Metabolic syndrome and chronic kidney disease: a Japanese perspective on a worldwide problem

Metabolic syndrome and obesity have causative roles in the development of chronic kidney disease (CKD). CKD leads to end-stage renal disease (ESRD), cardiovascular disease and death. The prevalence of metabolic syndrome is increasing worldwide in both developing and developed countries. Early detection and treatment of metabolic syndrome would be a cost-effective strategy to target the increasing prevalence of ESRD. Therefore, subjects with metabolic syndrome are candidates for CKD screening via dipstick proteinuria testing and serum creatinine measurements. The international community is beginning to share information on CKD through World Kidney Day, Kidney Disease Improving Global Outcomes, Commission for the Global Advancement of Nephrology, International Society of Nephrology and other scientific societies. The Japanese Society of Nephrology initiated the Asian Forum of CKD Initiative 2007 to discuss regional issues related to CKD in Asian countries. The clinical effects of metabolic syndrome vary among ethnic groups. A fundamental scientific question is the ethnic factor for calculating the glomerular filtration rate (GFR) using the Modification of Diet in Renal Disease Study equation. The incidence and prevalence of CKD are closely related with lifestyle factors such as diet, exercise, tobacco use, as well as other cultural differences. Research on the relationship between CKD and metabolic syndrome may provide clues to better understand the role of lifestyle-related factors and the age-related decline in GFR.