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

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.

An open prospective study.

20 acromegalic patients aged under 30 years, with normal blood pressure and glucose tolerance, and 20 age-matched control subjects.

Cardiac morphological parameters and indices of systolic and diastolic function at rest were studied by Doppler echocardiography.

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.

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.