Long-term effect of testosterone therapy on bone mineral density in hypogonadal men

Sex hormones, their receptors and bone health

Sex steroids regulate skeletal maturation and preservation in both men and women, as already recognized in the 1940s by Albright and Reifenstein. The impact of gonadal insufficiency on skeletal integrity has been widely recognized in adult men and women ever since. In the context of their skeletal actions, androgens and estrogens are no longer considered as just male and female hormones, respectively. Androgens can be converted into estrogens within the gonads and peripheral tissues and both are present in men and women, albeit in different concentrations. In the late 1980s, sex steroid receptors were discovered in bone cells. However, the understanding of sex steroid receptor activation and translation into biological skeletal actions is still incomplete. Due to the complex metabolism, sex steroids may have not only endocrine but also paracrine and/or autocrine actions. Also, circulating sex steroid concentrations do not necessarily reflect their biological activity due to strong binding to sex hormone binding globulin (SHBG). Finally, sex steroid signaling may include genomic and non-genomic effects in bone and non-bone cells. This review will focus on our current understanding of gonadal steroid metabolism, receptor activation, and their most relevant cellular and biological actions on bone.

In vivo microMRI-based finite element and morphological analyses of tibial trabecular bone in eugonadal and hypogonadal men before and after testosterone treatment

Osteoporosis is a major public health problem in men. Hypogonadal men have decreased BMD and deteriorated trabecular bone architecture compared with eugonadal men. Testosterone treatment improves their BMD and trabecular structure. We tested the hypothesis that testosterone replacement in hypogonadal men would also improve their bone's mechanical properties. Ten untreated severely hypogonadal and 10 eugonadal men were selected. The hypogonadal men were treated with a testosterone gel for 24 mo to maintain their serum testosterone concentrations within the normal range. Each subject was assessed before and after 6, 12, and 24 mo of testosterone treatment by microMRI of the distal tibia. A subvolume of each microMR image was converted to a microfinite element (microFE) model, and six analyses were performed, representing three compression and three shear tests. The anisotropic stiffness tensor was calculated, from which the orthotropic elastic material constants were derived. Changes in microarchitecture were also quantified using newly developed individual trabeculae segmentation (ITS)-based and standard morphological analyses. The accuracy of these techniques was examined with simulated microMR images. Significant differences in four estimated anisotropic elastic material constants and most morphological parameters were detected between the eugonadal and hypogonadal men. No significant change in estimated elastic moduli and morphological parameters was detected in the eugonadal group over 24 mo. After 24 mo of treatment, significant increases in estimated elastic moduli E(22) (9.0%), E(33) (5.1%), G(23) (7.2%), and G(12) (9.4%) of hypogonadal men were detected. These increases were accompanied by significant increases in trabecular plate thickness. These results suggest that 24 mo of testosterone treatment of hypogonadal men improves estimated elastic moduli of tibial trabecular bone by increased trabecular plate thickness.

Effect of testosterone therapy on lumbar spine and hip mineral density in elderly men

OBJECTIVE

The aim of the present study was to analyse the effect of testosterone therapy on bone mineral density in healthy elderly men who had low levels of total testosterone.

DESIGN

Randomized, double-blind, placebo-controlled study.

PARTICIPANTS

Forty-eight men over 60 years old with decreased testosterone levels (< or =320 ng/dL) comprised the study. Twenty-five out of 48 received intramuscular injections of testosterone enanthate every three weeks during 12 months; the remaining 23 participants formed the control group. All participants had measurements of bone mineral density (BMD) in both lumbar spine and hip before and at the end of the study as well as testosterone and 17-beta estradiol levels.

RESULTS

Testosterone treated group exhibited a significant (p < 0.05) increment (from 1.198 +/- 0.153 to 1.240 +/- 0.141 g/cm(2)) in lumbar BMD in parallel with a significant (p < 0.001) increment (from 301 +/- 32 to 471 +/- 107 ng/dL) in testosterone concentrations, whereas no significant change occurred in femoral neck BMD.

CONCLUSIONS

Testosterone therapy elicited a positive effect only in lumbar BMD in elderly men with diminished testosterone serum levels.

Overexpression of human hydroxysteroid (17beta) dehydrogenase 2 induces disturbance in skeletal development in young male mice

To understand the function of human hydroxysteroid (17beta) dehydrogenase 2 (HSD17B2) in the peripheral tissues in vivo, we studied the bone development in transgenic male mice ubiquitously expressing human HSD17B2. Bones of HSD17B2TG and WT males (26 days and 2 and 6 mo old) were analyzed by pQCT and histomorphometry, and data were correlated with serum testosterone (T), IGF-I, and osteocalcin concentrations. At the age of 26 days, the body weight of HSD17B2TG males was significantly lower, and the lengths of the tibia and femur of the HSD17B2TG males were significantly shorter. Histomorphometric and pQCT analyses showed lower trabecular and cortical BMD, a markedly smaller area of cortical bone at both of the diaphyses, and a smaller percentage of trabecular bone volume and thickness in the HSD17B2TG males. The data suggested slower osteoblast differentiation and a slower bone formation rate of femoral diaphysis on the periosteum but faster on the endocortical surface in HSD17B2TG males. The altered bone parameters were correlated with low serum T, IGF-I, and osteocalcin concentrations at the prepubertal age. Interestingly, after puberty, the bone parameters analyzed in the adult HSD17B2TG males were mostly normal, consistent with the normal body weight and normalized serum concentrations of IGF-I and T. In conclusion, HSD17B2TG males presented with growth retardation and a decreased bone formation rate at prepubertal age. These changes were associated with lower serum IGF-I, osteocalcin, and T concentrations. It is concluded that the enforced constitutive expression of HSD17B2 disturbs the coordinated action of IGF-I and sex steroids essential for pubertal bone growth.

Testosterone for the aging male; current evidence and recommended practice

An international consensus document was recently published and provides guidance on the diagnosis, treatment and monitoring of late-onset hypogonadism (LOH) in men. The diagnosis of LOH requires biochemical and clinical components. Controversy in defining the clinical syndrome continues due to the high prevalence of hypogonadal symptoms in the aging male population and the non-specific nature of these symptoms. Further controversy surrounds setting a lower limit of normal testosterone, the limitations of the commonly available total testosterone result in assessing some patients and the unavailability of reliable measures of bioavailable or free testosterone for general clinical use. As with any clinical intervention testosterone treatment should be judged on a balance of risk versus benefit. The traditional benefits of testosterone on sexual function, mood, strength and quality of life remain the primary goals of treatment but possible beneficial effects on other parameters such as bone density, obesity, insulin resistance and angina are emerging and will be reviewed. Potential concerns regarding the effects of testosterone on prostate disease, aggression and polycythaemia will also be addressed. The options available for treatment have increased in recent years with the availability of a number of testosterone preparations which can reliably produce physiological serum concentrations.

