PROSTATIC HYPERPLASIA - AN UNKNOWN FEATURE OF ACROMEGALY

This study was designed to investigate whether GH and insulinlike grow th factor I (IGF-I) excess could lead to the development of benign pro static hyperplasia and/or prostatic carcinoma. Prostatic diameters and volume as well as the occurrence of prostatic diseases were studied b y ultrasonography in 10 untreated acromegalic patients less than 40 yr of age and 10 age- and body mass index-matched healthy males. Serum G H, IGF-I, PRL, testosterone, dihydrotestosterone, prostate-specific an tigen, and prostatic acid phosphatase levels were assessed. All patien ts had secondary hypogonadism, as diagnosed by low testosterone levels , and 4 of 10 patients had hyperprolactinemia. After 1 yr of treatment with octreotide (0.3-0.6 mg/day), ultrasound scan and hormone paramet ers were repeated. The 4 hyperprolactinemic acromegalics were treated with octreotide and cabergoline (1-2 mg/week) to suppress PRL levels. Symptoms due to prostatic, seminal vesicle, and/or urethral disorders or obstruction were experienced by neither acromegalics nor controls. Digital rectal examination revealed no occurrence of prostatic nodules or other abnormalities. Compared to healthy subjects, a remarkable in crease in transversal prostatic diameter and volume was observed in ac romegalics. In healthy subjects, prostate volume ranged from 15.1-21.8 mL, whereas in acromegalics it ranged from 21.8-41.8 mL. Similarly, a n increased median lobe was observed. In fact, the transitional zone d iameter was just detectable in 5 of 10 controls, whereas it was measur able in all acromegalics (18 +/- 1.2 vs. 2.8 +/- 0.3 mm; P < 0.001). T he prevalence of periurethral calcifications was more than doubled in acromegalics (50%) compared to that in controls (20%). Treatment with octreotide for 1 yr produced normalization of circulating GH and IGF-I levels in 7 of 10 patients. In these 7 patients, ultrasound evaluatio n showed a significant reduction of the antero-posterior diameter (26. 1 +/- 1 vs. 28.9 +/- 1.6 mm; P < 0.01), the transversal diameter (44.9 +/- 2 vs. 48 +/- 2 mm; P < 0.01), and the cranio-caudal diameter (36. 5 +/- 1 vs. 41.3 +/- 1.5 mm; P < 0.001), whereas the transitional zone diameter was unchanged (16.4 +/- 1.5 vs. 17.4 +/- 1.7 mm). As a conse quence, a significant decrease in prostate volume was recorded (22.1 /- 1.1 vs. 29.8 +/- 2.5 mt; P < 0.001). Prostate Volume increased in 2 of the 3 patients who did not achieve normalization of GH and IGF-I a fter octreotide treatment. Finally, after treatment, serum testosteron e levels were significantly increased (from 1.5 +/- 0.3 to 3.5 +/- 0.3 mu g/L), whereas dihydrotestosterone, dehydroepiandrosterone sulfate, Delta(4)-androstenedione, 17 beta-estradiol, prostate-specific antige n, and prostatic acid phosphatase were unchanged. Serum PRL levels wer e suppressed after cabergoline treatment in all 4 hyperprolactinemic p atients throughout the study period. In conclusion, prostate enlargeme nt occurs in young acromegalics with a higher than expected prevalence of micro-and macrocalcifications. This suggests that a careful prosta te screening should be included in the work-up and follow-up of acrome galic males.