EFFECTS OF TREATMENT WITH OCTREOTIDE IN ACROMEGALIC PATIENTS - A MULTICENTER ITALIAN STUDY

Treatment of acromegaly is effective in reversing the reduced life-spa n of patients only when serum growth hormone (GH) concentrations are l owered to less than 2.5 mu g/l. Usual treatments achieve this goal in no more than 50-60% of patients. The effects of octreotide were studie d in a prospective, open label study with 68 acromegalic patients enro lled in 10 Italian centers. Octreotide was administered sc at a dose o f 100 mu g t.i.d. for 1 year. After 3 months of therapy, octreotide wa s effective in decreasing serum GH levels below 2.5 mu g/l in 16 out o f 64 acromegalic patients (25%). Fifteen of them had pretreatment GH l evels below 25 mu g/l. Insulin-like growth factor I (IGF-I) levels nor malized in about 40% of patients. No further GH reduction was observed after 1 year of treatment. The presence of abnormal GH responses to t hyrotropin-releasing hormone (TRH) and gonadotropin-releasing hormone was reduced from 54 to 24% and from 16 to 12%, respectively. Tumor shr inkage was observed in 50% of 26 non-irradiated patients after 12 mont hs of treatment. Both basal and TRH-stimulated serum prolactin levels significantly decreased in the 11 hyperprolactinemic patients. Althoug h serum thyrotropin, free triiodothyronine and free thyroxine concentr ations were not modified, a significant reduction of thyrotropin respo nse to TRH was observed in the 9th month of therapy. In non-diabetic p atients, an increase of mean blood glucose levels without modification s of fasting morning concentrations was found. About one-quarter of th e patients with overt diabetes mellitus had an impairment of their met abolic control. Main clinical symptoms of acromegaly improved in 70-80 % of patients. An 18% decrease of low-density-lipoprotein cholesterol and unchanged high-density-lipoprotein cholesterol levels were observe d in 35 patients studied. Triglyceride levels decreased in patients wi th hypertriglyceridemia pretreatment. Regarding side effects, gallston es were newly diagnosed in five patients, three patients dropped out b ecause of severe diarrhea and two diabetic patients dropped out due to worsening of their metabolic control. In conclusion, octreotide is an effective treatment of acromegaly, mainly in patients with moderate e levation of serum GH levels. The drug has also been proved to positive ly affect dyslipidemia.