Osteoporosis in men

With the aging of the population, there is a growing recognition that osteoporosis and fractures in men are a significant public health problem, and both hip and vertebral fractures are associated with increased morbidity and mortality in men. Osteoporosis in men is a heterogeneous clinical entity: whereas most men experience bone loss with aging, some men develop osteoporosis at a relatively young age, often for unexplained reasons (idiopathic osteoporosis). Declining sex steroid levels and other hormonal changes likely contribute to age-related bone loss, as do impairments in osteoblast number and/or activity. Secondary causes of osteoporosis also play a significant role in pathogenesis. Although there is ongoing controversy regarding whether osteoporosis in men should be diagnosed based on female- or male-specific reference ranges (because some evidence indicates that the risk of fracture is similar in women and men for a given level of bone mineral density), a diagnosis of osteoporosis in men is generally made based on male-specific reference ranges. Treatment consists both of nonpharmacological (lifestyle factors, calcium and vitamin D supplementation) and pharmacological (most commonly bisphosphonates or PTH) approaches, with efficacy similar to that seen in women. Increasing awareness of osteoporosis in men among physicians and the lay public is critical for the prevention of fractures in our aging male population.

Advances in male contraception

Despite significant advances in contraceptive options for women over the last 50 yr, world population continues to grow rapidly. Scientists and activists alike point to the devastating environmental impacts that population pressures have caused, including global warming from the developed world and hunger and disease in less developed areas. Moreover, almost half of all pregnancies are still unwanted or unplanned. Clearly, there is a need for expanded, reversible, contraceptive options. Multicultural surveys demonstrate the willingness of men to participate in contraception and their female partners to trust them to do so. Notwithstanding their paucity of options, male methods including vasectomy and condoms account for almost one third of contraceptive use in the United States and other countries. Recent international clinical research efforts have demonstrated high efficacy rates (90-95%) for hormonally based male contraceptives. Current barriers to expanded use include limited delivery methods and perceived regulatory obstacles, which stymie introduction to the marketplace. However, advances in oral and injectable androgen delivery are cause for optimism that these hurdles may be overcome. Nonhormonal methods, such as compounds that target sperm motility, are attractive in their theoretical promise of specificity for the reproductive tract. Gene and protein array technologies continue to identify potential targets for this approach. Such nonhormonal agents will likely reach clinical trials in the near future. Great strides have been made in understanding male reproductive physiology; the combined efforts of scientists, clinicians, industry and governmental funding agencies could make an effective, reversible, male contraceptive an option for family planning over the next decade.

Understanding the mechanisms of senile osteoporosis: new facts for a major geriatric syndrome

Knowledge of the underlying mechanisms of osteoporosis in older adults has significantly advanced in recent years. There is an acute loss of bone mineral density in the peri-menopausal period, followed by a more gradual and progressive decline, which is also seen in men. Markedly increased bone resorption leads to the initial fall in bone mineral density. With increasing age, there is also a significant reduction in bone formation. This is mostly due to a shift from osteoblastogenesis to predominant adipogenesis in the bone marrow. This study reviews new evidence on the pathophysiology of senile osteoporosis, with emphasis upon the mechanism of action of current osteoporosis treatments. New potential treatments are also considered, including therapeutic approaches to osteoporosis in elderly people that focus on the pathophysiology and potential reversal of the adipogenic shift in bone.

A case for clarity, consistency, and helpfulness: state-of-the-art clinical practice guidelines in endocrinology using the grading of recommendations, assessment, development, and evaluation system

CONTEXT

The Endocrine Society, and a growing number of other organizations, have adopted the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system to develop clinical practice guidelines and grade the strength of recommendations and the quality of the evidence. Despite the use of GRADE in several of The Endocrine Society's clinical practice guidelines, endocrinologists have not had access to a context-specific discussion of this system and its merits.

EVIDENCE ACQUISITION

The authors are involved in the development of the GRADE standard and its application to The Endocrine Society clinical practice guidelines. Examples were extracted from these guidelines to illustrate how this grading system enhances the quality of practice guidelines.

EVIDENCE SYNTHESIS

We summarized and described the components of the GRADE system, and discussed the features of GRADE that help bring clarity and consistency to guideline documents, making them more helpful to practicing clinicians and their patients with endocrine disorders.

CONCLUSIONS

GRADE describes the quality of the evidence using four levels: very low, low, moderate, and high quality. Recommendations can be either strong ("we recommend") or weak ("we suggest"), and this strength reflects the confidence that guideline panel members have that patients who receive recommended care will be better off. The separation of the quality of the evidence from the strength of the recommendation recognizes the role that values and preferences, as well as clinical and social circumstances, play in formulating practice recommendations.

State of the Art Reviews: Male Menopause: Fact or Fiction?

The possible existence of a menopause-like process in aging men has been speculated, given certain age-related hormonal and other biological changes noted to occur. Specifically, a slow decline in serum testosterone levels has been reported to occur with normal male aging. Androgen deficiency, which may result from this process, could have an effect on various systems and physiologic parameters, including bone density, body composition, sexual function, and the cardiovascular system, thus significantly affecting health and quality-of-life issues in older men. There has been an increasing interest in evaluating the possible use of testosterone replacement in preventing some detrimental aspects of aging and age-related hypogonadism, as well as in the investigation of the potential adverse effects of this therapy on different target organs. It is the purpose of this review to summarize currently available information with regard to the changes in testosterone and other hormones in older men, discuss their possible clinical manifestations and relationship with other age-related changes, and provide an updated description of testosterone replacement therapy for older men, including its indications, formulations, and safety considerations.

Cancer treatment-induced bone loss

PURPOSE OF REVIEW

Patients treated for cancer may be at risk for osteoporosis and fracture. Evaluation and treatment of patients with cancer treatment-induced bone loss should lead to fewer fractures. This review will help clinicians learn to identify, evaluate and treat cancer patients at risk.

RECENT FINDINGS

Survivors of childhood cancers and patients made hypogonadal by treatment for breast or prostate cancer are clearly at risk for osteoporosis and fracture. Use of aromatase inhibitors rather than tamoxifen for breast cancer will likely lead to more osteoporosis. Bisphosphonates prevent bone loss in many patients at risk.

SUMMARY

For many cancer patients, treatment with calcium, vitamin D, and bisphosphonates will likely decrease the consequences of cancer treatment-induced bone loss, namely fractures.

Androgen receptor stimulates bone sialoprotein (BSP) gene transcription via cAMP response element and activator protein 1/glucocorticoid response elements

Bone sialoprotein (BSP) is an early marker of osteoblast differentiation. Androgens are steroid hormones that are essential for skeletal development. The androgen receptor (AR) is a transcription factor and a member of the steroid receptor superfamily that plays an important role in male sexual differentiation and prostate cell proliferation. To determine the molecular mechanism involved in the stimulation of bone formation, we have analyzed the effects of androgens and AR effects on BSP gene transcription. AR protein levels were increased after AR overexpression in ROS17/2.8 cells. BSP mRNA levels were increased by AR overexpression. However, the endogenous and overexpressed BSP mRNA levels were not changed by DHT (10(-8) M, 24 h). Whereas luciferase (LUC) activities in all constructs, including a short construct (nts -116 to +60), were increased by AR overexpression, the basal and LUC activities enhanced by AR overexpression were not induced by DHT (10(-8)M, 24 h). The effect of AR overexpression was abrogated by 2 bp mutations in either the cAMP response element (CRE) or activator protein 1 (AP1)/glucocorticoid response element (GRE). Gel shift analyses showed that AR overexpression increased binding to the CRE and AP1/GRE elements. Notably, the CRE-protein complexes were supershifted by phospho-CREB antibody, and CREB, c-Fos, c-Jun, and AR antibodies disrupted the complexes formation. The AP1/GRE-protein complexes were supershifted by c-Fos antibody and c-Jun, and AR antibodies disrupted the complexes formation. These studies demonstrate that AR stimulates BSP gene transcription by targeting the CRE and AP1/GRE elements in the promoter of the rat BSP gene.

