Mortality trends over five decades in adult transgender people receiving hormone treatment: a report from the Amsterdam cohort of gender dysphoria.

BACKGROUND: Increased mortality in transgender people has been described in earlier studies. Whether this increased mortality is still present over the past decades is unknown. Therefore, we aimed to investigate trends in mortality over five decades in a large cohort of adult transgender people in addition to cause-specific mortality. METHODS: We did a retrospective cohort study of adult transgender people who visited the gender identity clinic of Amsterdam University Medical Centre in the Netherlands. Data of transgender people who received hormone treatment between 1972 and 2018 were linked to Statistics Netherlands. People were excluded if they used alternating testosterone and oestradiol treatment, if they started treatment younger than age 17 years, or if they had ever used puberty-blockers before gender-affirming hormone treatment. Standardised mortality ratios (SMRs) were calculated using general population mortality rates stratified by age, calendar period, and sex. Cause-specific mortality was also calculated. FINDINGS: Between 1972 and 2018, 8831 people visited the gender identity clinic. 4263 were excluded from the study for a variety of reasons, and 2927 transgender women and 1641 transgender men were included in the study, with a total follow-up time of 40 232 person-years for transgender women and 17 285 person-years for transgender men. During follow-up, 317 (10·8%) transgender women died, which was higher than expected compared with general population men (SMR 1·8, 95% CI 1·6-2·0) and general population women (SMR 2·8, 2·5-3·1). Cause-specific mortality in transgender women was high for cardiovascular disease, lung cancer, HIV-related disease, and suicide. In transgender men, 44 people (2·7%) died, which was higher than expected compared with general population women (SMR 1·8, 95% CI 1·3-2·4) but not general population men (SMR 1·2, 95% CI 0·9-1·6). Cause-specific death in transgender men was high for non-natural causes of death. No decreasing trend in mortality risk was observed over the five decades studied. INTERPRETATION: This observational study showed an increased mortality risk in transgender people using hormone treatment, regardless of treatment type. This increased mortality risk did not decrease over time. The cause-specific mortality risk because of lung cancer, cardiovascular disease, HIV-related disease, and suicide gives no indication to a specific effect of hormone treatment, but indicates that monitoring, optimising, and, if necessary, treating medical morbidities and lifestyle factors remain important in transgender health care. FUNDING: None.

Bone Development in Transgender Adolescents Treated With GnRH Analogues and Subsequent Gender-Affirming Hormones.

CONTEXT: Hormonal interventions in adolescents with gender dysphoria may have adverse effects, such as reduced bone mineral accrual. OBJECTIVE: To describe bone mass development in adolescents with gender dysphoria treated with gonadotropin-releasing hormone analogues (GnRHa), subsequently combined with gender-affirming hormones. DESIGN: Observational prospective study. SUBJECTS: 51 transgirls and 70 transboys receiving GnRHa and 36 transgirls and 42 transboys receiving GnRHa and gender-affirming hormones, subdivided into early- and late-pubertal groups. MAIN OUTCOME MEASURES: Bone mineral apparent density (BMAD), age- and sex-specific BMAD z-scores, and serum bone markers. RESULTS: At the start of GnRHa treatment, mean areal bone mineral density (aBMD) and BMAD values were within the normal range in all groups. In transgirls, the mean z-scores were well below the population mean. During 2 years of GnRHa treatment, BMAD stabilized or showed a small decrease, whereas z-scores decreased in all groups. During 3 years of combined administration of GnRHa and gender-affirming hormones, a significant increase of BMAD was found. Z-scores normalized in transboys but remained below zero in transgirls. In transgirls and early pubertal transboys, all bone markers decreased during GnRHa treatment. CONCLUSIONS: BMAD z-scores decreased during GnRHa treatment and increased during gender-affirming hormone treatment. Transboys had normal z-scores at baseline and at the end of the study. However, transgirls had relatively low z-scores, both at baseline and after 3 years of estrogen treatment. It is currently unclear whether this results in adverse outcomes, such as increased fracture risk, in transgirls as they grow older.

Prostate Cancer Incidence under Androgen Deprivation: Nationwide Cohort Study in Trans Women Receiving Hormone Treatment.

