable housing in the United States, and detail policy, community, and individual-level factors that contribute to the risk of unstable housing. Unstable housing likely affects kidney health via a complex interplay of individual and structural factors. Various screening tools are available for use by providers. Special considerations should be made when working with individuals experiencing unstable housing to meet their unique needs, facilitate health care engagement, and optimize outcomes. Housing interventions have been shown to improve outcomes and should be examined for their role in kidney disease.

Association of perceived stress and coping strategies with the renal function in middle-aged and older Japanese men and women

Elucidating the risk factors for chronic kidney disease is important for preventing end-stage renal disease and reducing mortality. However, little is known about the roles of psychosocial stress and stress coping behaviors in deterioration of the renal function, as measured by the estimated glomerular filtration rate (eGFR). This cross-sectional study of middle-aged and older Japanese men (n = 31,703) and women (n = 38,939) investigated whether perceived stress and coping strategies (emotional expression, emotional support seeking, positive reappraisal, problem solving, and disengagement) were related to the eGFR, with mutual interactions. In multiple linear regression analyses adjusted for age, area, lifestyle factors, and psychosocial variables, we found a significant inverse association between perceived stress and the eGFR in men (P_trend = 0.02), but not women. This male-specific inverse association was slightly attenuated after adjustment for the history of hypertension and diabetes and was more evident in lower levels of emotional expression (P_interaction = 0.003). Unexpectedly, problem solving in men (P_trend < 0.001) and positive reappraisal in women (P_trend = 0.002) also showed an inverse association with the eGFR. Perceived stress may affect the eGFR, partly through the development of hypertension and diabetes. The unexpected findings regarding coping strategies require the clarification of the underlying mechanisms, including the hormonal and immunological aspects.

A Scoping Review of Life-Course Psychosocial Stress and Kidney Function

Increased exposure to maternal psychosocial stress during gestation and adverse neonatal environments has been linked to alterations in developmental programming and health consequences in offspring. A programmed low nephron endowment, among other altered pathways of susceptibility, likely increases the vulnerability to develop chronic kidney disease in later life. Our aim in this scoping review was to identify gaps in the literature by focusing on understanding the association between life-course exposure to psychosocial stress, and the risk of reduced kidney function. A systematic search in four databases (PubMed, ProQuest, Wed of Science, and Scopus) was performed, yielding 609 articles. Following abstract and full-text review, we identified 19 articles meeting our inclusion criteria, reporting associations between different psychosocial stressors and an increase in the prevalence of kidney disease or decline in kidney function, mainly in adulthood. There are a lack of studies that specifically evaluated the association between gestational exposure to psychosocial stress and measures of kidney function or disease in early life, despite the overall evidence consistent with the independent effects of prenatal stress on other perinatal and postnatal outcomes. Further research will establish epidemiological studies with clear and more comparable psychosocial stressors to solve this critical research gap.

Incidence and predictors of early and delayed renal function decline after aortic aneurysm repair in the Vascular Quality Initiative database

BACKGROUND

Postoperative acute kidney injury (AKI) may complicate both open and endovascular aortic aneurysm repair (EVAR) and is associated with substantial morbidity, mortality, and health care expense. We aim to evaluate the incidence of postoperative AKI and factors associated with its occurrence and the effects of postoperative AKI on long-term renal function and mortality after open and EVAR in the Society for Vascular Surgery Vascular Quality Initiative registry.

METHODS

Elective aneurysm cases were identified including thoracic endovascular aortic aneurysm repair (TEVAR) and complex endovascular aortic aneurysm repair (cEVAR), infrarenal endovascular repair (EVAR) and infrarenal open repair (OAR) from 2003 to 2019. The preoperative estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease formula and stratified based on chronic kidney disease (CKD) grades. Postoperative AKI was defined per the Vascular Quality Initiative definition as a creatinine increase of 0.5 mg/dL or if postoperative dialysis was required. Patients on preprocedural hemodialysis and those with previous renal transplant were excluded. Demographics and procedural factors were evaluated for predicting in-hospital postoperative AKI (all approaches) and at 9 to 21 months of long-term follow-up (EVAR only) using logistic regression modeling.

RESULTS

We identified a total of 2813 cEVAR, 2995 TEVAR, 39,945 EVAR, and 8143 OAR patients. Of those, postoperative AKI occurred in 377 cEVAR (13.5%), 199 TEVAR (6.7%), 1099 EVAR (2.8%), and 1249 OAR (15.5%). Risk factors for postoperative AKI across all groups were worse preoperative eGFR, total number of blood transfusions, perioperative anemia, reinterventions, and postoperative respiratory complications. Additional procedure-specific risk factors of postoperative AKI were preoperative hemoglobin of less than 10 and contrast volume of 125 to 150 mL, hypertension, a low ejection fraction, and a history of percutaneous revascularization for EVAR; for both EVAR/cEVAR, renal artery coverage was a risk factor, whereas for OAR, male sex, non-White race, hypertension, suprarenal aortic cross-clamp, and increased renal ischemic time were risk factors. Among 8133 EVAR patients with long-term follow-up, a decrease in kidney function occurred in 56.7% of patients with postoperative AKI vs 19.9% without postoperative AKI (P < .001). The following risk factors were associated with a decrease in renal function at long-term follow-up: postoperative AKI, a preoperative eGFR of less than 90, and hypertension. A preoperative hemoglobin of greater than 12 was protective. Postoperative AKI was associated with significantly lower survival compared with no postoperative AKI across all procedures (log rank <0.001).

CONCLUSIONS

Postoperative AKI occurs more often in patients with worse preoperative renal function, lower preoperative hemoglobin, and in open surgeries with inter-renal or suprarenal cross-clamping. Importantly, postoperative AKI is associated with increased mortality across all types of aortic repair. Given the long-term impact of postoperative AKI on outcomes for all aortic repairs and the limitations of current insensitive functional indices, there is a need to seek more sensitive indicators of decreases in early renal structural in this population.

Association of Health Insurance Payer Type and Outcomes After Durable Left Ventricular Assist Device Implantation: An Analysis of the STS-INTERMACS Registry

BACKGROUND

Due to the high cost of left ventricular assist device (LVAD) therapy, payer type may be an important factor in determining eligibility. How payer type influences outcomes after LVAD implantation is unclear. We, therefore, aimed to study the association of health insurance payer type with outcomes after durable LVAD implantation.

