Increased levels of plasma neudesin in adult growth hormone deficiency and their relationship with plasma liver-expressed antimicrobial peptide-2 levels: a cross-sectional study

Purpose 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 a negative regulator of energy expenditure. Liver-expressed antimicrobial peptide (LEAP)-2 is a competitive antagonist of ghrelin on its receptor. An observational cross-sectional study was performed to test the hypothesis that plasma neudesin levels may be modified in aGHD. Given the role played in the energy balance, any possible relationships between neudesin, LEAP-2 and metabolic and anthropometric parameters were evaluated. Subjects and Methods Thirty-eight patients were included: 18 aGHD patients (7 females and 11 males, aged 59.7 & PLUSMN; 2.6 years, BMI 30.2 & PLUSMN; 2.2 kg/m(2)); 20 healthy controls (12 females and 8 males, aged 47.1 & PLUSMN; 2.5 years, BMI 24.1 & PLUSMN; 0.9 kg/m(2)). All patients were evaluated for glucose, insulin, HOMA and QUICKI index, total/LDL/HDL cholesterol, triglycerides, uric acid, and IGF-1. Plasma neudesin, LEAP-2, and ghrelin were measured by ELISA. Fat mass was evaluated by DEXA. Results Neudesin levels were significantly higher in aGHD versus controls. We confirmed the finding of significantly lower ghrelin levels and significantly higher LEAP-2/ghrelin ratio in aGHD patients and found a significant direct correlation between neudesin and LEAP-2 levels. A significant direct correlation between neudesin and fat mass percentage was found in the whole population. Conclusion These results suggest the onset of adaptive responses to an altered metabolic picture in aGHD. The changes in two distinct pathways that modulate food intake and the still limited knowledge about neudesin suggest future developments in this field.