Pituitary radiographic abnormalities and clinical correlates of hypogonadism in elderly males presenting with erectile dysfunction

Abstract

The prevalence of erectile dysfunction rises rapidly with age and is a frequent complaint presented in clinical practice. Although the etiology of erectile dysfunction is multifactorial, 10-20% of evaluationsdemonstrate testosterone deficiency. Testosterone deficiency due to secondary hypogonadism increases with age. Despite a higher prevalence of secondary hypogonadism in the elderly, there are no studiesaddressing hypothalamic-pituitary structural abnormalities in elderly impotent men with testosterone deficiency.We retrospectively reviewed the records of all elderly men who presented for generaloutpatient evaluation of erectile dysfunction from 1996 to 1999. To obtain a cohort control population, the records of 300 patients without erectile dysfunction were also reviewed. Amongst the erectiledysfunction patients, 225 were found to be testosterone deficient (testosterone < 300 ng/dl). Of these patients, 29 were additionally diagnosed with secondary hypogonadism based on a luteinizing hormone(LH) < 13 mIU/ml. Magnetic resonance imaging (MRI) or computed tomography (CT) imaging was available and reviewed in all patients diagnosed with secondary hypogonadism. Ten per cent of these patientshad hypothalamic-pituitary imaging abnormalities. The prevalence of pituitary tumors within our population was not significantly elevated compared to the previous general population studies. Small-vesselwhite matter disease, hyperlipidemia and history of compression fractures were significantly increased in both univariate and multivariate analysis in the erectile dysfunction group compared with the controlcohort.This study does not suggest that the use of hypothalamic-pituitary imaging in the evaluation of impotence in elderly men, in the absence of clinical characteristics of other hormonal loss orsella compression symptoms, will increase diagnosis of structural hypothalamic-pituitary abnormalities over that of the general population. However, the yield may increase with very low testosterone levels.These data suggest that there is an increase in ischemic white matter disease in elderly men with hypogonadism that may reflect microvascular injury to the hypothalamic-pituitary. Furthermore, these dataconfirm that low testosterone is associated with hyperlipidemia in the elderly. Future studies are required to assess the role of hypogonadism and hyperlipidemia, and to determine if treatment of the hormonedeficiency improves the lipid profile.