METHODS

Using STS-INTERMACS (Society of Thoracic Surgeons-Interagency Registry for Mechanically Assisted Circulatory Support), we studied nonelderly adults receiving a durable LVAD from 2016 to 2018 and compared all-cause mortality and postindex hospitalization adverse event episode rate by payer type. Multivariable Fine-Gray and generalized linear models were used to compare the outcomes.

RESULTS

Of the 3251 patients included, 26.0% had Medicaid, 24.9% had Medicare alone, and 49.1% had commercial insurance. Compared with commercially insured patients, mortality did not differ for patients with Medicaid (subdistribution hazard ratio, 1.00 [95% CI, 0.75-1.34], P=0.99) or Medicare (subdistribution hazard ratio, 1.09 [95% CI, 0.84-1.41], P=0.52). Medicaid was associated with a significantly lower adjusted incidence rate (incidence rate ratio, 0.88 [95% CI, 0.78-0.99], P=0.041), and Medicare was associated with a significantly higher adjusted incidence rate (incidence rate ratio, 1.16 [95% CI, 1.03-1.30], P=0.011) of adverse event episodes compared with commercially insured patients.

CONCLUSIONS

All-cause mortality after durable LVAD implantation did not differ significantly by payer type. Payer type was associated with the rate of adverse events, with Medicaid associated with a significantly lower rate, and Medicare with a significantly higher rate of adverse event episodes compared with commercially insured patients.

Optimism and telomere length among African American adults in the Jackson Heart Study

BACKGROUND

Optimism is linked with greater longevity in both White and African American populations. Optimism may enhance longevity by slowing cellular aging, for which leukocyte telomere shortening is a biomarker. However, limited studies have examined the association of optimism with leukocyte telomere length among African Americans.

METHODS

Data are from 723 men and 1244 women participating in the Jackson Heart Study (age = 21-93 years). We used multivariable linear regression models to conduct cross-sectional analyses examining whether higher optimism was associated with longer mean absolute leukocyte telomere length (assayed with Southern blot analysis). Models adjusted for sociodemographic characteristics, depressive symptomatology, health conditions, and health behavior-related factors. We also considered potential effect modification by key factors.

RESULTS

In the age-adjusted model, optimism, measured as a continuous variable, was not associated with leukocyte telomere length (β = 0.01, 95%CI: -0.02, 0.04). This association remained null in the fully-adjusted model (β = 0.02, 95%CI: -0.02, 0.05) and was also null when considering optimism as a binary measure (higher vs. lower optimism). We found no evidence of effect modification by sex, age, body mass index, income, or chronic conditions.

CONCLUSIONS

Optimism was not associated with leukocyte telomere length among African American adults. Future studies should investigate alternate biological and behavioral mechanisms that may explain the optimism-health association.

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.

Association of Educational Attainment With Incidence of CKD in Young Adults

Introduction

Chronic kidney disease (CKD) is greatly affected by social determinants of health. Whether low educational attainment is associated with incident CKD in young adults is unclear.

Methods

We evaluated the association of education with incident CKD in 3139 Coronary Artery Risk Development in Young Adults participants. We categorized education into low (high school and less), medium (college), and high (master’s and professional studies) groups. Incident CKD was defined as new development of estimated glomerular filtration rate (eGFR) <60 ml/min per 1.73 m² or urine albumin to creatinine ratio (ACR) ≥30 mg/g. Change in eGFR over 20 years was a secondary outcome.

Results

At baseline, mean age was 35.0 ± 3.6 years, 47% were Black, and 55% were women. Participants with lower educational attainment were less likely to have high income and health insurance and to engage in a healthy lifestyle. Over 20 years, 407 participants developed CKD (13%). Compared with individuals with low educational attainment, those with medium and high educational attainment had an unadjusted hazard ratios for CKD of 0.79 (95% confidence interval [CI] 0.65–0.97) and 0.44 (95% CI, 0.30–0.63), respectively. This association was no longer significant after adjusting for income, health insurance, lifestyle, and health status. Low educational attainment was significantly associated with a change in eGFR in crude and adjusted analyses, although the association was attenuated in the multivariable models (low: –0.83 [95% CI, –0.91 to –0.75], medium: –0.80 (95% CI, –0.95 to –0.64), and high: –0.70 (95% CI, –0.89 to –0.52) ml/min per 1.73 m² per yr).

Conclusions

Health care access, lifestyle, and comorbid conditions likely help explain the association between low educational attainment and incident CKD in young adults.

Neighborhood context and kidney disease in Philadelphia

Neighborhood context might influence the risk of chronic kidney disease (CKD), a condition that impacts approximately 10% of the United States population and is associated with significant morbidity, mortality, and costs. We included a sample of 23,692 individuals in Philadelphia, Pennsylvania, who were seen in a large academic primary care practice between January 1, 2016 and December 31, 2017. We used generalized linear equations to estimate the associations between indicators of neighborhood context (e.g., proximity to healthy foods stores, neighborhood walkability, social capital, crime rate, socioeconomic status) and CKD, adjusted for age, sex, race/ethnicity, and insurance coverage. Among those with CKD, secondary outcomes were poor glycemic control (hemoglobin A1c ≥ 6.5%) and uncontrolled blood pressure (systolic ≥ 140 mm Hg and/or diastolic ≥ 90 mm Hg). The cohort represented residents from 97% of Philadelphia census tracts. CKD prevalence was 10%. When all neighborhood context metrics were considered collectively, only lower neighborhood socioeconomic index (a composite assessment of neighborhood income, educational attainment, and occupation) was associated with a higher risk of CKD (lowest tertile vs. highest tertile: adjusted relative risk [aRR] 1.46 [1.25, 1.69]; mid-tertile vs. highest-tertile: aRR 1.35 [1.25, 1.52]). Among those with CKD, compared to residence in the most walkable neighborhoods (i.e., where most essential resources are accessible by foot), residence in neighborhoods with mid-level WalkScore® (i.e., where only some essential neighborhood resources are accessible by foot) was independently associated with poor glycemic control (aRR 1.20, 95% CI 1.01-1.42). These findings suggest a potential role for measures of neighborhood socioeconomic status in identifying communities that would benefit from screening and treatment for CKD. Studies are also needed to determine mechanisms to explain why residence in neighborhoods not easily navigated by foot or car might hinder glycemic control among people with CKD.

