Objective: Adult patients with GH deficiency (GHD) are at increased risk for cardiovascular morbidity and mortality. Endothelial function, vascular stiffness, and loss of circulating CD34+ cells are considered biomarkers for cardiovascular disease. The aim of this study was to assess vascular structure and function in relation to circulating CD34+ cells in adults with GHD before and during 1 year of recombinant human GH (rhGH) replacement.
Design: One-year intervention with rhGH.
Patients and methods: Vascular function (flow-mediated dilatation (FMD)) and structure (pulse wave velocity (PWV) and analysis) were assessed in 14 adult patients (nine men) with GHD (mean age 57 years, range 27-71 years). In addition, the number of CD34+ cells was evaluated using flow cytometric analysis. Study parameters were analyzed at baseline, and after 6 months and 1 year of rhGH replacement.
Results: rhGH replacement increased IGF-I levels from 10.4+/-4.5 mmol/l at baseline to 18.4+/-10.1 mmol/l, and 20.5+/-8.0 mmol/l, at 6 months, and 1 year respectively (P=0.001). FMD increased from 3.5+/-1.8% to 6.0+/-2.5% and 5.1+/-2.5% during 1 year of rhGH replacement (P=0.008). There was no beneficial effect on PWV, central pulse pressure, central systolic pressure, and augmentation index. The number of CD34+ cells increased from 794.9+/-798.8 to 1270.7+/-580.1 cells/ml and to 1356.9+/-759.0 cells/ml (P=0.010).
Conclusion: One year of rhGH replacement in adults with GHD improves endothelial function and increases the number of circulating CD34+ cells.