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Significance of hypogonadism in erectile dysfunction

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Abstract

To review the role and significance of hypogonadism, defined as a low testosterone (T) level, in erectile dysfunction (ED). Review of literature. Serum T is below 3 ng/ml in 12% of ED patients, including 4% before and 15% after the age of 50. Replacement studies in men with severe hypogonadism demonstrate that sexual desire and arousal, as well as the frequency of sexual activity and spontaneous erections are clearly T-dependant. Psychic erections are partly T-dependant. The effects of T upon sexual function are dose-dependant up to a threshold level that is consistent within an individual, but markedly variable between individuals, ranging from 2 to 4.5 ng/ml. More evidence is required to confirm a significant impact of T on the intrapenile vascular mechanisms of erections in men as it is the case in animals. No convincing association of T with ED has been found in epidemiological studies. As concerns clinical experience, although a meta-analysis of the randomized controlled trials established that T therapy consistently restores erectile function in young hypogonadal patients with T below 3.46 ng/ml, the effects of this treatment have been mostly disappointing when used alone in older patients consulting for ED who are subsequently diagnosed to have hypogonadism following routine T measurement. These poor results may probably be explained by the high prevalence of co-morbidities, and by the fact that ED itself may induce hypogonadism. Combination therapy with T and PDE5 inhibitor (PDE5I) may be effective in the hypogonadal ED patients when T therapy alone fails. However, more evidence is required to confirm the hypothesis that a minimum level of T is required for a complete effect of PDE5I in certain men, since a PDE5I was able to restore complete erections in severely hypogonadal men. Though a low T level is not always the only cause of ED in hypogonadal ED patients, there are important benefits in screening for hypogonadism in ED. A low T level justifies a 3 month trial of T therapy, before combining a PDE5I if T therapy alone fails

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References

  1. Buvat J, Shabsigh R, Guay A, Gooren L, Torres LO, Meuleman E (2006) Hormones, metabolism, aging and men’s health. In: Porst H, Buvat J (eds) Standard practice in sexual medicine. Blackwell, Malden, pp 225–286

    Chapter  Google Scholar 

  2. Luboshitzky R, Shen-Orr Z, Herer P (2003) Middle-aged men secrete less testosterone at night than young healthy men. J Clin Endocrinol Metab 88:3160–3166

    Article  CAS  PubMed  Google Scholar 

  3. Morgentaler A, Barquawi A, 0’Donnel C, Lynch J, Petrylak D, Crawford ED (2006) Is it necessary to obtain a serum testosterone test in the morning? Cross-sectional analysis of diurnal serum testosterone variation in aging male from a large national screening program. J Sex Med 3, Suppl 1, p 47, abstr.106

  4. Buvat J, Lemaire A (1997) Endocrine screening in 1022 men with erectile dysfunction: clinical significance and cost-effective strategy. J Urol 158:764–767

    Article  Google Scholar 

  5. Earle CM, Stuckey BG (2003) Biochemical screening in the assessment of erectile dysfunction: what tests decide future therapy? Urology 62:727–731

    Article  PubMed  Google Scholar 

  6. Maatman TJ, Montague DK (1986) Routine endocrine screening in impotence. Urology 27:499:502

    Article  CAS  PubMed  Google Scholar 

  7. Traish AM, Guay AT (2006) Are androgens critical for penile erections in humans? Examining the clinical and preclinical evidence. J Sex Med 3:382–407

    Article  CAS  PubMed  Google Scholar 

  8. Rosner W (2001) An extraordinarily inaccurate assay for free testosterone is still with us. J Clin Endocrinol Metab 86:2903

    Google Scholar 

  9. Vermeulen A, Verdonck L, Kaufman JM (1999) A critical evaluation of simple methods for the estimation of free testosterone in serum. J Clin Endocrinol Metab 84:3666–3672

    Article  CAS  PubMed  Google Scholar 

  10. Christ-Crain M, Mueller B, Gasser TC, Kraenzlin M, Trummler M, Huber P, Meier C (2004) Is there a clinical relevance of partial androgen deficiency of the aging male? J urol 172:624–627

