In this cross-sectional study of children and adolescents diagnosed with TDT, we identified that without height-adjusted BMD correction, age (OR = 1.138, 95% CI 1.041–1.248, P 0.05), IGF-1<-2SD (OR = 1.962, 95% CI 1.163–3.321, P 0.05), and hypogonadism (OR = 2.951, 95% CI 1.085–8.444, P 0.05) were significant independent risk factors associated with low bone mass. The gene discussed is IGF1; the disease is hypogonadism.