Funding for this research was provided by:
Natural Science Foundation of Fujian Province (2018I0006, 2019I0011, 2018Y4003)
Received: 1 September 2019
Accepted: 9 March 2020
First Online: 30 March 2020
Ethics approval and consent to participate
: The study was approved by the institutional review board of The First Affiliated Hospital of Fujian Medical University (ethical approval number: 2018–026). All individuals (or their parents) in the study population were informed about the current study and provided written consent obtained before enrolment in the study.
: Not applicable.
: The authors declare that they have no competing interests.