Methods
This is a cross-sectional study carried out in individuals diagnosed with SCA genotypes (HbS-S) between 6 and 18 years old, from the Pediatric Hematology Outpatient Clinic of Darcy Vargas Children Hospital, Sao Paulo, Brazil. The control group (CG) was composed by healthy individuals matched for age and sex, recruited from educational institutions in the city of Sao Paulo, Brazil. The research was approved by the Research Ethics Committee (Protocol number: 2.843.860). The informed consent form for the study was signed by the legal guardians. All participants signed the consent form and the parents or guardians signed the informed consent form.
Individuals who had neurological or musculoskeletal diseases or did not perform the tests properly were excluded, also those who were hospitalized in the last four weeks. Individuals in the control group who presented lung function < 80% of the predicted value were also excluded.