Supraphysiological doses of GH induce rapid changes in cardiac morphology and function
Cittadini, A.; Berggren, A.; Longobardi, S.; Ehrnborg, C.; Napoli, R.; Rosén, T.; Fazio, S.; Caidahl, K.; Bengtsson, B.-A.; Saccà, L.
Journal of Clinical Endocrinology and Metabolism 87(4): 1654-1659
2002
ISSN/ISBN: 0021-972X PMID: 11932297 DOI: 10.1210/jcem.87.4.8363Document Number: 259420
GH is an agent widely used in sport to improve physical performance and has been proposed as adjunctive therapy in several clinical conditions. However, its short-term effects on the normal human heart are poorly understood. Sixty young normal volunteers (30 males and 30 females) were enrolled in a multicenter, double-blind, placebo-controlled study. All subjects were randomized to receive GH (0.03 or 0.06 mg/kg.d) or placebo. A complete Doppler-echocardiographic examination was performed at baseline and after 4 wk of treatment. Low-dose GH did not significantly affect echocardiographic parameters. In contrast, high-dose GH increased left ventricular mass index by 12% (P < 0.05). The type of growth response was concentric, because left ventricular wall thickness but not diameter increased, leading to a 10% increase of relative wall thickness. These structural changes were associated with functional changes, including a significant increase in cardiac index and a decrease in peripheral vascular resistance; diastolic function was not altered. Fractional shortening and systemic blood pressure were unchanged in the two treatment groups. In conclusion, administration of GH for 4 wk at doses that simulate GH abuse in sport caused a high cardiac output state associated with concentric left ventricular remodeling.