Objective: Recent reports have suggested that the existence of associations between hormonal dysregulation and chronic upregulation of inflammatory markers, which may cause obesity-related disturbances. Thus, we examined whether acylated ghrelin (AcylG) and total ghrelin (TotG) levels could be associated with the following inflammatory markers: C-reactive protein (CRP), tumor necrosis factor α (TNF-α), and soluble TNF receptor 1 (sTNF-R1).
Design: Cross-sectional study consisting of 50 overweight and obese postmenopausal women.
Methods: AcylG and TotG levels were assessed at 0, 60, 160, 170, and 180 min of the euglycemic/hyperinsulinemic clamp (EHC). We evaluated insulin sensitivity, body composition, and blood lipid profiles as well as fasting concentrations of CRP, TNF-α, and sTNF-R1.
Results: In fasting conditions, sTNF-R1 was negatively correlated with AcylG (r = −0.48, P < 0.001) levels. In addition, AcylG/TotG was associated negatively with sTNF-R1 (r = −0.44, P = 0.002) and positively with TNF-α (r = 0.38, P = 0.009) values. During the EHC, TotG (at all time points) and AcylG (at 60 and 160 min) values were significantly decreased from fasting concentrations. AcylG maximal reduction and area under the curve (AUC) values were correlated to sTNF-R1 (r = −0.35, P = 0.02 and r = −0.34, P = 0.02, respectively). Meanwhile, the AcylG/TotG AUC ratio was associated negatively with sTNF-R1 (r = −0.29, P < 0.05) and positively with TNF-α (r = 0.36, P = 0.02). Following adjustments for total adiposity, sTNF-R1 remained correlated with fasting and maximal reduction AcylG values. Similarly, AcylG/TotG ratios remained significantly correlated with sTNF-R1 and TNF-α. Importantly, 23% of the variation in sTNF-R1 was independently predicted by fasting AcylG.
Conclusion: These results are the first to suggest that both fasting and EHC-induced AcylG profiles are correlated with fasting values of sTNF-R1, a component of the TNF-α system. Thus, AcylG may act, at least in part, as one mediator of chronic inflammatory activity in human obesity.