Is testosterone therapy for boys with constitutional delay of growth and puberty associated with impaired final height and suppression of the hypothalamo-pituitary-gonadal axis?

Testosterone Use in Adolescent Males: Current Practice and Unmet Needs

Testosterone replacement therapy (TRT) is routinely prescribed in adolescent males with constitutional delay of growth and puberty (CDGP) or hypogonadism. With many new testosterone (T) formulations entering the market targeted for adults, we review current evidence and TRT options for adolescents and identify areas of unmet needs. We searched PubMed for articles (in English) on testosterone therapy, androgens, adolescence, and puberty in humans. The results indicate that short-term use of  T enanthate (TE) or oral  T undecanoate is safe and effective in inducing puberty and increasing growth in males with CDGP. Reassuring evidence is emerging on the use of transdermal  T to induce and maintain puberty. The long-term safety and efficacy of TRT for puberty completion and maintenance have not been established. Current  TRT regimens are based on consensus and expert opinion, but evidence-based guidelines are lacking. Limited guidance exists on when and how  T should be administered and optimal strategies for monitoring therapy once it is initiated. Only  TE and  T pellets are US Food and Drug Administration approved for use in adolescent males in the United States. Despite the introduction of a wide variety of new  T formulations, they are designed for adults, and their metered doses are difficult to titrate in adolescents. In conclusion, TRT in adolescent males is hindered by lack of long-term safety and efficacy data and limited options approved for use in this population. Additional research is needed to identify the route, dose, duration, and optimal timing for TRT in adolescents requiring androgen therapy.

Differential diagnosis between constitutional delay of growth and puberty, idiopathic growth hormone deficiency and congenital hypogonadotropic hypogonadism: a clinical challenge for the pediatric endocrinologist

INTRODUCTION

Differential diagnosis between constitutional delay of growth and puberty (CDGP), partial growth hormone deficiency (pGHD) and congenital hypogonadotropic hypogonadism (cHH) may be difficult. All these conditions usually present with poor growth in pre- or peri-pubertal age and they may recur within one familial setting, constituting a highly variable, but somehow common, spectrum of pubertal delay.

EVIDENCE ACQUISITION

Narrative review of the most relevant English papers published between 1981 and march 2020 using the following search terms "constitutional delay of growth and puberty," "central hypogonadism," "priming," "growth hormone deficiency," "pituitary," "pituitary magnetic resonance imaging," with a special regard to the latest scientific acquisitions.

EVIDENCE SYNTHESIS

CDGP is by far the most prevalent entity in boys and recurs within families. pGHD is a rare, often idiopathic and transient condition, where hypostaturism presents more severely. Specificity of pGHD diagnosis is increased by priming children before growth hormone stimulation test (GHST); pituitary MRI and genetic analysis are recommended to personalize future follow-up. Diagnosing cHH may be obvious when anosmia and eunuchoid proportions concomitate. However, cHH can either overlap with pGHD in forms of multiple pituitary hormone deficiencies (MPHD) or syndromic conditions either with CDGP in family pedigrees, so endocrine workup and genetic investigations are necessary. The use of growth charts, bone age, predictors of adult height, primed GHST and low dose sex steroids (LDSS) treatment are recommended.

CONCLUSIONS

Only a step-by-step diagnostic process based on appropriate endocrine and genetic markers together with LDSS treatment can help achieving the correct diagnosis and optimizing outcomes.

Androgens During Infancy, Childhood, and Adolescence: Physiology and Use in Clinical Practice

We provide an in-depth review of the role of androgens in male maturation and development, from the fetal stage through adolescence into emerging adulthood, and discuss the treatment of disorders of androgen production throughout these time periods. Testosterone, the primary androgen produced by males, has both anabolic and androgenic effects. Androgen exposure induces virilization and anabolic body composition changes during fetal development, influences growth and virilization during infancy, and stimulates development of secondary sexual characteristics, growth acceleration, bone mass accrual, and alterations of body composition during puberty. Disorders of androgen production may be subdivided into hypo- or hypergonadotropic hypogonadism. Hypogonadotropic hypogonadism may be either congenital or acquired (resulting from cranial radiation, trauma, or less common causes). Hypergonadotropic hypogonadism occurs in males with Klinefelter syndrome and may occur in response to pelvic radiation, certain chemotherapeutic agents, and less common causes. These disorders all require testosterone replacement therapy during pubertal maturation and many require lifelong replacement. Androgen (or gonadotropin) therapy is clearly beneficial in those with persistent hypogonadism and self-limited delayed puberty and is now widely used in transgender male adolescents. With more widespread use and newer formulations approved for adults, data from long-term randomized placebo-controlled trials are needed to enable pediatricians to identify the optimal age of initiation, route of administration, and dosing frequency to address the unique needs of their patients.

