Endocrine Abstracts

Adult growth hormone deficiency (aGHD) is characterized by an altered metabolic profile and increased cardiovascular risk. Neudesin is a newly discovered protein mainly secreted from adipose tissue and brain, under evaluation for its possible activity as negative regulator of energy expenditure. Liver expressed antimicrobial peptide (LEAP)-2 is a competitive antagonist of ghrelin on its receptor. Spexin is a polypeptide related to the galanin-kisspeptin family, secreted along with insulin by pancreatic beta cells with insulin secretion blunting effect. Given the role played in metabolism and energy balance, plasma evaluation of the four peptides was performed and any possible relationships between them and metabolic/anthropometric parameters were evaluated. Thirty-eight patients were included: 18 aGHD patients (7 females and 11 males, aged 59.7±2.6 years, BMI 30.2±2.2 kg/m²); 20 healthy controls (12 females and 8 males, aged 47.1±2.5 years, BMI 24.1±0.9 kg/m²). aGHD was diagnosed by a GHRH plus arginine test. They were evaluated for glucose and insulin, HOMA and QUICKI index, total/lDL/HDL cholesterol, triglycerides, uric acid and IGF-1. Plasma neudesin, LEAP-2, ghrelin and spexin were measured by ELISA, according to manufacturers’ protocols. Fat mass percentage was evaluated by DXA. Data were expressed as Mean±SEM. AGHD patients showed significantly higher HOMA index and triglycerides, and lower HDL cholesterol than controls. Age and BMI significantly differed between aGHD patients and controls; however, no correlation between peptides and age or BMI was detected in aGHD patients, controls, or the overall enrolled population. Fat mass percentage was significantly higher in aGHD than controls, as expected (44.41±3.15 vs 32.2±3.64). Neudesin plasma levels (ng/ml) were significantly higher in aGHD patients than in controls (2.83±0.37 vs 1.55±0.12). Ghrelin plasma levels (nM) were significantly lower (0.91±0.08 vs 1.07±0.09), LEAP-2 (nM) significantly higher (5.19±0.42 vs 3.68±0.49) and consequently LEAP-2/ghrelin ratio significantly higher (6.29±0.84 vs 3.51±0.53) in aGHD patients than in healthy controls. Spexin levels (ng/ml) were similar in the two groups (aGHD 1.17±0.21 vs controls 1.25±0.10). A significant and strong direct correlation between neudesin and LEAP-2 was found both in aGHD patients and in the overall analyzed population. A significant direct correlation between neudesin and uric acid in aGHD patients was also found. Negative correlations were found between neudesin plasma levels and plasma concentrations of glucose and HDL cholesterol. On the contrary, neudesin plasma concentrations appeared positively correlated with the plasma levels of triglycerides. Finally, in the whole population, a significant direct correlation between neudesin and fat mass percentage was pointed out.