NOCTURNAL URINARY GROWTH-HORMONE EXCRETION IN GROWTH HORMONE-DEFICIENT CHILDREN ON AND OFF GROWTH-HORMONE TREATMENT

Non-compliance has been reported as a major issue in growth hormone (G H) therapy. We explored the use of urinary GH (uGH) measurements to mo nitor the GH treatment of 18 children (aged 5-16 years) diagnosed as G H deficient on the basis of history, phenotype, auxology and peak GH c oncentration during 2 provocation tests of <15 mU/1. Each child collec ted 5 consecutive overnight urine samples while on GH replacement sche dules, then discontinued treatment for 2 days and collected a further 5 urine samples. The mean mass of uGH excreted on treatment (8.6 ng, r ange 3.6-13.0 ng) was significantly greater than that off treatment (1 .2 ng, range 0.6-2.7 ng; p < 0.01). All uGH values on treatment exceed ed the mean nocturnal uGH excretion of normal age- and sex-matched chi ldren. The clear distinction between uGH levels on and off GH treatmen t indicates that uGH measurement would determine whether two or more G H injections had been missed. A series of uGH estimates over a 2-week period may provide a realistic perspective on injection frequency.