    Article  CAS  PubMed  Google Scholar 

  11. Nieschlag E, Swerdloff R, Behre HM, Gooren LJ, Kaufman JM, Legros JJ, Lunenfeld B, Morley JE, Schulman C, Wang C, Weidner W, Wu FC (2005) Investigation, treatment and monitoring of late-onset hypogonadism in males. ISA, ISSAM, and EAU recommendations. Eur Urol 48:1–4

    Article  CAS  PubMed  Google Scholar 

  12. Kaufman JM, Vermeulen A (2005) The decline of androgen levels in elderly men and its clinical and therapeutic implications. Endocr Rev 26:833–876

    Article  CAS  PubMed  Google Scholar 

  13. Mohr BA, Guay AT, O’Donnell AB, McKinlay JB (2005) Normal, bound and nonbound testosterone levels in normally ageing men: results from the Massachussets male aging study. Clin Endocrinol (Oxf) 62:64–73

    Article  CAS  Google Scholar 

  14. Bodie J, Lewis J, Schow D, Monga M (2003) Laboratory evaluations of erectile dysfunction: an evidence based approach. J Urol 169:2262–2264

    Article  PubMed  Google Scholar 

  15. Buvat-Herbaut M, Buvat J, Dancoine F,.Lemaire A, Marcolin G, Fourlinnie JC (1989) More than 30% of the impotent patients with normal values of serum total testosterone have low values of free, and even more of bioavailable serum testosterone. Serono symposia review, IV international congress of andrology, Fiorenza, suppl I:196

  16. Buvat J, Lemaire A, Ratasczyk J (1996) Rôle des hormones dans les dysfonctions sexuelles, l’homosexualité, le transsexualisme et les comportements sexuels déviants: conséquences diagnostiques et thérapeutiques. Contraception-Fertilité-Sexualité 24:834–846

    CAS  Google Scholar 

  17. Kim YC, Buvat J, Carson CC, Gooren LJ, Jarow J, Rajfer J, Vermeulen A (1999) Endocrine and metabolic aspects including treatment, In: Jardin A, Wagner G, Khoury S, Giuliano F, Padma-Nathan H, Rosen R, (eds) Erectile dysfunction, Proceedings of the first international consultation on erectile dysfunction, July 1–3, Paris, pp 205–240

  18. Jannini EA, Screponi E, Carosa E et al (1999) Lack of sexual activity from erectile dysfunction is associated with a reversible reduction in serum testosterone. Int J Androl 22:385–392

    Article  CAS  PubMed  Google Scholar 

  19. Carosa E, Martini P, Brandetti F et al (2004) Type V phosphodiesterase inhibitor treatments for erectile dysfunction increase testosterone levels. Clin Endocrinol (Oxf) 61:382–386

    Article  CAS  Google Scholar 

  20. Shabsigh R, Rafjer J, Aversa A, Traish AM, Yassin A, Kalinchenko SY, Buvat J (2006) The evolving role of testosterone in the treatment of erectile dysfunction. Int J Clin Pract 60:1087–1092

    Article  CAS  PubMed  Google Scholar 

  21. Shen ZJ, Zhou XL, Lu YL, Chen ZD (2003) Effects of androgen deprivation on penile ultrastructure. Asian J Androl 5:33–36

    CAS  PubMed  Google Scholar 

  22. Traish AM, Kim N (2005) The physiological role of androgens in penile erection: regulation of corpus cavernosum and structure. J Sex Med 2:759–770

    Article  CAS  PubMed  Google Scholar 

  23. Rogers RS. Graziottin TM. Lin CM. Kan YW. Lue T (2003) Intracavernosal vascular endothelial growth factor (VEGF) injection and adeno-associated virus-mediated VEGF gene therapy prevent and reverse venogenic erectile dysfunction in rats. Int J Impot Res 15:26–37

    Article  CAS  Google Scholar 

  24. Burnett AL (2004) Novel nitric oxide signaling mechanism regulate the erectile response. Int J Impot Res 16(Suppl1):S15–9

    Article  CAS  PubMed  Google Scholar 

  25. Park KH, Kim SW, Kim KD, Paick JS (1999) Effects of androgens on the expression of nitric oxide synthase mRNAs in rat corpus cavernosum. BJU Int 83:327–333

