Hypogonadism and erectile dysfunction： an overview

In humans androgen decline is presented as a clinical picture which includes decreased sexual interest, diminished erectile capasity, delayed or absent orgasms and reduced sexual pleasure. Additionally, changes in mood, diminished well being, fatigue, depression and irritability are also associated with androgen insufficiency. The critical role of androgens on the development, growth, and maintanence of the penis has been widely accepted. Although, the exact effect of androgens on erectile physiology still remains undetermined, recent experimental studies have broaden our understanding about the relationship between androgens and erectile function. Preclinical studies showed that androgen deprivation leads to penile tissue atrophy and alterations in the nerve structures of the penis. Furthermore, androgen deprivation caused to accumulation of fat containing cells and decreased protein expression of endothelial and neuronal nitric oxide synthases （eNOS and nNOS）, and phosphodiesterase type-5 （PDE-5）, which play crucial role in normal erectile physiology. On the light of the recent literature, we aimed to present the direct effect of androgens on the structures, development and maintanence of penile tissue and erectile physiology as well. Furhermore, according to the clinical studies we conclude the aetiology, pathophysiology, prevalance, diagnosis and treatment options of hypogonadism in aging men.     

Androgen Function in the Pathophysiology and Treatment of Male Huntington's Disease Patients

Low concentrations of circulating testosterone have been associated with dementia manifesting with advancing age and in neurodegenerative conditions. Huntington's disease (HD) is a dominantly inherited neurodegenerative disease with an invariably fatal outcome. Severe motor symptoms, psychosis and dementia are symptomatic hallmarks of the progression of HD that result from the dysfunction and death of neocortical and basal ganglia neurones. Treatments are directed toward manifest symptoms, although they are largely ineffectual in slowing or preventing disease progression. Emerging data have identified hypothamic pathologies in HD that result in endocrine disturbances. Clinically defined primary or secondary hypogonadism elicit low circulating testosterone concentrations and have been linked to the development of Alzheimer's disease in men. Examining similar neuroendocrine dysfunction in HD including the nature of manifest hypogonadism in male patients could allow an elucidation of the complex pathophysiology of HD and provide an impetus for hitherto untested testosterone replacement therapy.     

Effects of Transdermal Testosterone on Bone and Muscle in Older Men with Low Bioavailable Testosterone Levels,Low Bone Mass,and Physical Frailty

OBJECTIVES: To investigate the effects of testosterone supplementation on bone, body composition, muscle, physical function, and safety in older men. DESIGN: Double‐blind, randomized, placebo‐controlled trial. SETTING: A major medical institution. PARTICIPANTS: One hundred thirty‐one men (mean age 77.1 ± 7.6) with low testosterone, history of fracture, or bone mineral density (BMD) T‐score less than ?2.0 and frailty. INTERVENTION: Participants received 5 mg/d of testosterone or placebo for 12 to 24 months; all received calcium (1500 mg/d diet and supplement) and cholecalciferol (1,000 IU/d). MEASUREMENTS: BMD of hip, lumbar spine, and mid‐radius; body composition; sex hormones, calcium‐regulating hormones; bone turnover markers; strength; physical performance; and safety parameters. RESULTS: Ninety‐nine men (75.6%) completed 12 months, and 62 (47.3%) completed end therapy (mean 23 months; range 16–24 months for 62 who completed therapy). Study adherence was 54%, with 40% of subjects maintaining 70% or greater adherence. Testosterone and bioavailable testosterone levels at 12 months were 583 ng/dL and 157 ng/dL, respectively, in the treatment group. BMD on testosterone increased 1.4% at the femoral neck and 3.2% at the lumbar spine (P=.005) and decreased 1.3% at the mid‐radius (P<.001). There was an increase in lean mass and a decrease in fat mass in the testosterone group but no differences in strength or physical performance. There were no differences in safety parameters. CONCLUSION: Older, frail men receiving testosterone replacement increased testosterone levels and had favorable changes in body composition, modest changes in axial BMD, and no substantial changes in physical function.     

