The Relationship Between Body Mass Index and the Magnitude of Curve at Diagnosis of Adolescent Idiopathic Scoliosis: A Retrospective Chart Review

PURPOSE: To evaluate the relationship between body mass index (BMI) and spinal curvature in patients presenting with idiopathic scoliosis at a major pediatric tertiary care centre. PATIENTS AND METHODS: Retrospective chart review (2015–2019). Data extracted from patient’s first visit included age, sex, height, weight, spinal curvature (magnitude, location), referral source, physical activity participation (yes/no), pain (yes/no). Demographics were analyzed descriptively. The relationship between BMI and spinal curve magnitude was analyzed using Spearman correlation coefficient. Linear regression was applied to determine the relationship between BMI, curve magnitude, and curve location. Exploratory univariate analyses were conducted for BMI and referral source, pain, and skeletal maturity, and physical activity and pain. RESULTS: A total of 206 patient charts were included (177 females, 29 males). Patients presented with double major (41.3%), thoracic (26.7%), thoracolumbar (22.8%), and lumbar (9.2%) curves. Mean (SD) BMI percentile was 48.3 (30.5). No relationship existed between BMI percentile and curve magnitude with curve locations combined. However, a test for interaction revealed a positive relationship between BMI percentile and curve magnitude for adolescents with double major curves, and a negative relationship for adolescents with thoracic curves. Exploratory analyses suggested a relationship between BMI percentile and presence of pain, and between referral source and curve magnitude. No relationship was observed between BMI and skeletal maturity, or physical activity and pain. CONCLUSION: The relationship between BMI varied by curve location within this cohort, in which most patients presented with a BMI <85th percentile. Findings highlight the importance of sensitive history taking and careful physical examination for early detection of scoliosis.