Thyroid hormones and male sexual function
G. Corona1,2, W. Frederick3, G. Forti1, D. Lee4, D. OConnor5, T. ONeill4, N. Pendleton6, G. Bártfai7, S. Boonen8, F. Casanueva9, J. Finn4, A. Giwercman10, H. Thang11, I. Huhtaniemi12, K. Kula13, M. Lean14, M. Punab15, D. Vanderschueren16, E. Jannini17, E. Mannucci1 & M. Maggi1
Objective: The role of thyroid hormones in the control of erectile functioning has been only marginally investigated. The aim of this study is to investigate the association between thyroid and erectile function in a general population sample (European Male Aging study, EMAS study) and in patients seeking medical care for sexual dysfunction (University of Florence Study, UNIFI study).
Participants: Two different cohorts of subjects were evaluated. The first one derives from EMAS study, a multicenter survey performed on a sample of 3370 community dwelling men aged 4079 years (mean 60±11 years). The second cohort is a consecutive series of 3203 heterosexual male patients (mean age 51.8±13.0 years) attending our Andrology and Sexual Medicine Outpatient Clinic for sexual dysfunction at the University of Florence (UNIFI study). In the EMAS study all subjects were tested for thyroid-stimulating hormone (TSH) and free thyroxin (FT4). Similarly, TSH levels were checked in all patients in the UNIFI study, while FT4 only when TSH resulted outside the reference range.
Results: Overt hyperthyroidism (reduced TSH and elevated FT4, according to the reference range) was found in 0.3 and 0.2% of EMAS and UNIFI study, respectively. In the EMAS and UNIFI samples, TSH levels were inversely related with erectile dysfunction (ED). Overt hyperthyroidism was associated with an increased risk of severe erectile dysfunction (ED, hazard ratio=14 and 16 in the EMAS and UNIFI study, respectively; both P<0.05), after adjusting for confounding factors. These associations were conformed in nested case-control analyses, comparing subjects with overt hyperthyroidism to age, BMI, smoking status and testosterone-matched controls. Conversely, no association between hypothyroidism and ED was observed.
Conclusions: Erectile function should be evaluated in all individuals with hyperthyroidism. Conversely, assessment of thyroid function cannot be recommended as routine practice in all ED patients.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.