    Article  CAS  PubMed  Google Scholar 

  26. Baba K, Yajima M, Carrier S, Morgan DM, Nunes L, Lue TF et al (2000) Delayed testosterone replacement restores nitric oxide synthase-containing nerve fibres and the erectile response in rat penis. BJU Int 85:953–958

    Article  CAS  PubMed  Google Scholar 

  27. Traish AM, Park K, Dhir V, Kim NN, Moreland RB, Goldstein I (1999) Effects of castration and androgen replacement on erectile function in a rabbit model. Endocrinology 140:1861–1868

    Article  CAS  PubMed  Google Scholar 

  28. Morelli A, Filippi S, Mancina R, Luconi M, Vignozzi L, Marini M, Orlando C, Vannelli GB, Aversa A, Natali A, Forti G, Giorgi M, Jannini EA, Ledda F, Maggi M (2004) Androgens regulate phosphodiesterase type 5 expression and functional activity in corpora cavernosa. Endocrinology 145:2253–2263

    Article  CAS  PubMed  Google Scholar 

  29. Zhang XH, Morelli A, Luconi M, Vignozzi L, Filippi S, Marini M, Vannelli GB, Mancina R, Forti G, Maggi M (2005) Testosterone regulates PDE5 expression and in vivo responsiveness to tadalafil in rat corpus cavernosum. Eur Urol 47:409–416

    Article  CAS  PubMed  Google Scholar 

  30. Traish AM, Munarriz R, O’Connell L et al (2003) Effects of medical or surgical castration on erectile function in an animal model. J Androl 24:381–387

    PubMed  Google Scholar 

  31. Armagan A, Kim NN, Irwin G, Traish AM (2006) Dose-response relationship between testosterone an erectile function: evidence for the existense of a critical threshold. J Androl 27:517–526

    Article  CAS  PubMed  Google Scholar 

  32. Steidle C, Schwartz S, Jacoby K, Sebree T, Smith T, Bachand R (2003) AA2500 testosterone gel normalizes androgen levels in aging males with improvements in body composition and sexual function. J Clin Endocrinol Metab 88:2673–2681

    Article  CAS  PubMed  Google Scholar 

  33. O’Carrol R, Shapiro C, Bancroft J (1985) Androgens, behaviour and nocturnal erection in hypogonadal men: the effects of varying the replacement dose. Clin Endocrinol 23:527–538

    Article  Google Scholar 

  34. Wang C, Swerdloff RS, Iranmanesh A, Dobs A, Snyder PJ, Cunningham G, Matsumoto AM, Weber T, Berman N, the testosterone gel study group (2000) Transdermal testosterone gel improves sexual function, mood, muscle strength, and body composition parameters in hypogonadal men. J Clin Endocrinol Metab 85:839–853

    Google Scholar 

  35. Salmimies P, Kockott G, Pirke KM, Vogt HJ, Schill WB (1982) Effects of testosterone replacement on sexual behavior in hypogonadal men. Arch Sex Behav 11:345–353

    Article  CAS  PubMed  Google Scholar 

  36. Kwan M, Greenleaf WJ, Mann J, Crapo L, Davidson JM (1983) The nature of androgen action on male sexuality: a combined laboratory-self-report study on hypogonadal men. J Clin Endocrinol Metab 57:557–562

    Article  CAS  PubMed  Google Scholar 

  37. Bancroft J, Wu FCW (1983) Changes in erectile responsiveness during androgen therapy. Arch Sex Behav 12:59–66

    Article  CAS  PubMed  Google Scholar 

  38. Carani C, Granata AR, Fustini MF, Marrama P (1996) Prolactin and testosterone: their role in male sexual function. Int J Androl 19:48–54

    Article  CAS  PubMed  Google Scholar 

  39. Burris AS, Banks SM, Carter CS, Davidson JM, Sherins RJ (1992) A long-term, prospective study of the physiologic and behavioral effects of hormone replacement in untreated hypogonadal men. J Androl 13:297–304