Testosterone Therapy Improves the First Year Height Velocity in Adolescent Boys with Constitutional Delay of Growth and Puberty

BACKGROUND

Constitutional delay of growth and puberty (CDGP) can cause significant psychological distress in adolescent boys. Although testosterone usage in this group has not been shown to affect the final adult height, the effect on the first year height velocity has not been widely reported.

OBJECTIVES

The aim is to determine whether testosterone treatment improves the first year height velocity in boys with CDGP when compared to boys with CDGP who go through puberty spontaneously.

METHODS

Retrospective data from 23 adolescent boys with CDGP was analysed. Ten out of 23 boys (43%) received testosterone injection (testosterone enanthate, 125 mg), once every 6 weeks for 3 doses in total. Both the groups (treated and untreated) had their height, bone age and testicular volume measured at the baseline, The height velocity and final predicted adult height were compared at the end of one year between both the groups.

RESULTS

In the testosterone-untreated group, the mean (± SD) chronological age, bone age, height standard deviation scores (SDS) and testicular volume were 14.3 years (± 0.3),12.1 years (± 1.6), -1.9 (± 0.8) and 4.7 mL (± 1.1) respectively. Within the testosterone-treated group the mean (± SD) chronological age, bone age, height SDS and testicular volume at presentation were 14.4 years (± 0.4), 11 years (± 1.6), -2.1 SD(± 0.6) and 4.5 mL (± 1.2) respectively. The mean age of treatment with testosterone was 14.4 years (± 0.44). The mean height velocity one year after treatment was 8.4 cm/year (± 1.7) in the testosterone treated group when compared to 6.1 cm/year (± 2.1) in the patients who did not receive treatment (P = 0.01). There was no significant difference in the final predicted height between the 2 groups (P = 0.15).

CONCLUSIONS

Testosterone therapy improves the first year height velocity in boys with CDGP, without influencing their final predicted height.

An approach to constitutional delay of growth and puberty

Constitutional delay of growth and puberty is a transient state of hypogonadotropic hypogonadism associated with prolongation of childhood phase of growth, delayed skeletal maturation, delayed and attenuated pubertal growth spurt, and relatively low insulin-like growth factor-1 secretion. In a considerable number of cases, the final adult height (Ht) does not reach the mid-parental or the predicted adult Ht for the individual, with some degree of disproportionately short trunk. In the pre-pubertal male, testosterone (T) replacement therapy can be used to induce pubertal development, accelerate growth and relieve the psychosocial complaints of the adolescents. However, some issues in the management are still unresolved. These include type, optimal timing, dose and duration of sex steroid treatment and the possible use of adjunctive or alternate therapy including: oxandrolone, aromatase inhibitors and human growth hormone.

Priming with testosterone enhances stimulated growth hormone secretion in boys with delayed puberty

BACKGROUND AND OBJECTIVE

Tests for growth hormone (GH) deficiency are not always helpful in the differential diagnosis of physiological delay of growth and puberty and GH deficiency.

PATIENTS AND METHODS

To enhance diagnostic specificity, we used a single dose testosterone priming before repeating the arginine stimulation test in 26 boys with short stature and only early signs of puberty who failed to show an adequate response of serum GH in the first test.

RESULTS

77% (20/26 patients) increased their serum GH peak to more than 10 ng/ml, whereas six patients were still below this concentration.

CONCLUSION

We propose that testosterone priming is a useful tool to distinguish between physiological delay of growth and puberty and GH deficiency and should be included in the diagnostic procedure.

Final height outcome in both untreated and testosterone-treated boys with constitutional delay of growth and puberty

The present retrospective study is based on a historical follow-up of 49 boys with constitutional delay of growth and puberty (CDGP) who went into puberty spontaneously (27 cases) or induced by depotestosterone treatment, 50 mg/ month for 6 months (22 cases). At the time of puberty the two groups of boys were similar in bone age, height deficiency, target height (TH) and had similar predicted final heights (FH). Their FH was measured and compared with TH calculated from measured parents' heights. FH did not significantly differ between the untreated boys and those treated. In the two groups of patients FH was similar and corresponded to both TH and height predicted at puberty onset. This study confirms that most boys with CDGP spontaneously attain a FH within the target range (24/27 cases). A short-term and low dose course of depotestosterone can be used without adverse effects on FH. The Bayley-Pinneau method can be generally considered accurate for predicting FH in CDGP, although significant discrepancies between FH and predicted height have been recorded in a fair number of both untreated and treated boys.

