Standard Operating Procedures: Pubertas Tarda/Delayed Puberty—Male

Androgens and male sexual function

Sexual symptoms are the most specific determinants of low testosterone (T) observed during adulthood. In this narrative review, we summarize the most important evidence supporting the positive relationships between endogenous T levels and sexual activity in the adult male, by using preclinical and clinical observations. In addition, we also report an update of our previous meta-analysis evaluating the effects of T treatment (TRT) on sexual functioning in subjects with T deficiency. Available data indicate that TRT of symptomatic hypogonadal men can improve several aspects of sexual life, including erection. However, the effect is rather modest and lower in subjects with associated metabolic conditions. The specific observed effects are similar to those derived from lifestyle intervention. Since TRT might result in body composition improvement, it is reasonable to suppose that an initial treatment with T can improve the willingness of hypogonadal subjects to perform physical exercise and to adhere to a healthier behavior. Similar data were derived from animal models. However, it should be important to recognize that lifestyle modifications should be the first step to promote weigh reduction. TRT can be combined with lifestyle interventions only in symptomatic hypogonadal subjects especially in the presence of comorbid metabolic conditions.

Delayed puberty in boys in central Sweden: an observational study on diagnosing and management in clinical practice

OBJECTIVES

To compare the usefulness of the classical definition of delayed puberty (DP) in boys with puberty nomograms and to describe the management of DP in boys in a hospital-based setting.

STUDY DESIGN

Observational retrospective multicentre study with a short-term follow-up.

SETTING AND PARTICIPANTS

Boys diagnosed with DP during 2013-2015 at paediatric departments in four counties in central Sweden. The medical records of 165 boys were reviewed.

PRIMARY AND SECONDARY OUTCOME MEASURES

Number of boys with DP after re-evaluation of the diagnosis according to the classical definition in comparison with puberty nomograms. Description of investigations performed and treatment provided to boys with DP.

RESULTS

In total, 45 and 58 boys were found to have DP according to the classical definition and the nomograms, respectively. Biochemical and/or radiological testing was performed in 91% of the 58 boys, but an underlying disease was only found in 9% of them. Approximately 79% of the boys received testosterone treatment, either as injections of testosterone enanthate or as testosterone undecanoate.

CONCLUSIONS

Puberty nomograms may be helpful instruments when diagnosing pubertal disorders in boys as they are not limited to an age close to 14 years and also identify boys with pubertal arrest. The majority of boys with DP undergo biochemical or radiological examinations, but underlying diseases are unusual emphasising the need for structural clinical practice guidelines for this patient group.

Leptin receptor and prolactin in pubertal disorders and chronic kidney disease

BACKGROUND

Knowledge of chronic kidney disease (CKD) with pubertal disorders (PD) in adolescent boys is limited as few studies have explored this disorder. This study aimed to identify the usefulness of assessing hormonal parameters in male adolescents with CKD and their correlation with PD in a 12-month follow-up period.

METHODS

A prospective cohort study was conducted among male adolescents with CKD (stages IV and V). Data regarding the age at puberty onset were collected from the patients' clinical records and through interview. The patients were followed up for 12 months during their pubertal development. At the beginning, routine hormonal profile tests were performed to examine the patients' thyroid profile, prolactin levels, luteinizing hormone, follicle-stimulating hormone, testosterone, leptin, and receptor leptin. The hormonal profiles of patients with and without PD were compared. Comparisons between the groups were performed using the Student t-test and Fisher's exact tests. Logistic regression analysis was also performed.

RESULTS

Data of 64 patients (26/64 with PD) were analyzed. The median age was 15 years and the median time for CKD evolution was 11 months. No differences between groups were noted in the general or biochemical characteristics of the patients. The hormonal parameters, prolactin levels were higher and the free leptin and free thyroxine levels were lower in patients with PD. Leptin receptor levels of >0.90 ng/mL (risk ratio [RR], 8.6; P = 0.004) and hyperprolactinemia (RR, 21.3; P = 0.049) were the risk factors for PD.

CONCLUSIONS

Leptin receptor levels of >0.90 ng/mL and hyperprolactinemia are associated with the development of PD in male adolescents with CKD.

