Testosterone treatment of excessively tall boys

Sex-specific genetic effects across biomarkers

Sex differences have been shown in laboratory biomarkers; however, the extent to which this is due to genetics is unknown. In this study, we infer sex-specific genetic parameters (heritability and genetic correlation) across 33 quantitative biomarker traits in 181,064 females and 156,135 males from the UK Biobank study. We apply a Bayesian Mixture Model, Sex Effects Mixture Model (SEMM), to Genome-wide Association Study summary statistics in order to (1) estimate the contributions of sex to the genetic variance of these biomarkers and (2) identify variants whose statistical association with these traits is sex-specific. We find that the genetics of most biomarker traits are shared between males and females, with the notable exception of testosterone, where we identify 119 female and 445 male-specific variants. These include protein-altering variants in steroid hormone production genes (POR, UGT2B7). Using the sex-specific variants as genetic instruments for Mendelian randomization, we find evidence for causal links between testosterone levels and height, body mass index, waist and hip circumference, and type 2 diabetes. We also show that sex-specific polygenic risk score models for testosterone outperform a combined model. Overall, these results demonstrate that while sex has a limited role in the genetics of most biomarker traits, sex plays an important role in testosterone genetics.

Genetic influences on the development of grip strength in adolescence

Enhanced physical strength is a secondary sex characteristic in males. Sexual dimorphism in physical strength far exceeds sex differences in stature or total body mass, suggesting a legacy of intense sexual selection. Upper-body strength is a particularly promising marker of intrasexual competitiveness in young men. Consequently, it is assumed that sex-influenced gene expression contributes to the development of physical strength. It is unclear, however, whether the underlying sources of individual differences in strength development are comparable across sex. We obtained three measurements of hand-grip strength (HGS) over a six-year period spanning adolescence in male and female same-sex twins (N = 2,513). Biometrical latent growth models were used to partition the HGS variance at age 11 (intercept) and its growth over time (slope) into genetic and environmental components. Results demonstrated that variance around the intercept was highly heritable in both males and females (88% and 79%, respectively). In males, variance around the slope exceeded that of the intercept, while the reverse held for females. Additive genetic effects accounted for most (80%) of the variance around the slope in males, but were of less importance in females (heritability = 28%). Absolute genetic variance around the slope was nearly nine-fold higher in males. This striking disparity suggests that the developmental processes shaping HGS growth are different between the sexes. We propose that this might account for the sex-specific pattern of associations between HGS and external measures (e.g., digit ratio and physical aggression) typically reported in the literature. Our results underscore the role of endogenous androgenic influences in the development of physical strength.

Referrals for tall stature in children: a 25-year personal experience

AIM

Extreme tall stature may lead to a variety of concerns in tall children and their parents, leading to requests for treatment to reduce final height in some children. This study reviews referrals for tall stature to a single pediatric endocrinologist and results of treatment over 25 years from 1980 to 2004.

METHODS

Diagnoses, heights, target heights and estimated final heights at presentation, and final heights and complications in treated patients, were examined by retrospective chart review.

RESULTS

Of 345 referrals, 244 (71%) were girls and 101 (29%) were boys. Of the 68 (19.7%) treated, 53 (78%) were girls and 15 (22%) were boys. Most children had familial tall stature. Treated children were tall for their already tall families. Treatment reduced final heights compared with estimated final heights by (mean +/- standard error of the mean) 4.2 +/- 0.5 cm (P = 0.001) in girls and 5.1 +/- 0.8 cm (P < 0.001) in boys. Minor complications occurred in 27 (51%) girls, including 5 (9.4%) who stopped treatment because of weight gain, and 5 (33%) of boys. In more recent years, girls (but not boys) presented less frequently, were taller at presentation and opted for treatment less often, and at taller estimated final heights than in the earlier years.

CONCLUSIONS

Any benefits of high-dose sex steroid treatment of tall children in terms of reduced final height and improved self-image are at the expense of complications in many. Fewer tall girls being referred and treated probably reflects altered attitudes to tallness in society. Such treatment should seldom - if ever - be used in the future.

