Department of Experimental and Clinical Biomedical Sciences. University of Florence, Florence, Italy. Madrid, February 4 th, 2016

Transcription

1 Associations between thyroid hormones, ejaculatory machinery and semen parameters: possible mechanisms. Francesco Lotti, MD, PhD Sexual Medicine and Andrology Unit (Director: Prof. Mario Maggi) Department of Experimental and Clinical Biomedical Sciences European Academy of Andrology University of Florence, Florence, Italy Madrid, February 4 th, 2016

2 Hyperthyroidism greater propensity to ejaculate

3 Hyperthyroidism cause of acquired premature ejaculation

4 Although thyroid hormones (TH) excess could act on supraspinal regions which control ejaculation no study systematically evaluated, in humans, associations between TH and male genital tract organs involved in the ejaculation process.

5 Furthermore, only a few studies evaluated correlations between TH and semen parameters, without conclusive results.

6 Aim of the study: to investigate the associations between TH, clinical, seminal and male genital tract organs (assessed by ultrasound), in males of infertile couples

7 Methods Cross-sectional study Consecutive series of 172 males of infertile couples (WHO, 2000) 163 (38.7 ± 7.6 anni) without genetic abnormalities. Evaluation, within the same day: -medical history, physical examination - TSH, FT3, FT4 and other biochemical parameters - scrotal and transrectal color-doppler ultrasound before and after ejaculation - semen analysis (WHO, 2010)

8 Methods Evaluation also of seminal: -fructose levels: marker of secretory function of seminal vesicles -interleukin 8 (sil-8): marker of male genital tract inflammation

9 Methods TH reference ranges of Florence Central Lab: TSH = mu/l, FT4 = pmol/l, FT3 = pmol/l. Diagnosis: -subclinical hyperthyroidism: TSH <0.4 mu/l and FT3 and FT4i n the normal range -overt hyperthyroidism: TSH <0.1 mu/l and FT4 > 21 pmol/l -subclinical hypothyroidism: TSH > 4.5 mu/l and FT3 and FT4i n the normal range -overt hypothyroidism: TSH > 10 mu/l and FT4 < 11.5 pmol/l

10 Methods Confounders -age -calculated free testosterone (cft) -body mass index (BMI) -sexual abstinence -prolactin levels -pack-years of smoking -genital tract inflammation (sil-8) modulating -prostate and SV clinical and ultrasound -semen characteristics

11 Results N = 163 Euthyroidism: 145 (88.9%) Subclinical hyperthyroidism: 6 (3.7%) Subclinical hypothyroidism: 12 (7.4%) No overt hyper- or hypo-thyroidism All patients: TH levels in the normal range evaluation of physiological effect of TH

12 Ejaculate volume (ml) Ejaculate volume (ml) Ejaculate volume Scale r = 0.163, p < 0.05 r = 0.178, p < 0.05 Scale ft3 (pmol/l) ft4 (pmol/l) Adj.r = 0.167, p = Not confirmed FT3 after adjusting for confounders Adj. for: Age cft BMI Sexual abstinence PRL Smoking Inflammation (sil-8)

13 Seminal fructose (mg/ejaculate) Seminal fructose levels Seminal fructose (mg/ejaculatr) Scale r = 0.215, p < 0.05 r = 0.198, p < 0.05 Scale ft3 (pmol/l) Adj.r = 0.241, p = ft4 (pmol/l) Not confirmed FT3 after adjusting for confounders Adj. for: Age cft BMI Sexual abstinence PRL Smoking Inflammation (sil-8)

14 SV volume before ejaculation (ml) SV volume after eiaculation (ml) Seminal vesicles volume Scale r = 0.327, p < r = 0.301, p < Scale ft3 (pmol/l) ft3 (pmol/l) Adj. for: Age cft BMI Sexual abstinence PRL Smoking Inflammation (sil-8)

15 Seminal vesicles emptying Adj.r = 0.346, p < Adj. for: Age cft BMI Sexual abstinence PRL Smoking Inflammation (sil-8) ΔSV FT3

16 Comparison among eu-, hypo- and hyperthyroid men Kruskal-Wallis post-hoc Mann-Whitney: p < 0.01 hyper vs hypo p < 0.01 hyper vs eu ANCOVA* F = 10.38, p < 0.01 ; hyper vs hypo *Adj. for: Age cft BMI Sexual abstinence PRL Smoking Inflammation (sil-8) ΔSV Longitudinal diameter

17 Epididymal body diameters (mm) FT4 and epididymis Epididymal tail diameter (mm) r = , p < 0.01 r = , p < 0.01 ft4 (pmol/l) ft4 (pmol/l) Adj.r = , p = Adj.r = , p = After adjusting for confounders Adj. for: Age cft BMI Sexual abstinence PRL Smoking Inflammation (sil-8)

18 Semen parameters NO association of TSH, FT3 e FT4 with sperm parameters and sil-8

19 Conclusions Our data support, for the first time in humans, a permissive role of TH on the ejaculatory machinery through an action on SV and epididymal contraction, and a positive effect of TH on SV size. TH direct action on SV? TH receptors on SV? Conversely, NO associations between TH and sperm parameters were observed. TH in the normal range: no impact on sperm patrameters Acknowledgements Thank you Elisa Maseroli Noemi Fralassi Selene Degl Innocenti Luca Boni Elisabetta Baldi Mario Maggi