Conflict of interest

Tatsuhito Himeno, Hiromi Nakai-Shimoda, Yusuke Hayashi, Akihiro Matsumae, and Hiromi Matsumae declare that they have no conflict of interest. Hideki Kamiya received lecture fees from Novo Nordisk Pharma, Sanofi, Sumitomo Pharma, Nippon Boehringer Ingelheim, Eli Lilly Japan, Daiichi Sankyo, Ono Pharmaceutical, Kissei Pharmaceutical, Mitsubishi Tanabe Pharma, Kowa, Novartis Pharma, MSD, and Sanwa Kagaku Kenkyusho and research funding from Eli Lilly Japan, Ono Pharmaceutical, Kissei Pharmaceutical.

Human rights statement and informed consent

All procedures were in accordance with the Helsinki Declaration of 1964 and later versions. Informed consent was obtained from the patient for being included in the report.