ESPE Abstracts

Introduction: GH deficiency may be evaluated by spontaneous nocturnal GH secretion. Usually one night is examined. Since sleep may be disturbed by a new environment, a night to accustom is required by some investigators, which is questioned by others. Thus, we examined spontaneous nocturnal GH secretion during 2 consecutive nights.

Methods: 49 girls and 56 boys with suspicion of GH deficiency were examined between 10 pm and 8 am during 2 consecutive nights. Blood was taken every 20 min. via i.v. catheter, sleep was recorded by the study nurse and GH was determined by ECLIA.

Results: 26 Patients had reduced GH secretion in both nights, all of them had at least more than 6,5h continuous sleep. 29 had a reduced GH in one of the nights, 10 in the first and 19 in the second, so that no GH deficiency was noted. Sleep was slightly lower in the 1^st than in the 2^nd night (7.12h vs. 7.33h). The longest sleeping period was also higher in the 2^nd night (6.21 vs 6.55h) Likewise, mean GH as well as peak GH concentration was higher in the 2^nd night (4.45 vs 4.82 ng/ml and 15 vs 15,19 ng/ml). Statistically, there was a tendency towards longer sleep and higher GH secretion (P< 0,1) and a significant higher mean GH secretion in the 2^nd night (P<0.035).

Discussion: Evaluation of GH deficiency via assessment of spontaneous GH secretion should comprise of 2 consecutive nights instead of one to avoid overestimation of GH deficiency.