Endocrine Abstracts

Introduction: Regulation of adiponectin in GH deficiency (GHD), which presents visceral obesity, is still a matter of debate. No studies have evaluated circulating adiponectin isoforms in adult GHD subjects. Aim of this study was to evaluate total adiponectin (TA) and its isoforms (high molecular weight: HMW, medium molecular weight: MMW, low molecular weight: LMW) in hypopituitary adult subjects with and without GHD, in relation to weight, IGF1 and GH levels.

Methods: Cross-sectional study. 38 patients with hypothalamic-pituitary diseases (age, mean±S.E.M.: 48.8±3.7 years, 13 F) and suspected of GHD were evaluated at fasting for: i) GHRH+arginine test, ii) baseline IGF1 (Immulite), TA, HMW, MMW, LMW (EIA).

Results: 22/38 patients presented GHD according to BMI-dependent cut-off values. Patients with and without GHD had an overlapped BMI (28.1±1.3 vs 27.8±1.7 kg/m²). GHD patients showed lower TA (5.6±0.9 ng/ml) and HMW levels (1.7±0.5 ng/ml) compared to subjects without GHD (TA 9.0±1.4 ng/ml, P<0.01; HMW: 4.6±1.1 ng/ml, P<0.004). MMW and LMW levels showed a comparable trend, without reaching statistical significance. TA and HMW levels negatively correlated with BMI (r: −0.393, P<0.007, r: −0.357, P<0.01 respectively). HMW levels negatively correlated with GH peak (r: −0.251, P<0.05), even when controlled for BMI. No association was found with IGF1 levels. HMW and TA levels correlated with the GHD diagnosis, but, when controlled for BMI, the significance was maintained for HMW only (r: 0.290, P<0.05). Subjects in the lowest quartile of HMW had a low probability of not being GHD (OR 0.056, CI 95% 0.006–0.491, P<0.01).

Conclusions: In hypopituitary adult subject, the presence of GHD seems to be associated with reduced TA and HMW levels independently from BMI.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.