IGF-1 is associated with estimated bone strength in anorexia nervosa.

Abstract

Women with anorexia nervosa, a psychiatric disorder characterized by self-induced starvation and low body weight, have impaired bone formation, low bone mass, and an increased risk of fracture. IGF-1 and leptin are two nutritionally dependent hormones that have been associated with low bone mass in women with anorexia nervosa. We hypothesized that IGF-1 and leptin would also be positively associated with estimated bone strength in women with anorexia nervosa. In this cross-sectional study of 38 women (19 with anorexia nervosa and 19 normal-weight controls), we measured serum IGF-1 and leptin and performed finite element analysis of high-resolution peripheral quantitative CT images to measure stiffness and failure load of the distal radius and tibia. IGF-1 was strongly correlated with estimated bone strength in the radius (R = 0.52, p = 0.02 for both stiffness and failure load) and tibia (R = 0.55, p = 0.01 for stiffness and R = 0.58, p = 0.01 for failure load) in the women with anorexia nervosa but not in normal-weight controls. In contrast, leptin was not associated with estimated bone strength in the group of women with anorexia nervosa or normal-weight controls. IGF-1 is strongly associated with estimated bone strength in the radius and tibia in women with anorexia nervosa. Further studies are needed to assess whether treatment with recombinant human IGF-1 will further improve bone strength and reduce fracture risk in this population.