Influence of Insulin-Like Growth Factor-1 and Hepatocyte Growth Factor on Carotid Atherosclerosis and Cognitive Function in the Elderly

Objective: This study investigated the relationship between serum levels of two neurotrophic factors, insulin-like growth factor-1 (IGF-1) and hepatocyte growth factor (HGF), and carotid atherosclerosis and cognitive function in the elderly. Methods: Serum levels of IGF-1 and HGF, carotid artery intima-media thickness (IMT), and Mini-Mental State Examination (MMSE) scores were determined in 60 subjects over 65 years old (35 patients with vascular dementia and 25 without dementia). Results: In all subjects IGF-1 levels showed a significant positive correlation with the MMSE score (r = 0.262, p = 0.0427) and a negative correlation with the IMT (r = –0.284, p = 0.0277) and the HGF level (r = –0.422, p = 0.0007). HGF levels were significantly correlated with IMT (r = 0.259, p = 0.0455) and lipoprotein(a) levels (r = 0.279, p = 0.0372). Mean MMSE scores and IGF-1 levels were significantly lower in patients with vascular dementia than in the non-demented controls. Mean IMT and the frequency of atherosclerotic plaque in the carotid arteries as well as the serum levels of HGF, LDL cholesterol, lipoprotein(a) and lipid peroxides were significantly increased in the demented patients compared with the non-demented controls. Conclusion: A decrease of IGF-1 along with an increase of HGF may reflect an underlying biological process that influences cognitive decline as well as carotid atherosclerosis in the elderly.