Elevation of E-Selectin Concentrations may Correlate with Potential Endothelial Dysfunction in Individuals with Hypopituitarism During Therapy with Growth Hormone

Abstract

Increased mortality due to cardiovascular disease has been described in adult patients with untreated growth hormone (GH) deficiency. GH replacement therapy has been demonstrate to improve vascular reactivity and reverses early atherosclerotic changes in GH deficient adults. The objective of this study was the assessment of fibrinolytic markers, soluble adhesion molecules, inflammatory cytokines and endothelial function in hypopituitary adults with GH deficiency and with GH replacement therapy. We studied 20 GH deficient patients, 10 men and 10 women (aged, 43.4 +/- 8.4 years) under GH replacement therapy compared with a control group matched for age and body mass index, 9 men and 16 women. All subjects, patients and controls, were life-long non-smokers, normotensive and non-diabetic. The following variables were recorded: anthropometrical and body composition variables, serum concentrations of glucose, insulin and C-peptide; thrombin anti-thrombin fragments and fibrin degradation product D-dimer that were determined by an enzyme-linked-immunosorbent assay (ELISA); IGF-I by radioimmunoassay; C-reactive protein by highly sensitive immunonephelometry; E-selectine, P-selectine, soluble intercellular cell adhesion molecule-1, soluble vascular cell adhesion molecule-1, interleukin-6 and monocyte chemoattractant protein-1 by ELISA. The assessment of endothelial function in vivo was measured by Doppler. Patients with GH deficiency had higher hip/waist ratio and C-peptide and triglycerides concentrations than controls. Our results demonstrated no difference in fibrinolytic markers among patients and controls. E-selectin concentrations were higher in patients than in controls, 22.5+/-11.4 vs. 10.7+/-6.2 microg/L, p = 0.0001. P-selectin, soluble intercellular cell adhesion molecule-1, soluble vascular cell adhesion molecule-1, interleukin-6, monocyte chemoattractant protein-1 and C-reactive protein were similar in the 2 groups. Vascular reactivity and carotid intima-media thickness were also similar in patients and controls. In this study we have demonstrated in adults with GH deficiency under GH substitution elevation of E-selectin concentrations that may correlate with potential endothelial dysfunction suggesting that the protective effect of GH in these patients may be enhancing other mechanisms.