Everyday Discrimination and Kidney Function Among Older Adults: Evidence From the Health and Retirement Study

BACKGROUND

With advancing age, there is an increase in the time of and number of experiences with psychosocial stressors that may lead to the initiation and/or progression of chronic kidney disease (CKD). Our study tests whether one type of experience, everyday discrimination, predicts kidney function among middle and older adults.

METHODS

The data were from 10 973 respondents (ages 52-100) in the 2006/2008 Health and Retirement Study, an ongoing biennial nationally representative survey of older adults in the United States. Estimated glomerular filtration rate (eGFR) derives from the Chronic Kidney Disease Epidemiology Collaboration equation. Our indicator of everyday discrimination is drawn from self-reports from respondents. Ordinary Least Squared regression (OLS) models with robust standard errors are applied to test hypotheses regarding the link between everyday discrimination and kidney function.

RESULTS

Everyday discrimination was associated with poorer kidney function among respondents in our study. Respondents with higher everyday discrimination scores had lower eGFR after adjusting for demographic characteristics (B = -1.35, p < .05), and while attenuated, remained significant (B = -0.79, p < .05) after further adjustments for clinical, health behavior, and socioeconomic covariates.

CONCLUSIONS

Our study suggests everyday discrimination is independently associated with lower eGFR. These findings highlight the importance of psychosocial factors in predicting insufficiency in kidney function among middle-aged and older adults.

Area Deprivation and Risk of Death and CKD Progression: Long-Term Cohort Study in Patients under Unrestricted Nephrology Care

BACKGROUND

Area deprivation index (ADI) associates with prognosis in non-dialysis CKD. However, no study has evaluated this association in CKD patients under unrestricted nephrology care.

METHODS

We performed a long-term prospective study to assess the role of deprivation in CKD progression and mortality in stage 1-4 CKD patients under regular nephrology care, living in Naples (Italy). We used ADI calculated at census block levels, standardized to mean values of whole population in Naples, and linked to patients by georeference method. After 12 months of "goal-oriented" nephrology treatment, we compared the risk of death or composite renal outcomes (end-stage kidney disease or doubling of serum creatinine) in the tertiles of standardized ADI. Estimated glomerular filtration rate (eGFR) decline was evaluated by mixed effects model for repeated eGFR measurements.

RESULTS

We enrolled 715 consecutive patients (age: 64 ± 15 years; 59.1% males; eGFR: 49 ± 22 mL/min/1.73 m2). Most (75.2%) were at the lowest national ADI quintile. At referral, demographic, clinical, and therapeutic features were similar across ADI tertiles; after 12 months, treatment intensification allowed better control of hypertension, proteinuria, hypercholesterolaemia, and anaemia with no difference across ADI tertiles. During the subsequent long-term follow-up (10.5 years [interquartile range 8.2-12.6]), 166 renal events and 249 deaths were registered. ADI independently associated with all-cause death (p for trend = 0.020) and non-cardiovascular (CV) mortality (p for trend = 0.045), while CV mortality did not differ (p for trend = 0.252). Risk of composite renal outcomes was similar across ADI tertiles (p for trend = 0.467). The same held true for eGFR decline (p for trend = 0.675).

CONCLUSIONS

In CKD patients under regular nephrology care, ADI is not associated with CKD progression, while it is associated with all-cause death due to an excess of non-CV mortality.

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.

Housing Insecurity and Risk of Adverse Kidney Outcomes

Background

Housing insecurity is characterized by high housing costs or unsafe living conditions that prevent self-care and threaten independence. We examined the relationship of housing insecurity and risk of kidney disease.

Methods

We used longitudinal data from the Healthy Aging in Neighborhoods of Diversity across the Life Span study (Baltimore, MD). We used multivariable regression to quantify associations between housing insecurity and rapid kidney function decline (loss of >5 ml/min per 1.73 m² of eGFR per year) and, among those without kidney disease at baseline, incident reduced kidney function (eGFR <60 ml/min per 1.73 m²) and incident albuminuria (urine albumin-creatinine ratio [ACR] ≥30 mg/g).

Results

Among 1262 participants, mean age was 52 years, 40% were male and 57% were black. A total of 405 (32%) reported housing insecurity. After a median of 3.5 years of follow-up, rapid kidney function decline, incident reduced kidney function, and incident albuminuria occurred in 199 (16%), 64 (5%), and 74 (7%) participants, respectively. Housing insecurity was associated with increased odds of incident albuminuria (unadjusted OR, 2.04; 95% CI, 1.29 to 3.29; adjusted OR, 3.23; 95% CI, 1.90 to 5.50) but not rapid kidney function decline or incident reduced kidney function.

Conclusions

In this urban population, housing insecurity was associated with increased risk of subsequent albuminuria. Increased recognition of housing insecurity as a social determinant of kidney disease is needed, and risk-reduction efforts that specifically target populations experiencing housing insecurity should be considered.

Association Between Income Disparities and Risk of Chronic Kidney Disease: A Nationwide Cohort Study of Seven Million Adults in Korea

OBJECTIVE

To examine the association between income level and incident chronic kidney disease (CKD) in adults with normal baseline kidney function.

PATIENT AND METHODS

We studied the association between income level categorized into deciles and incident CKD in a national cohort comprised of 7,405,715 adults who underwent National Health Insurance Service health examinations during January 1, 2009, to December 31, 2015, with baseline estimated glomerular filtration rates (eGFRs) ≥60 mL/min/1.73 m². Incident CKD was defined as de novo development of eGFR <60 mL/min/1.73 m² (model 1) or ≥25% decline in eGFR from baseline values accompanied by eGFR <60 mL/min/1.73 m² (model 2).

RESULTS

During a median follow-up of 4.8 years, there were 122,032 of 7,405,715 (1.65%) and 55,779 of 7,405,715 (0.75%) incident CKD events based on model 1 and 2 definitions, respectively. Compared with income levels in the sixth decile, there was an inverse association between lower income level and higher risk for CKD up to the fourth decile, above which no additional reduction (model 1) or slightly higher risk for CKD (model 2) was observed at higher income levels. The multivariable-adjusted hazard ratios from the lowest to fourth deciles were 1.30 (95% CI, 1.26-1.33), 1.16 (95% CI, 1.13-1.19), 1.07 (95% CI, 1.05-1.10), and 1.06 (95% CI, 1.03-1.09) in model 1 and 1.32 (95% CI, 1.27-1.37), 1.18 (95% CI, 1.14-1.22), 1.08 (95% CI, 1.04-1.13), and 1.05 (95% CI, 1.01-1.09) in model 2, respectively. These associations persisted across various subgroups of age, sex, and comorbidity status.

