Participants
The electronic medical records of adolescents with non-deletional Hb H disease who were followed in the Pediatric Thalassemia Clinic, Khon Kaen University Hospital, from July 2021 to July 2022 were reviewed. Inclusion criteria were i) ages 10-20 years, ii) diagnosed with non-deletional Hb H disease with or without Hb E disease by Hb typing or genetic analysis, iii) regular follow-up at our clinic ≥1 year, and iv) had a complete medical record. Participants were excluded if they i) received medications affecting bone metabolism (except for glucocorticoid treatment for autoimmune hemolytic anemia, hormonal replacement therapies, vitamin D and calcium supplementation), and ii) had other chronic diseases affecting bone metabolism except thalassemia-related endocrine diseases.
Thirty-seven participants were eligible for the study. However, 5 participant blood samples were excluded from the Dkk-1 and bone turnover marker analysis due to nonfasting samples. Six participants received glucocorticoid and were excluded from the analysis of the prevalence of low BMD. The study was approved by the Khon Kaen University Ethics Committee in Human Research. Informed consent and assent (for participants <18 years) were obtained from all participants.