[Delayed physical growth and related factors in pediatric patients with transfusion-dependent thalassemia]

Objectives: To investigate the physical growth status of pediatric patients with transfusion-dependent thalassemia (TDT) and analyze the effects of treatment-related and socioeconomic factors on physical growth. Methods: Based on the specialized thalassemia database from gene therapy clinical research at the Institute of Hematology & Hospital of Blood Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, we collected data on height and weight development, family economic status, and medical records of 338 pediatric patients with TDT from October 2023 to May 2024. The length/height-for-age and body mass index (BMI) -for-age were classified based on the Growth Standard for Children under 7 Years of Age, Standard for Height Level Classification among Children and Adolescents Aged 7-18 Years, and Dietary Guidelines for Chinese Residents. Logistic regression analysis was conducted to assess the effects of family economic status and disease-related treatment on length/height-for-age and BMI-for-age. Results: Among the 338 patients, 118 were children and 220 were adolescents (192 males and 146 females), with a median age of 12 years (range: 0.8-18) and a median diagnosis duration of 10.3 years (range: 0.5-17.9). Subtypes included α-thalassemia [21 cases (6.2%) ], β-thalassemia [288 cases (85.2%) ], and combined αβ-thalassemia[29 cases (8.6%) ]. The monthly household income of patients was concentrated in 3 000-5 000 yuan (39.9%) and 5 001-10 000 yuan (34.9%), whereas 67.2% of the families had monthly medical expenses of <3 000 yuan. Of the patients, 75.5% received their first transfusion before 1 year of age. The proportions of children and adolescents with pretransfusion hemoglobin (HGB) of ≤70 g/L were 4.2% and 6.4%, respectively. Adolescents demonstrated significantly higher rates of transfusion frequency of <4 weeks/session, monthly red blood cell infusion of >2 U, serum ferritin (SF) of ≥5 000 μg/L, iron chelation therapy, and splenectomy compared with children (all P<0.05). Of the 338 patients, 26.0%, 22.8%, and 8.9% demonstrated stunted growth, underweight, and concurrent stunted growth with underweight, respectively. No significant difference was observed in the stunted growth rates between children (22.9%) and adolescents (27.7%) (P=0.402). However, the underweight rate in adolescents (26.8%) was significantly higher than that in children (15.3%) (P=0.023). The multivariate analysis determined the following risk factors for stunted growth: monthly household income of <10 000 yuan (5 001-10 000 yuan: OR=5.49, 95% CI: 1.48-35.76; 3 000-5 000 yuan: OR=6.87, 95% CI: 1.88-44.60; <3 000 yuan: OR=9.29, 95% CI: 2.20-64.77), pretransfusion HGB of ≤70 g/L (OR=3.25, 95% CI: 1.07-10.18), and SF of ≥5 000 μg/L (OR = 3.04, 95% CI: 1.20-7.70). Longer diagnostic duration was associated with underweight (OR=1.10, 95% CI: 1.01-1.20) . Conclusions: Children and adolescents with TDT with pretransfusion SF of ≥5 000 μg/L, HGB of ≤70 g/L, low monthly household income, or longer diagnosis duration were significantly more likely to experience delayed physical growth.