CONCLUSION

In this large nationwide cohort, lower income levels were associated with higher risk for incident CKD.

Chronic kidney disease and socio-economic status: a cross sectional study

Objective: This cross-sectional study investigated the relationship between individual-level markers of disadvantage, renal function and cardio-metabolic risk within an Indigenous population characterised by a heavy burden of chronic kidney disease and disadvantage.Design: Using data from 20 Indigenous communities across Australia, an aggregate socio-economic status (SES) score was created from individual-level socio-economic variables reported by participants. Logistic regression was used to assess the association of individual-level socio-economic variables and the SES score with kidney function (an estimated glomerular function rate (eGFR) cut-point of <60 ml/min/1.73 m²) as well as clinical indicators of cardio-metabolic risk.Results: The combination of lower education and unemployment was associated with poorer kidney function and higher cardio-metabolic risk factors. Regression models adjusted for age and gender showed that an eGFR < 60 ml/min/1.73 m² was associated with a low socio-economic score (lowest vs. highest 3.24 [95% CI 1.43-6.97]), remote living (remote vs. highly to moderately accessible 3.24 [95% CI 1.28-8.23]), renting (renting vs. owning/being purchased 5.76[95% CI 1.91-17.33]), unemployment (unemployed vs employed 2.85 [95% CI 1.31-6.19]) and receiving welfare (welfare vs. salary 2.49 [95% CI 1.42-4.37]). A higher aggregate socio-economic score was inversely associated with an eGFR < 60 ml/min/1.73 m² (0.75 [95% CI 063-0.89]).Conclusion: This study extends upon our understanding of associations between area-level markers of disadvantage and burden of end stage kidney disease amongst Indigenous populations to a detailed analysis of a range of well-characterised individual-level factors such as overall low socio-economic status, remote living, renting, unemployment and welfare. With the increasing burden of end-stage kidney disease amongst Indigenous people, the underlying socio-economic conditions and social and cultural determinants of health need to be understood at an individual as well as community-level, to develop, implement, target and sustain interventions.

Race and Sex Differences in Modifiable Risk Factors and Incident Heart Failure

OBJECTIVES

The purpose of this study was to examine race- and sex-based variation in the associations between modifiable risk factors and incident heart failure (HF) among the SCCS (Southern Community Cohort Study) participants.

BACKGROUND

Low-income individuals in the southeastern United States have high HF incidence rates, but relative contributions of risk factors to HF are understudied in this population.

METHODS

We studied 27,078 black or white SCCS participants (mean age: 56 years, 69% black, 63% women) enrolled between 2002 and 2009, without prevalent HF, receiving Centers for Medicare and Medicaid Services. The presence of hypertension, diabetes mellitus, physical underactivity, high body mass index, smoking, high cholesterol, and poor diet was assessed at enrollment. Incident HF was ascertained using International Classification of Diseases-9th revision, codes 428.x in Centers for Medicare and Medicaid Services data through December 31, 2010. Individual risk and population attributable risk for HF for each risk factor were quantified using multivariable Cox models.

RESULTS

During a median (25th, 75th percentile) 5.2 (3.1, 6.7) years, 4,341 (16%) participants developed HF. Hypertension and diabetes were associated with greatest HF risk, whereas hypertension contributed the greatest population attributable risk, 31.8% (95% confidence interval: 27.3 to 36.0). In black participants, only hypertension and diabetes associated with HF risk; in white participants, smoking and high body mass index also associated with HF risk. Physical underactivity was a risk factor only in white women.

CONCLUSIONS

In this high-risk, low-income cohort, contributions of risk factors to HF varied, particularly by race. To reduce the population burden of HF, interventions tailored for specific race and sex groups may be warranted.

Cross-sectional study of association between socioeconomic indicators and chronic kidney disease in rural-urban Ghana: the RODAM study

OBJECTIVES

Studies from high-income countries suggest higher prevalence of chronic kidney disease (CKD) among individuals in low socioeconomic groups. However, some studies from low/middle-income countries show the reverse pattern among those in high socioeconomic groups. It is unknown which pattern applies to individuals living in rural and urban Ghana. We assessed the association between socioeconomic status (SES) indicators and CKD in rural and urban Ghana and to what extent the higher SES of people in urban areas of Ghana could account for differences in CKD between rural and urban populations.

SETTING

The study was conducted in Ghana (Ashanti region). We used baseline data from a multicentre Research on Obesity and Diabetes among African Migrants (RODAM) study.

PARTICIPANTS

The sample consisted of 2492 adults (Rural Ghana, 1043, Urban Ghana, 1449) aged 25-70 years living in Ghana.

EXPOSURE

Educational level, occupational level and wealth index.

OUTCOME

Three CKD outcomes were considered using the 2012 Kidney Disease: Improving Global Outcomes severity of CKD classification: albuminuria, reduced glomerular filtration rate and high to very high CKD risk based on the combination of these two.

RESULTS

All three SES indicators were not associated with CKD in both rural and urban Ghana after age and sex adjustment except for rural Ghana where high wealth index was significantly associated with higher odds of reduced estimated glomerular filtration rate (eGFR) (adjusted OR, 2.38; 95% CI 1.03 to 5.47). The higher rate of CKD observed in urban Ghana was not explained by the higher SES of that population.

CONCLUSION

SES indicators were not associated with prevalence of CKD except for wealth index and reduced eGFR in rural Ghana. Consequently, the higher SES of urban Ghana did not account for the increased rate of CKD among urban dwellers suggesting the need to identify other factors that may be driving this.

