Ethnic Disparities in CKD Progression: A Comparative Study of CRIC and KNOW-CKD Cohorts.

KEY POINTS: Risk of all-cause mortality was significantly lower in KoreaN Cohort Study for Outcome in Patients with CKD group than that in the Chronic Renal Insufficiency Cohort group. Asian cohorts exhibited steeper eGFR decline slopes than that of the Black and White cohorts. Tailored clinical approaches and ethnicity-stratified studies are required to improve CKD management.

BACKGROUND

Ethnic differences in CKD progression remain understudied, particularly between Asian and Western populations. Therefore, we aimed to investigate ethnic disparities in CKD progression by comparing nationwide cohorts from South Korea (the KoreaN Cohort Study for Outcome in Patients with CKD [KNOW-CKD]) and the United States (the US Chronic Renal Insufficiency Cohort [CRIC]).

METHODS

A total of 4953 participants were included (69% from CRIC and 31% from KNOW-CKD). The primary outcome was CKD progression, defined as a 50% or greater decline of eGFR or kidney failure requiring KRT. In the secondary outcome analysis, we compared eGFR decline rates and all-cause mortality.

RESULTS

Of the 4953 participants, CKD progression occurred in 1285 and 570 in the KNOW-CKD and CRIC cohorts, with incidence rates of 67.9 and 41.7 per 1000 person-years, respectively. The hazard ratio for the KNOW-CKD compared with CRIC was 1.66 (95% confidence interval [CI], 1.45 to 1.89). The annual eGFR decline was steeper in KNOW-CKD participants than in CRIC participants (−2.51 versus −1.14 ml/min per 1.73 m2). Asian participants from the CRIC cohort exhibited a similar eGFR slope (95% CIs) (−2.10 [−2.69 to −1.52]) to those from KNOW-CKD (−2.50 [−2.67 to −1.52]), while the slope was −1.47 (−1.61 to −1.33) and −0.81 (−0.92 to −0.70) ml/min per 1.73 m2 per year for Black and White participants, respectively. However, the risk of mortality was significantly lower in KNOW-CKD participants compared with CRIC participants (hazard ratio, 0.51; 95% CI, 0.38 to 0.68).

CONCLUSIONS

CKD progression was faster in the Korean cohort than in the US cohort, with Asian participants in both cohorts showing similar eGFR decline rates. However, the Korean cohort had a lower risk of mortality, indicating potential ethnic or regional differences in disease progression and survival.