Testosterone therapy in the aging male

The decline, with aging, in serum concentrations of biologically active forms of testosterone in men is an indisputable fact and some men will eventually develop symptoms of late-onset hypogonadism (LOH) with its clinical consequences. LOH reduces quality of life and may pose important risk factors for frailty, changes in body composition, cardiovascular disease, sexual dysfunction and osteoporosis. Testosterone supplementation in cases of LOH will restore serum testosterone levels into the physiologic range; will restore metabolic parameters to the eugonadal state, increase muscle mass, strength, and function; maintaine or improve BMD reducing fracture risk; will improve neuropsychological function (cognition and mood); libido and sexual functioning; and enhance quality of life. The ultimate goals, however, are to maintain or regain a high quality of life, to reduce disability, to compress major illnesses into a narrow age range and to add life to years. To achieve these goals men must also adjust their lifestyle to optimize dietary habits, as well as to exercise and to abstain from smoking life-long. Monitoring these patients is a shared responsibility that cannot be taken lightly. The physician must emphasize to the patient the need for periodic evaluations and the patient must agree to comply with these requirements. The physician's evaluation should include an assessment of the clinical response and monitoring must be tailored to the indications and individual needs of the patient.

Comparison of dried plum supplementation and intermittent PTH in restoring bone in osteopenic orchidectomized rats

Bone loss was confirmed after 90 days in 50 6-month-old male Sprague Dawley rats that were sham-operated or orchidectomized (ORX). In this study, we have shown that dried plum (DP) has potent effects on bone in terms of bone mass, microarchitecture, and strength in osteopenic male rats. Although these changes may be mediated through the suppression of bone resorption, the fact that the restoration in some of the bone structural and biomechanical parameter shares some similarities with parathyroid hormone (PTH) should not be overlooked. Further investigation is needed on a mechanistic level to clarify the influence of DP on bone metabolism.

INTRODUCTION

This study was designed to investigate the extent to which DP reverses bone loss in osteopenic ORX rats and to compare its effects to PTH.

MATERIALS AND METHODS

Fifty, 6-month-old male Sprague Dawley rats were sham-operated or ORX, and bone loss was confirmed after 90 days. The ORX groups were assigned to control (AIN-93M) diet, 25% DP diet, or PTH (80 microg/kg) for 90 days.

RESULTS

DP induced an 11% increase in vertebral and femoral BMD compared to ORX-controls. BMD in the PTH-treated group was increased by 20.7% (vertebra) and 17.9% (femur). Vertebral trabecular bone volume (BV/TV) and number were increased by DP and trabecular separation was decreased compared to controls, which were similar to PTH. Alterations in trabecular bone of the femur were similar to those in the vertebra, but DP did not restore BV/TV to the same extent. Cortical thickness was improved by DP and further enhanced by PTH. DP tended to decrease urinary deoxypyridinoline and calcium, but did not alter alkaline phosphatase or osteocalcin.

CONCLUSION

We conclude that though the degree of improvement was not equivalent to PTH with regard to all parameters, DP reverses bone loss due to ORX and the mechanisms should be further investigated.

Gonadal steroids and bone metabolism in men

PURPOSE OF REVIEW

Over the past decade, our increasing awareness of the clinical importance of osteoporosis in men has stimulated intense interest in trying to better understand male skeletal physiology and pathophysiology. The present review focuses on a major focus of research in this area, namely the attempt to define the influence and therapeutic potential of gonadal steroids in male bone metabolism.

RECENT FINDINGS

Building on previous work defining the relative roles of androgens and estrogens in the developing male skeleton and in maintaining normal bone turnover, recent studies have begun to define these issues from epidemiologic, physiologic and therapeutic perspectives. With access to data from large prospectively defined populations of men, investigators are confirming and challenging existing hypotheses and forwarding new concepts. Clinical trials have expanded beyond standard androgen replacement studies to explore more complex hormonal interventions. Physiologic investigation has continued to probe the mechanisms underlying the differential and independent roles of androgens and estrogens in male bone metabolism.

SUMMARY

Recent work has added significantly to our understanding of the role of gonadal steroids in male skeletal physiology. Nonetheless, further research is necessary to build on these initial human studies and to capitalize on rapidly emerging advances in our understanding of the basic biology of bone metabolism.

Klinefelter syndrome in clinical practice

Klinefelter syndrome is the most common sex-chromosome disorder; it affects approximately one in every 660 men. This syndrome is characterized by the presence of one or more extra X chromosomes, and the karyotype 47,XXY is the most prevalent type. The 'prototypic' man with Klinefelter syndrome has traditionally been described as tall, with narrow shoulders, broad hips, sparse body hair, gynecomastia, small testicles, androgen deficiency, azoospermia and decreased verbal intelligence. A less distinct phenotype has, however, been described. Klinefelter syndrome is an underdiagnosed condition; only 25% of the expected number of patients are diagnosed, and of these only a minority are diagnosed before puberty. Patients with Klinefelter syndrome should be treated with lifelong testosterone supplementation that begins at puberty, to secure proper masculine development of sexual characteristics, muscle bulk and bone structure, and to prevent the long-term deleterious consequences of hypogonadism; however, the optimal testosterone regimen for patients with Klinefelter syndrome remains to be established.

Drug insight: testosterone preparations

Testosterone has been used for substitution therapy in testicular and hypothalamopituitary diseases for almost six decades, with injectable testosterone esters and implanted testosterone pellets being the mainstay of treatment. Growing interest in the possible use of testosterone in nonclassical situations such as male contraception, aging (late-onset hypogonadism), muscle-wasting conditions like HIV, erectile dysfunction, and female hypoactive sexual disorder has stimulated research, leading to the development of several new modes of administration of testosterone. Transdermal patches, gels, mucoadhesive sustained-release buccal tablets and long-acting testosterone esters are designed to provide testosterone levels that approximate normal physiologic levels, to improve patient acceptability, and to further increase the number of treatment options available. In this Review, we briefly describe the chemistry, mechanism of action, and metabolism of testosterone. We then discuss the pharmacokinetics, advantages, and disadvantages of various formulations and summarize the various preparations currently available.

Bone mineral density in survivors of childhood brain tumours

BACKGROUND

Osteopenia has been reported in children surviving acute lymphoblastic leukaemia, apparently as consequence of therapy. Few studies have been published on bone mineral density (BMD) evaluation in children surviving from brain tumours. The endocrine system in these patients is frequently affected as consequence of therapeutic interventions such as cranial irradiation and anti-neoplastic agents: growth hormone deficiency is the most common adverse sequel. The pathogenesis of osteopenia in brain cancer survivors is multi-factorial but still uncertain.

OBJECTIVE

The aim of this study is to examine bone mass in 12 brain cancer survivors and its relationship with their hormonal status.

RESULTS AND DISCUSSION

We observed that most of the patients had a BMD that was lower than normal in both the lumbar column and in the femoral neck. Bone mass loss was higher in the lumbar region rather than in the femoral neck, due to spinal radiation therapy and to the effect of hormonal deficiencies. Particularly hypogonadism, but also multiple hormonal deficiencies, are associated with lower BMD values. Experience in clinical care of these patients suggests the importance of periodic evaluations of BMD, especially in those with secondary hormone deficiencies. Moreover, the periodic assessment of the hypothalamus-pituitary function is essential for an early diagnosis of hormonal insufficiency, primarily hypogonadism, to precociously detect bone mineral loss and to prevent pathological fractures, thus improving the quality of life.

