Introduction: Previous reports support the hypothesis of an age dependent derangement of the hypothalamuspituitary axis occurring in PWS subjects. In this context, transition years represent an important phase of growth process when somatic development reaches its completion. In the general population, GH deficiency (GHD) during the transition phase is associated with deterioration of body composition, metabolic alterations and reduced bone mineral density. PWS subjects have reduced muscle mass, increased risk of cardiovascular disease and osteoporosis, similarly to what observed in patients with non-syndromal GHD. Consequently, assessment of the GH status from late teenage years until 67 years after achievement of final height may be particularly helpful in the management of PWS in this particular period. The objective of this study was to investigate the GH response to combined GHRH+arginine administration in a large group of PWS patients during the transition period.
Patients and methods: Sixty-six patients with genetically-confirmed PWS, 29 males, aged 20.0+2.6 years (mean+S.D.), were studied. Forty-seven subjects were obese, 11 overweight and 8 normal weight. Pituitary GH secretion was evaluated by dynamic testing with GHRH+arginine. In order to define GHD, we have adopted the cut-off limit specific for transition phase (GH peak (GHp) <19 μg/l) (Corneli et al., Eur J Endocrinol 2007). In addition, the appropriate BMI-related diagnostic cut-off limits of GHp have been used (Corneli et al., Eur J Endocrinol 2005).
Results: Fifty-two patients had GHp <19 μg/l (78.7%). Accordingly to the cut-off limits related to BMI, 13 obese PWS subjects (27.6%) could be defined as severe GHD (GHp<4.2 μg/l) as well as three overweight patients (27.3%) (GHp<8 μg/l), whereas none of normal weight individuals had GHp<11.5 μg/l.
Conclusion: Our findings showed that an impairment of GH response occurred in a significant percentage of PWS during transition phase, with an evident impact of their weight status.
18 Sep 2014 - 20 Sep 2014