Reduction of excessive height in boys by bilateral percutaneous epiphysiodesis around the knee

In this study, the results of percutaneous epiphysiodesis as a surgical method to decrease final height is described in 15 boys with a predicted final height of more than 205 cm. A total of 17 boys with a height prediction between 195 and 209 cm without treatment were included as controls. The study period was from 1995-2002 and patients were followed for a mean period of 3.9 years (range 2.3-6.5 years) after surgery; controls were followed for 8.3 years (range 2.0-12.1 years). Final height in the treated boys was 203.6 cm (range 195.5-214.5 cm) compared to the predicted height of 210.6 cm (range 205.7-222.7 cm). The reduction in final height versus the predicted height was 7 cm and ranged between 1.2 and 13.8 cm. Final height in the control boys was 199.9 cm (range 191.3-206.7 cm). No significant side-effects of epiphysiodesis were observed. Besides final height reduction, epiphysiodesis resulted in normalisation of body proportions, expressed as the subischial leg length/sitting height ratio. This ratio in the operated patients at final height was 0.96 (range 0.90-1.01) and in the controls 0.94 (range 0.88-1.03).

CONCLUSION

Epiphysiodesis can be advised as a method to decrease final height in boys with predicted tall stature. An additional advantage of this method is a normalisation of body proportions.

Growth-reductive therapy in children with marfan syndrome

OBJECTIVES

To determine the accuracy and precision of 2 height-prediction methods in Marfan syndrome and to assess the growth-reductive effect and side effects of sex hormone treatment.

STUDY DESIGN

In a retrospective study in 31 untreated (17 boys) and 43 treated patients (21 boys) with Marfan syndrome, we assessed bone age and predicted adult height by 2 methods. The accuracy of the methods was assessed in the untreated group. The effect of therapy was corrected for outcome in the untreated group and other confounding variables with multivariate analysis.

RESULTS

Accuracy strongly varied with sex, chronological age, and prediction method. Overall precision was low. Treatment was started at a mean age of 12.8 +/- 1.4 years (boys) and 11.4 +/- 1.2 years (girls). With multiple regression analysis, a statistically significant effect was observed only in boys using a pharmacologic dosage (5.5 cm, 95% CI 0.96-10.1 cm; P = .02). Side effects were worsening of acne and weight and muscle gain.

CONCLUSIONS

In adolescents with Marfan syndrome, the accuracy and precision of 2 height-prediction methods were limited. The apparent growth-reductive effect of sex hormone treatment appears similar to earlier reports on adolescents with constitutional tall stature. There were no clinically important short-term side effects.

Overgrowth

The predominant influences on fetal growth are maternal and placental factors. Post-natal growth is regulated by a complex interaction between genetic, environmental and hormonal influences. The role of the growth hormone insulin-like growth factor (GH-IGF) system is explored, including the emerging role of IGF-2 in fetal growth. Increasing understanding of the genetics of overgrowth and short stature syndromes is contributing greatly to basic understanding of growth regulation. A range of prenatal overgrowth syndromes is discussed, including those associated with neonatal hyperinsulinism and hypoglycaemia.Post-natal overgrowth may be caused by a diverse range of normal variant conditions, endocrine disorders, chromosomal abnormalities and other genetic syndromes. An approach to diagnosis is presented and major conditions discussed in detail. Sex-steroid therapy for height limitation continues to be a controversial area with uncertainty about height prediction, benefits achieved and possible long-term side-effects.

Combined treatment with testosterone (T) and ethinylestradiol (EE2) in constitutionally tall boys: is treatment with T plus EE2 more effective in reducing final height in tall boys than T alone?