CONTEXT: Trans women (male sex assigned at birth, female gender identity) mostly use antiandrogens combined with estrogens and can subsequently undergo vaginoplasty including orchiectomy. Because the prostate remains in situ after this procedure, trans women are still at risk for prostate cancer. OBJECTIVE: To assess the incidence of prostate cancer in trans women using hormone treatment. The incidence of prostate cancer in trans women using hormone treatment. DESIGN: In this nationwide retrospective cohort study, data of participants were linked to the Dutch national pathology database and to Statistics Netherlands to obtain data on prostate cancer diagnosis and mortality. SETTING: Gender identity clinic. PARTICIPANTS: Trans women who visited our clinic between 1972 and 2016 and received hormone treatment were included. MAIN OUTCOME MEASURES: Standardized incidence ratios (SIRs) were calculated using the number of observed prostate cancer cases in our cohort and the number of expected cases based on age-specific incidence numbers from the Netherlands Comprehensive Cancer Organization. RESULTS: The study population consisted of 2281 trans women with a median follow-up time of 14 years (interquartile range 7-24), and a total follow-up time of 37 117 years. Six prostate cancer cases were identified after a median 17 years of hormone treatment. This resulted in a lower prostate cancer risk in trans women than in Dutch reference males (SIR 0.20, 95% confidence interval 0.08-0.42). CONCLUSIONS: Trans women receiving androgen deprivation therapy and estrogens have a substantially lower risk for prostate cancer than the general male population. Our results support the hypothesis that androgen deprivation has a preventive effect on the initiation and development of prostate cancer.

Hypertrophic osteoarthropathy: estrogens, prostaglandinE2, prostaglandin A2, and the inflammatory reflex.

It has been claimed that hyperestrogenism occurs in hypertrophic osteoarthropathy (HOA), but not in simple clubbing. However, one of our patients had simple clubbing and hyperestrogenism. We therefore measured estrogens, androgens, sex hormone-binding globulin (SHBG), and gonadotropins in five patients with HOA and in 18 patients with simple clubbing. Of the patients with HOA, 80% had a high urinary estriol concentration. In their serum, 80% had high estrone, 0% high estradiol, and 40% high SHBG. Of the patients with simple clubbing, 89% had a high urinary estriol concentration. In their serum, 76% had high estrone, 6% high estradiol, and 31% high SHBG. In all patients, urinary estriol concentration correlated positively with the degree of clubbing. Serum concentration of androstenedione, testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) was mostly normal, but androstenedione concentration correlated positively with the degree of clubbing. Spider angiomas were present in 74%, palmar erythema in 39%, and gynecomastia in 9%. Urinary creatinine concentration was low in 48% and correlated positively with the degree of clubbing. We reject the claim that hyperestrogenism occurs in HOA, but not in simple clubbing. Hyperestrogenism occurs both in HOA and in simple clubbing. Our results also support earlier reports that clubbing and HOA are associated with spider angiomas, palmar erythema, gynecomastia, adrenal cortical hyperfunction, muscle atrophy, and water retention. These results led to a new hypothesis on the pathogenesis of HOA, involving estrogens, prostaglandin E2, prostaglandin A2, and the inflammatory reflex.

Endocrinology of Transgender Medicine.

Gender-affirming treatment of transgender people requires a multidisciplinary approach in which endocrinologists play a crucial role. The aim of this paper is to review recent data on hormonal treatment of this population and its effect on physical, psychological, and mental health. The Endocrine Society guidelines for transgender women include estrogens in combination with androgen-lowering medications. Feminizing treatment with estrogens and antiandrogens has desired physical changes, such as enhanced breast growth, reduction of facial and body hair growth, and fat redistribution in a female pattern. Possible side effects should be discussed with patients, particularly those at risk for venous thromboembolism. The Endocrine Society guidelines for transgender men include testosterone therapy for virilization with deepening of the voice, cessation of menses, and increases of muscle mass and facial and body hair. Owing to the lack of evidence, treatment of gender nonbinary people should be individualized. Young people may receive pubertal suspension, consisting of GnRH analogs, later followed by sex steroids. Options for fertility preservation should be discussed before any hormonal intervention. Morbidity and cardiovascular risk with cross-sex hormones is unchanged among transgender men and unclear among transgender women. Sex steroid-related malignancies can occur but are rare. Mental health problems such as depression and anxiety have been found to reduce considerably following hormonal treatment. Future studies should aim to explore the long-term outcome of hormonal treatment in transgender people and provide evidence as to the effect of gender-affirming treatment in the nonbinary population.

Endocrine treatment of aging transgender people.

