1. Department of Medicine and Clinical Science, Okayama Saiseikai General Hospital, Okayama, Japan
2. Center for Chronic Kidney Disease, Peritoneal Dialysis, Okayama Saiseikai General Hospital, Okayama, Japan
3. Department of Brain Science, Okayama Saiseikai General Hospital, Okayama, Japan
4. Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, and Department of Nephrology, Okayama Saiseikai General Hospital, Okayama, Japan