Genetic insights into human isolated gonadotropin deficiency

The identification of naturally occurring genetic mutations has provided unique insight into the current knowledge of the human hypothalamic-pituitary-gonadal axis. In the past decade, several monogenic causes have been reported in patients with isolated gonadotropin deficiency. Kallmann Syndrome is a clinically and genetically heterogeneous disorder, characterized by isolated hypogonadotropic hypogonadism and anosmia or hyposmia. To date, loss-of-function mutations in the genes encoding anosmin-1 (KAL1) and fibroblast growth factor receptor 1 (FGFR1) have been described in the X-linked and autosomal dominant forms of this syndrome, respectively. More recently, several heterozygous, homozygous or compound heterozygous mutations in the G protein-coupled prokineticin receptor-2 (PROKR2) and one of its ligands, prokineticin-2 (PROK2) were described in Kallmann syndrome. In addition, complex genetic transmission (digenic inheritance) was recently demonstrated in this condition. Regarding isolated hypogonadotropic hypogonadism without olfactory abnormalities, loss-of-function mutations in the Gonadotropin-releasing hormone (GnRH) receptor (GnRH-R) or the G-protein coupled receptor 54 (GPR54) genes, both encoding transmembrane receptors, have been described, as well as FGFR1 mutations. Finally, mutations of the beta sub-units of LH and FSH have been described in patients with selective gonadotropin deficiency. We review the role of these distinct genetic factors in human isolated hypogonadotropic hypogonadism.     

Prostate‐specific antigen changes and prostate cancer in hypogonadal men treated with testosterone replacement therapy

OBJECTIVES

To retrospectively review hypogonadal men receiving testosterone replacement therapy (TRT), and evaluate the changes in prostate‐specific antigen (PSA) levels over an extended period, and thus evaluate the occurrence of prostate cancer, as a primary concern in treating late‐onset hypogonadism (LOH) is the potential increased risk of prostate cancer; we also recorded the cardiovascular effects of TRT.

PATIENTS AND METHODS

In all, 81 hypogonadal men (mean age 56.8 years) were followed for a mean (range) of 33.8 (6–144) months after starting TRT. All men had a normal baseline PSA level before TRT and had routine laboratory investigations, including measurements of body mass index (BMI), haematocrit, lipid profile, and liver function tests (LFTs). Testosterone and PSA levels were assessed every 6–12 months. Patients with a biopsy‐confirmed or recent history of prostatitis before treatment were excluded. TRT was discontinued in men who developed prostate cancer.

RESULTS

Before and 36 months after treatment the total testosterone levels were 241.1 and 379.8 ng/dL (P < 0.05), respectively. Four men (4.9%) developed prostate cancer at a mean (range) of 32.5 (22–41) months after starting TRT. In men without prostate cancer (95.1%), PSA levels did not increase significantly at 1‐year intervals for 5 years. There was no statistical difference in PSA level change from baseline to 36 months when patients without prostate cancer were stratified into groups according to age (≤50, 55–65 and ≥70 years). In men with prostate cancer there was an increase in mean PSA level from baseline to 18 months of 1.8 ng/mL, and to 36 months of 3.2 ng/mL (P < 0.05). Total cholesterol improved from 203.8 to 166.6 mg/dL (P < 0.05) after 36 months of TRT; the BMI, haematocrit and LFTs did not change significantly.

CONCLUSIONS

LOH is an increasingly prevalent disease characterized by a symptomatically low testosterone level, and TRT is effective in normalizing serum testosterone levels, providing a beneficial cardiovascular effect, and improving sexual function and overall quality of life. PSA levels remain stable after normalization of testosterone for ≥5 years, prostate cancer can be effectively diagnosed and treated in men taking TRT, and the incidence of prostate cancer among men with LOH on TRT is no greater than that in the general population.     

Hypogonadotropic Hypogonadism in a Patient with Morbid Obesity

Obesity has recently become one of the most important public health problems. It is associated with a high rate of mortality, mainly because of cardiovascular disease, and can cause hormonal abnormalities such as hypogonadotropic hypogonadism. Weight loss is very beneficial for obese patients, because it results in improvement or even normalization of these conditions. In this report, we describe a morbidly obese patient with hypogonadotropic hypogonadism, which was probably caused by hyperprolactinemia and exacerbated by obesity-induced hormonal imbalances. After medical treatment for hyperprolactinemia and bariatric surgery, the patient’s hormonal status became normal. Although morbid obesity can cause hypogonadotropic hypogonadism in men, the differential diagnosis should include other potential causes of hypogonadism if free testosterone levels are below normal.     

