Received: 6 May 2020
Accepted: 10 February 2021
First Online: 23 February 2021
Ethics approval and consent to participate
: Not applicable, because this is a narrative review without original research data.
: Not applicable, because this is a narrative review without original research data, without patient inclusion and without patient information.
: This review was written independently. The authors did not receive financial or professional help with the preparation of the manuscript. <b>NP</b> has been an advisory board member of TrigoCare International, Abbott, AstraZeneca, Elpen, MSD, Novartis, Novo Nordisk, Sanofi-Aventis and Takeda; has participated in sponsored studies by Eli Lilly, MSD, Novo Nordisk, Novartis and Sanofi-Aventis; received honoraria as a speaker for AstraZeneca, Boehringer Ingelheim, Eli Lilly, Elpen, Galenica, MSD, Mylan, Novartis, Novo Nordisk, Pfizer, Sanofi-Aventis, Takeda and Vianex; and attended conferences sponsored by TrigoCare International, AstraZeneca, Boehringer Ingelheim, Eli Lilly, Novartis, Novo Nordisk, Pfizer and Sanofi-Aventis. The other authors report no conflicts of interest.