IMPE Abstracts

During transition phase, pituitary hormones, particularly GH, play a relevant role on body composition and bone maturation. Aim: to evaluate the effect of rhGH discontinuation during this period, particularly regarding time without treatment, IGF1 levels and the presence of hydrocortisone concomitant therapy on body composition and bone mass. Fourteen transition GHD patients (females:7) were evaluated by dual X-ray absorptiometry (DXA) after a period of discontinuation. Multiple pituitary deficiencies were present in 13/14 (8 with ACTH deficiency), all on adequate replacement. We evaluated: etiology, age at evaluation, time of GH treatment suspension, BMI, IGF1 level, body composition: fat mass (FM) and lean mass (LM), Z-score of BMD, femoral neck (FN), lumbar spine (LS) with Trabecular Bone Score (TBS) analysis (index of trabecular microarchitecture), total body and BMC, FM distribution, BMC/LM ratio and lean mass index (LMI). DXA evaluation was performed at 19.5 yr (15.1-24.2); GH treatment had been suspended 2.9 yr (0.4-9.0) before evaluation; BMI was 23.0 Kg/m2 (18.3-40.1) and IGF1 SDS level: -2.3 (-7.5 to -1.8). Body composition values were (median/range):

LM and LMI: 11/14 and 13/14 showed lower values than normal, respectively. FM was increased with abdominal distribution (8/14), particularly in women, despite the fact that 6/7 had normal BMI. No correlation was found between the variables studied and IGF1 levels or concomitant hydrocortisone therapy. A positive correlation was found between treatment suspension time and BMC/LM (r=0.64, P=0.0161, Spearman test). Conclusions: our results show an important impact on body composition in patients during the transition period, particularly an increase in FM and a decrease in LM and LMI. The high BMC/LM would reflect a greater impact of the suspension on muscle mass, which was more pronounced the longer the GH treatment was withdrawn. These results would indicate that these patients have adequate BMC and preservation of their bone microarchitecture (perhaps related to the previous GH therapy) for their LM, but the latter could be clearly diminished. Perhaps, the decrease in LM could affect BMD in a time dependent-manner. These findings would support the maintenance of treatment during the transition stage and the avoidance of suspension for long periods to prevent deterioration of body composition.