Introduction: Chemerin is a novel adipokine with do-cumented role in obesity-related inflammation, oxida-tive stress and early atherosclerosis. However, its relati-on with clinical anthropometric indices and metabolic parameters in obesity is controversial. Adiponectin is an adipokine with protective metabolic role and is mar-ker of insulin resistance (IR). On the other hand, there are scarce clinical data in metabolic healthy, morbidly obese patients.
Objective: Our study investigated the relation of circu-lating levels of chemerin, adiponectin and chemerin/ adiponectin ratio, as a new parameter, in this particular fenotype of obesity.
Methods: Our study enrolled 25 morbidly obese pati-ents and 25 age- and gender matched non-obese con-trol subjects. None of the enrolled patients had more than two criteria for defining metabolic syndrome, diagnosed or treated cardiovascular/metabolic disea-se. Serum chemerin and adiponectin were measured quantitatively by specific Human ELISA kits (ab155430, ab999680, respectively, Abcam Cambridge, U.K.). Li-pid profile, fasting plasma glucose, insulinemia, IR (HOMA formula) and insulin sensitivity (IS – QUICKI index) were determined. The clinical anthropometric indices were body mass index (BMI), waist circumfe-rence (WC), waist to hip circumference ratio (WHR), the index of central obesity (ICO). Blood pressure (BP) was measured and mean BP was estimated.
Results: Serum chemerin was significantly higher in obese group compared to non-obese subjects (me-dian value 11.56 vs. 9.10 ng/mL, p=0.0001). Serum adiponectin followed paradoxically the same trend (18.05±1.55 vs. 16.36±1.49 ng/mL, p=0.0003) sugges-tive for adiponectin resistance. Chemerin/adiponectin ratio also remained significantly higher in obese group (0.67±0.18 vs. 0.55±0.12, p=0.0052). Metabolic para-meters had normal mean values in both groups. Insu-linemia had higher values in obese group (median va-lue 18.8 vs. 5.98 μU/mL, p=0.0004) and was associated with decreased IS (0.13±0.02 vs. 0.16±0.02, p=0.0004) and IR (HOMA-IR 4.91 vs. 1.28, p=0.0012). Serum chemerin and chemerin/adiponectin ratio were rela-ted to WC (r=0.37), WHR (r=0.36) and ICO (r=0.47), systolic and mean BP (p<0.005), but not to BMI and metabolic parameters (p>0.05). Serum adiponectin was not related to any of the studied parameters (p >0.05). In multiple linear regression models chemerin was an independent predictor of WHR (p=0.013) and decreased IS (p=0.003). In a separate linear regression model fasting plasma glucose determined chemerin le-vels (R2 ajustat 0.77; p=0.018).
Conclusions: In metabolic healthy morbidly obese pa-tients serum chemerin is not related to metabolic chan-ges, but correlates with clinical anthropometric indices, except BMI, and is an independent predictor of WHR and decreased IS. Chemerin/adiponectin ratio is also a useful parameter, superior to serum adiponectin levels. Our data sustain the potential role of chemerin in the pathophysiology of obesity.