Male hypogonadism

01.11.2009

Englisch

9783837411775

UNI-MED

UNI-MED Science

Nein

Friedrich Jockenhövel

192

3

Gebundene Ausgabe

Contents 1. Anatomy and physiology of the testis 11 1.1. Hypothalamic-hypophyseal regulation 11 1.2. Spermatogenesis 14 1.3. Testosterone and androgen effect 15 1.3.1. Testosterone biosynthesis 15 1.3.2. Transport of testosterone in the blood 17 1.3.3. Metabolism of testosterone 17 1.3.4. Structure and function of the androgen receptor 18 1.3.5. Biological effects of testosterone 21 1.3.6. Testosterone and the metabolic syndrome 24 1.4. From zygote to man 26 1.4.1. Sexual differentiation 26 1.4.1.1. Differentiation of gonadal structure 27 1.4.1.2. Differentiation of somatic gender 27 1.4.1.3. Differentiation of external genitalia and urogenital sinus 28 1.4.2. Development during puberty 29 2. Hypogonadism in men 33 2.1. Clinical picture of hypogonadism 33 2.2. Causes and differential diagnosis of hypogonadism 36 2.2.1. Hypothalamic male hypogonadism 36 2.2.1.1. Idiopathic hypogonadotropic hypogonadism and Kallmann’s syndrome 36 2.2.1.2. Delayed puberty 41 2.2.1.3. Underweight, anorexia nervosa 44 2.2.1.4. Prader-Labhart-Willi syndrome and Angelman’s syndrome 44 2.2.1.5. Laurence-Moon-Bardet-Biedl syndrome 45 2.2.1.6. Rare syndromes 45 2.2.1.7. Secondary GnRH secretion disorder as a result of other diseases 45 2.2.2. Hypophyseal causes of male hypogonadism 46 2.2.2.1. Hypopituitarism 46 2.2.2.2. Hyperprolactinemia and prolactinoma 51 2.2.2.3. Selective deficiency of biologically active LH or FSH 53 2.2.3. Testicular causes of male hypogonadism 54 2.2.3.1. Congenital and acquired anorchidism 54 2.2.3.2. Malpositioning of the testes 55 2.2.3.3. Orchitis 56 2.2.3.4. Klinefelter’s syndrome 57 2.2.3.5. XX-Man 60 2.2.3.6. Noonan syndrome 60 2.2.3.7. XYY-syndrome 61 2.2.3.7.1. Male pseudohermaphroditism 61 2.2.3.7.2. Gonadal dysgenesis 61 2.2.3.8. Testicular defects 62 2.2.3.8.1. Differential diagnosis and therapy of male pseudohermaphroditism 63 2.2.4. Target organ-related causes of male hypogonadism 64 2.2.4.1. Androgen resistance (androgen receptor defects) 64 2.2.4.2. 5a-reductase deficiency 69 2.2.4.3. Oviduct persistence 70 2.2.4.4. Absence of estrogen effect in man 70 2.2.5. Hypogonadism due to systemic diseases and exogenous toxins 71 2.2.5.1. Systemic (general) diseases 71 2.2.5.1.1. Liver cirrhosis 71 2.2.5.1.2. Enteropathies 72 2.2.5.1.3. Kidney diseases 72 2.2.5.1.4. Diabetes mellitus 73 2.2.5.1.5. Hemochromatosis 73 2.2.5.1.6. Sickle cell anemia 73 2.2.5.1.7. Thyroid diseases 73 2.2.5.1.8. Hypercortisolism 74 2.2.5.1.9. Malignoma 74 2.2.5.1.10. Generalized infections 74 2.2.5.1.11. Myotonic dystrophy 75 2.2.5.1.12. Transverse syndrome 75 2.2.5.1.13. Epilepsy 75 2.2.5.1.14. Cystic fibrosis and Young’s syndrome 76 2.2.5.2. Medication, radiation, drugs and environmental toxins 76 2.2.5.2.1. Medications 76 2.2.5.2.2. Exposure to radiation and heat 79 2.2.5.2.3. Drugs 80 2.2.5.2.4. Environmental toxins 80 3. Diagnostic work-up of hypogonadism 83 3.1. Case history and physical examination 83 3.2. Hormone analysis 84 3.2.1. Testosterone, LH and FSH 84 3.2.2. Additional hormone parameters 86 3.3. Other biochemical parameters 87 3.4. Semen analysis 87 3.5. Testicular biopsy 88 3.6. Sonography of scrotum and prostate 88 3.7. Osteodensitometry 90 3.8. Nuclear magnetic resonance imaging of the hypophysis 91 3.9. Chromosome analysis and biomolecular investigations 91 4. Androgen treatment options 93 4.1. Preparations 93 4.1.1. Oral androgens 95 4.1.1.1. Mesterolone 95 4.1.1.2. Oral testosterone undecanoate 96 4.1.1.3. Buccal testosterone 96 4.1.1.4. 17a-alkylated androgens 97 4.1.2. Intramuscular and subcutaneous administration 98 4.1.2.1. Testosterone propionate 98 4.1.2.2. Testosterone enanthate and testosterone cypionate 98 4.1.2.3. Intramuscular testosterone undecanoate 99 4.1.2.4. Testosterone implants (pellets) 100 4.1.2.5. 19-Nortestosterone and its esters 101 4.1.3. Transdermal application 102 4.1.3.1. Testosterone gel 102 4.1.3.2. Dihydrotestosterone gel 103 4.1.3.3. Non-scrotal testosterone patches 103 4.1.4. Future and experimental possibilities of androgen substitution 103 4.1.5. Summarizing assessment and differential therapy 104 4.2. Indications for androgen administration 108 4.2.1. Primary and secondary hypogonadism 108 4.2.2. Induction of puberty 111 4.2.3. Excessive growth 111 4.2.4. Transsexuality (female-to-male) 112 4.2.5. Late-onset hypogonadism 112 4.2.6. Primary and secondary osteoporosis 112 4.2.7. Weight loss in consumptive diseases 113 4.2.8. Hereditary angioedema 114 4.2.9. Male contraception 114 4.2.10. Aplastic and renal anemia 114 4.2.11. Abnormally small penis (micropenis) in the newborn 114 4.2.12. Non-indicated applications of androgens 115 4.3. Evaluation procedures before and during treatment with androgens 115 4.4. Contraindications to androgen substitution 116 4.5. Side-effects 117 4.6. Abuse of androgenic anabolic steroids 118 5. Androgen deficiency in older men 121 5.1. Age-associated changes in androgen production 121 5.2. Clinical symptoms in older men (testosterone deficiency syndrome) 124 5.3. Clinical symptoms and diagnosis of testosterone deficiency in older men 127 5.4. Contraindications and monitoring of testosterone treatment in older men 130 5.5. Effects of testosterone substitution in older men 132 5.5.1. Influence on bone metabolism 132 5.5.2. Influence on musculature and body composition 133 5.5.3. Influence on lipid metabolism 134 5.5.4. Influence on vascular reactivity 134 5.5.5. Influence on erythropoiesis 135 5.5.6. Influence on mental well-being and cognitive abilities 136 5.5.7. Influence on the prostate 136 5.6. Differential therapy 138 6. Estrogen substitution in men 141 6.1. Estrogen production in men 141 6.2. Age-related changes in estrogen levels 141 6.3. Physiological significance of estrogens in men 141 6.4. Clinical studies on estrogen therapy in men 143 6.5. Side-effects of estrogen therapy in men 144 6.6. Concluding remarks on estrogen therapy in men 144 7. Case reports 145 8. Literature 170 Index 189

240 mm

17 cm