Obesity in the ageing man

As the population is ageing globally, both ageing and obesity are recognized as major public health challenges. The aim of this narrative review is to present and discuss the current evidence on the changes in body composition, energy balance and endocrine environment that occur in the ageing man. Obesity in the ageing man is related to changes in both body weight and composition due to alterations in energy intake and total energy expenditure. In addition, somatopenia (decreased GH secretion), late-onset hypogonadism (LOH), changes in thyroid and adrenal function, as well as changes in appetite-related peptides (leptin, ghrelin) and, most importantly, insulin action are related to obesity, abnormal energy balance, redistribution of the adipose tissue and sarcopenia (decreased muscle mass). A better understanding of the complex relationship of ageing-related endocrine changes and obesity could lead to more effective interventions for elderly men.     

GnRH receptor and GPR54 inactivation in isolated gonadotropic deficiency

Isolated hypogonadotropic hypogonadism (IHH) is defined by a complete or partial impaired secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). In the regulation of the gonadotropic axis, the gonadotropin-releasing hormone (GnRH) and its receptor have evolved as a central element in fetal life, at puberty, and for reproduction in adulthood. GnRH resistance due to GnRH receptor (GnRHR) germ-line mutations was the first genetic alteration identified in patients with IHH. GnRHR mutated receptors are associated with impaired GnRH binding, intracellular trafficking or ligand-induced signal transduction, leading to various degrees of LH and FSH deficiency. Loss-of-function mutations of the GnRH receptor account for 50% of familial cases of IHH without anosmia. In 2003, mutations of GPR54 were identified in patients with IHH, opening a new pathway in the physiological regulation of puberty and reproduction. Kisspeptins, which are the natural ligands of GPR54, are potent stimulators of the LH and FSH secretion via the control of GnRH secretion or modulation of the pituitary response to GnRH stimulation. Genotype-phenotype correlations in IHH due to GnRHR and GPR54 mutations indicate that similar mutations may lead to a variable phenotype and suggest that the pituitary might have its own pubertal maturation independent from GnRH. These two causes of IHH result in a more quantitative than qualitative defect of the gonadotropic axis activation. Molecular genetics of IHH has led to a major breakthrough in the neuroendocrine regulation of the gonadotropic axis. New insights into the understanding of the initiation of puberty and in the therapeutic management of defects of the gonadotropic axis have emerged from these studies.     

Age-related changes in plasma androgen levels and their association with cardiovascular risk factors in male Japanese office workers

Aim:   To assess the age-related change in plasma androgen levels in healthy middle-aged men and whether any clinical parameters are associated with the hormonal change.
Methods:   The study was comprised of male Japanese office-workers aged 40–64 years, who had undergone an annual health check-up in 2002 and 2007 (96 and 76 men, respectively). Body mass index and blood pressure were measured, and serum concentration of lipids, glucose and uric acid in addition to plasma total testosterone, free testosterone and dehydroepiandrosterone sulfate (DHEA-S) levels were determined in the morning after an overnight fast. The 5-year hormonal changes and their associations with clinical parameters were analyzed in 33 men who repeated the examination at both check-ups. The cross-sectional associations of hormonal levels with clinical parameters were also investigated.
Results:   Age was negatively associated with free testosterone ( r  = −0.399, P  < 0.001 in 2002; r  = −0.458, P  < 0.001 in 2007) and DHEA-S ( r  = −0.233, P  = 0.02 in 2002; r  = −0.336, P  < 0.01 in 2007) but not with total testosterone, while the 5-year changes of free testosterone and DHEA-S levels were not significant and showed no associations with major cardiovascular risk factors. Cross-sectionally, after adjustment for age, linear regression analysis showed a positive association between free testosterone and blood hemoglobin and a negative association between total testosterone and serum uric acid.
Conclusion:   In Japanese middle-aged men, 5-year androgen decline is too subtle to detect, and endogenous androgen levels seem to have relatively weak association with cardiovascular risk profiles.     

Hypomyelination,hypogonadotropic hypogonadism,hypodontia – First Polish patient

The term 4H was suggested for the rare, novel entity with hypomyelination, hypogonadotropic hypogonadism and hypodontia. A combination of clinical findings with ataxia and endocrinological abnormalities, brain MRI and dentition history are crucial for the diagnosis. We present the first Polish patient with this disease with repeated brain MRI, MRI of the pituitary gland and orthopantomogram.