THE VALUE OF URINARY GROWTH-HORMONE DETERMINATION FOR ASSESSMENT OF GROWTH-HORMONE DEFICIENCY AND COMPLIANCE WITH GROWTH-HORMONE THERAPY

Objective.-To compare the 24-hour integrated concentrations of plasma growth hormone with growth hormone levels in a simultaneously collecte d sample of urine. Setting.-Pediatric endocrine diagnostic unit. Patie nts.-Forty-six children (41 male and five female) aged 6 to 19 years u nderwent measurement of integrated concentrations of growth hormone an d simultaneous urine collection. Measurements and Results.-Integrated concentration of plasma growth hormone was correlated with urinary gro wth hormone levels from both the 24-hour (r=.67; P<.0001) and 12-hour overnight (r=.52; P<.001) measurements. Peak growth hormone response t o paired stimulation was not correlated with either the 24-hour (r=.26 ; P<.23; n=28) or 12-hour (r=.16; P<.48; n=28) urinary growth hormone levels. The mean 24- and 12-hour urinary growth hormone levels for the patients with normal integrated concentrations of growth hormone were significantly higher than those in patient groups having subnormal in tegrated concentrations of growth hormone (P<.05). However, there was considerable overlap in the 12- and 24-hour urinary growth hormone lev els between the patients with normal and those with subnormal integrat ed concentrations of growth hormone. Only one patient who had subnorma l integrated concentrations of growth hormone had a 24-hour urinary gr owth hormone level higher than 9 ng, and none had a 12-hour urinary gr owth hormone level higher than 7 ng. The mean 12- and 24-hour urinary growth hormone levels were significantly higher in patients who receiv ed growth hormone injection than in those with normal spontaneous inte grated concentrations of growth hormone and had no overlap with patien ts who had subnormal integrated concentrations of growth hormone. Conc lusions.-(1) Urinary and integrated concentrations of plasma growth ho rmone are correlated; (2) patient diagnoses based on integrated plasma growth hormone levels exhibit a high degree of overlap of urinary gro wth hormone; and (3) urinary growth hormone levels can serve to monito r compliance with growth hormone therapy.