Racial Differences and Contributory Cardiovascular and Non-cardiovascular Risk Factors Towards Chronic Kidney Disease Progression In Young To Middle-Aged Black And White American Adults

BackgroundThe progression of chronic kidney disease (CKD) is higher in Black than in White Americans but studies have mainly focused on racial differences within advanced CKD. We evaluated CKD progression in Black and White participants over 20 years and the contribution of conventional cardiovascular and non-traditional risk factors to racial disparities in CKD progression. MethodsThis study was based on 2,175 Black and 2,207 White adults in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Both estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (UACR) were measured at study year 10 (age 27-41y) and every five years for 20 years. The outcome was CKD progression through No CKD into Low, Moderate, High, or Very High Risk that was based on categories of eGFR and UACR in combination. The association between race and CKD progression as well as the contribution of risk factors to racial differences were assessed in multivariable-adjusted Cox proportional hazards models. ResultsBlack participants had higher CKD transition probabilities than White participants and more prevalent risk factors during the 20-year period studied. Hazard ratios for CKD transition for Black (vs White participants) were 1.38 from No CKD into [≥] Low Risk, 2.25 from [≤] Low Risk into [≥] Moderate Risk, and 4.49 for from [≤] Moderate Risk into [≥] High Risk. Racial differences in CKD progression from No CKD into [≥] Low Risk were primarily explained by forced vital capacity (54.8%), hypertension (30.9%), and obesity (20.8%). Similar findings were observed for the race difference in transition from [≤] Low Risk into [≥] Moderate Risk, but little of the race difference in transition [≤] Moderate Risk into [≥] High Risk was explained. ConclusionsIn this longitudinal study, Black compared to White participants had a higher risk of CKD progression, and this discrepancy may be partly explained by conventional cardiovascular and non-traditional risk factors. Clinical PerspectiveO_ST_ABSWhat Is New?C_ST_ABS{blacksquare} In 20 years of follow-up, young Black American adults had higher risk of chronic kidney disease (CKD) progression than their White counterparts, and the differences were larger in transitions to more advanced categories. {blacksquare}Additionally, Black individuals had more conventional cardiovascular and non-traditional characteristics known to increase risk of CKD. What Are the Clinical Implications?{blacksquare} Periodic screening for elevated albuminuria and eGFR would be helpful, particularly among young Black individuals. {blacksquare}Future studies should evaluate if regular monitoring of eGFR and albuminuria in young Black individuals is helpful in preventing progression in CKD.