Idiopatic GH Neurosecretory Dysfunction (GHNSD): A Possible Cause of GH Deficiency (GHD)

FREIRE A; KESELMAN A; CHIESA A; ROPELATO G; BERGADÁ I

Lima , Perú

Congreso; XX REUNION ANUAL SOCIEDAD LATINOAMERICANA DE ENDOCRINOLOGIA PEDIATRICA; 2008

SLEP

GHNSD was described by Spiliotis et al in 1984.Since then,this entity was reported in patients after cranial radiation therapy.However, the diagnosis of idiopathic GHNSD has been questioned. We describe 3 prepubertal patients aged 12,7.8 and 6.3 years with height of .4.2, .3.3 and .4.3 SDS,respectively and delay in bone age from 3 to 5 years.Target height was normal,without a history of constitutional delay.Psychosocial deprivation was included.Arginine-clonidine tests showed a maximum GH peak of 10.8,16.8 and 17.1 ng/ml,and serum IGF1 (SDS)levels were .4.64,.2.3 and .2.8 respectively. An increase of IGF-1 >60%in the GH generation tests excluded GH insensitivity.A twelve-hour 20 minutes sampling nocturnal pulsatile GH secretion was performed and compared with normal prepubertal controls (C). Spontaneous mean ±SD GH levels (ng/ml)were 0.69 ±0.3, 1.3 ±0.8 and 1.4 ±0.8 vs 4.4 ±1.4 in C.Pulse amplitude were 0.6 ±0.39,1.9 ±2.1 and 3.4 ±0.37 vs 8.5 ±4.3 in C.Max GH were 1.21,4.2 and 4.6 vs 18.2 ±9.5 in C.All these values were significantly lower than C,while the number of pulses were not. GH treatment at a mean dose of 0.23 mg/k/wk resulted in growth acceleration at year one from a baseline of 4.1,4.0,and 3.2 cm/yr,to 10.1,10.2 and 7.6 cm/yr,respectively. These data show that idiopatic GHNSD should be considered when other causes of GHD are excluded even without a history of cranial irradiation.The 12-hour spontaneous nocturnal GH sampling is an alternative test to delineate who might benefit from GH treatment.