High serum levels of IGF-I and IGFBP3 may increase comorbidity risk for asthmatic patients.

OBJECTIVE: Asthma is known as a chronic inflammatory lung disease which has also systemic features. Insulin-like growth factor I (IGF-I) plays a role for asthma pathogenesis. Controversially, IGF-binding protein 3 (IGFBP3) blocks asthma development. That is why IGF-I and IGFBP3 are targeted for future therapeutic treatments of asthma. We aimed to investigate serum level of IGF-I and IGFBP3 in patients with asthma. This study was performed in 27 asthma and 23 healthy individuals. Serum levels of IGF-I and IGFBP3 were measured by human ELISA assay kits. Serum levels of IGF-I and IGFBP3 were significanlty higher in the asthma group than the control group. Significant negative correlation was found between IGF-I and asthma control test (ACT) puan, O2 saturation, Forced Expiratory Volume in 1 second/ Forced Vital Capacity (FEV1/FVC), Forced Expiratory Flow 25 second/75 second (FEF2575) (%). Significant positive correlation was found between IGFBP3 and IGF-I, systolic blood pressure. Significant negative correlation was found between IGF-I and FEV1 (ml).
RESULTS: Our results indicate that the serum levels of IGF-I and IGFBP3 are significanlty elevated in the asthma group. We assume that current treatment strategies are not really good enough for asthma. We suppose further strategies which are seeking to balance IGF-I and IGFBP3 should be developed for more effective and curative treatment of asthma (Tab. 2, Fig. 2, Ref. 22).