Little information is available on cardiac involvement in GH-deficient adults. Thus, we evaluated cardiac structure and function by means of one- and two-dimensional echocardiography in 11 adult patients [3 women and 8 men; mean age, 27.2 +/- 3.8 (+/- SD) yr] affected with GH deficiency. Twelve age- and sex-matched normal subjects served as the control group. All patients had been treated with extractive GH over 9 yr, and therapy withdrawal had been performed at least 3 yr before entering the study. GH-deficient patients had significantly lower values of interventricular septum (7.1 +/- 1 vs. 9 +/- 0.4 mm; P < 0.01) and left ventricular posterior wall thickness (6.1 +/- 1 vs. 9 +/- 0.4 mm; P < 0.01), which resulted in a significantly smaller left ventricular mass index (54 +/- 11 vs. 85 +/- 15 g/m2; P < 0.001). The left ventricular end-diastolic and end-systolic diameters did not differ significantly after correction for body area surface, whereas ejection phase indices showed lower values, with a fractional shortening of 34 +/- 4% vs. 38 +/- 5% (P < 0.05) and an ejection fraction of 59 +/- 9% vs. 69 +/- 10% (P < 0.05). In conclusion, the results of this study demonstrate the involvement of cardiac muscle in patients affected with GH deficiency.