Association of serum IGF1 with endothelial function: results from the population-based study of health in Pomerania

Objective: IGF1 mediates multiple physiological and pathophysiological responses in the cardiovascular system. The aim of this study was to analyze the association between serum IGF1 as well as IGF-binding protein 3 (IGFBP3) levels and endothelial function measured by flow-mediated dilation (FMD). Design: Cross-sectional population-based observational study. Methods: The study population comprised 1482 subjects (736 women) aged 25-85 years from the Study of Health in Pomerania. Serum IGF1 and IGFBP3 levels were determined by chemiluminescence immunoassays. FMD measurements were performed using standardized ultrasound techniques. FMD values below the sex-specific median were considered low. Results: In males, logistic regression analyses revealed an odds ratio (OR) of 1.27 (95% confidence interval (CI) 1.07-1.51; P=0.008) for decreased FMD for each decrement of IGF1 S. D. after adjustment for major cardiovascular confounders. In females, no significant relationship between serum IGF1 and FMD was found (OR 0.88, CI 0.74-1.05; P=0.147). After exclusion of subjects with the current use of antihypertensive medication, these findings were similar (males: OR 1.40, CI 1.12-1.75; P=0.003; females: O=0.95, CI 0.77-1.16; P=0.595). There was no association between serum IGFBP3 levels and FMD in both sexes. Conclusions: Low serum IGF1 levels are associated with impaired endothelial function in males. In women, serum IGF1 is not associated with endothelial function.