1. ¹Andrology Unit, Department of Clinical Physiopathology, University of Florence, Florence, Italy
2. ²Diabetes Section Geriatric Unit, Department of Critical Care, University of Florence, Florence, Italy
3. ³Psychiatry Unit, Department of Neurological and Psychiatric Sciences, University of Florence, Florence, Italy
4. ⁴Endocrinology Unit, Department of Internal Medicine, Polytechnic University of Marche, Ancona, Italy
5. ⁵Endocrinology Unit, Maggiore-Bellaria Hospital, Bologna, Italy
6. ⁶International Institute of Sexology, Florence, Italy

Correspondence: Professor M Maggi, Andrology Unit, Department of Clinical Physiopathology, Viale Pieraccini 6, 50139 Florence, Italy. E-mail: m.maggi@dfc.unifi.it

⁷These two authors contributed equally to this work

Received 2 March 2005; Revised 20 June 2005; Accepted 20 June 2005; Published online 1 September 2005.

Abstract

Patients with diabetes mellitus (DM) were more often hypogonadal than normal fasting glucose subjects. The aim of this investigation is the assessment of characteristics and psychobiological correlates of DM associated with hypogonadism (DMAH). The Structured Interview SIEDY^© was used along with several biochemical, psychological and instrumental investigations in a series of more than 1200 patients with erectile dysfunction (ED); 16% of whom with type II DM. Hypogonadism was defined as circulating total testosterone (T) below 10.4 nmol/l. The prevalence of hypogonadism was 24.5% in DM versus 12.6% in the rest of the sample (P<0.0001); differences in the prevalence of hypogonadism retained significance after adjustment for age and BMI. DMAH was associated with typical hypogonadism-related symptoms, such as reduction in sexual desire, leading to a decreased number of sexual attempts, and with higher depressive symptomatology. In DMAH, testis size and LH concentrations were significantly reduced, suggesting a central origin of the disease. At penile Duplex ultrasound examination, diabetic patients and in particular hypogonadal type II diabetic patients showed lower levels of basal and dynamic (after PGE₁ injection) peak systolic velocity and acceleration, when compared to the rest of the sample, even after adjustment for age and BMI. Our results show that hypogonadism is frequently associated with type II DM, at least in the 6th decade. DMAH might exacerbate sexual dysfunction by reducing libido and mood and further compromising penile vascular reactivity.