1 Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan; Department of Internal Medicine, Chiba Aoba Municipal Hospital, Chiba, Japan.
2 Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. Electronic address: yoshiromaezawa@chiba-u.jp.
3 Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan.
4 Department of Diabetes, Metabolism and Endocrinology, University: School of Medicine, International University of Health and Welfare, 4-3, Kozunomori, Narita, Chiba 286-8686, Narita, Japan. Electronic address: minoru.takemoto@iuhw.ac.jp.