Acculturation and chronic kidney disease in the Hispanic community health study/study of Latinos (HCHS/SOL)

Hispanics/Latinos are burdened by chronic kidney disease (CKD). The role of acculturation in this population has not been explored. We studied the association of acculturation with CKD and cardiovascular risk factor control. We performed cross-sectional analyses of 13,164 U.S. Hispanics/Latinos enrolled in the HCHS/SOL Study between 2008 and 2011. Acculturation was measured using the language and ethnic social relations subscales of the Short Acculturation Scale for Hispanics, and proxies of acculturation (language preference, place of birth and duration of residence in U.S.). CKD was defined as estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m² or urine albumin-to-creatinine ratio ≥ 30 mg/g. On multivariable analyses stratified by age, lower language subscale score was associated with higher odds of CKD among those older than 65 (OR 1.29, 95% CI, 1.03, 1.63). No significant association was found between proxies of acculturation and CKD in this age strata. Among individuals aged 18–44, a lower language subscale score was associated with lower eGFR (β = −0.77 ml/min/1.73 m², 95% CI −1.43, −0.10 per 1 SD increase) and a similar pattern was observed for ethnic social relations. Among those older than 65, lower language subscale score was associated with higher log-albuminuria (β = 0.12, 95% CI 0.03, 0.22). Among individuals with CKD, acculturation measures were not associated with control of cardiovascular risk factors. In conclusion, lower language acculturation was associated with a higher prevalence of CKD in individuals older than 65. These findings suggest that older individuals with lower language acculturation represent a high risk group for CKD.

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Among Hispanics/Latinos, lower language acculturation was associated with a higher prevalence of chronic kidney disease in older individuals.

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Based on our findings, older individuals with lower language acculturation represent a high-risk group for chronic kidney disease.

Cost-effectiveness of multidisciplinary care in mild to moderate chronic kidney disease in the United States: A modeling study

BACKGROUND

Multidisciplinary care (MDC) programs have been proposed as a way to alleviate the cost and morbidity associated with chronic kidney disease (CKD) in the US.

METHODS AND FINDINGS

We assessed the cost-effectiveness of a theoretical Medicare-based MDC program for CKD compared to usual CKD care in Medicare beneficiaries with stage 3 and 4 CKD between 45 and 84 years old in the US. The program used nephrologists, advanced practitioners, educators, dieticians, and social workers. From Medicare claims and published literature, we developed a novel deterministic Markov model for CKD progression and calibrated it to long-term risks of mortality and progression to end-stage renal disease. We then used the model to project accrued discounted costs and quality-adjusted life years (QALYs) over patients' remaining lifetime. We estimated the incremental cost-effectiveness ratio (ICER) of MDC, or the cost of the intervention per QALY gained. MDC added 0.23 (95% CI: 0.08, 0.42) QALYs over usual care, costing $51,285 per QALY gained (net monetary benefit of $23,100 at a threshold of $150,000 per QALY gained; 95% CI: $6,252, $44,323). In all subpopulations analyzed, ICERs ranged from $42,663 to $72,432 per QALY gained. MDC was generally more cost-effective in patients with higher urine albumin excretion. Although ICERs were higher in younger patients, MDC could yield greater improvements in health in younger than older patients. MDC remained cost-effective when we decreased its effectiveness to 25% of the base case or increased the cost 5-fold. The program costed less than $70,000 per QALY in 95% of probabilistic sensitivity analyses and less than $87,500 per QALY in 99% of analyses. Limitations of our study include its theoretical nature and being less generalizable to populations at low risk for progression to ESRD. We did not study the potential impact of MDC on hospitalization (cardiovascular or other).

CONCLUSIONS

Our model estimates that a Medicare-funded MDC program could reduce the need for dialysis, prolong life expectancy, and meet conventional cost-effectiveness thresholds in middle-aged to elderly patients with mild to moderate CKD.

The Landscape of Diabetic Kidney Disease in the United States

PURPOSE OF REVIEW

The purposes of this review are to identify population characteristics of important risk factors for the development and progression of diabetic kidney disease (DKD) in the United States and to discuss barriers and opportunities to improve awareness, management, and outcomes in patients with DKD.

RECENT FINDINGS

The major risk factors for the development and progression of DKD include hyperglycemia, hypertension, and albuminuria. DKD disproportionately affects minorities and individuals with low educational and socioeconomic status. Barriers to effective management of DKD include the following: (a) limited patient and healthcare provider awareness of DKD, (b) lack of timely referrals of patients to a nephrologist, (c) low patient healthcare literacy, and (d) insufficient access to healthcare and health insurance. Increased patient and physician awareness of DKD has been shown to enhance patient outcomes. Multifactorial and multidisciplinary interventions targeting multiple risk factors and patient/physician education may provide better outcomes in patients with DKD.

Associations between socioeconomic status and chronic kidney disease: a meta-analysis

BACKGROUND

Socioeconomic status (SES) has long been conjectured to be associated with the incidence and progression of chronic kidney disease (CKD), but few studies have examined this quantitatively. This meta-analysis aims to fill this gap.

METHODS

A systematic literature review was performed using Medline and EMBASE to identify observational studies on associations between SES and incidence and progression of CKD, published between 1974 and March 2017. Individual results were meta-analysed using a random effects model, in line with Meta-analysis of Observational Studies in Epidemiology guidelines.

RESULTS

In total, 43 articles met our inclusion criteria. CKD prevalence was associated with several indicators of SES, particularly lower income (OR 1.34, 95% CI (1.18 to 1.53), P<0.001; I²=73.0%, P=0.05); lower education (OR 1.21, 95% CI (1.11 to 1.32), P<0.001; I²=45.20%, P=0.034); and lower combined SES (OR 2.18, 95% CI (1.64 to 2.89), P<0.001; I²=0.0%, P=0.326). Lower levels of income, occupation and combined SES were also significantly associated with progression to end-stage renal disease (risk ratio (RR) 1.24, 95% CI (1.12 to 1.37), P<0.001; I²=66.6%, P=0.006; RR 1.05, 95% CI (1.01 to 1.09), P=0.012; I²=0.0%, P=0.796; and RR 1.39, 95% CI (1.09 to 1.79), P=0.009; I²=74.2%, P=0.009). Subgroup analyses generally confirmed these results, except in a few cases, such as an inverse association related to particular socioeconomic backgrounds and where results were adjusted by more disease-related risk factors.

CONCLUSION

Lower income was most closely associated with prevalence and progression of CKD, and lower education was significantly associated with its prevalence. Evidence for other indicators was inconclusive.

Relationship between educational and occupational levels, and Chronic Kidney Disease in a multi-ethnic sample- The HELIUS study

BACKGROUND

Ethnic minority groups in high-income countries are disproportionately affected by Chronic Kidney Disease (CKD) for reasons that are unclear. We assessed the association of educational and occupational levels with CKD in a multi-ethnic population. Furthermore, we assessed to what extent ethnic inequalities in the prevalence of CKD were accounted for by educational and occupational levels.

