ESPE Abstracts (2014) 82 P-D-2-3-443

The Effect of Two Different GH Dosages on Final Height and Bone Geometry

Fiorenzo Lupia, Mauro Bozzolab, Fabio Buzic, Silvia Longhia, Amelia Mascolob, Alba Pilottad, Rossella Portob, Giulia Ruffinazzib, Valentina Zattonid & Giorgio Radettia

aOspedale Regionale, Bolzano, Italy; bUniversità di Pavia, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy; cOspedale Carlo Poma, Mantova, Italy; dSpedali Civili, Brescia, Italy

Background: GH has a strong positive influence on bone stimulating both bone elongation and increase in size by enhancing the accrual of trabecular and cortical bone up to the attainment of peak bone mass in young adult.

Aim of the study: We compared the effect of two different GH dosages on statural growth and bone geometry in two groups of GH-deficient children at final height. Data has been collected retrospectively from 1994 to 2013.

Patients and methods: We evaluated 121 (86 males and 35 females) children of two different cohorts. group 1 (44 patients) had been treated with GH at a mean dose of 0.3 mg/kg per week and group 2 (77 patients) at 0.2 mg/kg per week. The auxological data were collected at the beginning and at the end of treatment. A digitalized X-ray obtained at final height for the determination of bone age was used to study bone geometry.

Results: Height was corrected for mid-parental height (parentally adjusted height SDS), while the following parameters were employed to assess bone geometry: metacarpal index (MI), cross-sectional area (CSA), cortical area (CA), and medullary area (MA).

Height: At the beginning of treatment was significantly shorter in group 1 than in group 2 (−0.18 vs −0.63; P<0.002), while at the end of treatment there was no difference between the two groups (0.15 vs 0.11). Height gain was significantly higher in group 1 than in group 2 (0.33 vs −0,52; P<0.001). Bone geometry: MI was significantly greater in group 1 (0.62 vs 0.55; P<0.001) as well as CA (−46.87 vs 42.69; P<0,005), while MA was significantly lower in group 1 (8.48 vs 11.65; P<0.002). There was no difference in total cross sectional area.

Conclusions: Higher GH doses elicit a significantly greater statural gain and an improvement of the bone geometry by stimulating the growth of the cortical area.