Paediatric and adult-onset male hypogonadism

The hypothalamic-pituitary-gonadal axis is of relevance in many processes related to the development, maturation and ageing of the male. Through this axis, a cascade of coordinated activities is carried out leading to sustained testicular endocrine function, with gonadal testosterone production, as well as exocrine function, with spermatogenesis. Conditions impairing the hypothalamic-pituitary-gonadal axis during paediatric or pubertal life may result in delayed puberty. Late-onset hypogonadism is a clinical condition in the ageing male combining low concentrations of circulating testosterone and specific symptoms associated with impaired hormone production. Testosterone therapy for congenital forms of hypogonadism must be lifelong, whereas testosterone treatment of late-onset hypogonadism remains a matter of debate because of unclear indications for replacement, uncertain efficacy and potential risks. This Primer focuses on a reappraisal of the physiological role of testosterone, with emphasis on the critical interpretation of the hypogonadal conditions throughout the lifespan of the male individual, with the exception of hypogonadal states resulting from congenital disorders of sex development.

The natural history of classic galactosemia: lessons from the GalNet registry

BACKGROUND

Classic galactosemia is a rare inborn error of carbohydrate metabolism, caused by a severe deficiency of the enzyme galactose-1-phosphate uridylyltransferase (GALT). A galactose-restricted diet has proven to be very effective to treat the neonatal life-threatening manifestations and has been the cornerstone of treatment for this severe disease. However, burdensome complications occur despite a lifelong diet. For rare diseases, a patient disease specific registry is fundamental to monitor the lifespan pathology and to evaluate the safety and efficacy of potential therapies. In 2014, the international Galactosemias Network (GalNet) developed a web-based patient registry for this disease, the GalNet Registry. The aim was to delineate the natural history of classic galactosemia based on a large dataset of patients.

METHODS

Observational data derived from 15 countries and 32 centers including 509 patients were acquired between December 2014 and July 2018.

RESULTS

Most affected patients experienced neonatal manifestations (79.8%) and despite following a diet developed brain impairments (85.0%), primary ovarian insufficiency (79.7%) and a diminished bone mineral density (26.5%). Newborn screening, age at onset of dietary treatment, strictness of the galactose-restricted diet, p.Gln188Arg mutation and GALT enzyme activity influenced the clinical picture. Detection by newborn screening and commencement of diet in the first week of life were associated with a more favorable outcome. A homozygous p.Gln188Arg mutation, GALT enzyme activity of ≤ 1% and strict galactose restriction were associated with a less favorable outcome.

CONCLUSION

This study describes the natural history of classic galactosemia based on the hitherto largest data set.

Inhibin B plus LH vs GnRH agonist test for distinguishing constitutional delay of growth and puberty from isolated hypogonadotropic hypogonadism in boys

OBJECTIVE

The distinction between constitutional delay of growth and puberty (CDGP) and isolated hypogonadotropic hypogonadism (IHH) in males with delayed puberty is difficult but important for timely treatment. We assessed the accuracy of the GnRH agonist test (triptorelin 0·1 mg) in comparison with inhibin B alone or in combination with basal LH for the diagnosis of IHH.

PATIENTS AND MEASUREMENTS

Ninety-seven prepubertal males aged 13·7-17·5 year, with testicular volumes ≤4 ml, were examined every 6 months. CDGP was defined by a testicular volume ≥8 ml after 18 months, and IHH was defined by a testicular volume <5 ml after 24 months follow-up. Inhibin B concentrations were measured by ELISA, and LH concentrations were measured by CLIA.

RESULTS

At follow-up, the cohort comprised 52 boys with CDGP and nine with IHH. The other patients were lost for follow-up (n = 10), had not reached follow-up yet (n = 20) or did not reach a definite testicular volume (n = 6). Basal LH <0·3 IU/l, stimulated LH (4 h) <5·3 IU/l or inhibin B <111 pg/ml had 100% sensitivity for IHH. Only LH (4 h) <5·3 IU/l had a specificity of 100%, and the specificities of basal LH <0·3 IU/l (88%) or inhibin B <110 pg/ml (92%) were lower. The combination of LH <0·3 IU/l with inhibin B <111 pg/ml increased the specificity to 98·1%.

CONCLUSIONS

The LH response 4 h after GnRH agonist stimulation has an excellent accuracy for the diagnosis of IHH in prepubertal boys with delayed puberty. However, the measurement of inhibin B and basal LH in combination is a valid, reliable and less-invasive alternative test.