    CAS  PubMed  Google Scholar 

  40. Gooren LJ (1987) Androgen levels and sex functions in testosterone-treated hypogonadal men. Arch Sex Behav 16:463–473

    Article  CAS  PubMed  Google Scholar 

  41. Kelleher S, Conway AJ, Handelsman DJ. 2004. Blood testosterone threshold for androgen deficiency symptoms. J Clin Endocrinol Metab 89:3813–3817

    Article  CAS  PubMed  Google Scholar 

  42. Seftel AD, Mack RJ, Secrest AR, Smith TM (2004) Restorative increases in serum testosterone levels are significantly correlated to improvements in sexual functioning. J Androl 25:963–972

    PubMed  Google Scholar 

  43. Carani C, Bancroft J, Granata A, Del Rio G, Marrama P (1992) Testosterone and erectile function, nocturnal penile tumescence and rigidity, and erectile response to visual erotic stimuli in hypogonadal and eugonadal men. Psychoneuroendocrinology 17:647–654

    Article  CAS  PubMed  Google Scholar 

  44. Gray PB, Sigh AB, Woodhouse LJ, Storer TW, Casaburi R, Dzekov C, Dzekov J, Sinha-Hikim I, Bhasin S (2005) Dose-dependant effects of testosterone on sexual function, mood, and visuospatial cognition in older men. J Clin Endocrinol Metab 16:39–45

    Google Scholar 

  45. O’Carroll R, Bancroft J (1984) Testosterone therapy for low sexual interest and erectile dysfunction in men: a controlled study. Br J Psych 145:146–151

    Article  CAS  Google Scholar 

  46. WHO (1982) Task force on psychosocial research in family planning. Hormonal contraception for men: acceptability and effects on sexuality. Stud Fam Plan 13:328–342

    Article  Google Scholar 

  47. Anderson RA, Bancroft J, Wu FCW (1992) The effects of exogenous testosterone on sexuality and mood of normal men. J Clin Endocrinol Metab 75:1503–1507

    Article  CAS  PubMed  Google Scholar 

  48. Carani C, Granata AR, Bancroft J, Marrama P (1995) The effects of testosterone replacement on nocturnal penile tumescence and rigidity and erectile response to visual erotic stimuli in hypogonadal men. Psychoneuroendocrinology 20:743–753

    Article  CAS  PubMed  Google Scholar 

  49. O’Connor DB, Archer J, Wu FCW (2004) Effects of testosterone on mood, aggression and sexual behaviour in young men: a double blind, placebo controlled, cross over study. J Clin Endrocrinol Metab 89:2837–2845

    Article  CAS  Google Scholar 

  50. Schiavi RC, Schreiner-Engel P, White D, Mandeli J (1991) The relationship between pituitary-gonadal function and sexual behavior in healthy aging men. Psychosom Medicine 53:363–374

    CAS  Google Scholar 

  51. Feldman HA, Goldstein I, Hatzichristou DG, Krane RJ, McKinlay JB (1994) Impotence and its medical and psychosocial correlates: results of the Massachusetts male aging study. J Urol 151:54–61

    CAS  PubMed  Google Scholar 

  52. Rhoden EL, Teloken C, Mafessoni R, Souto CA (2002) Is there any relation between serum levels of total tesosterone and the severity of erectile dysfunction? Int J Impot Res 14:167–171

    Article  CAS  PubMed  Google Scholar 

  53. Beutel ME, Wiltink J, Hauck EW, Auch D, Behre HM, Brahler E, Weidner W (2005) Correlations between hormones, physical, and affective parameters in aging urologic outpatients. Eur Urol 47:749–55

    Article  CAS  PubMed  Google Scholar 

  54. Corona G, Mannucci E, Mansani R, Petrone L, Bartolini M, Giommi R, Mancini M, Forti G, Maggi M (2004) Ageing and pathogenesis of erectile dysfunction. Int Journal Impot Res 16:395–402

    Article  CAS  Google Scholar 

  55. Travison TG, Araujo AB, Morley JE, O’Donnell AB, McKinlay JB (2006) The relationship between libido and testosterone in aging men results from the Massachussetts male aging study. J Clin Endocrinol Metab 91:2509–2513

