LONG-TERM CARDIOVASCULAR EFFECTS OF GROWTH-HORMONE TREATMENT IN GH-DEFICIENT ADULTS - PRELIMINARY DATA IN A SMALL-GROUP OF PATIENTS

OBJECTIVE The long-term cardiovascular effects of GH administration in adults are of major clinical importance, given the increasing use of such treatment, We have evaluated long-term cardiovascular effects of recombinant human GH (rhGH) substitution in GH deficient men, DESIGN S .c. rhGH 0.5 U/kg/week or placebo was administered in a 6-month double -blind, cross-over study, followed (after a year without substitution) by a 42-month period of open GH substitution, PATIENTS We evaluated 7 GH-deficient men serially and compared the results with 21 men matche d in terms of age and height, MEASUREMENTS Investigations included exe rcise tests and Doppler-echocardiography to determine exercise capacit y and cardiovascular performance, RESULTS Heart rate and systolic bloo d pressure at rest increased with GH substitution to the level of the controls, as did diastolic blood pressure after an initial reduction, Age-adjusted exercise capacity increased during the study and we found no evidence of ischaemic heart disease on exercise EGG. Stroke volume increased with GH substitution, thereby normalizing the initially red uced cardiac index, There was no significant change in left atrial or ventricular internal dimensions, systolic function as measured by frac tional shortening, or diastolic function as measured by isovolumic rel axation time and left ventricular filling (A/E ratio), However, a lowe r atrial emptying index than that seen among controls might indicate s ome diastolic disturbance and there was a definite increase in left ve ntricular wall thickness compared with controls (to 25.2 +/- 1.5 vs 19 .7 +/- 0.4 mm, P < 0.001). CONCLUSIONS We found that GH substitution i n GH-deficient adults had a beneficial effect on physical performance and cardiac output. The concomitant increase in left ventricular mass index might be an effect of an excessive substitution dose.