Could SCGF-beta levels be associated with inflammation markers and insulin resistance in male patients suffering from obesity-related NAFLD?

One of the pathologic hallmarks of obesity is macrophage infiltration of adipose tissue that has been confirmed as source of multipotent adult stem cells. Stem cell growth factor-beta (SCGF-β) shows activity on granulocyte/macrophage progenitor cells in combination with granulocyte macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF). Obesity-associated inflammation induces insulin resistance (IR), which is central to nonalcoholic fatty liver disease (NAFLD) or hepatic steatosis (HS). We searched for relationship between levels of SCGF-β and those of C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-β (TNF-β), interleukin-12p40 (IL-12p40), interleukin-10 (IL-10), ferritin, GM-CSF and M-CSF and between SCGF-β concentrations and IR in obese patients with HS. Eighty obese patients were retrospectively studied. Serum cytokines levels were appreciated by magnetic bead-based multiplex immunoassays. IR was evaluated by homeostatic model assessment (HOMA), HOMA-derived β-cell function (HOMA-B%), quantitative insulin sensitivity check Index (QUICKI) and single point insulin sensitivity estimator (SPISE). HS and spleen volume were assessed by ultrasonography (US). SCGF-β and IL-6 levels predicted HOMA values (p = 0.032 and 0.041, respectively) only in males. In male patients, CRP and IL-6 levels (p = 0.007) predicted SCGF-β concentrations (p = 0.03 and 0.007, respectively), which in turn predicted HS at US, p = 0.037. SCGF-β levels were linked to IR and HS severity with the mediation role of CRP. IL-10 levels negatively predicted SCGF-β concentrations (p = 0.033). M-CSF levels predicted serum concentration of both TNF-β and IL-12p40 (p = 0.00), but did not predict serum IL-10 (p = 0.30). Prediction of HOMA values by SCGF-β levels, likely mediated by markers of inflammation, characterizes this study, shedding some light on mechanisms inducing/worsening IR of male patients with obesity-related NAFLD.