Correlation analysis of monocyte subsets and insulin resistance considering fetuin-A involvement in patients with type 2 diabetes

摘要

Background Fetuin-A is a multifunctional circulating glycoprotein that can induce insulin resistance. Lately, adipose tissue has gained prominence as an effector site of fetuin-A. Although fetuin-A—induced proinflammatory polarization and migration of macrophages plays a crucial role, it remains obscure whether monocyte subsets in circulation could simulate characteristics of macrophages in adipose tissues. This study aims to investigate the correlation between monocyte subsets with fetuin-A and its relevant insulin resistance. Results We evaluated serum fetuin-A levels in 107 patients with type 2 diabetes (T2D). Using flow cytometry, we classified monocyte subsets into three subtypes: (a) classical, CD14_(++)CD16_(?); (b) intermediate, CD14_(++)CD16_(+), the most proinflammatory one; (c) and nonclassical, CD14_(+)CD16_(++). We assessed the insulin resistance by the homeostasis model assessment for insulin resistance (HOMA-IR) in 68 patients without insulin injections. We observed no correlation between fetuin-A levels and classical ( ρ ?=???0.005; P ?=?0.959), intermediate ( ρ ?=?0.022; P ?=?0.826), and nonclassical monocyte counts ( ρ ?=?0.063; P ?=?0.516), respectively. In addition, no significant correlation was found between log (HOMA-IR) and classical ( ρ ?=?0.052; P ?=?0.688), intermediate ( ρ ?=?0.054; P ?=?0.676), and nonclassical monocyte counts ( ρ ?=?0.012; P ?=?0.353), respectively. However, serum fetuin-A levels showed positive correlation with log (HOMA-IR) ( ρ ?=?0.340; P ?=?0.007). Multiple regression analyses revealed a significant relationship between fetuin-A and log (HOMA-IR) ( β ?=?0.313; P ?=?0.016), but not with monocyte subsets. Conclusions Monocyte subsets in circulation, including proinflammatory intermediate monocytes, were not associated with fetuin-A and insulin resistance.