Body composition analysis in adolescents idiopathic scoliosis and its correlation with the severity of scoliosis

To analyze the body composition of adolescents idiopathic scoliosis(AIS) patients at different stages of skeletal maturity and to explore the correlation between body composition and the severity of scoliosis. Data were collected from 243 patients diagnosed with AIS who fulfilled the specified inclusion and exclusion criteria at the Spine Surgery Outpatient Clinic of Xiangya Hospital, Central South University, during the period from 2023 to 2024. The data encompassed basic demographic information, radiological assessments, and body composition metrics. Patients were categorized based on Risser grade (0-5) and Cobb angle, with classifications of mild (< 20°), moderate (20-40°), and severe (≥ 40°) scoliosis. A comparative analysis of body composition across the different groups was conducted, alongside an investigation into its correlation with the severity of scoliosis. As the Risser sign grade increases, the age, height, weight, and BMI of AIS patients gradually increase (p < 0.05), while the muscle percentage of the whole-body, trunk, and limbs gradually decrease (p < 0.05). Patients in the mild group have significantly higher muscle percentage and significantly lower subcutaneous fat percentage compared to the moderate and severe groups (p < 0.05) ; the whole-body muscle percentage and the ratio of it to subcutaneous fat percentage have a weak negative correlation with the rotation of the apical vertebra (AVR) (r = - 0.131, p = 0.042; r = - 0.169, p = 0.009), and the whole-body subcutaneous fat percentage has a weak positive correlation with AVR (r = 0.150, p = 0.021). In AIS patients, as skeletal maturity progresses, there is a gradual decrease in both whole-body and local muscle percentage. The whole-body muscle percentage and whole-body subcutaneous fat percentage exhibit a weak correlation with the curvature associated with scoliosis. During conservative treatment, increasing the percentage of whole-body muscle mass while reducing the percentage of whole-body subcutaneous fat may be beneficial for patients with AIS.