[Serum immunoglobulin concentration and the risk of type 2 diabetes mellitus in adults in Tianjin City: a prospective cohort study].

ABSTRACT

Objective: To evaluate the association between immunoglobulin concentration and the risk of type 2 diabetes mellitus (T2DM) in adults in Tianjin City. Methods: Based on the Tianjin Chronic Low-grade Systemic Inflammation and Health (TCLSIHealth) cohort from January 2010 to December 2018, subjects who had completed the measurement of baseline immunoglobulin concentration and blood glucose concentration and not been diagnosed with any type of diabetes at baseline were selected in this study. The collected data included the concentration of serum immunoglobulin (IgG, IgM, IgA and IgE), fasting blood glucose and other potential confounders. The subjects were divided into four groups from Q1 to Q4 according to the quartiles of baseline immunoglobulin concentration. The multivariable Cox regression model was used to assess the association between the baseline immunoglobulin concentration and T2DM. Results: A total of 6 315 subjects aged (50.1±10.0) years were included. About 390 subjects were newly diagnosed with T2DM during the follow-up period. The incidence rate was 16.8/1 000 person-years. After adjusting for age, sex, waist circumference, smoking status, drinking status, eosinophil ratio, metabolic syndrome, first-or second-degree family history, and reciprocal adjusting for other immunoglobulin concentrations, compared to the lowest quartile concentration group Q1, subjects in group Q4 with the highest quartile of IgG concentration showed a lower risk of T2DM (HR=0.71, 95%CI 0.52-0.97), and subjects in group Q4 with the highest quartile of IgM concentration also had a decreased risk of T2DM (HR=0.66, 95%CI 0.47-0.91). Subjects in group Q4 with the highest quartile of IgA concentration had an increased risk of T2DM (HR=1.56, 95%CI 1.18-2.07). The risk of T2DM decreased with the increase of serum IgG and IgM concentrations (Ptrend=0.018, Ptrend=0.010) and increased with the increase of serum IgA concentrations (Ptrend<0.001). No association was found between the concentration of IgE and T2DM risk (HR=0.99, 95%CI 0.74-1.31, Ptrend=0.891). Conclusion: The concentration of IgG and IgM is negatively associated with the risk of T2DM, and the concentration of IgA is positively associated with the risk of T2DM in Tianjin City. The concentrations of IgG, IgM and IgA could be a predictor of hyperglycemia and T2DM.