Short-term effect of testosterone treatment on reduced bone density in boys with constitutional delay of puberty

We studied bone mineral content (BMC), bone mineral density (BMD), cortical thickness/total width (CT/TW) ratio and cortical area/total area (CA/TA) ratio in boys with constitutional delay of puberty and the effect of short-term testosterone treatment on bone mass. Seventeen boys (age 13.1-15.8 years) who met the family history and the clinical criteria of constitutional delay of puberty were selected and enrolled in the study. All subjects were eating a diet assuring an adequate intake of calories and calcium. A subset of 8 boys (group A) was treated with testosterone depot (100 mg/month x 6 months) while 9 boys (group B) were not. At inclusion, BMC and BMD were reduced in the patients according to their chronological age (BMC -4.04 +/- 1.34 standard deviation scores [SDS]; BMD -2.95 +/- 0.56 SDS), statural age (BMC -1.75 +/- 0.79 SDS; BMD -1.69 +/- 0.78 SDS), and bone age (BMC -1.80 +/- 0.65 SDS; BMD -1.86 +/- 0.68 SDS). No significant differences between the groups were found (group A: BMC 0.480 +/- 0.57 g/cm, BMD 0.488 +/- 0.037 g/cm2, CT/TW ratio 0.43 +/- 0.4, CA/TA ratio 0.68 +/- 0.04; group B: BMC 0.476 +/- 0.060, p = NS vs. group A; BMD 0.491 +/- 0.036 g/cm2, p = NS vs. group A). At 12 months of follow-up, BMC, BMD, CT/TW ratio, and CA/TA ratio significantly increased in group A (BMC 0.70 +/- 0.13 g/cm, delta +41.1 +/- 28.8%, p < 0.003 vs. 0 month; BMD 0.617 +/- 0.082 g/cm2, delta +26.2 +/- 13.6%, p < 0.005 vs. 0 month; CT/TW ratio 0.52 +/- 0.05, delta +20.59 +/- 10.65%, p < 0.001 vs. 0 month; CA/TA ratio 0.77 +/- 0.05 vs. 0 month; CT/TW ratio 13.60 +/- 6.65%, p < 0.004 vs 0 month), but not in group B (BMC: 0.48 +/- 0.05 g/cm; delta +5.1 7.8%, p = NS vs. 00 month; BMD: 0.492 +/- 0.037 g/cm2; delta +0.54 +/- 8.7%, p = NS vs. 0 month; CT/TW ratio 0.44 +/- 0.04, delta +4.04 +/- 6.75%, p = NS vs. 0 month; CA/TA ratio 0.68 +/- 0.05, delta +2.39 +/- 5.90%, p = NS vs. 0 month). We conclude that boys with constitutional delay of puberty have reduced BMC and BMD. The delay in statural and bone ages did not totally account for the decreased bone mass. Testosterone treatment for 6 months significantly increased BMC, BMD, CT/TW ratio, and CA/TA ratio in these patients, but definitive conclusions on the efficacy of the treatment in improving adult bone mass can be drawn only when our patients reach early childhood.

Long term treatment with low dose testosterone in constitutional delay of growth and puberty: effect on bone age maturation and pubertal progression

We compared the effects of long term low dose treatment with testosterone on pubertal growth and sexual development in boys with constitutional delay of growth and puberty (CDGP). We treated 24 boys with intramuscular monthly injections with low dose testosterone enanthate (33-50 mg) for 20 months, at a chronological age of 14.5 +/- 1.0 years and SDS height of -3.31 and compared their response to a group of 14 control boys. Treated patients showed an earlier and significant increase in height velocity compared to controls, 10.1 vs 4.0 cm/year, while the latter group showed their growth spurt twelve months later. Both groups showed an initial acceleration in bone age without impairment of predicted adult height. During the first 12 months of treatment the increment of testicular volume in the treated patients was slightly slower than controls; however the earlier the puberty, the slower the testicular increment compared to controls. We conclude that treatment of boys with constitutional delay of growth with low dose testosterone is effective in improving their height velocity without impairment of predicted final height. Progression of testicular volume during treatment in some patients is more delayed; however, after treatment it increased normally.

The effects of oxandrolone on the growth hormone and gonadal axes in boys with constitutional delay of growth and puberty

OBJECTIVE

We studied the effects of oxandrolone on serum concentrations of LH, FSH, testosterone, GH, SHBG, DHEAS, IGF-I and insulin in boys with constitutional delay of growth and puberty.

DESIGN

Ten boys with constitutional delay of growth and puberty, mean age 13.8 years (range 12.4-15.5) were studied. Twenty-four-hour serum concentration profiles of GH, LH and FSH were constructed by drawing blood samples at 20-minute intervals. Three study occasions over a period of 6 months were chosen to assess hormone concentrations before, during and 6 weeks after a 3-month course of oxandrolone (2.5 mg once daily) therapy.

