Relationship between serum levels of immunoglobulins and metabolic syndrome in an adult population: A population study from the TCLSIH cohort study.

BACKGROUND AND AIMS Metabolic syndrome (MetS) is a combination of metabolic disorders that increase the risk of developing cardiovascular disease, and inflammation is considered as a pathological basis for MetS. Immunoglobulins (Igs) are the major secretory products of the adaptive immune system. However, no large-scale population study has focused on a possible relationship between Igs and MetS. We designed a cross-sectional study to investigate the relationship between Igs and prevalence of MetS in a large-scale adult population. METHODS AND RESULTS A total of 10,289 participants were recruited among residents in Tianjin, China. Metabolic syndrome was defined in accordance with the criteria of the American Heart Association scientific statements of 2009. Serum levels of Igs were determined by immunonephelometry. Multiple logistic regression models were used to assess the relationship between the quintiles of serum levels of Igs and the prevalence of MetS. The overall prevalence of MetS was 36.1%. The mean (standard deviation) values of Igs (IgG, IgE, IgM, and IgA) were 1205.7 (249.3) mg/dL, 93.1 (238.9) IU/mL, 105.7 (57.3) mg/dL, and 236.2 (97.6) mg/dL, respectively. The adjusted odds ratios (95% confidence interval) of MetS for the highest quintile of Igs (IgG, IgE, IgM, and IgA), when compared to the lowest quintile, were 0.81 (0.70, 0.95), 0.97 (0.83, 1.12), 1.13 (0.97, 1.33), and 1.52 (1.30, 1.77), respectively. CONCLUSIONS This study demonstrated that decreased IgG and increased IgA are independently related to a higher prevalence of MetS. The results indicate that the Igs might be useful predictive factors for MetS in the general adult population.