METHODS

Cross-sectional analysis of baseline data from the Healthy Life in an Urban Setting (HELIUS) study of 21,433 adults (4,525 Dutch, 3,027 South-Asian Surinamese, 4,105 African Surinamese, 2,314 Ghanaians, 3,579 Turks, and 3,883 Moroccans) aged 18 to 70 years living in Amsterdam, the Netherlands. Three CKD outcomes were considered using the 2012 KDIGO (Kidney Disease: Improving Global Outcomes) severity of CKD classification. Comparisons between educational and occupational levels were made using logistic regression analyses.

RESULTS

After adjustment for sex and age, low-level and middle-level education were significantly associated with higher odds of high to very high-risk of CKD in Dutch (Odds Ratio (OR) 2.10, 95% C.I., 1.37-2.95; OR 1.55, 95% C.I., 1.03-2.34). Among ethnic minority groups, low-level education was significantly associated with higher odds of high to very-high-risk CKD but only in South-Asian Surinamese (OR 1.58, 95% C.I., 1.06-2.34). Similar results were found for the occupational level in relation to CKD risk.

CONCLUSION

The lower educational and occupational levels of ethnic minority groups partly accounted for the observed ethnic inequalities in CKD. Reducing CKD risk in ethnic minority populations with low educational and occupational levels may help to reduce ethnic inequalities in CKD and its related complications.

SES, Chronic Kidney Disease, and Race in the U.S.: A Systematic Review and Meta-analysis

CONTEXT

The risk of chronic kidney disease (CKD) in the U.S. is higher in individuals with low SES than in those with high SES. However, differences in these risks between African Americans and whites are unclear.

EVIDENCE ACQUISITION

Studies published through August 30, 2016 in Medline and EMBASE were searched. From the seven studies (1,775,267 participants) that met inclusion criteria, association estimates were pooled by race in meta-analysis. The ratio of association estimates and the corresponding 95% CIs for African Americans and whites were also pooled in meta-analysis. Additionally, meta-regression analysis was used to explore whether race is related to the strength of SES-CKD association. The analysis was conducted in September 2016.

EVIDENCE SYNTHESIS

The risk of CKD in low-SES people was 58% higher in African Americans (relative risk=1.58, 95% CI=1.33, 1.84) and 91% higher in whites (relative risk=1.91, 95% CI=1.47, 2.35) compared with their high-SES counterparts. The relative risk of CKD in low SES (versus high SES) was lower in African Americans than in whites (relative risk ratio=0.71, 95% CI=0.65, 0.77). Results from meta-regression analyses also indicated that race is potentially related to the strength of the association between low SES and CKD (p for difference between whites and African Americans=0.001).

CONCLUSIONS

The risk of CKD in low SES (versus high SES) is higher in whites than in African Americans.

The smell of renal protection against chronic kidney disease: Hydrogen sulfide offers a potential stinky remedy

Chronic kidney disease (CKD) is a common global health challenge characterized by irreversible pathological processes that reduce kidney function and culminates in development of end-stage renal disease. It is associated with increased morbidity and mortality in addition to increased caregiver burden and higher financial cost. A central player in CKD pathogenesis and progression is renal hypoxia. Renal hypoxia stimulates induction of oxidative and endoplasmic reticulum stress, inflammation and tubulointerstitial fibrosis, which in turn, promote cellular susceptibility and further aggravate hypoxia, thus forming a pathological vicious cycle in CKD progression. Although the importance of CKD is widely appreciated, including improvements in the quality of existing therapies such as dialysis and transplantation, new therapeutic options are limited, as there is still increased morbidity, mortality and poor quality of life among CKD patients. Growing evidence indicates that hydrogen sulfide (H₂S), a small gaseous signaling molecule with an obnoxious smell, accumulates in the renal medulla under hypoxic conditions, and functions as an oxygen sensor that restores oxygen balance and increases medullary flow. Moreover, plasma H₂S level has been recently reported to be markedly reduced in CKD patients and animal models. Also, H₂S has been established to possess potent antioxidant, anti-inflammatory, and anti-fibrotic properties in several experimental models of kidney diseases, suggesting that its supplementation could protect against CKD and retard its progression. The purpose of this review is to discuss current clinical and experimental developments regarding CKD, its pathophysiology, and potential cellular and molecular mechanisms of protection by H₂S in experimental models of CKD.

Current State and Future Trends to Optimize the Care of Chronic Kidney Disease in African Americans

BACKGROUND

African Americans (AAs) suffer the widest gaps in chronic kidney disease (CKD) outcomes compared to Caucasian Americans (CAs) and this is because of the disparities that exist in both health and healthcare. In fact, the prevalence of CKD is 3.5 times higher in AAs compared to CAs. The disparities exist at all stages of CKD. Importantly, AAs are 10 times more likely to develop hypertension-related kidney failure and 3 times more likely to progress to kidney failure compared to CAs.

SUMMARY

Several factors contribute to these disparities including genetic and social determinants, late referrals, poor care coordination, medication adherence, and low recruitment in clinical trials. Key Messages: The development and implementation of CKD-related evidence-based approaches, such as clinical and social determinant assessment tools for medical interventions, more widespread outreach programs, strategies to improve medication adherence, safe and effective pharmacological treatments to control or eliminate CKD, as well as the use of health information technology, and patient-engagement programs for improved CKD outcomes may help to positively impact these disparities among AAs.

Ideal Cardiovascular Health, Cardiovascular Remodeling, and Heart Failure in Blacks: The Jackson Heart Study

BACKGROUND

The lifetime risk of heart failure (HF) is higher in the black population than in other racial groups in the United States.

