The Relationship Between Immigration Status and Chronic Kidney Disease Risk Factors in Immigrants and US-Born Adults

A population-based cohort study defined estimated glomerular filtration rate decline and kidney failure among Canadian immigrants

The link between immigrant status, a key social determinant of health, and kidney disease remains uncertain. To evaluate this, we compared incident adverse kidney outcomes between immigrants and non-immigrants using Canadian provincial health administrative data. We conducted a population-based observational cohort study of all adult Ontario residents (immigrants and non-immigrants) with normal baseline kidney function (estimated glomerular filtration rate (eGFR) 70 mL/min/1.73m2 or more). Multivariable Cox proportional hazard regression modeling was used to evaluate the relationship between immigrant status and the composite adverse kidney outcome of 40% eGFR decline or kidney failure. The study cohort included 10,440,210 individuals with 22% immigrants and 78% non-immigrants. The mean (Standard Deviation) age and eGFR were 45 (17) years and 102 (16) mL/min/1.73m2, respectively. Immigrants experienced a 27% lower hazard for the composite adverse kidney outcome (adjusted hazard ratio 0.73 [95% Confidence Interval 0.72-0.74]) compared to non-immigrants which was primarily driven by 40% eGFR decline. However, immigrants also experienced a 12% lower hazard for incident kidney failure (0.88 [0.84-0.93]) compared to non-immigrants. Results were consistent upon accounting for the competing risk of death and adjusting for baseline albuminuria. As has been demonstrated with other chronic diseases, these novel findings suggest that a "healthy immigrant effect" also extends to kidney disease. Differential kidney disease outcomes were identified among immigrants based on refugee status and world region of origin which may inform health policy decision-making toward targeted screening strategies and more cost-effective resource allocation for immigrant populations.

Nativity, Racial/Ethnic, and Length of US Residence Differences in Chronic Kidney Disease: National Health and Nutrition Examination Survey 2011-March 2020

Rationale

The chronic kidney disease (CKD) burden in the US varies by race/ethnicity. It was unclear whether nativity status influences these disparities. This study compared CKD prevalence by nativity status, race and ethnicity, and length of US residence.

Study Design

Cross-sectional analysis.

Setting/Participants

We drew a weighted sample of 13,636 adults representing 155,147,141 Hispanic, White, Black, and Asian adults from the pooled 2011-March 2020 National Health and Nutrition Examination Survey (NHANES), which included 155,147,141 US- and foreign-born adults.

Exposures

Nativity (US- or foreign-born), race/ethnicity, and length of US residence.

Outcome

We defined CKD as eGFR <60mL/min/1.73m2 or a urinary albumin-to-creatinine ratio ≥30 mg/g.

Analytical Approach

Survey-weighted multivariable Poisson models estimated associations among nativity status, race, and ethnicity, length of US residence, and CKD, adjusting for covariates.

Results

The prevalence of CKD among US-born adults was 14.0%, vs. 11.5% of foreign-born. Foreign-born adults were less likely to have CKD (prevalence rate ratio [PRR]: 0.75, 95% CI 0.60-0.93) than US-born adults, adjusting for age, sex, and socioeconomic factors. Black adults were more likely to have CKD than White adults (PRR: 1.44, 95% CI 1.23-1.68); this difference was greater among US-born adults (PRR: 1.48, 95% CI 1.25-1.76). Among Hispanic and Asian adults, age- and sex-adjusted prevalence of CKD increased with longer length of residence in the US.

Conclusions

There are clear CKD disparities related to nativity location and length of US residence, and these vary by race/ethnicity. Interventions addressing the unique challenges faced by populations most at risk for CKD, such as access to healthcare barriers and socioeconomic disparities, may help mitigate the burden of CKD and promote health equity.

Incident chronic kidney disease among Canadian immigrants: a population-based cohort study

Introduction

A 'healthy immigrant effect' has been demonstrated for a number of chronic health conditions including cardiovascular disease, diabetes mellitus and dementia; however, the link between immigrant status and kidney health remains uncertain. We sought to compare the risk for incident chronic kidney disease (CKD) between Canadian immigrants and non-immigrants.

Methods

We conducted a population-level, observational cohort study of all adult (≥18 years of age) Ontario residents, including foreign-born immigrant Canadian citizens and non-immigrant Canadian citizens by birth, with normal baseline kidney function (outpatient estimated glomerular filtration rate (eGFR) ≥70 mL/min/1.73 m2) between 1 April 2007 and 30 September 2020 using provincial health administrative data. Multivariable Cox proportional hazard regression modelling was used to evaluate the relationship between immigrant status and the development of incident CKD (outpatient eGFR <60 mL/min/1.73m2).