Estrogens have been shown to rapidly inhibit longitudinal growth in tall boys. To antagonize the initial growth accelerating effect of T, 41 boys with an initial height prediction in excess of 203 cm were treated prospectively with either T enanthate (TE) 250 mg/wk im in combination with ethinylestradiol (EE2) 0.1 mg/d taken orally for the first 5.8 +/- 0.47 wk (mean +/- SE) of treatment (group 1, n = 20) or with TE alone (group 2, n = 21). Patients were randomized to one or the other treatment regimen. Mean (+/-SE) predicted adult height was 206.8 +/- 0.7 cm in group 1 and 206.4 +/- 0.8 cm in group 2. Total duration of treatment was 16.1 +/- 0.8 months and 14.0 +/- 1.2 months in group 1 and 2, respectively (NS). EE2-induced side effects in group 1 (gynecomastia) were limited and fully reversible. No negative long-term sequelae were found at final height with respect to hypothalamic-pituitary-gonadal axis activity and to testis volumes. Although there was a tendency to a lower initial growth velocity measured by knemometry in group 1 (0.30 +/- 0.05 vs. 0.38 +/- 0.05 mm/wk, NS), final height did not differ in both study groups (195.0 +/- 0.8 cm in group 1, 194.6 +/- 0.8 cm in group 2). Similarly, height reduction (initial predicted adult height minus final height) was not significantly different between the two groups (12.0 +/- 0.9 cm in group 1, 11.7 +/- 0.9 cm in group 2). In conclusion, the addition of EE2 during the initial treatment phase to high-dose T in tall boys has no significant effect on height reduction. The results of this clinical trial suggest that the initial growth inhibiting effect of EE2 on the epiphyseal growth plates is overridden by the long-term administration of high dose TE.

Computer-aided skeletal age scores in healthy children, girls with Turner syndrome, and in children with constitutionally tall stature

The manual Tanner-Whitehouse 2 method has recently been transformed into a computer-aided skeletal age scoring system (CASAS), which rates either the complete TW-RUS score (13b model) or a subset consisting of radius, ulna, and the four bones of the third finger (6b model). In this study the reliability of CASAS was evaluated in healthy children, and the 13b model was compared with the manual ratings and with the 6b model in (subgroups of) 151 healthy children, 87 girls with Turner syndrome, and 362 children with constitutionally tall stature. In addition, reference curves for bone maturation in Turner syndrome and constitutionally tall stature are presented. Some of mean differences in methods were statistically significant; however, because these mean differences were less than 0.4 bone age "year," they are clinically not significant. In all comparisons the range of the difference between the methods (either with the 6b or the 13b model) was considerable, but the combined within- and between-components of variance (0.7%) were in the same order of magnitude as reported for the manual readings. In general, the percentage of equal stage ratings on duplicate assessments was high (+/- 90%). Our data indicate that this computerized method is applicable in these groups of children. The use of the 6b model seems preferable because it is less time-consuming than the rating of 13 bones. In view of the percentages of manual insertions of a stage (up to 8% in all groups) the clinical use of this CASAS version (3.5) seems to be more efficient, particularly with longitudinal studies. Manual substitution of a stage should be avoided, and when performed its percentage and the limits for the acceptance of disagreement should be reported.

High dose testosterone therapy for reduction of final height in constitutionally tall boys: does it influence testicular function in adulthood?

OBJECTIVE

We have studied the effect of treatment with high doses of androgens during puberty on testicular function in adult men with constitutionally tall stature, taking into account confounding factors interfering with sperm quality, since existing published data do not include whether testicular function is impaired by such treatment.

DESIGN

Historical cohort study.

PATIENTS

Forty-three previously androgen treated tall men (cases) and 30 non-treated tall men (controls).

MEASUREMENTS

Physical examination, semen analysis and plasma levels of LH, FSH, testosterone (T), sex hormone binding globulin (SHBG) and inhibin.

RESULTS

Sperm quality and testis volume were comparable between cases and controls. Mean sperm concentration was 66.4 x 10(6)/ml in cases and 66.2 x 10(6)/ml in controls. A left-sided varicocele was found in 45% of the cases and 37% of the controls. In cases we observed a significant effect of the age at start of androgen therapy on sperm motility (regr. coeff. (SE): 4.92 (2.41)%, P = 0.048). In addition, testicular size at start of therapy had a significant effect on sperm concentration (regr. coeff. (SE): 5.57 (1.54) x 10(6)/ml, P = 0.0012) and on total sperm count (regr. coeff. (SE): 43.1 (7.73) x 10(6), P = 0.0001). Plasma levels of T, SHBG and inhibin were not statistically different between the groups. Cases had significantly higher FSH levels (mean (SD) 3.3 (2.2) vs 2.1 (0.8) IU/I, P = 0.004) and significantly lower LH levels (mean (SD) 2.3 (0.9) vs 3.1 (1.4) IU/I, P = 0.019). We found a significant effect of age at start of therapy on plasma FSH level in the treated men (regr. coeff. (SE): -0.73 (0.18) IU/I, P = 0.0003).

