Rapid reduction of left ventricular hypertrophy in acromegaly after suppression of growth hormone hypersecretion.

OBJECTIVE

To examine the possible role of growth hormone as a pathogenetic factor in the development of myocardial hypertrophy in acromegaly.

DESIGN

An uncontrolled clinical trial.

SETTING

Tertiary-care medical center.

PATIENTS: Sixteen patients with acromegaly were stratified into two groups: Group I (n = 10) had left ventricular hypertrophy (LVH), and group II (n = 6) did not have LVH.

INTERVENTION: Therapy with octreotide acetate (SMS 201-995), a long-acting somatostatin analog (mean dose, 538 micrograms/d), was administered for 2 months.

MEASUREMENTS: Plasma growth hormone and insulin-like growth factor I (IGF-I) concentrations, hand volume, and echocardiographic left ventricular dimensions and mass were measured at baseline and at 1 week and 2 months after the start of therapy.

RESULTS

Before octreotide therapy, both groups had similar hand volumes and similar growth hormone and IGF-I hypersecretion. Both groups showed a reduction in growth hormone at 2 months (mean reduction, 13.7 micrograms/L in patients with LVH [P < 0.01] and 14.1 micrograms/L in patients without LVH [P < 0.05]). Plasma IGF-I was also decreased (mean reduction, 305 micrograms/L in patients with LVH [P < 0.01] and 304 micrograms/L in patients without LVH [P < 0.05]). Reduction of growth hormone and IGF-I hypersecretion in patients with LVH was associated with a rapid decrease in left ventricular mass (339 g to 299 g, P < 0.01) within 1 week, which was sustained at 2 months (274 g, P < 0.04). Patients without LVH showed no statistical change in left ventricular mass. In patients with LVH, the decrease in left ventricular mass correlated with the octreotide-induced decrease in growth hormone (r = 0.79, P less than 0.05) but not with blood pressure. Blood pressure, left ventricular dimensions, and percent of fractional shortening were not altered by therapy in either group. Hand volume decreased in both groups.

CONCLUSIONS

Normalization of growth hormone secretion is associated with reduction of left ventricular mass in acromegalic patients with LVH within 1 week of initiating therapy with octreotide.