Results

The study cohort included 10 440 210 Ontario residents, consisting of 22% immigrants (n=2 253 360) and 78% (n=8 186 850) non-immigrants. The mean (SD) age and eGFR were 45 (17) years and 102 (16) mL/min/1.73 m2, respectively, and 54% of individuals were female. A total of 117 028 immigrants (5%, 7 events per 1000 person-years) and 984 277 non-immigrants (12%, 16 events per 1000 person-years) developed incident CKD during follow-up. Immigrants experienced a 20% lower risk for incident CKD compared with non-immigrants (adjusted HR 0.80, 95% CI 0.80 to 0.81). Consistent findings were seen for refugee and non-refugee immigrants, immigrants with remote (1985-2004) and recent (2005-2020) landing dates, and immigrants from different world regions. Results were similar on re-defining incident CKD as two outpatient eGFR measurements <60 mL/min/1.73 m2 at least 90 days apart, treating death as a competing risk, and adjusting for baseline albuminuria.

Conclusion

Immigrants experience a lower risk for incident CKD compared with non-immigrants. These findings provide evidence of a 'healthy immigrant effect' in relation to kidney health.

Blood metabolomic shift links diet and gut microbiota to multiple health outcomes among Hispanic/Latino immigrants in the U.S

Immigrants from less industrialized countries who are living in the U.S. often bear an elevated risk of multiple disease due to the adoption of a U.S. lifestyle. Blood metabolome holds valuable information on environmental exposure and the pathogenesis of chronic diseases, offering insights into the link between environmental factors and disease burden. Analyzing 634 serum metabolites from 7,114 Hispanics (1,141 U.S.-born, 5,973 foreign-born) in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), we identified profound blood metabolic shift during acculturation. Machine learning highlighted the prominent role of non-genetic factors, especially food and gut microbiota, in these changes. Immigration-related metabolites correlated with plant-based foods and beneficial gut bacteria for foreign-born Hispanics, and with meat-based or processed food and unfavorable gut bacteria for U.S.-born Hispanics. Cardiometabolic traits, liver, and kidney function exhibited a link with immigration-related metabolic changes, which were also linked to increased risk of diabetes, severe obesity, chronic kidney disease, and asthma.

Graphical abstract

Highlights

A substantial proportion of identified blood metabolites differ between U.S.-born and foreign-born Hispanics/Latinos in the U.S.Food and gut microbiota are the major modifiable contributors to blood metabolomic difference between U.S.-born and foreign-born Hispanics/Latinos.U.S. nativity related metabolites collectively correlate with a spectrum of clinical traits and chronic diseases.

Epidemiology and referral patterns of patients living with chronic kidney disease in Johannesburg, South Africa: A single centre experience

Chronic kidney disease (CKD) is a significant contributor to the global burden of non-communicable disease. Early intervention may facilitate slowing down of progression of CKD; recognition of at-risk patient groups may improve detection through screening. We retrospectively reviewed the clinical records of 960 patients attending a specialist nephrology outpatient clinic during the period 1 January 2011-31 December 2021. A significant proportion (47.8%) of patients were referred with established CKD stage G4 or G5. Non-national immigration status, previous diagnosis with diabetes, and advancing age were associated with late referral; antecedent diagnosis with HIV reduced the odds of late referral. Black African patients comprised most of the sample cohort and were younger at referral and more frequently female than other ethnicities; non-nationals were younger at referral than South Africans. Hypertension-associated kidney disease was the leading ascribed aetiological factor for CKD (40.7% of cases), followed by diabetic kidney disease (DKD) (19%), glomerular disease (12.5%), and HIV-associated kidney disease (11.8%). Hypertension-related (25.9%) and diabetic (10.7%) kidney diseases were not uncommon in people living with HIV. Advancing age and male sex increased the likelihood of diagnosis with hypertensive nephropathy, DKD and obstructive uropathy; males were additionally at increased risk of HIV-associated kidney disease and nephrotoxin exposure, as were patients of Black African ethnicity. In summary, this data shows that hypertension, diabetes, and HIV remain important aetiological factors in CKD in the South African context. Despite the well-described risk of CKD in these disorders, referral to nephrology services occurs late. Interventions and policy actions targeting at-risk populations are required to improve referral practices.

Disparities in chronic kidney disease-the state of the evidence

PURPOSE OF REVIEW

The purpose of this review was to assess the prevalence of United States chronic kidney disease (CKD) health disparities, focusing on racial/ethnic groups, immigrants and refugees, sex or gender, and older adults.

RECENT FINDINGS

There are major racial/ethnic disparities in CKD, with possible contributions from the social determinants of health, socioeconomics, and racial discrimination. Racial/ethnic minority patients experience faster progression to end-stage kidney disease (ESKD) and higher mortality predialysis, however, once on dialysis, appear to live longer. Similarly, men are quicker to progress to ESKD than women, with potential biological, behavioral, and measurement error factors. There is a lack of substantial evidence for intersex, nonbinary, or transgender patients. There are also strikingly few studies about US immigrants or older adults with CKD despite the fact that they are at high risk for CKD due to a variety of factors.

SUMMARY

As providers and scientists, we must combat both conscious and unconscious biases, advocate for minority patient populations, and be inclusive and diverse in our treatment regimens and provision of care. We need to acknowledge that sufficient evidence exists to change treatment guidelines, and that more is required to support the diversity of our patient population.