Funding for this research was provided by:
National Natural Science Foundation of China (81300693)
Beijing Hospital (BJH-2019-185)
Research Special Fund for Public Welfare Industry of Health (201302008)
Received: 19 March 2020
Accepted: 5 March 2021
First Online: 19 March 2021
: The protocol was approved by the Biomedical Ethics Committee of Beijing Hospital and Beijing Institute of Geriatrics, Beijing, China.
: Not applicable.
: The authors declare that they have no competing interests.