Chronic Kidney Disease Progression And Prediction Of Clinical Cardiovascular Disease And Total Mortality: The Coronary Artery Risk Development In Young Adults (Cardia) Study

Introduction: The Kidney Disease Improving Global Outcomes (KDIGO)Guidelines proposed a chronic kidney disease (CKD) risk assessment matrix based on estimated glomerular filtration (eGFR) together with albuminuria categories (urine albumin-to-creatinine (ACR)). This classification system tends to focus on nuances at the severe CKD end of the spectrum among middle-aged and older adults. We expanded the KDIGO risk categories to include less severe manifestations of CKD, applicable to a generally healthy population in young adulthood. Hypothesis: CKD progression in its less severe range is common and predicts CVD and total mortality starting in generally healthy young adults. Methods: In a community-based sample of black and white men and women, both eGFR (creatinine) and spot urine ACR were assayed at study year 10 (age 27-41y) and every 5 y for 20 y through year 30. We expanded the 4 KDIGO risk categories by adding 2 less severe categories (see Figure). We estimated CKD stage prevalence at each exam and transition probabilities, including 4389 participants by year 30. We used proportional hazards regression with time-varying CKD stage, age, sex, and race as predictors of the endpoints any incident CVD or total death. Results: As expected, extreme risk was seen in 131 people (3% prevalence) who reached stages 4-6 (See Figure). Important increases in risk (hazard ratios 1.55 to 3.11) occurred in 1601 people (36% prevalence) who reached stages 2-3. Transition to higher stage (mostly by 1 stage) occurred in 5-10% per 5 years (~30% in 20 years). Conclusions: These data suggest that clinically important changes occur in CKD risk staging throughout middle age, though most of these changes are currently regarded as minor occurrences. Research should explore whether more aggressive, low risk treatment options, which currently exist, would be beneficial in people with small changes in CKD stage, starting in young adulthood.