Clinical relevance of insulin-like growth factor-1 to cardiovascular risk markers

Objective: Insulin-like growth factor-1 (IGF-1) is an anabolic hormone, the levels of which decline with age. The present study aimed to determine the impact of age-related declines in serum IGF-1 levels on various physiological processes. Design: We retrospectively reviewed the medical records of patients whose serum IGF-1 levels were estimated in our department, and assessed the relationships between serum IGF-1 levels and various physiological parameters. Results: A total of 427 patients with a mean (± standard deviation) age of 52.8 (± 17.1) years were included in the analysis. The levels of serum IGF-1 showed significant positive correlation with those of hemoglobin and hematocrit, and negative correlation with the presence of inflammatory and fibrin-related markers including C-reactive protein (CRP) and procalcitonin (PCT), and D-dimer and fibrin degradation products (FDP). These tendencies persisted after exclusion of patients with pituitary disease. Conclusions: In this study population of diverse diseases and backgrounds, a decline in serum IGF-1 levels with age was associated with an increase in inflammatory and fibrin-related markers. This may explain the correlation between low serum IGF-1 levels and an increased risk of cardiovascular events. Our findings suggest that serum IGF-1 is a clinically relevant marker of cardiovascular risk, particularly in males.