Funding for this research was provided by:
Norges Teknisk-Naturvitenskapelige Universitet
Article History
Received: 13 September 2019
Accepted: 27 May 2020
First Online: 10 June 2020
Ethics approval and consent to participate
: All participants in the HUNT study signed a written consent form to participate and the Regional Committee for Medical Research Ethics approved the study.
: Not applicable.
: The authors declare that they have no competing interests.