1. Department of Hematology, Endocrinology and Metabolism, Niigata University Faculty of Medicine, Niigata 951-8510, Japan
2. Department of Human Life Science, Tokushima Bunri University, Tokushima 770-7514, Japan
3. Department of Health and Nutrition, University of Niigata Prefecture, Niigata 950-8680, Japan
4. Department of Pediatrics, Niigata University Medical and Dental Hospital, Niigata 951-8520, Japan