Growth Hormone Deficiency in Patients with Chronic Heart Failure and Beneficial Effects of Its Correction

CONTEXT: A reduced activity of the GH/IGF-I axis in chronic heart failure (CHF) has been described by several independent groups and is associated with poor clinical status and outcome. OBJECTIVE: The aim of the current study was to investigate the prevalence of GH deficiency in a patient population with CHF and evaluate the cardiovascular effects of GH replacement therapy. DESIGN AND SETTING: The randomized, single-blind, controlled trial was conducted at the Federico II University. PARTICIPANTS: One hundred fifty-eight patients with CHF, New York Heart Association class II-IV, underwent a GH stimulation test. Sixty-three patients satisfied the criteria for GH deficiency, and 56 of them were enrolled in the trial. INTERVENTION: The treated group (n = 28) received GH at a replacement dose of 0.012 mg/kg every second day (approximately 2.5 IU). MAIN OUTCOMES MEASURES: Changes in physical performance and various cardiovascular indexes were measured. RESULTS: GH replacement therapy improved quality of life score (from 46 +/- 5 to 38 +/- 4; P < 0.01), increased peak oxygen uptake and exercise duration (from 12.9 +/- .9 to 14.5 +/- 1 ml/kg x min and from 520 +/- 36 to 586 +/- 43 sec, respectively; P < 0.01), and flow-mediated vasodilation (from 8.8 +/- 1.3 to 12.7 +/- 1.2%; P < 0.01). GH increased left ventricular ejection fraction (from 34 +/- 2 to 36 +/- 2%; P < 0.01) and reduced circulating N-terminal pro-brain natriuretic peptide levels (from 3201 +/- 900 to 2177 +/- 720 pg/ml; P = 0.006). No significant changes from baseline were observed in controls. CONCLUSIONS: As many as 40% of patients with CHF are GH deficient. GH replacement therapy in these patients improves exercise capacity, vascular reactivity, left ventricular function, and indices of quality of life.