CONCLUSIONS

Treatment with high doses of androgens for reduction of final height in constitutionally tall stature has no long-term side-effect on sperm quality, testicular volume or plasma testosterone levels. However, treated men had significantly higher plasma levels of FSH compared with controls. The meaning of this difference remains to be established. Varicocele was present in 42% of the adult tall men.

Effect of the long-acting somatostatin analogue SMS 201-995 on growth rate and reduction of predicted adult height in ten tall adolescents

Ten adolescents (four boys and six girls) aged 11.5 to 17 years, presenting with constitutionally tall stature were treated with twice daily subcutaneous injections of 250 micrograms of SMS 201-995 (Sandostatin). Results are reported after 6 and 12 months of therapy. Reduction of growth rate was obtained in 9 patients and correlated with the reduction of 24-hour growth hormone pulsatility and with the decrease of plasma Somatomedin-C values. Moreover, acceleration of bone maturation on SMS 201-995 therapy occurred in seven patients, and mean bone age increased from 13.3 years to 14.5 and 15.8 years after 6 and 12 months of SMS therapy. The mean reduction of predicted adult height was 4.9 cm at the last evaluation after 6 or 12 months of therapy. The dual effect of SMS 201-995 on growth rate and bone maturation suggests that it may be an alternative treatment to reduce adult height.

Adverse effects of anabolic steroids

Anabolic steroids are used therapeutically for various disorders and as ergogenic aids by athletes to augment strength, muscular development, and to enhance performance. There is a wide range of concomitant temporary and permanent adverse effects with steroid administration. Several well-documented adverse actions of these hormones may develop rapidly within several weeks or less (i.e. altered reproductive function) or require up to several years of steroid intake (i.e. liver carcinoma). More recent studies indicate that glucose intolerance, insulin resistance, increased cardiovascular disease risk profiles, cerebral dangers, musculoskeletal injuries, prostate cancer, psychosis and schizophrenic episodes, among others, accompany anabolic steroid intake. There is, at present, no evidence to support the claim that athletes are less susceptible to adverse effects than those individuals receiving hormone treatment in a clinical setting. Based on the available information which has accumulated primarily from cross-sectional, short term longitudinal, and case studies, there is a need: (a) to develop a comprehensive battery of specific and sensitive markers of adverse effects, particularly those that would be able to detect the onset of adverse actions; and (b) to conduct controlled long term longitudinal studies in order to fully understand the extensiveness and mechanisms involved in the occurrence of adverse effects.

The results of short-term (6 months) high-dose testosterone treatment on bone age and adult height in boys of excessively tall stature

Forty-nine pubertal tall boys with a mean height prediction of 203.59 cm according to the Bayley-Pinneau (BP) method were treated prospectively with 500 mg testosterone-oenanthate every 2 weeks for a period of 6 months. Before therapy chronological age (CA) was 14.14 years and bone age (BA) 13.88 years using the Greulich-Pyle (GP) method. During therapy BA advanced by 1.37 years. It continued to accelerate during the 6 months following therapy with a mean delta BA/delta CA being 3.01 at 3 months and 2.24 at 6 months after therapy. The 6 months value was only slightly less than the delta BA/delta CA of 2.47 obtained during therapy. The reduction in adult height was 7.26 cm or 50.8% of the predicted further growth in 12 boys with a long-term follow up of 2.5 years. This is similar to the 51.6% or 9.63 cm observed in 50 boys with a long-term follow up after 14.25 month treatment until a BA of 17 years or more. It is concluded that in the majority of cases high-dose testosterone therapy in boys of tall stature can be limited to a 6-month treatment period. Reassessment of the height prediction after a 6-month interval without therapy should define those patients who have to resume treatment because of their remaining excessive growth potential.