    Article  CAS  PubMed  Google Scholar 

  56. Davidson JM, Chen JJ, Crapo L, Gray GD, Greenleaf WJ, Catania JA (1983) Hormonal changes and sexual function in aging men. J Clin Endocrinol Metab 57:71–77

    Article  CAS  PubMed  Google Scholar 

  57. Ahn HS, Park CM, Lee SW (2002) The clinical relevance of sex hormone levels and sexual activity in the ageing male. BJU Int 89:526–530

    Article  CAS  PubMed  Google Scholar 

  58. Tsujiruma A, Matsumiya K, Matsuoka Y, Takahashi T, Koga M, Iwasa A, Takeyama M, Okuyama A (2003) Bioavailable testosterone with age and erectile dysfunction. J Urol 170:2345–2347

    Article  CAS  Google Scholar 

  59. Stoleru S, Redoute J, Costes N, Lavenne F, Le Bars D, Dechaud H, Forest MG, Pugeat M, Cinotti L, Pujol JF (2003) Brain processing of visual sexual stimuli in men with hypoactive sexual desire disorder. Psychiatry Res: Neuroimaging 124:67–86

    Article  PubMed  Google Scholar 

  60. Redoute J, Stoleru S, Pugeat M, Costes N, Lavenne F, Le Bars D, Dechaud H, Cinotti L, Pujol JF (2005) Brain processing of visual sexual stimuli in treated and untreated hypogonadal patients. Psychoneuroendocrinology 30:461–482

    Article  CAS  PubMed  Google Scholar 

  61. Schultheiss D, Badalyan R, Pilatz A, Gabouev AI, Schlote N, Wefer J, von Wasielewski R, Mertsching H, Sohn M, Stief CG, Jonas U (2003) Androgen and estrogen receptors in the human corpus cavernosum penis immunohistochemical and cell culture results. World J Urol 21:320–324

    Article  CAS  PubMed  Google Scholar 

  62. Foresta C, Caretta N, Rossato M, Garolla A, Ferlin A (2004) Role of androgens in erectile function. J Urol 171:2358–2362

    Article  CAS  PubMed  Google Scholar 

  63. Aversa A, Isidori AM, De Martino MU, Caprio M, Fabbrini E, Rocchietti-March M, et al (2000) Androgens and penile erection: evidence for a direct relationship between free testosterone and cavernous vasodilation in men with erectile dysfunction. Clin Endocrinol (Oxf) 53:517–522

    Article  CAS  Google Scholar 

  64. Aversa A, Isidori AM, Spera G, Lenzi A, Fabbri A (2003) Androgens improve cavernous vasodilation and response to sildenafil in patients with erectile dysfunction. Clin Endocrinol (Oxf) 58:632–638

    Article  CAS  Google Scholar 

  65. Isidori AM, Gianetta E, Gianfrilli D, Greco EA, Bonifacio V, Aversa A, Isidori A, Fabbri A, Lenzi A (2005) Effects of testosterone on sexual function in men: results of a meta-analysis. Clin Endocrinol (Oxf) 63:381–394

    Article  CAS  Google Scholar 

  66. Kropman RF, Verdijk R, Lycklama A, Nijohlt AAB, Roefsema F (1991) Routine endocrine screening in impotence: significance and cost effectiveness. Int J Impot Res 3:87–94

    Google Scholar 

  67. Morales A, Johnson B, Heaton JW, Clark A (1994) Oral androgens in the treatment of hypogonadal impotent men. J Urol 152:1115–1118

    CAS  PubMed  Google Scholar 

  68. Morales A, Johnston B, Heaton JPW, Lundie M (1997) Testosterone supplementation for hypogonadal impotence: assessment of biochemical measures and therapeutic outcomes. J Urol 157:849–854

    Article  CAS  PubMed  Google Scholar 

  69. Rakic Z, Starcevic V, Starcevic VP, Marinkovic J (1997) Testosterone treatment in men with erectile disorder and low levels of testosterone in serum. Arch Sex Behav 26:495–504

    Article  CAS  PubMed  Google Scholar 

  70. Wylie K, Davies-South D (2004) A study of treatment choices in men with erectile dysfunction and reduced androgen levels. J Sex Mar Ther 30:107–114

