Relative Growth Hormone Deficiency and Cortisol Excess Are Associated with Increased Cardiovascular Risk Markers in Obese Adolescent Girls

Abstract

Context: Obesity in adolescents is increasingly prevalent and its impact on cardiovascular risk important to determine. Hormonal predictors of cardiovascular risk markers in obese adolescents are not known. Objective: Our objective was to examine whether relative GH deficiency and cortisol excess are determinants of increased cardiovascular risk markers in obese teenage girls. Design and Setting: A cross-sectional study was conducted at a clinical research center. Study participants: Thirty girls (15 obese girls and 15 normal-weight controls) 12–18 years old matched for maturity and race. Main Outcome Measures: Inflammatory markers of cardiovascular risk including high-sensitivity C-reactive protein (hsCRP), TNF-α receptors 1 and 2, E-selectin, soluble intercellular adhesion molecule-1, and IL-6 were analyzed. Leptin, adiponectin, and 24-h urine free cortisol (UFC) were also measured. A GHRH-arginine stimulation test was performed. Results: The hsCRP levels were higher in obese girls than controls (4.63 ± 4.81 vs. 0.67 ± 0.72 mg/liter; P = 0.002 after log conversion), as were other markers of cardiovascular risk. Eight of the 15 obese girls but no normal-weight girl had hsCRP higher than 3 mg/liter (P = 0.002). Body mass index sd score was higher than 4.0 in 87.5% of girls with hsCRP higher than 3 mg/liter and no girls with hsCRP less than 3 mg/liter. Girls with hsCRP higher than 3 mg/liter had higher UFC and lower peak GH compared with those with hsCRP less than 3 mg/liter. Peak GH was an important negative predictor of most markers of increased cardiovascular risk. In addition to peak GH, UFC and adiponectin independently predicted hsCRP. Conclusion: Relative GH deficiency and cortisol excess are significant contributors to increased levels of markers of cardiovascular risk in obese adolescent girls.