RESUMO
OBJECTIVE: In children with idiopathic short stature (ISS) we studied the growth-promoting effect at 4 years of recombinant human growth hormone (rhGH) therapy in three dose regimens and evaluated whether increasing the dosage after the first year could prevent a decline in height velocity (HV). DESIGN: Included were 223 patients who were treated with subcutaneous administrations of rhGH 6 days per week. They were randomized to three groups: 3 IU/m2 body surface/day, 4.5 IU/m2/day, and 3 IU/m2/day during the first year and 4.5 IU/m2/day thereafter, corresponding with dosages of 0.2 and 0.3 mg/kg body weight/week, respectively. Growth was compared with a standard of 229 untreated children with ISS [ISS standard]. RESULTS: During the first year of treatment HV almost doubled and was higher with 4.5 IU/m2 than with 3 IU/m2. In the second year HV no longer differed among the groups, but increasing the dosage slowed the rate of the fall of HV. During 4 years of therapy the height SD score for age increased by a mean (SD) of 2.5 (1.0) [ISS standards], or 1.2 (0.7) (British standards), bone age increased by 4.8 (1.3) years, and predicted adult height SD score increased by 1.5 (0.7). After 4 years the results of the group with 4.5 IU/m2 were slightly better than those of the other groups. When dropouts were included in the analysis (assuming a stable height SD score after discontinuation of rhGH therapy), height gain was still significant. CONCLUSIONS: During 4 years of rhGH therapy, growth and final height prognosis improved, slightly more with 4.5 IU/m2 than with 3 IU/m2 or 3 to 4.5 IU/m2. However, bone age advanced on average 4.8 years during this period; therefore, any effect on final height will probably be modest.
Assuntos
Transtornos do Crescimento/tratamento farmacológico , Hormônio do Crescimento/administração & dosagem , Crescimento/efeitos dos fármacos , Estatura/efeitos dos fármacos , Criança , Relação Dose-Resposta a Droga , Feminino , Retardo do Crescimento Fetal , Transtornos do Crescimento/fisiopatologia , Humanos , Masculino , Análise de RegressãoRESUMO
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.