Kidney Week

Abstract: FR-OR055

Kidney Function Decline Among African Americans with Sickle Cell Trait and Sickle Cell Disease

Session Information

• Genes, Environment, and Lifestyle: Risk Factors for CKD
  November 08, 2019 | Location: Salon C, Walter E. Washington Convention Center
  Abstract Time: 05:18 PM - 05:30 PM

Category: CKD (Non-Dialysis)

• 2101 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention

Authors

• Olaniran, Kabir O., Massachusetts General Hospital, Boston, Massachusetts, United States

Kabir O. Olaniran, MD, MPH



Dr. Kabir Olaniran is a clinical researcher at the Massachusetts General Hospital Kidney Research Center in Boston and recently accepted a position as an Assistant Professor at the University of Texas Southwestern Medical Center Division of Nephrology. Dr. Olaniran earned his medical degree at the University of Lagos, College of Medicine in Nigeria. He completed a residency in internal medicine at Lincoln Medical Center in the Bronx, New York and received his nephrology training at the combined Brigham and Women’s Hospital / Massachusetts General Hospital Harvard Medical School program in Boston. He also holds a master’s degree in public health from the Harvard School of Public Health. Dr. Olaniran was a recipient of the 2018 American Society of Nephrology (ASN) Ben J. Lipps Fellowship grant, the ASN William E. Mitch International Scholars Award, and the Massachusetts General Hospital Dennis A. Ausiello Outstanding Postdoctoral Fellow Award. Dr. Olaniran’s primary clinical and research interest is kidney disease in individuals with sickle cell disorders and sickle cell trait.

• Allegretti, Andrew S., Massachusetts General Hospital, Boston, Massachusetts, United States

Andrew S. Allegretti,

• Zhao, Sophia, Massachusetts General Hospital, Boston, Massachusetts, United States

Sophia Zhao,

• Eneanya, Nwamaka D., University of Pennsylvania, Philadelphia, Pennsylvania, United States

Nwamaka D. Eneanya,

• Thadhani, Ravi I., Cedars-Sinai, Los Angeles, California, United States

Ravi I. Thadhani,

• Nigwekar, Sagar U., Massachusetts General Hospital, Boston, Massachusetts, United States

Sagar U. Nigwekar,

• Kalim, Sahir, Massachusetts General Hospital/ Harvard Medical School, Cambridge, Massachusetts, United States

Sahir Kalim,

Background

Sickle cell trait (SCT) and disease (SCD) are felt to be independent risk factors for chronic kidney disease (CKD) among African Americans (AA). However, the understanding of the trajectory of kidney function decline and its predictors in patients with SCT/SCD remains limited. We aimed to describe longitudinal kidney function decline and associated risk factors among adult AA with SCT/SCD.

Methods

We performed a multi-center observational study of adult AA patients with hemoglobin electrophoresis to ascertain the presence of SCT or SCD (exposure) and normal hemoglobin phenotype (reference). We included patients with a baseline estimated glomerular filtration rate (eGFR) ≧29 ml/min/1.73m², at least 3 eGFR values between 2005-2018 and at least 1 year between the first and last eGFR values. Outcomes of interest were the difference in the mean change in eGFR per year (evaluated using linear mixed models) and incident stage 3 CKD (described using Cox proportional hazards).

Results

We identified 10,210 patients (1,251 SCT, 230 SCD and 8,729 reference) with a median follow-up of 8 (IQR 5-11) years and a median of 17 (IQR 10-30) eGFR values. The mean age was 36 (±13) years, 86% were female and baseline eGFR was 113 (±27) ml/min/1.73m². Compared to the reference, eGFR declined 0.45 ml/min/1.73m²/year faster in SCT (p<0.01) and 1.28 ml/min/1.73m²/year faster in SCD (p<0.01). SCD patients’ eGFR declined 0.83 ml/min/1.73m²/year faster (p<0.01) than the SCT patients. These results were consistent after multivariable adjustment. Compared to the reference, incident stage 3 CKD was higher in SCT (hazard ratio [HR] 1.26; 95% confidence interval (CI), 1.05-1.51), and SCD (HR 2.37; 95% CI, 1.43-3.93) after multivariable adjustment. Males, diabetes mellitus, and a baseline eGFR ≥90ml/min/1.73m² were associated with faster eGFR decline in SCT/SCD.

Conclusion

SCT/SCD is associated with a significantly faster eGFR decline compared to normal hemoglobin phenotype among AA patients. A dose-response relationship between sickle hemoglobin and kidney dysfunction may exist. Prospective and mechanistic studies are needed to develop best practices to attenuate eGFR decline in AA patients with SCT/SCD. Physicians caring for AAs need to consider SCT/SCD status and SCT/SCD interactions with comorbidities when evaluating CKD risk.