    Article  Google Scholar 

  71. Greenstein A, Mabjeesh NJ, Sofer M, Kaver I, Matzkin H, Chen J (2005) Does sildenafil combined with testosterone gel improve erectile dysfunction in hypogonadal men in whom testosterone supplement therapy alone failed? J Urol 173:530–532

    Article  CAS  PubMed  Google Scholar 

  72. Mulhall JP, Valenzuela R, Aviv N, Parker M (2004) Effect of testosterone supplementation on sexual function in hypogonadal men with erectile dysfunction. Urology 63:348–353

    Article  PubMed  Google Scholar 

  73. Kalinchenko SY, Kozlov GI, Gontcharov NP, Katsiya GV (2003) Oral testosterone undecanoate reverses erectile dysfunction associated with diabetes mellitus in patients failing on sildenafil citrate therapy alone. Aging Male 6:94–99

    Article  CAS  PubMed  Google Scholar 

  74. Shamloul R, Ghanem H, Fahmy I, El-Meleigy A, Ashoor S, Elnashaar A, Kamel I (2005) Testosterone therapy can enhance erectile function response to Sildenafil in patients with PADAM: a pilot study. J Sex Med 2:559–564

    Article  CAS  PubMed  Google Scholar 

  75. Buvat J, Lemaire A, Alexandre B, Ratasczyk J (2002) Effects of Androgen therapy in 38 patients with low total, free, and/or bioavailable testosterone. Int J Impot Res, 14, Suppl 3:S36

  76. Rochira V, Balestrieri A, Madeo B, Granata ARM, Carani C (2006) Sildenafil improves sleep-related erections in hypogonadal men: evidence from a randomized, placebo-controlled, cross-over study of a synergistic role of both testosterone and sildenafil on penile erections. J Androl 27:165–175

    Article  CAS  PubMed  Google Scholar 

  77. Guay AT, Perez JB, Jacobson J, Newton RA (2001) Efficacy and safety of Sildenafil citrate for treatment of Erectile Dysfunction in a population with associated organic risk factors. J Androl 22:793–797

    CAS  PubMed  Google Scholar 

  78. Rosenthal BD, May NR, Metro MJ, Harkaway RC, Ginsberg PC (2006) Adjunctive use of AndroGel (testosterone gel) with sildenafil to treat erectile dysfunction in men with acquired androgen deficiency syndrome after failure using sildenafil alone. Urology 67:571–574

    Article  PubMed  Google Scholar 

  79. Yassin AA, Saad F, Died HE (2006) Testosterone and erectile function in hypogonadal men unresponsive to tadalafil: results from an open-label uncontrolled study. Andrologia 38:61–68

    Article  CAS  PubMed  Google Scholar 

  80. Shabsigh R, Kaufman JM, Steidle C, Padma-Nathan (2004) Randomized study of testosterone gel as adjunctive therapy to sildenafil in hypogonadal men with erectile dysfunction who do not respond to sildenafil alone. J Urol 172:658–663

    Article  CAS  PubMed  Google Scholar 

  81. Purvis K, Landgren B, Cekan Z, Diczfaluzy E (1976) Endocrine effects of masturbation. J Endocrinol 70:439–444

    Article  CAS  PubMed  Google Scholar 

  82. Christiansen K, Knussman R, Couwenbergs C (1985) Sex hormones and stress in the human male. Hormones and Behav 19:426–440

    Article  CAS  Google Scholar 

  83. Christiansen K, Hars O (1995) Effects of stress anticipation and stress coping strategies on salivary testosterone levels. J Psychophysiol 3:264–269

    Google Scholar 

  84. Carosa E, Benvenga S, Trimarchi F et al (2002) Sexual inactivity results in reversible reduction of LH bioavailability. Int J Impot Res 14:93–99

    Article  CAS  PubMed  Google Scholar 

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    Jacques Buvat & Gilbert Bou Jaoudé

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Buvat, J., Bou Jaoudé, G. Significance of hypogonadism in erectile dysfunction. World J Urol 24, 657–667 (2006). https://doi.org/10.1007/s00345-006-0131-x

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