High quality empirical data assessing morbidity and mortality and cancer incidence among transgender people are almost non-existent. Sex hormone treatment of conditions in older non-transgender people might as yet be taken as the best available analogy to hormone administration to aging transgender persons. Testosterone administration to transgender men carries little risk with regard to cardiovascular disease and cancer. A dose adaptation may be needed in men with a high hematocrit or cardiac insufficiency. In transgender men, even after breast ablation, breast cancer may occur in residual mammary tissue. Treatment with estrogens (specifically oral ethinylestradiol) of transgender women, particularly in combination with progestins, carries a significant relative risk of developing cardiovascular disease (almost a twofold incidence compared to the general population). The dose of estrogens may have to be reduced with aging. A change from oral to probably safer transdermal estrogens must be considered. Though rare, tumors of the breasts, prostate, meninges and pituitary have been encountered. Based upon the available expertise, initiation of cross-sex hormone treatment in elderly subjects is without disproportionate risks.

The occurrence of benign brain tumours in transgender individuals during cross-sex hormone treatment.

Benign brain tumours may be hormone sensitive. To induce physical characteristics of the desired gender, transgender individuals often receive cross-sex hormone treatment, sometimes in higher doses than hypogonadal individuals. To date, long-term (side) effects of cross-sex hormone treatment are largely unknown. In the present retrospective chart study we aimed to compare the incidence of common benign brain tumours: meningiomas, pituitary adenomas (non-secretive and secretive), and vestibular schwannomas in transgender individuals receiving cross-sex hormone treatment, with those reported in general Dutch or European populations. This study was performed at the VU University Medical Centre in the Netherlands and consisted of 2555 transwomen (median age at start of cross-sex hormone treatment: 31 years, interquartile range 23-41) and 1373 transmen (median age 23 years, interquartile range 18-31) who were followed for 23 935 and 11 212 person-years, respectively. For each separate brain tumour, standardized incidence ratios with 95% confidence intervals were calculated. In transwomen (male sex assigned at birth, female gender identity), eight meningiomas, one non-secretive pituitary adenoma, nine prolactinomas, and two vestibular schwannomas occurred. The incidence of meningiomas was higher in transwomen than in a general European female population (standardized incidence ratio 4.1, 95% confidence interval 1.9-7.7) and male population (11.9, 5.5-22.7). Similar to meningiomas, prolactinomas occurred more often in transwomen compared to general Dutch females (4.3, 2.1-7.9) and males (26.5, 12.9-48.6). Noteworthy, most transwomen had received orchiectomy but still used the progestogenic anti-androgen cyproterone acetate at time of diagnosis. In transmen (female sex assigned at birth, male gender identity), two cases of somatotrophinomas were observed, which was higher than expected based on the reported incidence rate in a general European population (incidence rate females = incidence rate males; standardized incidence ratio 22.2, 3.7-73.4). Based on our results we conclude that cross-sex hormone treatment is associated with a higher risk of meningiomas and prolactinomas in transwomen, which may be linked to cyproterone acetate usage, and somatotrophinomas in transmen. Because these conditions are quite rare, performing regular screenings for such tumours (e.g. regular prolactin measurements for identifying prolactinomas) seems not necessary.

The Amsterdam Cohort of Gender Dysphoria Study (1972-2015): Trends in Prevalence, Treatment, and Regrets.

BACKGROUND: Over the past decade, the number of people referred to gender identity clinics has rapidly increased. This raises several questions, especially concerning the frequency of performing gender-affirming treatments with irreversible effects and regret from such interventions. AIM: To study the current prevalence of gender dysphoria, how frequently gender-affirming treatments are performed, and the number of people experiencing regret of this treatment. METHODS: The medical files of all people who attended our gender identity clinic from 1972 to 2015 were reviewed retrospectively. OUTCOMES: The number of (and change in) people who applied for transgender health care, the percentage of people starting with gender-affirming hormonal treatment (HT), the estimated prevalence of transgender people receiving gender-affirming treatment, the percentage of people who underwent gonadectomy, and the percentage of people who regretted gonadectomy, specified separately for each year. RESULTS: 6,793 people (4,432 birth-assigned male, 2,361 birth-assigned female) visited our gender identity clinic from 1972 through 2015. The number of people assessed per year increased 20-fold from 34 in 1980 to 686 in 2015. The estimated prevalence in the Netherlands in 2015 was 1:3,800 for men (transwomen) and 1:5,200 for women (transmen). The percentage of people who started HT within 5 years after the 1st visit decreased over time, with almost 90% in 1980 to 65% in 2010. The percentage of people who underwent gonadectomy within 5 years after starting HT remained stable over time (74.7% of transwomen and 83.8% of transmen). Only 0.6% of transwomen and 0.3% of transmen who underwent gonadectomy were identified as experiencing regret. CLINICAL IMPLICATIONS: Because the transgender population is growing, a larger availability of transgender health care is needed. Other health care providers should familiarize themselves with transgender health care, because HT can influence diseases and interact with medication. Because not all people apply for the classic treatment approach, special attention should be given to those who choose less common forms of treatment. STRENGTHS AND LIMITATIONS: This study was performed in the largest Dutch gender identity clinic, which treats more than 95% of the transgender population in the Netherlands. Because of the retrospective design, some data could be missing. CONCLUSION: The number of people with gender identity issues seeking professional help increased dramatically in recent decades. The percentage of people who regretted gonadectomy remained small and did not show a tendency to increase. Wiepjes CM, Nota NM, de Blok CJM, et al. The Amsterdam Cohort of Gender Dysphoria Study (1972-2015): Trends in Prevalence, Treatment, and Regrets. J Sex Med 2018;15:582-590.

