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 1st than in the 2nd night (7.12h vs. 7.33h). The longest sleeping period was also higher in the 2nd night (6.21 vs 6.55h) Likewise, mean GH as well as peak GH concentration was higher in the 2nd 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 2nd 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.
27 - 29 Sep 2018
European Society for Paediatric Endocrinology