Apparent growth hormone levels in plasma and urine. Methodological "artefacts"

Urinary growth hormone reflects plasma levels, if a normal renal function is assured. It offers the advantages of easy repetition over prolonged periods of time. It is an easy tool to assess physiological and pathophysiological aspects of the "amount" of growth hormone secreted in a given clinical situation. It can be used to control therapy and reassess the "growth hormone status" at any time during a treatment period. It cannot, however, replace the assessment of responses of the system to a given stimulus and will not reflect the pulsatility of plasma levels.