The pattern of growth in children with constitutional tall stature from birth to age 9 years. A longitudinal study

A study was made of the longitudinal growth pattern of 29 girls and 36 boys with constitutional tall stature (CTS) from birth to age 9 years. In these children, all of whom had a normal birth length, there was very rapid growth during the first 4 years of life, following which growth velocity dropped to normal and remained parallel to the 50th percentile. In the 49 subjects for whom actual final height was also obtained there was a very good agreement between this and the final height as predicted by Tanner's method from the height at ages 4 and 8 years. Significant differences were found between the mean maternal, paternal and mid-parental height and the tall stature of their offspring, but there was a very good correlation between the individual patients final height and their parental heights. The findings of this study stress the importance of periodical measurements of length and height in all children during the first few years of life so as to have appropriate data on which to base future considerations of possible therapy.

The combined effect of growth hormone and oxandrolone in patients with growth hormone deficiency

Twenty patients with growth hormone deficiency ranging in age from 5 5/12 to 15 8/12 years were treated for 12 months with a combination of human growth hormone and oxandrolone, followed by a period of six months off both medications. Eight of the patients received the combined therapy during the first year of hGH treatment, and 12 during either the second or fourth years of hGH administration. In considering growth velocity alone, the addition of anabolic steroid was beneficial. The bone age advanced rapidly when oxandrolone was added during the first year of hGH treatment, and less rapidly in subsequent years. The increased growth velocity, however, compensated for the acceleration of bone maturation and the overall effect of the combined treatment was beneficial, particularly when used after the first year of hGH treatment. We conclude that there is no advantage to using oxandrolone during the first year of hGH therapy, that oxandrolone in the appropriate dose is of benefit in subsequent years of hGH treatment, and that because of the individual variation in bone maturation, bone age should be frequently assessed.

Prediction of adult height with various methods in Finnish children

Successive height predictions were made by several methods for a group of healthy Finnish children (30 boys and 30 girls), examined annually at ages of 7 to 17 years (1st series) and for 7 boys aged 14 to 19 years with familial delayed growth and puberty (2nd series). The methods used were those of Bayley & Pinneau (BP), Walker (W), Tanner et al. (T) and RWT, and two simple principles: the relative height method (RH) which assumes constancy of height S.D.S. throughout growth, and the index of potential height (IPH) method which assumes constancy of height S.D.S. for bone age (BA). The predictions with RH, W and IPH were inaccurate. BP, T and RWT were for the 1st series as accurate as for the basic series of the respective methods, and none was superior to the others. The BA of average Finns was delayed as compared with the standards of Greulich-Pyle Atlas. When corrections were made for this delay, the IPH method gave predictions comparable in accuracy to BP, T or RWT. In the 2nd series prediction was more accurate with the corrected IPH, BP and RWT methods than with those using BA according to TW2RUS.

Bayley-Pinneau, Roche-Wainer-Thissen, and Tanner height predictions in normal children and in patients with various pathologic conditions

Bayley-Pinneau, Roche-Wainer-Thissen, and Tanner height predictions at various chronologic ages were compared with final adult height in 56 normal subjects and in 34 patients with abnormal growth pattern (11 with familial tall stature, 7 with idiopathic precicious puberty, 6 with Turner syndrome, and 10 with primordial small stature or Silver-Russell syndrome). The two recent methods (Roche-Wainer-Thissen and Tanner) gave very accurate results and were superior to the Bayley-Pinneau method in normal subjects and in patients with familial tall stature. However, they overestimated adult height grossly in precocious puberty and moderately in Turner syndrome and in primordial small stature. It is concluded that calculations based on coefficients and regression equations obtained from normal children (as in the Roche-Wainer-Thissen and Tanner methods) can only be used in normal children or in patients with normal growth potential under adequate treatment. Calculations based on percentages of adult height (as in the Bayley-Pinneau method) are preferable in conditions in which the growth potential in relation to bone maturation is inherently reduced and cannot be corrected by treatment.

The long and the short

The diagnostic problems posed by unusually great height at various ages are discussed, together with the principles governing treatment to curtail height by exhibition of oestrogens or androgens. Short stature is then discussed in terms of an initial approach to assessment and diagnosis, followed by a systematic one. The main agents used in treatment are briefly mentioned, together with some details concerning the use of human growth hormone (hGH).