Echocardiographic evidence for a direct effect of GH/IGF-I hypersecretion on cardiac mass and function in young acromegalics

OBJECTIVE: The interpretation of echocardiographic abnormalities in acromegalic patients is complicated by non-specific age-related diseases, many of which are commoner in acromegaly. We have therefore investigated the cause-effect relationship between GH/IGF-I hypersecretion and precocious cardiovascular abnormalities in a series of young acromegalic patients. DESIGN: An open prospective study. PATIENTS: 20 acromegalic patients aged under 30 years, with normal blood pressure and glucose tolerance, and 20 age- matched control subjects. MEASUREMENTS: Cardiac morphological parameters and indices of systolic and diastolic function at rest were studied by Doppler echocardiography. RESULTS: Left ventricular mass (LVM) and LVM index (LVMI) were higher in acromegalics than in control subjects (215.0 ± 15.4 g vs 140.8 ± 8.5 g, P = 0.0002 and 109.8 ± 5.9 g/m2 vs 82.1 ± 3.7 g/m2, P = 0.0008, respectively), reaching values of left ventricular hypertrophy in 4 patients (20%). Both ejection fraction and fractional shortening were normal (66.4 ± 2.1% vs 62.2 ± 1.9% and 37.5 ± 1.5% vs 35.8 ± 1.3%, respectively), indicating normal left ventricular systolic function. Abnormalities of left and right diastolic ventricular filling were found, which consisted of an increased isovolumic relaxation time (99.2 ± 2.7 ms vs 89.0 ± 2.7 ms, P = 0.01) and impaired mitral and tricuspidal flow velocity curves. CONCLUSIONS: An increase in cardiac mass and subclinical biventricular diastolic dysfunction were observed in young acromegalic patients. These findings argue for a direct cause-effect relationship between GH/IGF-I hypersecretion and myocardial abnormalities, and indicate that careful cardiological evaluation is mandatory in all acromegalics, whatever their age.