Endocrine Treatment of Gender-Dysphoric/Gender-Incongruent Persons: An Endocrine Society Clinical Practice Guideline.

Objective: To update the "Endocrine Treatment of Transsexual Persons: An Endocrine Society Clinical Practice Guideline," published by the Endocrine Society in 2009. Participants: The participants include an Endocrine Society-appointed task force of nine experts, a methodologist, and a medical writer. Evidence: This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation approach to describe the strength of recommendations and the quality of evidence. The task force commissioned two systematic reviews and used the best available evidence from other published systematic reviews and individual studies. Consensus Process: Group meetings, conference calls, and e-mail communications enabled consensus. Endocrine Society committees, members and cosponsoring organizations reviewed and commented on preliminary drafts of the guidelines. Conclusion: Gender affirmation is multidisciplinary treatment in which endocrinologists play an important role. Gender-dysphoric/gender-incongruent persons seek and/or are referred to endocrinologists to develop the physical characteristics of the affirmed gender. They require a safe and effective hormone regimen that will (1) suppress endogenous sex hormone secretion determined by the person's genetic/gonadal sex and (2) maintain sex hormone levels within the normal range for the person's affirmed gender. Hormone treatment is not recommended for prepubertal gender-dysphoric/gender-incongruent persons. Those clinicians who recommend gender-affirming endocrine treatments-appropriately trained diagnosing clinicians (required), a mental health provider for adolescents (required) and mental health professional for adults (recommended)-should be knowledgeable about the diagnostic criteria and criteria for gender-affirming treatment, have sufficient training and experience in assessing psychopathology, and be willing to participate in the ongoing care throughout the endocrine transition. We recommend treating gender-dysphoric/gender-incongruent adolescents who have entered puberty at Tanner Stage G2/B2 by suppression with gonadotropin-releasing hormone agonists. Clinicians may add gender-affirming hormones after a multidisciplinary team has confirmed the persistence of gender dysphoria/gender incongruence and sufficient mental capacity to give informed consent to this partially irreversible treatment. Most adolescents have this capacity by age 16 years old. We recognize that there may be compelling reasons to initiate sex hormone treatment prior to age 16 years, although there is minimal published experience treating prior to 13.5 to 14 years of age. For the care of peripubertal youths and older adolescents, we recommend that an expert multidisciplinary team comprised of medical professionals and mental health professionals manage this treatment. The treating physician must confirm the criteria for treatment used by the referring mental health practitioner and collaborate with them in decisions about gender-affirming surgery in older adolescents. For adult gender-dysphoric/gender-incongruent persons, the treating clinicians (collectively) should have expertise in transgender-specific diagnostic criteria, mental health, primary care, hormone treatment, and surgery, as needed by the patient. We suggest maintaining physiologic levels of gender-appropriate hormones and monitoring for known risks and complications. When high doses of sex steroids are required to suppress endogenous sex steroids and/or in advanced age, clinicians may consider surgically removing natal gonads along with reducing sex steroid treatment. Clinicians should monitor both transgender males (female to male) and transgender females (male to female) for reproductive organ cancer risk when surgical removal is incomplete. Additionally, clinicians should persistently monitor adverse effects of sex steroids. For gender-affirming surgeries in adults, the treating physician must collaborate with and confirm the criteria for treatment used by the referring physician. Clinicians should avoid harming individuals (via hormone treatment) who have conditions other than gender dysphoria/gender incongruence and who may not benefit from the physical changes associated with this treatment.

