Echocardiographic dimensions and function in adults with primary growth hormone resistance (Laron Syndrome)

Patients with primary growth hormone (GH) resistance-Laron Syndrome (LS)-ha ve no GH signal transmission, and thus, no generation of circulating insuli nlike growth factor-I (IGF-I), and should serve as a unique model to explor e the controversies concerning the longterm effect of GH/IGF-I deficiency o n cardiac dimension and function, We assessed 8 patients with LS (4 men, 4 women) with a mean ( +/- SD) age of 38 +/- 7 years (range 22 to 45), and 8 aged-matched controls (4 men, 4 women) with a mean age of 38 +/- 9 years (r ange 18 to 47) by echocardiography at rest, following exercise, and during dobutamine administration. Left ventricular (LV) septum, posterior wall, an d end-diastolic diameter were significantly reduced in untreated patients w ith LS compared with the control group (p <0.05 for all). Systolic Doppler- derived parameters, including LV stroke volume, stroke index, cardiac outpu t, and cardiac index, were significantly lower (p <0.05 for all) than in th e control subjects, whereas LV diastolic Doppler parameters, including mitr al valve waves E, A, E/A ratio, and E deceleration time, were similar in bo th groups. LV ejection fraction at rest as well as the stress-induced incre ment of the LV ejection fraction were similar in both groups. Our results s how that untreated patients with long-term IGF-I deficiency hove reduced ca rdiac dimensions and output but normal LV ejection fraction at rest and LV contractile reserve following stress, (C) 2000 by Excerpta Medico, Inc.