Insulin-like growth factor-1, insulin-like growth factor binding protein-3, and cardiovascular disease risk factors in young black men and white men: the CARDIA Male Hormone Study.

Cross-sectional studies have found associations between components of the insulin-like growth factor (IGF) system and hypertension, total cholesterol, and low density lipoprotein cholesterol. Using partial correlation analysis and longitudinal analysis of data collected at the year 2, year 7, and year 10 examinations, the authors assessed the associations of IGF-1 and IGF binding protein-3 (IGFBP-3) with cardiovascular disease risk factors in 544 Black and 747 White male participants in the Coronary Artery Risk Development in Young Adults (CARDIA) Male Hormone Study who were aged 20-34 years at year 2 (1987-1988). There were no consistent independent associations with blood pressure. Cross-sectionally, there were some inverse associations between IGF-1 and lipid levels in White men (strongest r = -0.095 (p = 0.02) for total cholesterol at year 7) and positive associations between IGFBP-3 and lipid levels in Black and White men (for log(triglycerides), r = 0.072-0.136). Longitudinally, a 1,000-ng/ml increase in IGFBP-3 was associated with 3.7-mg/dl and 2.6-mg/dl higher total cholesterol levels and 2.6-mg/dl and 1.7-mg/dl higher low density lipoprotein cholesterol levels in Black men and White men (p < 0.05), respectively. These findings do not support a strong link between IGF-1 and IGFBP-3 and blood pressure, but they do support the possibility of important relations between IGFBP-3 and lipid levels in young adult men.