Intravenous lipid infusion and total plasma fatty acids positively modulate plasma acylated ghrelin in vivo

TY - JOUR

T1 - Intravenous lipid infusion and total plasma fatty acids positively modulate plasma acylated ghrelin in vivo

AU - Barazzoni, R.

AU - Gortan Cappellari, G.

AU - Semolic, A.

AU - Ius, M.

AU - Dore, F.

AU - Giacca, M.

AU - Zanetti, M.

AU - Vinci, P.

AU - Guarnieri, G.

PY - 2017/6/1

Y1 - 2017/6/1

N2 - Background & aims Ghrelin is a gastric orexigenic hormone whose activating acylation plays a relevant role in the regulation of energy balance. Nutritional modulators of ghrelin acylation and plasma acylated ghrelin (AG) concentration remain however largely undefined. We aimed at investigating whether circulating free fatty acids (FFA) contribute to regulate plasma AG and its ratio (AG/TG) to total hormone (TG). Methods Plasma FFA, TG, AG and AG/TG were measured in a primary outpatient care setting in a community-based population cohort of 850 individuals (age 54 ± 10 years, M/F: 408/442) from the North-East Italy MoMa study. 150-min intravenous lipid infusions in rodents (10% lipids, 600 μl/h) were used to investigate the potential causal role of FFA in the regulation of plasma ghrelin profile. Results Plasma FFA were associated positively with AG and AG/TG while negatively with TG (P < 0.01). Associations between FFA, AG and AG/TG remained statistically significant (P < 0.02) in multiple regression analysis including HOMA insulin resistance and metabolic confounders, and both AG and AG/TG but not TG increased through plasma FFA quartiles (P < 0.01). Consistent with these findings, intravenous lipid infusion with plasma FFA elevation caused elevations of AG and AG/TG (P < 0.05) with no TG modifications. Conclusions The current findings demonstrate a novel role for circulating FFA availability to up-regulate plasma AG, which could involve FFA-induced stimulation of ghrelin acylation.

AB - Background & aims Ghrelin is a gastric orexigenic hormone whose activating acylation plays a relevant role in the regulation of energy balance. Nutritional modulators of ghrelin acylation and plasma acylated ghrelin (AG) concentration remain however largely undefined. We aimed at investigating whether circulating free fatty acids (FFA) contribute to regulate plasma AG and its ratio (AG/TG) to total hormone (TG). Methods Plasma FFA, TG, AG and AG/TG were measured in a primary outpatient care setting in a community-based population cohort of 850 individuals (age 54 ± 10 years, M/F: 408/442) from the North-East Italy MoMa study. 150-min intravenous lipid infusions in rodents (10% lipids, 600 μl/h) were used to investigate the potential causal role of FFA in the regulation of plasma ghrelin profile. Results Plasma FFA were associated positively with AG and AG/TG while negatively with TG (P < 0.01). Associations between FFA, AG and AG/TG remained statistically significant (P < 0.02) in multiple regression analysis including HOMA insulin resistance and metabolic confounders, and both AG and AG/TG but not TG increased through plasma FFA quartiles (P < 0.01). Consistent with these findings, intravenous lipid infusion with plasma FFA elevation caused elevations of AG and AG/TG (P < 0.05) with no TG modifications. Conclusions The current findings demonstrate a novel role for circulating FFA availability to up-regulate plasma AG, which could involve FFA-induced stimulation of ghrelin acylation.

KW - Acylation

KW - Free fatty acids

KW - Ghrelin

UR - http://www.scopus.com/inward/record.url?scp=85006355694&partnerID=8YFLogxK

U2 - 10.1016/j.clnu.2016.05.017

DO - 10.1016/j.clnu.2016.05.017

M3 - Article

C2 - 27312085

AN - SCOPUS:85006355694

SN - 0261-5614

VL - 36

SP - 775

EP - 781

JO - CLINICAL NUTRITION

JF - CLINICAL NUTRITION

IS - 3

ER -