Aetiology, diagnosis, and management of hypopituitarism in adult life

Hypopituitarism is a complex medical condition associated with increased morbidity and mortality, requires complicated treatment regimens, and necessitates lifelong follow up by the endocrinologist. The causes, clinical features, and the management of hypopituitarism including endocrine replacement therapy are considered in this review article.

Estrogen receptor alpha genotype confers interindividual variability of response to estrogen and testosterone in mesenchymal-stem-cell-derived osteoblasts

Hormone replacement therapy is effectively used to prevent postmenopausal bone loss. Variation in response to the therapy is, however, frequently seen. In addition, the direct effects of sex steroids on isolated human bone marrow stromal cells have been reported to vary depending on the donor, but the biological mechanisms are not understood. The aim of this study was to investigate the effects of 17beta-estradiol (E2) and testosterone in human-bone-marrow-derived mesenchymal stem cell (MSC) cultures from both female and male donors of various ages. The osteoblast differentiation capacity and activity of the MSCs were quantified in vitro by measuring alkaline phosphatase activity and calcium deposition. We show here that also the osteoblast responses of MSCs to sex hormones vary widely depending on the donor. When the results from all donors were analyzed together, treatment with E2 increased calcium deposition significantly by MSCs of both sexes but ALP activity only in the male MSCs. Testosterone had no effect on ALP activity nor calcium deposition in either sex. To further characterize the individual variation, we investigated estrogen receptor alpha PvuII restriction site polymorphism with PCR. Restriction fragment-length polymorphism was assigned as P or non-P, P signifying the absence of the restriction site. Our results indicate that higher basal osteoblast differentiation capacity of MSCs is associated with the presence of the P allele in females, whereas higher response to sex steroids treatment is associated with the non-P allele. These results could help explain the contradictory effects of E2 on osteoblasts in vitro and might also provide new insights to understanding the differences in responses to hormone replacement therapy.

Epidemiology and pathophysiology of osteoporosis in men

Osteoporosis in men is an unrecognized but growing problem as the number of men who live to old age increases. The 10-year fracture risk at age 50 quadruples by age 80, and in general the incidence rate of osteoporotic fracture in men is about half that of women. Of note, the mortality and morbidity after hip fracture are much greater in men. There are many men whose osteoporosis is the result of specific causes such as oral glucocorticoid therapy, hypogonadism, or androgen withdrawal therapy for prostate cancer. In addition there are several interesting syndromes of osteoporosis in middle-aged men; these men usually present with vertebral fractures. As knowledge about the prevalence and etiology of osteoporosis in men increases, it will be recognized and treated in more men, in hopes of preventing fracture.

Testosterone Hormone Replacement Therapy: State-of-the-Art and Emerging Technologies

In the human male, testosterone is the major circulating androgen. The clinical effects of androgen are numerous, and testosterone deficiency is associated with a number of clinical abnormalities. At present, a variety of preparations containing testosterone is available for the treatment of androgen deficiency. Ideally, those treatments have to produce and maintain physiologic serum concentrations of the hormone. This article reviews the current existing testosterone dosage forms on the market with their advantages and drawbacks and examines new and emerging technology developments concerning this therapy. In particular, the latest innovations in transdermal delivery are explored.

Effects of vitamin K2 on the development of osteopenia in rats as the models of osteoporosis

Vitamin K2 is widely used for the treatment of osteoporosis in Japan. To understand the effects of vitamin K2 on bone mass and bone metabolism, we reviewed its effects on the development of osteopenia in rats, which characterizes models of osteoporosis. Vitamin K2 was found to attenuate the increase in bone resorption and/or maintain bone formation, reduce bone loss, protect against the loss of trabecular bone mass and its connectivity, and prevent the decrease in strength of the long bone in ovariectomized rats. However, combined treatment of bisphosphonates and vitamin K2 had an additive effect in preventing the deterioration of the trabecular bone architecture in ovariectomized rats, while the combined treatment of raloxifene and vitamin K2 improved the bone strength of the femoral neck. The use of vitamin K2 alone suppressed the increase in trabecular bone turnover and endocortical bone resorption, which attenuated the development of cancellous and cortical osteopenia in orchidectomized rats. In addition, vitamin K2 inhibited the decrease in bone formation in prednisolone-treated rats, thereby preventing cancellous and cortical osteopenia. In sciatic neurectomized rats, vitamin K2 suppressed endocortical bone resorption and stimulated bone formation, delaying the reduction of the trabecular thickness and retarding the development of cortical osteopenia. Vitamin K2 also prevented the acceleration of bone resorption and the reduction in bone formation in tail-suspended rats, which counteracted cancellous bone loss. Concomitant use of vitamin K2 with a bisphosphonate ameliorated the suppression of bone formation and more effectively prevented cancellous bone loss in tail-suspended rats. Vitamin K2 stimulated renal calcium reabsorption, retarded the increase in serum parathyroid hormone levels, and attenuated cortical bone loss primarily by suppressing bone resorption in calcium-deficient rats while maintaining the strength of the long bone in rats with magnesium deficiency. These findings suggest that vitamin K2 may not only stimulate bone formation, but may also suppress bone resorption. Thus, vitamin K2 could regulate bone metabolism in rats, which represented the various models of osteoporosis. However, the effects of vitamin K2 on bone mass and bone metabolism seem to be modest.

A study of male patients with forearm fracture in Northern Ireland

Osteoporosis, although considered less common, still occurs in men. We present a cross-sectional study of a group of Northern Ireland men with low-trauma forearm fractures to determine the presence of osteoporosis and screen for secondary causes of low bone mineral density. Male patients aged 30-75 years, presenting with distal forearm fracture in 2000-2001 in Northern Ireland, were identified through a Colles fracture database. A total of 37 subjects consented to have bone mineral density measurements undertaken at the femoral neck, spine and forearm using a Lunar expert bone densitometer. Twenty-seven percent of the men had osteoporosis at the spine, femoral neck or forearm, as defined by a bone mineral density score of less than -2.5. We also found that 49% of patients had vitamin D insufficiency or deficiency, 27% had low serum testosterone, 14% had abnormal liver function test results, and 14% had raised parathyroid hormone. Only one patient received advice or treatment regarding osteoporosis at the time of fracture. Increased awareness of male osteoporosis and the need for screening for potential secondary causes in this group of patients is required, both at primary and secondary care level.

Quality of Life in Prostate Cancer Patients Taking Androgen Deprivation Therapy

OBJECTIVES

To examine the effect of androgen deprivation therapy (ADT) on health-related quality of life (HRQOL), self-reported HRQOL was compared in prostate cancer patients receiving short- (< 6 months) or long-term (> or = 6 months) ADT and healthy controls.

DESIGN

Cross-sectional study.

SETTING

Academic medical center in Pittsburgh, Pennsylvania.

PARTICIPANTS

Ninety-six men, including those with prostate cancer receiving short-term, long-term, and no ADT and healthy controls. Men taking medications or having diseases known to affect bone mineral metabolism were excluded.

MEASUREMENTS

The 36-item Short Form Medical Outcomes Study Health Survey (an HRQOL assessment) and a comorbidity index were administered to each participant. Characteristics, including body composition (assessed using dual-energy x-ray absorptiometry) and gonadal status (serum total and free testosterone) were measured approximately 3 months or less before the HRQOL assessment.

