HIGHER GROWTH HORMONE LEVELS ARE ASSOCIATED WITH ERECTILE DYSFUNCTION IN MALE PATIENTS WITH ACROMEGALY

Objective: To investigate in vivo correlates of erectile dysfunction (ED) in male patients with acromegaly. Methods: Fifty-one male patients with acromegaly were assessed by the International Index of Erectile Function-5 and Acromegaly Quality of Life (Acro-QoL) questionnaires. The measurement of serum nitric oxide (NO) were performed in patients and age-matched nonacromegalic controls. Results: Among 51 patients analyzed, 32 (62.7%) had ED. Patients with ED showed lower Acro-QoL scores regarding global (69.8 +/- 17.7 versus 79.4 +/- 11.2; P = .035) and personal relationship dimensions (59.6 +/- 22.1 versus 76.8 +/- 17.6; P = .012) than non-ED patients. ED patients were older (44.5 +/- 11.2 years versus 33.2 +/- 8.5 years; P = 04) and showed higher growth hormone (GH) levels (15.5 mu g/L[interquartile range of 9.5 to 34.5 mu g/L] versus 5.9 mu g/L [interquartile range of 3.4 to 13.9 mu g/L]; P = .001) compared to non-ED patients. The cutoff values for identifying ED were 7.9 mu g/L for random GH and 53 mu g/L for GH nadir after oral administration of 75 g of glucose. There was no significant difference in total testosterone levels between the two groups (6.36 +/- 4.24 nmol/L versus 9.54 +/- 5.50 nmol/L; P = .299). The NO levels in patients with acromegaly were significantly lower than those in nonacromegalic controls (8.77 +/- 1.78 mu mol/L versus 19.19 +/- 5.02 mu mol/L, respectively; P = .049). Furthermore, the NO levels were even lower in ED patients than those in non-ED patients (5.14 +/- 0.98 mu mol/L versus 12.09 +/- 3.44 mu mol/L; P = .027). Conclusion: Our study showed that ED is prevalent in male acromcgalic patients and may be associated with systemic endothelial dysfunction induced by excessive GH. Further studies investigating the mechanism of GH and ED are required.