Multiple linear regression analysis showed that IGF-1 burden was negatively correlated with the preoperative BMD Z score at L1 (Figure 1(a)) (r = −0.398, p=0.007, R = 0.631) and L1–L4 (Figure 1(b)) (r = −0.387, p=0.01, R = 0.619) in patients with GH-secreting pituitary adenoma. Here, IGF1 is linked to pituitary gland adenoma.