P-0554-Association of serum chemerin with insulin resistance and pancreatic beta cell dysfunction in prediabetic subjects 
Author Block: K.L. Shams, I. A. Hossain, M. Hasan, L. Ali;
1Dept of Radiology & Imaging, Bangladesh Institute of Health Sciences General Hospital, Dhaka, Bangladesh; 2Dept of Biochemistry and Cell Biology, Bangladesh University of Health Sciences, Dhaka, Bangladesh; 3Dept of Biochemistry and Molecular Biology, Rajshahi University, Rajshahi Bangladesh. E-mail: kanizlaila75@gmail.com
Background and aims: Prediabetic subjects are known to be associated with insulin resistance and pancreatic beta cell dysfunction; however, the risk factors and underlying mechanism(s) of these defects vary substantially from population to population. The novel adipokine, chemerin has been suggested to be involved in insulin resistance in obesity and type 2 diabetes. 
Aims: In the context of the previous findings of primarily insulin resistance in impaired glucose tolerance (IGT) and pancreatic β cell dysfunction in impaired fasting glucose (IFG) subjects in Bangladeshi population, the present study was undertaken to investigate the association of serum chemerin with these two major defects among prediabetic subjects.
Materials and methods: Under an observational analytic study a group of 28 IGT (M/F 16/12; age in years, 40±9, BMI in kg/m2 26±3 M±SD), 29 IFG (21/8; 48±8; 25±5), 26 IFG-IGT (14/12; 46±8; 26±3) and 37 normal glucose tolerance (NGT) (19/18; 42±9; 24±2) subjects were investigated for serum glucose, lipid profile, insulin (ELISA) and chemerin (ELISA) levels. Insulin secretory capacity (HOMA%B) and insulin sensitivity (HOMA%S) were calculated from fasting serum glucose and fasting serum insulin values by homeostasis model assessment (HOMA). Data were analyzed by univariate and bivariate analysis as appropriate.
Results: Mean (±SD) S chemerin levels (ng/ml, M±SD) in the NGT, IGT, IFG and IFG-IGT subjects were 58±29, 83±49, 67±46 and 87±36 respectively. Compared to NGT only IGT and IFG-IGT subjects showed significantly higher levels of S chemerin (p=0.018 and p=0.001 respectively). The IGT subjects showed significantly lower HOMA%S compared to the NGT and the markers for insulin sensitivity was negatively correlated with S chemerin (r=-0.394, p=0.048) in this group. In line with this finding, HOMA-IR showed a reverse trend with S chemerin in IGT (r=0.376, p=0.036) and IFG-IGT (r=0.296, p=0.046) subjects. HOMA%B was significantly lower in IFG subjects compared to NGT (103.07±31.65 vs 143.08±33.40, M±SD; p<0.001) and the markers for β cell secretory capacity showed a negative correlation with S chemerin (r=-0.273, p=0.042) in this group. The IFG-IGT subjects showed significantly lower HOMA%S compared to the NGT (49±17 vs 62±27, M±SD; p=0.005) and the markers for insulin sensitivity was negatively correlated with S chemerin (r=-0.435, p=0.034) in this group.
Conclusion: Serum chemerin is elevated in both IGT and IFG-IGT subjects. Although serum chemerin is associated with both insulin sensitivity and insulin secretion, however, its concentration in serum is elevated only in those prediabetic conditions which are related to insulin resistance. The underlying reason for this discrepancy needs to be investigated further.