Clonidine and testosterone in patients with constitutional delayed growth

Abstract

Constitutional delayed growth (CDG) is defined as that condition in which height is below the third percentile in Tanner Whitehouse growth curves, associated to a similar delay in skeletal maturity (Greulich and Pyle Atlas), and to the absence of deficiencies of Growth and Thyroid hormones or of nutritional and psychosocial conditions. The subjects of this study were 15 boys and 6 girls (age 13.4 ± 3.1 years, range 10.9-16). Thirteen boys and 1 girl were at a prepuberal stage of development at the beginning of the study. In order to check the spontaneous growth velocity (GV), the patients were followed for a four-month period before starting any treatment. The boys under 13 years and all the girls received clonidine during a 4-12 month period (0.1 mg/m2/day). With this drug the boys Increased their GV from 5.9 ± 3.12 cm/year to 7.04 ± 2.23 cm/year (NS), and the girls from 5.53 ± 2.31 to 6.45 ± 1.18 cm/year (NS). However, two subgroups were clearly differentiated: the children who had some response to clonidine and those who did not. In the boys that responded, the spontaneous GV before clonidine was significantly less than that of those who did not respond (3.8 ± 3.27 vs 7.67 ± 1.66 cm/year) (P< 0.05). The figures for the girls were 3.5 ± 0.86 and 7.57 ± 0.4 cm/year, respectively (P< 0.01 ). Nine boys received Testosterone Enantate (250 mg I.M./month for four doses); five of them had previously received clonidine. The GV before Testosterone, 5.0 ± 2.59 compared to post-testosterone, 9.26 ± 2.4 cm/year was significantly lower (P< 0.01 ). The delay In skeletal maturation, as defined by the bone age/chronological age Index, dld not have any bearing on the eventual response to clonldine, nor this response was attributable to a progress In the sexual maturity index (Tanner) during treatment with clonidine. We conclude that a subnormal spontaneous GV (Iess than 4 cm/year) in these children may have a predictive value for an eventual response to clonidine treatment. Yet, more cases need to be studied to be able to draw finer conclusions.