Effectiveness and tolerability of parenteral testosterone undecanoate: a post-marketing surveillance study.

This observational post-marketing study of parenteral testosterone undecanoate (TU) in a non-selected population aimed to: examine the effectiveness of TU as treatment of hypogonadism; record adverse drug reactions (ADR) quantitatively particularly regarding polycythemia, prostate safety and cardiovascular-related metabolic risk factors; and verify whether recommended injection intervals apply to routine clinical practice. Eight hundred and seventy subjects from 259 outpatient units scheduled to visit the clinic six times were included. Effectiveness and tolerability of TU administration were assessed on a 4-point scale. Body weight, waist girth, blood pressure, hemoglobin levels, hematocrit, prostate-specific antigen (PSA), and digital rectal prostate examination were assessed. Over 90% of subjects completed the observational duration of 52.8 ± 9.7 weeks (mean ± SD) and 56% judged effectiveness as very good, 30.8% as good. 63.1% judged tolerability as very good, and 24.4% as good. No adverse effects on indicators of cardiovascular risk were observed. Polycythemia occurred in one subject and a supranormal hematocrit in one subject. Four subjects developed supranormal PSA levels. Prostate carcinoma was found in one subject, one subject had recurrence of a previously surgically treated prostate carcinoma, and the other two showed no indication of malignancy. Parenteral TU is safe, effective, and well-tolerated in clinical practice proving a good therapeutic option for hypogonadism.

Diagnosing hypogonadism and treating decisions in different parts of the world: shifts in patterns between 2006 and 2015.

AIM: Variations in diagnosing and treating testosterone (T) deficiency between different regions of the world were analyzed in 2006, and repeated in 2010. At present, the changes since 2006 were analyzed. METHODS: About 731 physicians were interviewed in Europe, South Africa, Central and South America regarding factors determining: (1) prescription of T or withholding T, (2) factors in the long-term use of T and the role of T formulations therein, (3) awareness of the wider spectrum of action of T (cardiometabolic disease) (4) reimbursement of T and its impact on (continued) use and (5) best strategies for information on T for physicians. RESULTS: Total T was a key factor in identifying hypogonadism, but for >80% of physicians, clinical symptoms were weighed during diagnosis. Once diagnosed, >85% received T treatment, but the treatment compliance was problematic. Of these patients, 36% decided not to start or continue the treatment. CONCLUSION: More hypogonadal men are treated than before, but ∼20% goes unidentified. Physicians have a greater awareness that T deficiency can be an element in cardiovascular and metabolic disease, but more education of physicians on diagnosis and treatment of hypogonadism are needed. Problems with reimbursement of T are barriers in the prescription of T and its use by patients.

Effects of intermission and resumption of long-term testosterone replacement therapy on body weight and metabolic parameters in hypogonadal in middle-aged and elderly men.

OBJECTIVE: In addition to primary and secondary ('classical') hypogonadism, hypogonadism occurring in middle-aged and elderly men has been recognized. There is evidence that restoring T levels to normal improves body weight, serum lipids and glucose levels. DESIGN: Observational registry study. PATIENTS: Two hundred and sixty-two hypogonadal, middle-aged and elderly, men received testosterone replacement treatment (TRT). After having been on TRT for a mean duration of 65·5 months, TRT was temporarily intermitted in 147 patients for a mean of 16·9 months (Group I) due to cost reimbursement issues and in seven men due to prostate cancer. All these men resumed TRT for a mean period of 14·5 months. Of the cohort, 115 men were treated continuously (designated as Group C). To compare on-treatment to off-treatment periods, three periods of equal duration were defined: pre-intermission (on TRT), during intermission (off TRT) and post-intermission (on TRT after resumption of TRT). For proper comparison, the same periods were analysed for those patients who continued TRT throughout (Group C). MEASUREMENTS: Variables of body weight, glucose metabolism, lipids, blood pressure and C-reactive protein (CRP). RESULTS: In Group C there was a continuous improvement of body weight, serum lipids, glucose, HbA1c , blood pressure and CRP. In Group I there was a similar initial improvement which was reversed upon intermission of T administration but which appeared again when T treatment was reinstated. CONCLUSIONS: Our observation indicates that T administration improves body weight and metabolic factors in men with hypogonadism but withdrawal of T reverses these beneficial effects to appear again when TRT is resumed.

