Trajectories of kidney function over 10 years in patients with chronic kidney disease: a 10 year follow-up of FROM-J study

Background The frontier of renal outcome modifications in Japan 10 (FROM-J10) study is a 10 year longitudinal cohort study evaluating the long-term outcomes of treatment according to the clinical guidelines for chronic kidney disease (CKD) by primary care physicians. This study aimed to identify distinctive trajectories of kidney function among patients with CKD and evaluate the patient characteristics associated with each trajectory using the FROM-J10 study data. Method This secondary study used 10 years of data from 2379 patients aged between 40 and 74 years with CKD stages from G1 to G5 in the FROM-J10 study. Group-based trajectory modeling was applied to the change in estimated glomerular filtration rate (eGFR) over time, and patients were classified into distinct groups that followed similar trajectories. Multivariate logistic analysis was performed for patient characteristics associated with each trajectory. Results In total, 2257 patients with at least three eGFR values were included in this study. Two distinct trajectories of eGFR decline were identified: progressive decline ( n = 1240, 54.9%) and gradual decline ( n = 1017, 45.1%). In multivariate logistic analysis with gradual eGFR decline as a reference, proteinuria was associated with progressive eGFR decline in CKD from G2 to G4 + 5; lower albumin in G2, G3a, and G4 + 5; and lower hemoglobin in G3a to G4 + 5. Conclusions In patients with CKD adequately treated by primary care physicians, kidney function declined very slowly over 10 years. We suggest that patient characteristics identified as progressive eGFR decline, proteinuria, and lower albumin and hemoglobin levels should be managed appropriately in clinical practice.