The insulin-like growth factor binding protein 3 ternary complex is reduced in cirrhosis

Background/Aims: In healthy adults, serum insulin-like growth factor I (IGF -I), IGF binding protein 3 (IGFBP-3) and acid labile subunit (ALS) form a 1 50-kDa ternary complex under the control of growth of hormone (GH). Approxi mately 80-90% of circulating IGF-I is bound to the ternary complex. In cirr hosis the GH/IGF axis is severely disturbed and the individual components o f the ternary complex are reduced. However, the degree of ternary complex f ormation in cirrhosis has not previously been described. Methods: Serum IGF -I, IGFBP-3, ALS, the 150-kDa ternary complex and IGFBP-3 proteolysis were all measured in six compensated and six decompensated cirrhotic patients an d compared to six healthy controls. Results: Patients with compensated cirr hosis had decreased levels of IGF-I (55%), IGFBP-3 (64%) and ALS (53%), and in the decompensated patients these levels were decreased even further: IG F-I (32%), IGFBP-3 (37%) and ALS (27%) compared to healthy controls. The le vels of the ternary complex followed this pattern, with low levels seen in the compensated patients (66%) and a further reduction in the decompensated patients (27%). Ternary complex levels correlated negatively with the Chil d-Pugh score. No increase in IGFBP-3 proteolysis was found in cirrhotic pat ients compared to healthy controls. Conclusion: Cirrhosis is associated wit h reduced levels of the 150-kDa ternary IGFBP-3 complex correlating with th e degree of liver disease.