Upregulation of salivary α2 macroglobulin in patients with type 2 diabetes mellitus

We investigated the expression of salivary alpha 2-macroglobulin (alpha 2-MG) in patients with type 2 diabetes mellitus (T2DM) to investigate its value for predicting damage to the salivary glands. A total of 116 patients with T2DM and 60 patients with impaired fasting glucose (IFG) were included in this study. Sixty health volunteers were enrolled as a control group. Unstimulated saliva was collected at 8 a.m. prior to breakfast. Expression of alpha 2-MG was determined using an enzyme-linked immunosorbent assay. The correlation between salivary alpha 2-MG, serum alpha 2-MG, and concentration of fasting glucose was analyzed using Pearson correlation analysis. No significant difference was observed in the expression of serum alpha 2-MG in the T2DM group, IFG group, and control group (P > 0.05). Compared with the control group and IFG group, a statistical difference was observed in the salivary alpha 2-MG in the T2DM group (P < 0.01). No statistical difference was observed in the salivary alpha 2-MG in the IFG group compared with the control group (P > 0.05). In the patients with T2DM, a close correlation was identified in the expression of serum alpha 2-MG and salivary alpha 2-MG (r = 0.52, P < 0.01). A poor correlation was identified between salivary alpha 2-MG and blood sugar level (r = -0.12, P = 0.199). The expression of salivary alpha 2-MG showed a remarkable increase in T2DM patients, which may be associated with functional disorders of the salivary gland.