METHODS AND RESULTS

We measured the Life's Simple 7 ideal cardiovascular health metrics in 4195 blacks in the JHS (Jackson Heart Study; 2000-2004). We evaluated the association of Simple 7 metrics with incident HF and left ventricular structure and function by cardiac magnetic resonance (n=1188). Mean age at baseline was 54.4 years (65% women). Relative to 0 to 2 Simple 7 factors, blacks with 3 factors had 47% lower incident HF risk (hazard ratio [HR], 0.53; 95% confidence interval [CI], 0.39-0.73; P<0.0001); and those with ≥4 factors had 61% lower HF risk (HR, 0.39; 95% CI, 0.24-0.64; P=0.0002). Higher blood pressure (HR, 2.32; 95% CI, 1.28-4.20; P=0.005), physical inactivity (HR, 1.65; 95% CI, 1.07-2.55; P=0.02), smoking (HR, 2.04; 95% CI, 1.43-2.91; P<0.0001), and impaired glucose control (HR, 1.76; 95% CI, 1.34-2.29; P<0.0001) were associated with incident HF. The age-/sex-adjusted population attributable risk for these Simple 7 metrics combined was 37.1%. Achievement of ideal blood pressure, ideal body mass index, ideal glucose control, and nonsmoking was associated with less likelihood of adverse cardiac remodeling by cardiac magnetic resonance.

CONCLUSIONS

Cardiovascular risk factors in midlife (specifically elevated blood pressure, physical inactivity, smoking, and poor glucose control) are associated with incident HF in blacks and represent targets for intensified HF prevention.

Associations between Long-Term Particulate Matter Exposure and Adult Renal Function in the Taipei Metropolis

BACKGROUND

Studies on the effect of air pollutions on kidney diseases are still limited.

OBJECTIVE

We aimed to investigate the associations between particulate matter (PM) exposures and renal function among adults.

METHODS

We recruited 21,656 adults as participants from 2007 to 2009. The Taiwanese Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation was used to derive the estimated glomerular filtration rate (eGFR). Subjects with an eGFR lower than 60 mL/min/1.73 m2 were defined as having chronic kidney disease (CKD). Land use regression (LUR) models were used to estimate individual exposures to PM with an aerodynamic diameter < 10 μm (PM10), coarse particles (PMCoarse), fine particles (PM2.5), and PM2.5Absorbance. Generalized linear and logistic regression models were used to estimate the associations between PM exposure and renal function.

RESULTS

An IQR increase in PM10 (5.83 μg/m3) was negatively associated with eGFR by -0.69 (95% CI: -0.89, -0.48) mL/min/1.73 m2 and positively associated with the prevalence of CKD with adjusted OR = 1.15 (95% CI: 1.07, 1.23). An IQR increase in PMCoarse (6.59 μg/m3) was significantly associated with lower eGFR by -1.07 (95% CI: -1.32, -0.81) mL/min/1.73 m2 and CKD with OR = 1.26 (95% CI: 1.15, 1.38). In contrast, neither outcome was significantly associated with PM2.5 or PM2.5Absorbance. Stratified analyses indicated that associations of CKD with both PM10 and PMCoarse were limited to participants < 65 years of age, and were stronger (for PM10) or limited to (PMCoarse) women. Associations also appeared to be stronger in those without (vs. with) hypertension, and in normal versus overweight participants.

CONCLUSIONS

Exposure during the previous year to PM10 and PMCoarse, but not PM2.5 or PM2.5Absorbance, was associated with reduced renal function among Taiwanese adults.

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.

African American patient knowledge of kidney disease: A qualitative study of those with advanced chronic kidney disease

Kidney disease is a costly and prevalent condition that affects African Americans more than any other group. The purpose of this study was to determine the knowledge of kidney disease African American patients have about their disease. Four qualitative focus groups were conducted with kidney disease patients in which the patients gave thoughts and opinions on kidney disease and various components and factors of the condition. The data were independently reviewed and analyzed using Qualrus coding software. Dominant themes discussed in the focus groups included: causes of kidney disease, patient thoughts on dialysis as a treatment for kidney disease, information source for disease knowledge, thoughts on God and faith, reaction to kidney disease, and types of treatment available. The study found that the majority of patients were unaware of specific causes and risk factors of kidney disease, were unsure of available treatments, and had a severe lack of knowledge and support system in dealing with the condition. Early prevention and education programs aimed at high-risk populations would be very beneficial in decreasing the incidence and increase of kidney disease.

Serum phosphate and social deprivation independently predict all-cause mortality in chronic kidney disease

Background

Hyperphosphataemia is linked to cardiovascular disease and mortality in chronic kidney disease (CKD). Outcome in CKD is also affected by socioeconomic status. The objective of this study was to assess the associations between serum phosphate, multiple deprivation and outcome in CKD patients.

Methods

All adult patients currently not on renal replacement therapy (RRT), with first time attendance to the renal outpatient clinics in the Glasgow area between July 2010 and June 2014, were included in this prospective study. Area socioeconomic status was assessed as quintiles of the Scottish Index of Multiple Deprivation (SIMD). Outcomes were all-cause and cardiovascular mortality and commencement of RRT.

Results

The cohort included 2950 patients with a median (interquartile range) age 67.6 (53.6–76.9) years. Median (interquartile range) eGFR was 38.1 (26.3–63.5) ml/min/1.73 m², mean (±standard deviation) phosphate was 1.13 (±0.24) mmol/L and 31.6 % belonged to the most deprived quintile (SIMD quintile I). During follow-up 375 patients died and 98 commenced RRT. Phosphate ≥1.50 mmol/L was associated with all-cause (hazard ratio (HR) 2.51; 95 % confidence interval (CI) 1.63-3.89) and cardiovascular (HR 5.05; 95 % CI 1.90–13.46) mortality when compared to phosphate 0.90–1.09 mmol/L in multivariable analyses. SIMD quintile I was independently associated with all-cause mortality. Phosphate did not weaken the association between deprivation index and mortality, and there was no interaction between phosphate and SIMD quintiles. Neither phosphate nor SIMD predicted commencement of RRT.

Conclusions

Multiple deprivation and serum phosphate were strong, independent predictors of all-cause mortality in CKD and showed no interaction. Phosphate also predicted cardiovascular mortality. The results suggest that phosphate lowering should be pursued regardless of socioeconomic status.

