[1] Univ Tsukuba, Inst Clin Med, Dept Internal Med Endocrinol Metab, Tsukuba, Ibaraki 3058575, Japan
[2] Jichi Med Sch, Dept Internal Med, Tochigi 3290498, Japan
[3] Toho Univ, Sch Med, Dept Lab Med, Tokyo 1438541, Japan
[4] Chiba Univ, Dept Internal Med 2, Chiba 2608677, Japan
[5] Saitama Med Ctr, Saitama Med Sch, Dept Total Hlth Management, Kawagoe, Saitama 3508550, Japan
[6] Teikyo Univ, Dept Internal Med, Tokyo 1738606, Japan
[7] Univ Tokyo, Branch Hosp, Dept Internal Med, Tokyo 1128688, Japan
[8] Mitsui Mem Hosp, Dept Internal Med, Tokyo 1018643, Japan
[9] Tokyo Womens Univ, Sch Med, Ctr Diabet, Tokyo 1628666, Japan
[10] Asahi Life Fdn, Inst Adult Dis & Res, Tokyo 1000005, Japan
[11] Asahi Life Fdn, Inst Diabet Care & Res, Tokyo 1000005, Japan