RESULTS

As expected, men receiving ADT had significantly lower levels of testosterone, free testosterone, and lean body mass, as well as greater body fat and comorbidity index (all P<.01) than men not receiving ADT (i.e., men with prostate cancer and healthy controls). Participants receiving ADT reported significantly poorer QOL in the areas of physical function (P<.001), general health (P<.001), and physical health component summary (P<.001) than men not receiving ADT. There were no significant differences in HRQOL outcomes between participants receiving short- or long-term ADT. Comorbidity and testosterone levels were associated with several QOL scales. After controlling for the significant joint predictors of comorbidity and total testosterone using hierarchical regression analysis, ADT was no longer a significant predictor, and only comorbidity and total testosterone contributed to the explanation of the variance of the physical health component summary. Comorbidity alone contributed to the explanation of the variance in physical function, bodily pain, general health, and vitality.

CONCLUSION

Patients with prostate cancer who were receiving ADT experience worse HRQOL than those not receiving ADT, but duration of ADT was not a contributing factor. After controlling for comorbidity, total testosterone level rather than ADT accounted for a small yet statistically significant percentage of the total variance of the physical health component summary. These findings have important clinical implications regarding the decision to treat prostate cancer patients with ADT.

Male hormonal contraception: a safe option?

Hormonal male contraception is based on the administration of testosterone alone or more likely with a progestogen. Testosterone has been used for several decades for the treatment of male hypogonadism, with an excellent safety record. Use as part of a contraceptive regimen by healthy people for prolonged periods will necessitate careful re-examination of safety issues. Although potential male contraceptive regimens have been investigated for many years, there have been mostly small-scale studies unable to assess safety. This is now changing, with larger studies of regimens underway. This, and the increasing involvement of the pharmaceutical industry, means that much more data will shortly be forthcoming and it is hoped that this will also provide valuable information relevant to normal male health. The main areas of interest are the cardiovascular system and the prostate, but bone health and body composition are also important, as are behavioral and psychologic aspects. The development of this field also allows the investigation of potential health benefits, which may be related to the use of synthetic androgens with tissue-selective metabolism or action.

Male hypogonadism : an update on diagnosis and treatment

Male hypogonadism is one of the most common endocrinologic syndromes. The diagnosis is based on clinical signs and symptoms plus laboratory confirmation via the measurement of low morning testosterone levels on two different occasions. Serum luteinizing hormone and follicle-stimulating hormone levels distinguish between primary (hypergonadotropic) and secondary (hypogonadotropic) hypogonadism. Hypogonadism associated with aging (andropause) may present a mixed picture, with low testosterone levels and low to low-normal gonadotropin levels. Androgen replacement therapy in hypogonadal men has many potential benefits: improved sexual function, an enhanced sense of well-being, increased lean body mass, decreased body fat, and increased bone density. However, it also carries potential risks, including the possibility of stimulating the growth of an occult prostate cancer. The benefits of androgen therapy outweigh the risks in men with classic hypogonadism. However, for men with mild hypogonadism or andropause, the balance between benefits and risks is not always clear. Unfortunately, studies to date have included too small a number of patients and have been too short in duration to provide meaningful data on the long-term risks versus the benefits of androgen replacement therapy in these populations. Several products are currently marketed for the treatment of male hypogonadism. Weekly-to-biweekly injections of testosterone cypionate (cipionate) or testosterone enanthate (enantate) are widely used, as they are economical and generally well tolerated. However, once-daily transdermal therapies have become increasingly popular and now include both patch and gel systems. Intramuscular injection of testosterone undecanoate is an attractive new therapy that can be administered quarterly. To confirm an adequate replacement dosage, assessment of clinical responses and measurement of serum testosterone levels generally suffice. For selected men, serial measurement of bone mineral density during androgen therapy might be helpful to confirm end-organ effects. For men aged >50 years, we advocate measurement of hematocrit for detection of polycythemia and a digital rectal examination with a serum prostate-specific antigen level measurement for prostate cancer screening during the first few months of androgen therapy. Subsequently, a hematocrit should be obtained yearly or after changes in therapy, and annual prostate cancer screening can be offered to the patient after a discussion of its risks and benefits.

Effect of aromatase inhibition on bone metabolism in elderly hypogonadal men

Both estrogens and androgens play important roles in skeletal development and maintenance in men. The relative importance of estrogens and androgens in male bone metabolism, however, remains undefined. Anastrozole is an oral aromatase inhibitor that decreases estrogen production and increases androgen production in men. Currently, anastrozole is being investigated as a potential agent for the treatment of hypogonadism in aging men. Because anastrozole lowers estrogen levels and raises androgen levels, its effect on bone metabolism is difficult to predict. To assess the effects of anastrozole on bone turnover, we randomized 37 elderly (ages 62-74) mildly hypogonadal men (serum testosterone <350 ng/dl) to receive either anastrozole 1 mg daily (n=12), anastrozole 1 mg twice weekly (n=11), or daily placebo (n=14) for 12 weeks. Serum gonadal steroid levels, serum and urine biochemical markers of bone turnover, serum osteoprotegerin, and total body bone mineral density were measured at baseline and week 12. Mean serum levels of total and bioavailable testosterone increased substantially in both treated groups. Specifically, mean +/- SD bioavailable testosterone levels increased from 99+/-31 ng/dl to 207+/-65 ng/dl in the group receiving 1 mg of anastrozole daily and from 115+/-37 ng/dl to 178+/-55 ng/dl in the subjects receiving 1 mg of anastrozole twice weekly ( p <0.001 vs placebo for both groups). Serum estradiol levels decreased modestly in both treated groups (from 26+/-8 pg/ml to 17+/-6 pg/ml in the daily treatment group and from 27+/-8 pg/ml to 17+/-5 pg/ml in the twice-weekly treatment group, p <0.001 vs placebo for both groups). Despite these hormonal changes, no increases in biochemical markers of bone resorption were observed. Specifically, mean serum N-telopeptide and urinary deoxypyridinoline concentrations remained stable in both treated groups over the 12-week treatment period. Similarly, serum biochemical markers of bone formation (osteocalcin and amino-terminal propeptide of type 1 collagen), serum osteoprotegerin, and total body bone mineral density did not change. These data demonstrate that although short-term administration of anastrozole decreases serum estradiol levels in elderly men with mild hypogonadism, this intervention does not adversely affect bone metabolism over a 12-week period. This lack of an effect may be due to the concomitant increase in testosterone production, the relative modest effect on estradiol production, or a combination of both factors. These results suggest that anastrozole therapy is unlikely to have an adverse effect on bone metabolism when taken over extended periods and may prove to be a valuable method of normalizing testosterone production in older men.

