Serum Insulin-like Growth Factor-I and its Binding Protein 3 in their Relation to Intima Media Thickness: Results of the Study of Health in Pomerania (SHIP).

Abstract

Objective: Previous studies detected associations between lower insulin-like growth factor I (IGF-I) levels and increased risk of congestive heart failure or ischemic heart disease. The aim of the present study was to assess the association of IGF-I and its binding protein 3 (IGFBP-3) with the carotid intima-media thickness (IMT) as marker of asymptomatic cardiovascular disease. Design and population: From the population-based Study of Health in Pomerania (SHIP), a total of 2,286 participants aged 45 years or older with readable ultrasound of the carotid arteries were available for the present analyses. Methods and measurements: Serum IGF-I and IGFBP-3 levels were categorized into three groups (low, moderate, high) according to the sex-specific 10th and 90th percentile. Analyses of variance (ANOVA) and logistic regression analyses adjusted for age, waist circumference, diabetes, hypertension, and creatinine clearance were performed. Results: After adjusting for confounding factors, IGF-I and the IGF-I/IGFBP3 ratio were positively related to IMT in analyses of variance. Logistic regression analyses confirmed these findings and showed that high IGF-I levels, a high IGF-I/IGFBP3 ratio, and low IGFBP-3 levels were associated to higher odds of increased IMT. Conclusion: In conclusion, high IGF-I or high IGF-I/IGFBP3 ratio values and low IGFBP-3 levels are associated with increased IMT. Therefore systemic levels of the IGF axis or alterations in the balance of its components are associated with subclinical atherosclerotic disease.