TREATMENT OF GROWTH DELAY IN BOYS WITH ISOLATED GROWTH-HORMONE DEFICIENCY

We report our experience in treating growth delay in boys with isolated growth hormone deficiency (IGHD) receiving biosynthetic human growth hormone. The study was performed in 15 boys with IGHD receiving GH. At the chronological age of 13.1 (1.1) years (SD), 13 were prepubertal, two were in early puberty and there was a mean bone age delay of 2.5 (1.4) years. A growth spurt was induced by either depot testosterone or oxandrolone. There was an increase in growth rate from 5.7 (1.6) cm/year, occurring the year before anabolic or sex steroid therapy, to 8.1 (1.2) cm/year during treatment (p < 0.05), followed by 7.3 (1.9) cm/year the year after the cessation of treatment (p < 0.05). There was no significant change in height so score for bone age, which was -0.69 (0.97) at the commencement of anabolic or sex steroid therapy and -0.53 (0.84) at the end of treatment. Before the induced growth spurt, there was equal body proportion between sitting height and subischial leg length, which had no significant change following androgen treatment. Spontaneous progress in pubertal development was achieved by all patients with an increase in testicular volume from a mean of 2.9 (2-8) to 6.1 (4-10) ml. The pattern of growth presented by patients treated with oxandrolone or those with testosterone was similar. Our data suggest that growth delay and delayed puberty, in patients with IGHD during concomitant growth hormone therapy, can be treated without deterioration in height prognosis. Bringing forward the timing of pubertal growth into the normal range, which is usually delayed in boys with IGHD, may prevent prolonged growth deceleration and psychological distress, which are common sequelae. Intervention should be offered to patients thought to have ''isolated'' GHD if their puberty is delayed. Normal progression of testicular volumes through puberty will confirm the diagnosis of ''isolated'' GHD. Our data also have implications for the mechanism of the growth spurt of puberty, especially the relative importance of GH and androgens.