Traditional Risk Factors Explain Higher Risk of CKD in Black Americans

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The higher incidence of chronic kidney disease (CKD) among Black compared with White US adults is largely explained by traditional CKD risk factors, concludes a study in the American Journal of Kidney Diseases.

The analysis included 4198 Black and 7799 White participants from the “Reasons for Geographic and Racial Differences in Stroke” (REGARDS) study. All were at least 45 years old at enrollment in 2003–2007, with a baseline estimated glomerular filtration rate (eGFR) greater than 60 mL/min/1.73 m2. CKD incidence and risk factors were compared between Black and White participants. The study definition of CKD was eGFR of less than 60 mL/min/1.73 m2 with a decline of at least 40% from baseline or kidney failure. At 9.4 years' follow-up, CKD incidence was 9%, ranging from 4% for adults aged 45 to 54 years to 18% in those aged 75 or older. Black race was associated with higher risk of eGFR change during follow-up, after adjustment for age, sex, and race.

However, the racial association was no longer significant in a fully adjusted model accounting for all risk factors. Independent risk factors for CKD included age, low income, residence in the Southeastern “Stroke Belt” states, systolic blood pressure, body mass index, diabetes, hyperlipidemia, and albuminuria.

Risk factors were similar on analysis of CKD incidence. For both eGFR change and CKD, albuminuria was a stronger risk factor in Black compared with White adults and for participants living in the Stroke Belt.

There are known racial disparities in the prevalence and associated costs of CKD in the US population. There are few data on the incidence of and risk factors for CKD in a contemporary US population, including possible differences by race, sex, or region.

Modifiable risk factors, such as diabetes, hypertension, and obesity, account for most of the increased incidence of CKD among Black Americans, the new results suggest. Further study is needed to clarify the importance of albuminuria and Stroke Belt residence as risk factors for incident CKD and eGFR decline [Cheung KL, et al. Risk factors for incident CKD in Black and White Americans: The REGARDS study. Am J Kidney Dis, published online ahead of print January 5, 2023. doi: 10.1053/j.ajkd.2022.11.015;].