Selective androgen receptor modulator treatment improves muscle strength and body composition and prevents bone loss in orchidectomized rats

The partial agonist activity of a selective androgen receptor modulator (SARM) in the prostate was demonstrated in orchidectomized rats. In the current study, we characterized the full agonist activity of S-3-(4-acetylamino-phenoxy)-2-hydroxy-2-methyl-N-(4-nitro-3-trifluoromethyl-phenyl)-propionamide (a structurally related SARM referred to in other publications and hereafter as S-4) in skeletal muscle, bone, and pituitary of castrated male rats. Twelve weeks after castration, animals were treated with S-4 (3 or 10 mg/kg), dihydrotestosterone (DHT) (3 mg/kg), or vehicle for 8 wk. S-4 (3 and 10 mg/kg) restored soleus muscle mass and strength and levator ani muscle mass to that seen in intact animals. Similar changes were also observed in DHT-treated (3 mg/kg) animals. Compared with the anabolic effects observed in muscle, DHT (3 mg/kg) stimulated prostate and seminal vesicle weights more than 2-fold greater than that observed in intact controls, whereas S-4 (3 mg/kg) returned these androgenic organs to only 16 and 17%, respectively, of the control levels. S-4 (3 and 10 mg/kg) and DHT (3 mg/kg) restored castration-induced loss in lean body mass. Furthermore, S-4 treatment caused a significantly larger increase in total body bone mineral density than DHT. S-4 (3 and 10 mg/kg) also demonstrated agonist activity in the pituitary and significantly decreased plasma LH and FSH levels in castrated animals in a dose-dependent manner. In summary, the strong anabolic effects of S-4 in skeletal muscle, bone, and pituitary were achieved with minimal pharmacologic effect in the prostate. The tissue-selective pharmacologic activity of SARMs provides obvious advantages over steroidal androgen therapy and demonstrates the promising therapeutic utility that this new class of drugs may hold.

The decline of androgen levels in elderly men and its clinical and therapeutic implications

Aging in men is accompanied by a progressive, but individually variable decline of serum testosterone production, more than 20% of healthy men over 60 yr of age presenting with serum levels below the range for young men. Albeit the clinical picture of aging in men is reminiscent of that of hypogonadism in young men and decreased testosterone production appears to play a role in part of these clinical changes in at least some elderly men, the clinical relevancy of the age-related decline in sex steroid levels in men has not been unequivocally established. In fact, minimal androgen requirements for elderly men remain poorly defined and are likely to vary between individuals. Consequently, borderline androgen deficiency cannot be reliably diagnosed in the elderly, and strict differentiation between "substitutive" and "pharmacological" androgen administration is not possible. To date, only a few hundred elderly men have received androgen therapy in the setting of a randomized, controlled study, and many of these men were not androgen deficient. Most consistent effects of treatment have been on body composition, but to date there is no evidence-based documentation of clinical benefits of androgen administration to elderly men with normal or moderately low serum testosterone in terms of diminished morbidity or of improved survival or quality of life. Until the long-term risk-benefit ratio for androgen administration to elderly is established in adequately powered trials of longer duration, androgen administration to elderly men should be reserved for the minority of elderly men who have both clear clinical symptoms of hypogonadism and frankly low serum testosterone levels.

Effect of testosterone replacement on trabecular architecture in hypogonadal men

We evaluated the effect of testosterone treatment on trabecular architecture by microMRI in 10 untreated severely hypogonadal men. After 2 years, microMRI parameters of trabecular connectivity improved significantly, suggesting the possibility that testosterone improves trabecular architecture.

INTRODUCTION

Osteoporosis, characterized by low BMD and diminished bone quality, is a significant public health problem in men. Hypogonadal men have decreased BMD and deteriorated trabecular architecture compared with eugonadal men, and testosterone treatment improves their BMD. We tested the hypothesis that testosterone replacement in hypogonadal men would also improve their trabecular architecture.

MATERIALS AND METHODS

We selected 10 untreated severely hypogonadal men and treated them with a testosterone gel for 24 months to maintain their serum testosterone concentrations within the normal range. Each subject was assessed before and after 6, 12, and 24 months of testosterone treatment by magnetic resonance microimaging (microMRI) of the distal tibia and by DXA of the spine and hip. The microMRI parameters reflect the integrity of the trabecular network and include the ratio of all surface voxels (representing plates) to curve voxels (representing rods) and the topological erosion index, a ratio of topological parameters expected to increase on trabecular deterioration to those expected to decrease. The higher the surface-to-curve ratio and the lower the topological erosion index, the more intact the trabecular network.

RESULTS

Serum testosterone concentrations increased to midnormal after 3 months of treatment and remained normal thereafter. After 24 months of testosterone treatment, BMD of the spine increased 7.4% (p<0.001), and of the total hip increased 3.8% (p=0.008). Architectural parameters assessed by microMRI also changed: the surface-to-curve ratio increased 11% (p=0.004) and the topological erosion index decreased 7.5% (p=0.004).

CONCLUSIONS

These results suggest the possibility that testosterone replacement of hypogonadal men improves trabecular architecture.

Advances in male hormone substitution therapy

Increased awareness of the clinical diagnosis of male hypogonadism has resulted in the wider use of androgen substitution therapy. Clinical signs and symptoms together with a low serum testosterone level confirm the diagnosis of male hypogonadism. Androgen replacement results in improved sexual function, mood, muscle mass and bone density in most hypogonadal men. Such benefits must be assessed against potential risks. In older men, the potential risks of androgen treatment of hypogonadism are not known. Many delivery systems for androgen substitution are now available; the preparation chosen depends on the choice of the patient and his physician. Selective androgen receptor modulators offer tissue selective biological effects and the possibility of attaining maximum efficacy and minimum adverse effects.

Preventing and treating the complications of hormone therapy

Hormonal manipulation in the form of androgen-deprivation therapy for prostate cancer was introduced by Huggins and Hodges in 1941 and resulted in a Nobel Prize in 1966. Hormonal therapy initially had been used in metastatic prostate cancer, but the indications have been expanded including failed local therapy, locally advanced prostate cancer, and neoadjuvant or adjuvant therapy in high-risk localized prostate cancer. In view of the magnitude of the problem of prostate cancer and relatively frequent use of hormonal manipulation, it is important for clinicians to be aware of common side effects, prevention, and treatment to improve quality of life and reduce morbidity and mortality in patients with prostate cancer. This review focuses on the common side effects of hormonal treatment such as osteoporosis, anemia, hot flashes, erectile dysfunction, muscle wasting, gynecomastia, decline in cognitive function, depression, increase in body fat and metabolic changes, and their prevention and treatment.

ISA, ISSAM and EAU recommendations for the investigation, treatment and monitoring of late-onset hypogonadism in males: scientific background and rationale

Prescription sales for testosterone products have substantially increased over the last several years reflecting the growing awareness of physicians for the potential benefits of testosterone replacement therapy in men with hypogonadism. Indiscriminate administration of testosterone poses a risk and has to be deprecated. Testosterone supplementation to treat late-onset hypogonadism (LOH), a term for androgen deficiency in elderly men, is still controversially discussed mainly due to a lack of large, controlled clinical trials on efficacy and safety. To provide guidance for physicians primarily dealing with aging men, ISSAM is periodically updating and publishing its recommendations as new data become available [Morales A, Lunenfeld B. International Society for the Study of the Aging Male. Investigation, treatment and monitoring of late-onset hypogonadism in males. Official recommendations of ISSAM. International Society for the Study of the Aging Male. Aging Male 2002;5:74-86 and Morales A, Lunenfeld B. Androgen replacement therapy in aging men with secondary hypogonadism. Draft recommendations for endorsement by ISSAM. Aging Male 2001;4:1]. Following a panel discussion at the 4th ISSAM Congress in Prague in February 2004, the International Society of Andrology (ISA), the International Society for the Study of the Aging Male (ISSAM) and the European Association of Urology (EAU) revised existing recommendations on the definition, diagnosis and management of LOH. The recommendations are based on the currently available scientific data on androgen supplementation therapy and should be regarded as provisional until larger-scale, long-term studies are available. While certainly not intending to be exhaustive, this review will highlight some relevant background information and provide the underlying scientific rationale for the ISA, ISSAM and EAU recommendations on LOH published in this issue.

