Supraphysiological doses of GH induce rapid changes in cardiac morphology and function.
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.
Cittadini
Antonio
A
Department of Internal Medicine and Cardiovascular Sciences, Federico II University, 80131 Naples, Italy.
Berggren
Annika
A
Longobardi
Salvatore
S
Ehrnborg
Christer
C
Napoli
Raffaele
R
Rosén
Thord
T
Fazio
Serafino
S
Caidahl
Kenneth
K
Bengtsson
Bengt-Ake
BA
Saccà
Luigi
L
D000328:Adult; D002302:Cardiac Output / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004452:Echocardiography; D005260:Female; D013006:Growth Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D006321:Heart / Q000033:anatomy & histology* / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008297:Male; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000627:therapeutic use; D012016:Reference Values; D020257:Ventricular Remodeling
D011994:Recombinant Proteins; D013006:Growth Hormone