Prevalence and Correlates of CKD in Hispanics/Latinos in the United States

BACKGROUND AND OBJECTIVES

The prevalence of ESRD among Hispanics/Latinos is 2-fold higher than in non-Hispanic whites. However, little is known about the prevalence of earlier stages of CKD among Hispanics/Latinos. This study estimated the prevalence of CKD in US Hispanics/Latinos.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a cross-sectional study of 15,161 US Hispanic/Latino adults of Cuban, Dominican, Mexican, Puerto Rican, Central American, and South American backgrounds enrolled in the multicenter, prospective, population-based Hispanic Community Health Study/Study of Latinos (HCHS/SOL). In addition, the prevalence of CKD in Hispanics/Latinos was compared with other racial/ethnic groups in the 2007-2010 National Health and Nutrition Examination Survey (NHANES). Prevalent CKD was defined as an eGFR <60 ml/min per 1.73 m(2) (estimated with the 2012 Chronic Kidney Disease Epidemiology Collaboration eGFR creatinine-cystatin C equation) or albuminuria based on sex-specific cut points determined at a single point in time.

RESULTS

The overall prevalence of CKD among Hispanics/Latinos was 13.7%. Among women, the prevalence of CKD was 13.0%, and it was lowest in persons with South American background (7.4%) and highest (16.6%) in persons with Puerto Rican background. In men, the prevalence of CKD was 15.3%, and it was lowest (11.2%) in persons with South American background and highest in those who identified their Hispanic background as "other" (16.0%). The overall prevalence of CKD was similar in HCHS/SOL compared with non-Hispanic whites in NHANES. However, prevalence was higher in HCHS/SOL men and lower in HCHS/SOL women versus NHANES non-Hispanic whites. Low income, diabetes mellitus, hypertension, and cardiovascular disease were each significantly associated with higher risk of CKD.

CONCLUSIONS

Among US Hispanic/Latino adults, there was significant variation in CKD prevalence among Hispanic/Latino background groups, and CKD was associated with established cardiovascular risk factors.

Chronic kidney disease (CKD) treatment burden among low-income primary care patients

OBJECTIVE

This study explored the self-management strategies and treatment burden experienced by low-income US primary care patients with chronic kidney disease.

METHODS

Semi-structured interviews were conducted with 34 patients from two primary care practices on Buffalo's East Side, a low-income community. Qualitative analysis was undertaken using an inductive thematic content analysis approach. We applied normalization process theory (NPT) to the concept of treatment burden to interpret and categorize our findings.

RESULTS

The sample was predominantly African-American (79%) and female (59%). Most patients (79%) had a diagnosis of stage 3 CKD. Four major themes were identified corresponding to NPT and treatment burden: (1) coherence--making sense of CKD; (2) cognitive participation--enlisting support and organizing personal resources; (3) collective action--self-management work; and (4) reflexive monitoring--further refining chronic illness self-care in the context of CKD. For each component, we identified barriers hindering patients' ability to accomplish the necessary tasks.

CONCLUSIONS

Our findings highlight the substantial treatment burden faced by inner-city primary care patients self-managing CKD in combination with other chronic illnesses. Health care providers' awareness of treatment burden can inform the development of person-centered care plans that can help patients to better manage their chronic illnesses.

Serum Phosphorus Levels, Race, and Socioeconomic Status in Incident Hemodialysis Patients

OBJECTIVE

We sought to examine the relationship between race, socioeconomic status, and serum phosphorus levels in patients with end-stage renal disease incident to hemodialysis (HD) at a large, integrated health-care delivery system in Southern California.

DESIGN

Retrospective cohort study.

SUBJECTS

A total of 5,778 adult patients who initiated HD at our institution between January 1, 2007 and June 30, 2013.

MAIN OUTCOME MEASURES

Unadjusted and adjusted time-averaged serum phosphorus levels and actual phosphorus levels over time. Phosphorus levels were also analyzed by repeated measures as a continuous measure and by phosphorus category. Baseline patient covariates included age, self-reported race, gender, cause of end-stage renal disease, and Charlson comorbidity index scores. Education and income level were estimated using geocoded data.

RESULTS

A total of 68,372 phosphorus levels were available for 4,862 patients. Estimated annual family income fell below $40,001 in 66.1% of African Americans (AAs) and 62.7% of Hispanics compared with 43.5% of Asians and 43.7% of whites, P < .0001. Educational level fell into the highest category for whites (70.8%) compared with AA (44.8%) or Hispanic (30.5%) patients, P < .0001. Adjusted time-averaged phosphorus levels were lower among Hispanics (4.33 mg/dL, 95% confidence interval [CI] 4.27-4.40) compared with Asian (4.54 mg/dL, 95% CI 4.45-4.64, P < .001) and white patients (4.48 mg/dL, 95% CI 4.43-4.54, P < .001) but similar to AA patients. Asian patients experienced a significant increase in phosphorus levels over time (0.11 mg/dL per year, P < .0001). There were no significant effects of race, time, or race by time interactions in the unadjusted and adjusted categorical analyses of phosphorus levels.

CONCLUSIONS

Our findings suggest that serum phosphorus levels are similar among HD patients, irrespective of race or socioeconomic status.

Socioeconomic disparities in chronic kidney disease: a systematic review and meta-analysis

CONTEXT

Evidence on the strength of the association between low SES and chronic kidney disease (CKD; measured by low estimated glomerular filtration rate [eGFR], high albuminuria, low eGFR/high albuminuria, and renal failure) is scattered and sometimes conflicting. Therefore, a systematic review and meta-analysis was performed to summarize the strength of the associations between SES and CKD and identify study-level characteristics related to this association.

EVIDENCE ACQUISITION

Studies published through January 2013 in MEDLINE and Embase were searched. From 35 studies that met the inclusion criteria, association estimates were pooled per CKD measure in the meta-analysis (performed between 2013 and 2014). Meta-regression analysis was used to identify study-level characteristics related to the strength of the SES-CKD association.

EVIDENCE SYNTHESIS

Low SES was associated with low eGFR (OR=1.41, 95% CI=1.21, 1.62), high albuminuria (OR=1.52, 95% CI=1.22, 1.82), low eGFR/high albuminuria (OR=1.38, 95% CI=1.03, 1.74), and renal failure (OR=1.55, 95% CI=1.40, 1.71). Differences in SES measures across studies were not related to the strength of associations between low SES and any of the CKD measures (low GFR, p=0.63; high albuminuria, p=0.29; low eGFR/high albuminuria, p=0.54; renal failure, p=0.31). Variations in the strength of associations were related to the level of covariate adjustment for low eGFR (p<0.001) and high albuminuria (p<0.001).

CONCLUSIONS

Socioeconomic disparities in CKD were fairly strong, irrespective of how SES was measured. Variations in the strength of the associations were related to the level of covariate adjustment, particularly for low eGFR and high albuminuria.