Oral testosterone in oil plus dutasteride in men: a pharmacokinetic study

Testosterone (T) is not administered orally, because it has been reported to be rapidly metabolized by the liver. We hypothesized that sufficient doses of T or T enanthate (TE), administered orally in oil, would result in clinically useful elevations in serum T. We also hypothesized that coadministration of dutasteride (D) with T or TE would minimize increases in serum DHT seen previously with oral administration. Therefore, we conducted a pharmacokinetic study of oral T and TE in oil, with and without concomitant D, in normal men whose T production had been temporarily suppressed by the GnRH antagonist acyline. Thirteen healthy men (mean age, 24 +/- 6 yr) were enrolled and assigned to oral T (n = 7) and oral TE (n = 6) groups and were administered 200, 400, or 800 mg of either T or TE in sesame oil in the morning on 3 successive days 24 h after receiving acyline. Blood samples for measurement of serum T and dihydrotestosterone were obtained before T or TE administration and 0.5, 1, 2, 4, 6, 8, 10, 12, and 24 h after administration. Subjects were then administered D for 4 d before repeating the sequence of T or TE doses with D. Serum T was significantly increased in a dose-dependent fashion with the administration of oral T or TE in oil. Coadministration of D with oral T or TE significantly increased the 24-hr average serum T levels compared with administration of T or TE alone [average serum T after 400 mg dose, 8.7 +/- 3.0 nmol/l (T) and 8.3 +/- 5.7 nmol/l (TE) vs. 16.1 +/- 5.8 nmol/l (T +D) and 15.0 +/- 8.8 nmol/l (TE + D); P < 0.05 for T vs. T and D]. The administration of oral T or TE in oil combined with D results in unexpected and potentially therapeutic increases in serum T. Additional studies of this combination as a novel form of oral androgen therapy are warranted.

Male Osteoporosis

Osteoporosis is a common condition in men affecting approximately 2 million males in the US. Compared with women, osteoporosis develops later in life and the incidence of osteoporosis-related fractures is lower in men. The morbidity and mortality associated with osteoporotic fractures are much greater in men compared with women, and secondary causes of osteoporosis are more frequently (in approximately 50% of cases) identified in men compared with women with osteoporosis. Excessive alcohol consumption, glucocorticoid excess and hypogonadism are the most commonly identified causes. Primary osteoporosis in men has been linked to changes in sex steroid secretion, the growth hormone-insulin-like growth factor-1 (GH-IGF-1) axis and the vitamin D-parathyroid hormone (PTH) 25-hydroxyvitamin D [25(OH)D]-PTH system. Diagnosing osteoporosis in men is complicated by an ongoing debate on whether to use sex-specific reference values for bone mineral density (BMD) or female reference values. The International Society for Clinical Densitometry recommended using a T score of -2.5 or less of male reference values to diagnose osteoporosis in men who are > or =65 years of age. However, this definition is yet to be validated in terms of fracture incidence and prevalence. Ensuring adequate calcium and vitamin D intake is the cornerstone of any regimen aimed at preventing or treating osteoporosis in men. Bisphosphonates are currently the therapy of choice for treatment of male osteoporosis. A short course of parathyroid hormone (1-34) [teriparatide] may be indicated for men with very low BMD or in those in whom bisphosphonate therapy is unsuccessful. The use of testosterone-replacement therapy for the prevention and treatment of male osteoporosis remains controversial but likely to benefit osteoporotic men with evident hypogonadism.

Testosterone increases bone mineral density in female-to-male transsexuals: a case series of 15 subjects

OBJECTIVE

Testosterone therapy for osteoporosis has not been studied extensively in women because of its potential to cause virilization. Female-to-male transsexuals are genetic females who suffer from gender dysphoria and thus take supra-physiologic doses of testosterone to change from the female to male phenotype. The aim of this study is to examine the effects of testosterone treatment on the genetic female skeleton.

PATIENTS AND DESIGN

A group of 15 female-to-male transsexuals was prospectively enrolled for observation over a 2-year period. The subjects had a mean age of 37.0 +/- 3.0 years. All of the subjects self-administered testosterone esters intramuscularly at a mean dose of 70.7 +/- 4.5 mg weekly.

MEASUREMENTS

The subjects had measurements of bone mineral density (BMD) by dual X-ray absorptiometry (DXA) of the femoral neck and spine (L2-L4) at 12-month intervals. They had determinations of serum oestradiol, testosterone, soluble RANKL (sRANKL), osteoprotegerin (OPG) and urine N-telopeptide (NTX) at the date of enrolment and at the end of 2 years. results There was a significant positive increase in mean BMD of 7.8% at the femoral neck and a nonsignificant increase in mean BMD of 3.1% at the spine over 2 years. The levels of testosterone reached the upper normal range for males and the levels of oestradiol declined to near the postmenopausal range. sRANKL levels decreased significantly in female-to-male transsexuals who newly initiated testosterone therapy. There was no significant change in urine NTX or serum OPG during the study.

CONCLUSIONS

We conclude that supra-physiologic testosterone therapy increases BMD at the hip while maintaining BMD at the spine in female-to-male transsexuals. The effects of testosterone may be the result of testosterone hormone directly acting on the bone or indirectly through aromatization to oestradiol. Lower RANKL levels coupled with unchanged OPG levels results in an increased OPG/RANKL ratio, which may be beneficial to the bone by inhibiting osteoclastogenesis.

Testosterone replacement therapy: current trends and future directions

Male hypogonadism is characterized by abnormally low serum testosterone levels associated with typical symptoms, including mood disturbance, sexual dysfunction, decreased muscle mass and strength, and decreased bone mineral density. By restoring serum testosterone levels to the normal range using testosterone replacement therapy, many of these symptoms can be relieved. For many years, injectable testosterone esters or surgically implanted testosterone pellets have been the preferred treatment for male hypogonadism. Recently, newer treatment modalities have been introduced, including transdermal patches and gels. The development of a mucoadhesive sustained-release buccal tablet is the latest innovation, which will provide patients with an additional option. The availability of new treatment modalities has helped to renew interest in the management of male hypogonadism, highlighting the need to address a number of important but previously neglected questions in testosterone replacement therapy. These include the risks and benefits of treatment in different patient populations (e.g. the elderly) and the need for evidence-based diagnosis and treatment monitoring guidelines. While some recommendations have been developed in individual countries, up-to-date, internationally accepted evidence-based guidelines that take into account national differences in clinical practice and healthcare delivery would optimize patient care universally.