The gonadal function in obese adolescents: review

This review deals with the relationship between obesity in male adolescents and gonadal function. The article is structured in two main paragraphs; the first one is about population studies that have assessed puberty timing and its mode of onset in relation with body weight to evaluate if and how the latter can influence the gonadal function in this phase of life. These studies analyze issues such as increased BMI and early onset of male puberty, gender differences, secular trend toward early onset of puberty in males, effects of a different body composition on male puberty and consequences of a different stage of childhood obesity on the onset of male puberty. The second paragraph examines the possible mechanisms through which, obesity may alter the timing of puberty in young males, including the role of SHBG, leptin, insulin resistance, ghrelin, GH-IGF-1 axis, AR polymorphisms, primary testicular dysfunction, retinol binding protein 4 (RBP-4) and liver function abnormalities. However, despite the numerous studies in the literature, the etiology of gonadal disfunction in obese adolescents on puberty remains uncertain.

Factors affecting spermatogenesis upon gonadotropin-replacement therapy: a meta-analytic study

A meta-analysis was performed to systematically analyse the results of gonadotropin and GnRH therapy in inducing spermatogenesis in subjects with hypogonadotropic hypogonadism (HHG) and azoospermia. An extensive Medline and Embase search was performed including the following words: 'gonadotropins' or 'GnRH', 'infertility', 'hypogonadotropic', 'hypogonadism' and limited to studies in male humans. Overall, 44 and 16 studies were retrieved for gonadotropin and GnRH therapy, respectively. Of those, 43 and 16 considered the appearance of at least one spermatozoa in semen, whereas 26 and 10 considered sperm concentration upon gonadotropin and GnRH, respectively. The combination of the study results showed an overall success rate of 75% (69-81) and 75% (60-85) in achieving spermatogenesis, with a mean sperm concentration obtained of 5.92 (4.72-7.13) and 4.27 (1.80-6.74) million/mL for gonadotropin and GnRH therapy, respectively. The results upon gonadotropin were significantly worse in studies involving only subjects with a pre-pubertal onset HHG, as compared with studies involving a mixed population of pre- and post-pubertal onset [68% (58-77) vs. 84% (76-89), p = 0.011 and 3.37 (2.25-4.49) vs. 12.94 (8.00-17.88) million/mL, p < 0.0001; for dichotomous and continuous data, respectively]. A similar effect was observed also upon GnRH. No difference in terms of successful achievement of spermatogenesis and sperm concentration was found for different FSH preparations. Previous use of testosterone replacement therapy (TRT) did not affect the results obtained with gonadotropins. Finally, a higher success rate was found for subjects with lower levels of gonadotropins at the baseline and for those using both human chorionic gonadotropin and FSH. Gonadotropin therapy, even with urinary derivatives, is a suitable option in inducing/restoring fertility in azoospermic HHG subjects. Gonadotropins appear to be more efficacious in subjects with a pure secondary nature (low gonadotropins) and a post-pubertal onset of the disorder, whereas previous TRT does not affect outcome.

An update on male hypogonadism therapy

INTRODUCTION

Men who have symptoms associated with persistently low serum total testosterone level should be assessed for testosterone replacement therapy.

AREAS COVERED

Acute and chronic illnesses are associated with low serum testosterone and these should be recognized and treated. Once the diagnosis of male hypogonadism is made, the benefits of testosterone treatment usually outweigh the risks. Without contraindications, the patient should be offered testosterone replacement therapy. The options of testosterone delivery systems (injections, transdermal patches/gels, buccal tablets, capsules and implants) have increased in the last decade. Testosterone improves symptoms and signs of hypogonadism such as sexual function and energy, increases bone density and lean mass and decreases visceral adiposity. In men who desire fertility and who have secondary hypogonadism, testosterone can be withdrawn and the patients can be placed on gonadotropins. New modified designer androgens and selective androgen receptor modulators have been in preclinical and clinical trials for some time. None of these have been assessed for the treatment of male hypogonadism.

EXPERT OPINION

Despite the lack of prospective long-term data from randomized, controlled clinical trials of testosterone treatment on prostate health and cardiovascular disease risk, the available evidence suggests that testosterone therapy should be offered to symptomatic hypogonadal men.