Received: 21 February 2020
Accepted: 13 July 2020
First Online: 31 July 2020
Ethics approval and consent to participate
: This study was approved by the Ethics Committee of the Complutense University of Madrid, Spain (number 18/067-E). All subjects were included in the study after signing the informed consent of the father, mother, or legal guardian.
: Not applicable.
: The data analyzed in the current study are available from the corresponding author on reasonable request.
: The authors declare that they have no competing interests.