Circulating zonulin levels in newly diagnosed Chinese type 2 diabetes patients

AIMS: Studies suggest that type 2 diabetes mellitus is associated with increased gut permeability. Human zonulin is the only physiological mediator discovered to date that is known to regulate gut permeability reversibly by disassembling intestinal tight junctions. However, the relationship between zonulin and type 2 diabetes remains to be defined, and no Chinese population-based data were reported. The aim of this study was to investigate the association between serum zonulin levels and type 2 diabetes in a Chinese Han population.

METHODS: 143 newly diagnosed type 2 diabetes patients, 124 patients with impaired glucose tolerance and 121 subjects with normal glucose tolerance were enrolled in this study. Serum zonulin was measured by ELISA.

RESULTS: Patients with type 2 diabetes had higher serum zonulin levels than impaired or normal glucose tolerant subjects. Serum zonulin correlated with body mass index, waist-to-hip ratio, triglyceride, total cholesterol, HDL-C, fasting plasma glucose, 2h plasma glucose, HbA1c, tumor necrosis factor α, interleukin 6, HOMA-IR and QUICK index using correlation analysis (p < 0.05 for all). Multivariate stepwise regression analysis showed that zonulin levels were independently associated with insulin resistance (β = 0.024, p = 0.005). In logistic regression analysis, zonulin levels were an independent predictor of type 2 diabetes (OR = 1.080, p = 0.037).

CONCLUSIONS: Serum zonulin levels are significantly elevated in newly diagnosed Chinese Type 2 diabetes patients, and are associated with dyslipidemia, inflammation and insulin resistance, indicating a potential role of zonulin in the pathophysiology of type 2 diabetes in Chinese.