Hydroxyproline excretion in pituitary dwarfs treated with therapeutic doses of human growth hormone

Hydroxyproline excretion in the urine was measured in five pituitary dwarfs during a 4-month period of treatment with 10 IU/week of growth hormone and during 4 months following treatment, in order to assess its value as an index of therapeutic response. The excretion of hydroxyproline was found to be within normal limits (26–57 mg/24 h/m2) on control days, and this excretion presented a gradual increase in the last 2 months of treatment; this was, however, not of statistical significance. After cessation of treatment, hydroxyproline levels returned to pretreatment values. The clinical effect was significant in all patients, who gained 2–5 cm within the 4 months of treatment, as compared to an anual increase of 1–3 cm during the pretreatment year. The above results suggest that hydroxyproline excretion cannot be considered as a reliable parameter of the therapeutic response of pituitary dwarfs to chronic growth hormone treatment with the established doses. © 1973 S. Karger AG, Basel