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Supraphysiological doses of GH induce rapid changes in cardiac morphology and function
Antonio Cittadini1, Annika Berggren, Salvatore Longobardi
1Department of Internal Medicine and Cardiovascular Sciences, Federico II University, 80131 Naples, Italy.
Insights
High-dose growth hormone (GH) significantly increases left ventricular mass and alters cardiac function in healthy adults. This study reveals potential cardiac remodeling from GH abuse in sports, impacting heart performance.
Area of Science:
- Cardiology
- Endocrinology
- Sports Medicine
Background:
- Growth hormone (GH) is used in sports for performance enhancement and as therapy.
- Short-term effects of GH on the healthy human heart remain unclear.
Purpose of the Study:
- To investigate the short-term cardiac effects of growth hormone (GH) in healthy young adults.
- To determine if GH administration leads to cardiac structural or functional changes.
Main Methods:
- Multicenter, double-blind, placebo-controlled study.
- Sixty healthy volunteers received GH (0.03 or 0.06 mg/kg.d) or placebo for 4 weeks.
- Doppler-echocardiography assessed cardiac parameters at baseline and after treatment.
Main Results:
- Low-dose GH showed no significant cardiac effects.
- High-dose GH increased left ventricular mass index by 12% (P < 0.05).
- Concentric remodeling occurred, with increased wall thickness and relative wall thickness.
- Cardiac index increased, and peripheral vascular resistance decreased.
- Diastolic function, fractional shortening, and blood pressure remained unchanged.
Conclusions:
- Four weeks of high-dose GH administration, simulating sport abuse levels, induces a high cardiac output state.
- GH causes concentric left ventricular remodeling in healthy individuals.
- These findings highlight potential cardiac risks associated with GH use in sports.
Abstract:
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.