Cross-sectional correlates of increased IL-18 but reduced fetuin-A and oxytocin with adiposity and blood indices in metabolic syndrome patients with and without prediabetes

Background: Oxytocin (OXT), fetuin-A and interleukin-18 (IL-18) are involved in the development and progression of metabolic syndrome (MetS) and prediabetes (pre/T2DM). Aims, participants and methods: This study aimed to compare and correlate the plasma levels of OXT, fetuin-A and IL-18 with clinical parameters, haematological indices and adiposity indices in Jordanian MetS subjects. In a cross-sectional study, 30 normoglycaemic lean study participants (control), 30 MetS study participants, and 29 MetS pre/T2DM study participants were recruited. Results: Median circulating levels of both OXT and fetuin-A were lower in MetS and MetS pre/T2DM versus control group. OXT (pg/ml; median interquartile range): MetS 1975.4 and MetS pre/T2DM 1403 versus control 4176.6 (p = 0.009 and p = 0.001, respectively). For fetuin-A (ng/ml), MetS (5784) and MetS pre/T2DM (2154) were lower versus control (6756.3) (p = 0.040 and p = 0.007, respectively). Neither biomarker was described as substantially different in MetS versus MetS pre/T2DM (p = 0.071 and p = 0.155, respectively). Conversely, a non-significant increase in IL-18 was observed in the MetS and MetS pre/T2DM groups compared to normoglycaemic lean controls (232 and 287.5, p > 0.05 versus 108 for both). In addition, conicity index (C-index), atherogenicity index (TG-HDL-C), waist to hip ratio, mean platelet volume (MPV; fl) and red cell distribution width (RDW-CV%) in both MetS and MetS pre/T2DM were significantly higher (p < 0.001) versus controls. However all above MetS-related indices were not ascribed any statistically marked variation in the MetS group when compared to the MetS pre/T2DM group. Both total study pool of recruits’ fetuin-A (Spearman r = –2.66, p = 0.049) as well as MetS pre/T2DM group IL-18 (Spearman r = 0.380, p = 0.046) were inversely correlated with RDW-CV%. OXT in MetS inversely correlated with waist circumference/hip circumference ratio (Spearman r = −0.387, p = 0.038). No other pronounced associations between biomarkers could be detected in any study arm. Conclusion: These findings substantiate the clinical relevance and significance of OXT, fetuin-A and IL-18 as surrogate screening/prognostic tools and therapeutic targets to predict/prevent metabolic dysregularities and anomalies.