ABSTRACT
OBJECTIVE: It has been suggested that adipose-derived cytokines act as insulin sensitizers/insulin-mimetics and some others may induce insulin resistance. In order to elucidate the potential role of novel adipocytokines in the pre-diabetes states, circulating levels of novel adipocytokines were evaluated in first-degree relatives of subjects with type 2 diabetes mellitus (FDRs). METHOD: Serum omentin-1, adiponectin and retinol-binding protein 4 (RBP4) levels were measured in 179 subjects (90 glucose tolerant FDRs and 89 age- and sex-matched healthy controls) using enzyme-linked immunosorbent assay (ELISA) methods. RESULTS: There was no significant difference between the two groups regarding serum RBP4 concentrations. However, serum omentin-1 (median [interquartile range], 6.18 [4.06-11.52]ng/ml versus 10.50 [4.30-20.60]ng/ml, p=0.004) and adiponectin (mean±SD, 10.07±4.0 µg/ml versus 20.66±8.12 µg/ml, p<0.0001) levels were significantly lower in FDRs when compared with the controls. In multiple logistic regression analysis, FDRs showed a significant association with lower circulating omentin-1 and adiponectin levels, even after adjustments were made for age, sex, body mass index, blood pressure measures, and biochemical parameters including glucose status, lipid profile, insulin levels and HOMA-IR (OR=0.49, CI [0.30-0.79]; p=0.004 and OR=0.74, CI [0.67-0.82]; p<0.0001, respectively). However, FDRs did not show a significant association with serum RBP4 levels in different models of regression analyses. CONCLUSIONS: The FDRs showed significant associations with lower omentin-1 and adiponectin levels. A potential role for these adipokines in the FDRs' increased risk of diabetes needs to be further elucidated.