Effects of long-term testosterone replacement therapy, with a temporary intermission, on glycemic control of nine hypogonadal men with type 1 diabetes mellitus - a series of case reports.

Type 2 diabetes mellitus (T2DM) is often associated with obesity and subnormal serum testosterone (T) levels. Until 5 years ago there was no indication that men with type 1 diabetes mellitus (T1DM) had subnormal serum T. But recent studies indicate that about 10% of men with T1DM suffer from hypogonadism, as a rule aged men and men with obesity. While hypogonadal men with T2DM benefit from normalization of their serum T, this has not been investigated in men with T1DM. Nine men with T1DM, erectile dysfunction and hypogonadism (total testosterone ≤ 12 nmol/L) received testosterone replacement therapy (TRT). In seven men TRT was intermitted: one man with prostate malignancy and six men because of problems of reimbursement. Incidentally, this provided an opportunity to monitor the effects of withdrawal and of the reinstatement of TRT. In all men, glycemic control (serum glucose and HbA1c), weight, waist circumference, lipid profiles and erectile function improved upon TRT. The seven men whose TRT was intermitted showed a deterioration which improved again upon reinstatement of TRT. The data suggest that aging and obese men with T1DM might have subnormal T levels and that their glycemic control, lipid profiles and erectile function might benefit from TRT.

Testosterone therapy in men with Crohn's disease improves the clinical course of the disease: data from long-term observational registry study.

BACKGROUND: Crohn's disease is an inflammatory chronic bowel disease characterized by an imbalanced production of pro-inflammatory mediators (tumor necrosis factor-α) and an increased recruitment of leukocytes to the site of inflammation. Low serum testosterone is associated with an increase in inflammatory factors, while testosterone administration reduces them. There is evidence for an immunomodulatory effect of testosterone on differentiation of regulatory T cells. MATERIALS AND METHODS: The research was carried out in clinics in Germany and Syria. The study was a cumulative, prospective, registry study with an increasing number of men over time receiving testosterone. While men diagnosed with Crohn's disease received appropriate treatment for Crohn's disease, they were tested for testosterone deficiency (cut-off point ≤12.1 nmol/L). In total, 92 men received parenteral testosterone undecanoate 1000 mg/12 weeks for up to 7 years. Fourteen men opted not to receive testosterone and served as a comparison group. RESULTS: In men receiving testosterone, the Crohn's Disease Activity Index declined from 239.36±36.96 to 71.67±3.26 at 84 months (p<0.0001 vs. baseline). C-reactive protein levels decreased from 12.89±8.64 to 1.78±1.37 mg/L at 84 months (p<0.0001 vs. baseline). Leukocyte count decreased from 11.93±2.85 to 6.21±1.01×109/L (p<0.0001 at 84 months vs. baseline). No changes were observed in the comparison group. There were no significant side effects of testosterone. CONCLUSIONS: Normalizing serum testosterone in hypogonadal men with Crohn's disease had a positive effect on the clinical course, also evidenced by biochemical parameters. Testosterone administration appeared safe.

Elderly men over 65 years of age with late-onset hypogonadism benefit as much from testosterone treatment as do younger men.

PURPOSE: To investigate the potential benefits of testosterone administration to elderly men (>65 years) with late-onset hypogonadism (LOH) in comparison with younger men and to assess the safety of testosterone administration to elderly men. MATERIALS AND METHODS: A total of 561 hypogonadal men from two registry studies were divided into age groups of ≤65 years (group Y, n=450; range, 32-65 years) and >65 years (group O, n=111; range, 66-84 years). Following an initial 6-week interval, all men were treated with 3-month injections of parenteral testosterone undecanoate for up to 6 years. RESULTS: Over the 6 years, there was a progressive decrease of body weight and waist circumference. Beneficial effects on lipids and other metabolic factors and on psychological and sexual functioning progressed over the first 24 to 42 months and were sustained. Rather than a deterioration, there was an improvement of urinary parameters. Prostate volume and prostate-specific antigen increased moderately. Hematocrit levels increased but remained within safe margins. CONCLUSIONS: The benefits of restoring serum testosterone in men with LOH were not significantly different between men older than 65 years of age and younger men. There were no indications that side effects were more severe in elderly men. The effects on prostate and urinary function and hematocrit were within safe margins. Age itself need not be a contraindication to testosterone treatment of elderly men with LOH.