Background: Estimated glomerular filtration rate (eGFR) and albuminuria (proteinuria) are both important determinants of the risk of cardiovascular disease (CVD), end-stage renal disease (ESRD), and mortality. Few studies, however, have examined the risk factor profiles based on eGFR and proteinuria among the general population.
Methods: Data of the newly developed nationwide screening program of the Specific Health Check-up and Guidance System (Tokutei-Kensin) initiated in 2008 were used in this study. The aim of this screening, targeting people 40-74 years of age, was to detect those with metabolic syndrome and to offer those services regarding lifestyle modifications that will lead to the reduction of diabetes mellitus (DM) and DM-related ESRD. Individual records of 580,000 participants in 69 cities and towns and 3 union cohorts throughout Japan were anonymously provided and included in the present study.
Results: Details of 332,174 participants (57.3% of the total) with both serum creatinine and dipstick urine test data were analyzed. Mean (SD) age was 63.6 (8.3) years and 40.6% were men. The mean (SD) eGFR was 75.0 (16.2) ml/min/1.73 m(2) and 5.4% had proteinuria. The prevalence of chronic kidney disease (CKD) stage 3, 4, and 5 was 14.2%, 0.2%, and 0.07%, respectively. The prevalence of DM, hypertension, and history of stroke and heart disease was correlated with the combination of eGFR and degree of proteinuria.
Conclusion: The findings of the present study indicate that CKD and risk factors for CVD are quite common among middle-aged Japanese. CKD classification based on eGFR and proteinuria may be useful for predicting CVD, mortality rate, and ESRD in the Japanese population.