RESULTS

Growth velocity increased during oxandrolone treatment and stayed higher after therapy (pre 3.9 +/- 0.5; on 6.3 +/- 0.8; post 6.4 +/- 0.9 cm/year (mean +/- SEM) two way ANOVA, F = 5.3, P = 0.02). Oxandrolone had androgenic effects, suppressing mean serum LH concentrations from 1.7 +/- 0.3 to 1.1 +/- 0.2 U/I and serum testosterone concentrations from 1.9 +/- 0.6 to 0.8 +/- 0.1 nmol/l. SHBG concentrations were also reduced from 130.9 +/- 14.6 to 30.7 +/- 7.3 nmol/l. Serum GH concentration fell slightly from 5.9 +/- 0.6 to 4.8 +/- 0.5 mU/l. After cessation of treatment, there was a significant 'rebound' in mean 24-hour serum LH (2.6 U/l +/- 0.4) and testosterone concentrations (3.2 +/- 0.9 nmol/l) but no change in serum GH concentrations. SHBG values also rose but not to the same extent as those observed before therapy (82.0 +/- 8.4 nmol/l). There were no statistically significant differences in serum concentrations of FSH, DHEAS, IGF-I and insulin over the study period. In a stepwise multiple regression analysis of factors that might influence the growth rate observed, the 24-hour mean serum testosterone concentration and the treatment (on or off) with oxandrolone were the main influences. The relationship was described by the equation Height velocity = 0.69 (24-hour mean serum testosterone concentration)+1.70 (treatment regimen)+3.37 (adjusted R2 = 0.35, F = 8.39, P = 0.001).

CONCLUSIONS

Oxandrolone has an androgenic action as shown by changes in serum LH, testosterone and SHBG concentrations and by the lack of effect on FSH. No effect of oxandrolone on the GH axis was documented. We suggest that the growth promoting effects of oxandrolone are related in part to the mild androgenic effects of the steroid and the growth acceleration following oxandrolone withdrawal may reflect increasing total serum testosterone concentrations and decreasing levels of SHBG and progress in puberty.

Does constitutional delayed puberty cause segmental disproportion and short stature?

We have reviewed the growth of 98 boys and 34 girls with constitutional delay of growth and puberty followed until final height. At presentation chronological age was 14.1 (1.3) years (SD) in the boys and 13.0 (1.3) years in the girls. At presentation all patients were either prepubertal or in early pubertal maturation (4 ml testicular volume in the boys and breast stage II in the girls). Twenty-nine boys (30%) and 2 girls (6%) were treated with either sex or anabolic steroids. Mean height SDS in the boys at presentation was -2.7 (0.7) which rose to -1.9 (0.9) at final height attainment. This was significantly lower than the predicted final height SDS of -1.4 (0.8) and mid-parental height SDS of -0.5 (0.7). Similar results were obtained for the girls with a height SDS at presentation of -3.2 (0.8) which increased to -2.3 (0.7) at final height which was significantly lower than predicted final height SDS of -1.7 (0.6) and mid-parental height SDS of -0.8 (0.8). Both sexes had a relatively short sitting height at presentation; sitting height SDS -3.4 (1.0) and subischial leg length SDS -2.2 (1.0) in the boys and sitting height SDS -3.6 (1.1) and subischial leg length SDS -2.5 (0.7) in the girls. The relative disproportion between the segments had no significant change at final height. We are unable to explain the failure to achieve final height potential and the relatively disproportionate stature. Our data suggest that the late timing of the onset of puberty may be deleterious to spinal growth and consequently final height.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of oral testosterone undecanoate on growth, body composition, strength and energy expenditure of adolescent boys

OBJECTIVE

We determined the effect of 3 months of daily, 40 mg oral testosterone undecanoate on growth, body composition, hand grip and quadriceps muscle strength, and total free-living daily energy expenditure in boys with constitutionally delayed puberty.

DESIGN

Double blind, placebo controlled study.

PATIENTS

Eighteen boys with constitutionally delayed puberty, mean (SD) age 13.2 (1.6) years.

MEASUREMENTS

Body composition measurements were made by skinfold thickness, bioelectrical impedance and stable isotope dilution (H2(18)O) methods. Energy expenditure was assessed by the doubly-labelled water (2H2(18)O) technique.

RESULTS

Height velocity increased from 5.4 (0.8) to 8.1 (0.6) cm/year (P < 0.05) in the 3 months after active therapy. Fat-free mass increased more with therapy (2.7 (0.3) kg) over the 6-month study period than with placebo (1.7 (0.4) kg, P < 0.5). Height velocity increases correlated with daily increases in fat-free mass (r = 0.68, P = 0.005) in the study group as a whole. Energy expenditure and muscle strength increased similarly in both groups. Predicted adult height decreased in the group which was treated with testosterone undecanoate.

CONCLUSIONS

Testosterone undecanoate (40 mg daily for 3 months) significantly increased height velocity and fat-free mass velocities after 6 months but not muscle strength, endurance or total daily energy expenditure.