Hormone profiles, body mass index and aging male symptoms: results of the Androx Vienna Municipality study

Aging in the male is accompanied by steroid hormonal decline, and men may develop symptoms associated with hypogonadism. Increased awareness of 'andropause' in recent years has led to greater demand for hormonal assessments, resulting in a rising burden for health economics. We conducted a cross-sectional study to define men at risk for hypogonadism, in whom further hormonal investigation should be performed. We examined 664 blue-collar workers aged 40-60 years at their workplace and determined hormonal status and body mass index (BMI). Men with an abnormal urogenital status and those on medication that might affect endocrine status were excluded from the study. All participants completed the validated Aging Male Symptom (AMS) questionnaire and obtained scores for psychological symptoms, somatovegetative symptoms, and sexual symptoms. Multiple logistic regression analyses revealed a significantly increased risk (represented by the odds ratio) of psychological symptoms for men with low levels of testosterone and/or bioavailable testosterone (BAT). Increased BMI as well as low testosterone levels and/or low BAT levels raised the risk of somatovegetative symptoms. Each decrease of BAT by 1 ng/ml caused an approximately 1.8-fold increase of the risk (odds ratio = 1.832, p = 0.005). Additional independent risk factors were increased age and low luteinizing hormone (LH) level. Men aged 55 years with BMI > 28 kg/m2 and with somatovegetative symptoms and moderate or severe psychological symptoms had a 7.2-fold increase in the risk of a BAT level < 1.5 ng/ml compared to men without these risk factors (p < 0.001). Sensitivity and specificity were 75% and 71%, respectively. The AMS score combined with age and BMI provides an easy and convenient method to identify men with probable androgen deficiency who require hormonal assessment.

Testosterone metabolism and replacement therapy in patients with end-stage renal disease

Hypogonadism is common among men with end-stage renal disease (ESRD), beginning before the need for dialysis and not improved with the initiation of dialysis. Many of the manifestations of hypogonadism, such as bone disease and muscle wasting, are also frequently seen among dialysis patients. There have been few studies of testosterone replacement therapy in this patient population, but available data suggest that testosterone can be administered without adjustment of the doses used in hypogonadal men with normal renal function. Extrapolation from results of treatment of hypogonadal older men with normal renal function suggests that testosterone replacement could improve libido and could have salutary effects on muscle mass and bone mineral density in patients with kidney disease. However, caution is warranted because of the potential side effects of testosterone therapy, and further research is needed to more precisely define the balance of risk and benefit in patients with chronic kidney disease. Specifically it will be important to determine the prevalence and clinical significance of hypogonadism in ESRD patients in the modern era and to measure the effects of replacement therapy on various symptoms of hypogonadism as well as on overall quality of life, physical functioning, and survival.

Androgens and bone

Loss of estrogens or androgens increases the rate of bone remodeling by removing restraining effects on osteoblastogenesis and osteoclastogenesis, and also causes a focal imbalance between resorption and formation by prolonging the lifespan of osteoclasts and shortening the lifespan of osteoblasts. Conversely, androgens, as well as estrogens, maintain cancellous bone mass and integrity, regardless of age or sex. Although androgens, via the androgen receptor (AR), and estrogens, via the estrogen receptors (ERs), can exert these effects, their relative contribution remains uncertain. Recent studies suggest that androgen action on cancellous bone depends on (local) aromatization of androgens into estrogens. However, at least in rodents, androgen action on cancellous bone can be directly mediated via AR activation, even in the absence of ERs. Androgens also increase cortical bone size via stimulation of both longitudinal and radial growth. First, androgens, like estrogens, have a biphasic effect on endochondral bone formation: at the start of puberty, sex steroids stimulate endochondral bone formation, whereas they induce epiphyseal closure at the end of puberty. Androgen action on the growth plate is, however, clearly mediated via aromatization in estrogens and interaction with ERalpha. Androgens increase radial growth, whereas estrogens decrease periosteal bone formation. This effect of androgens may be important because bone strength in males seems to be determined by relatively higher periosteal bone formation and, therefore, greater bone dimensions, relative to muscle mass at older age. Experiments in mice again suggest that both the AR and ERalpha pathways are involved in androgen action on radial bone growth. ERbeta may mediate growth-limiting effects of estrogens in the female but does not seem to be involved in the regulation of bone size in males. In conclusion, androgens may protect men against osteoporosis via maintenance of cancellous bone mass and expansion of cortical bone. Such androgen action on bone is mediated by the AR and ERalpha.

Risks and benefits of hormone replacement therapy in older men

The use of testosterone in older men, known as male hormonal replacement therapy or androgen replacement therapy, has become of increasing interest to both the medical and lay communities over the past decade. Even though the knowledge of the potential benefits and risks of male Androgen Replacement Therapy has increased dramatically, there is still much that needs to be determined. Although there are a number of potential benefits of male Androgen Replacement Therapy and data concerning clinical effects of such replacement have accumulated, as yet there have not been any large multicenter randomized controlled trials of this therapy. It is the purpose of this article to review what is currently known about the possible risks and benefits of male Androgen Replacement Therapy by discussing the clinical trials to date.

Androgen Replacement Therapy

The major goal of androgen substitution is to replace testosterone at levels as close to physiological levels as is possible. For some androgen-dependent functions testosterone is a pro-hormone, peripherally converted to 5alpha-dihydrotestosterone (DHT) and 17beta-estradiol (E2), of which the levels preferably should be within normal physiological ranges. Furthermore, androgens should have a good safety profile without adverse effects on the prostate, serum lipids, liver or respiratory function, and they must be convenient to use and patient-friendly, with a relative independence from medical services. Natural testosterone is viewed as the best androgen for substitution in hypogonadal men. The reason behind the selection is that testosterone can be converted to DHT and E2, thus developing the full spectrum of testosterone activities in long-term substitution. The mainstays of testosterone substitution are parenteral testosterone esters (testosterone enantate and testosterone cipionate) administered every 2-3 weeks. A major disadvantage is the strongly fluctuating levels of plasma testosterone, which are not in the physiological range at least 50% of the time. Also, the generated plasma E2 is usually supraphysiological. A major improvement is parenteral testosterone undecanoate producing normal plasma levels of testosterone for 12 weeks, with normal plasma levels of DHT and E2 also. Subcutaneous testosterone implants provide the patient, depending on the dose of implants, with normal plasma testosterone for 3-6 months. However, their use is not widespread. Oral testosterone undecanoate dissolved in castor oil bypasses the liver via its lymphatic absorption. At a dosage of 80 mg twice daily, plasma testosterone levels are largely in the normal range, but plasma DHT tends to be elevated. For two decades transdermal testosterone preparations have been available and have an attractive pharmacokinetic profile. Scrotal testosterone patches generate supraphysiological plasma DHT levels, which is not the case with the nonscrotal testosterone patches. Transdermal testosterone gel produces fewer skin irritations than the patches and offers greater flexibility in dosage. Oromucosal testosterone preparations have recently become available. Testosterone replacement is usually of long duration and so patient compliance is of utmost importance. Therefore, the patient must be involved in the selection of type of testosterone preparation. Administration of testosterone to young individuals has almost no adverse effects. With increasing age the risk of adverse effects on the prostate, the cardiovascular system and erythropoiesis increases. Consequently, short-acting testosterone preparations are better suited for aging androgen-deficient men.

Andropause: Symptom Management for Prostate Cancer Patients Treated With Hormonal Ablation

Andropause, or the age-related decline in serum testosterone, has become a popular topic in the medical literature over the past several years. Andropause includes a constellation of symptoms related to lack of androgens, including diminished libido, decreased generalized feeling of well-being, osteoporosis, and a host of other symptoms. The andropause syndrome is very prominent in men undergoing hormonal ablation therapy for prostate cancer. Most significant in this population are the side effects of hot flashes, anemia, gynecomastia, depression, cognitive decline, sarcopenia, a decreased overall quality of life, sexual dysfunction, and osteoporosis with subsequent bone fractures. The concept of andropause in prostate cancer patients is poorly represented in the literature. In this article, we review the current literature on the symptoms, signs, and possible therapies available to men who cannot take replacement testosterone.