Oxandrolone in constitutional delay of growth: analysis of the growth patterns up to final stature

Stanozolol regulates proliferation of growth plate chondrocytes via activation of ERalpha in GnRHa-treated adolescent rats

Improving the final adult height is one of the most important aims for treatment of central precocious puberty. Stanozolol (ST) is a synthetic derivative of androgen. In this study, we investigated the effects and the mechanisms of ST on the proliferation of growth plate chondrocytes isolated from adolescent rats treated with gonadotropin-releasing hormone analogue (GnRHa). Treatment with ST resulted in time- and concentration-dependent effects on proliferation as determined by MTT and proliferating cell nuclear antigen (PCNA) assays. Western blotting showed that ST increased the phosphorylation level of the estrogen receptor alpha (ERalpha), but not the androgen receptor (AR). Pharmacological inhibition of ERalpha and mitogen-activated protein kinase (MAPK) attenuated the effects of ST on the proliferation of growth plate chondrocytes. A molecular dynamics simulation showed hydrophobic interactions between ST and ERalpha. These results suggested that ERalpha, but not AR, partially mediates the ST-driven proliferation of growth plate chondrocytes, and that multiple pathways may be involved in the mechanism of action of ST.

Progressive reduction of relative height in childhood predicts adult stature below target height in boys with constitutional delay of growth and puberty

BACKGROUND/AIMS

In some adolescents with constitutional delay of growth and puberty (CDGP), the reduction in relative height (height SDs) starts already in childhood, before puberty. Some subjects with CDGP do not reach their target height (TH). We investigated whether early height SD reduction or testosterone treatment in low doses (1-2 mg/kg/month) influence final height (FH).

METHODS

The growth of 70 adult men with a history of CDGP was investigated. 31 subjects (13 treated with testosterone) had progressive height SD reduction between 3 and 9 years, and in 39 (17 treated with testosterone) no such reduction was seen.

RESULTS

In untreated subjects without early height SD reduction, FH was closer to TH than in those with such reduction (FH - TH 0.05 +/- 0.94 vs. -0.63 +/- 0.50 SD, p = 0.009). FH - TH did not differ between the testosterone-treated and untreated subjects in the group with early height SD reduction (FH - TH -0.36 +/- 0.48 vs. -0.63 +/- 0.50 SD, p = 0.15), nor in the group without such reduction (FH - TH -0.08 +/- 0.70 vs. 0.05 +/- 0.94 SD, p = 0.64).

CONCLUSION

Subjects with early height SD reduction do not attain FH consistent with their genetic height potential, whereas those without such reduction do. Treatment with low doses of testosterone does not adversely affect FH.

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.

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.