Funding for this research was provided by:
National Institute on Aging (R01-AG034853-01A2)
National Institute of Diabetes and Digestive and Kidney Diseases (3T32DK007219-41S1)
Received: 15 October 2018
Accepted: 18 December 2018
First Online: 3 January 2019
Ethics approval and consent to participate
: The institutional review boards of participating institutions approved the study protocol, and written informed consent was obtained from all study participants. The University of California, San Francisco and San Francisco Veterans Affairs Medical Center Institutional Review Board approved the present analysis (IRB approval number 14–14671).
: Not applicable
: The authors declare that they have no competing interests.
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