Proteinuria is a Key Factor Predicting the Progression of CKD: Nine- Year Follow-Up of Retrospective Health Examinee’s Cohort, Okinawa Study

With the advent of an aging society, chronic kidney disease (CKD) is increasing not only in Japan but also worldwide, with 10 million patients in Japan and more than 100 million in China, India, and Southeast Asia. While low-protein diets have been effective in prolonging the life span of CKD patients, their success has not been consistent. However, this promising approach offers hope for the future. In Japan, mass health checkups have worked to prevent cancer and lifestyle-related diseases. Okinawa consists of 20 municipalities (11 on the main island and nine on remote islands), and population movement is minimal, making it easy to track changes over time. The population of Okinawa is 1.47 million (as of October 2023), which is 1.2% of Japan's (124.64 million). The incidence of chronic dialysis patients is about 3,500 per 1 million population. The average age of dialysis patients is over 70. In this paper, using a Cox regression model, we examined the factors leading to the end stage of CKD in a database of approximately 40,000 persons who were retrospectively followed for ten years. Nine factors significantly related to eGFR decline: 1. eGFR: estimated Glomerular Filtration Rate, 2. Cre: Creatinine, 3. UP: dipstick Urinary Protein level, 4. SBP; systolic blood pressure, 5. Hct: Hematocrit, 6.LDH: lactate dehydrogenase, 7.Urinary glucose, 8. Alb: serum Albumin, 9. FBG: Fasting Blood Glucose. The degree of urinary protein significantly advances CKD. Diabetes itself may be a risk factor for proteinuria, but the degree of glucosuria did not affect proteinuria until the late stage. Proteinuria was the essential factor in predicting CKD progression to the end stage.