Serum Immunoglobulin M Concentration Varies with Triglyceride Levels in an Adult Population: Tianjin Chronic Low-Grade Systemic Inflammation and Health (TCLSIHealth) Cohort Study

Persistent low-grade inflammation is thought to underlie the pathogenesis of many chronic diseases, such as cardiovascular diseases and metabolic syndrome. Autoimmunity is correlated with increased levels of chronic low-grade inflammation, and immunoglobulin M (IgM) is reactive to autoantigens and believed to be important for autoimmunity. Triglyceride (TG) is fatty acid carrier and initiator of oxidative stress, and it has been hypothesized that TG stimulates B cells to secrete IgM. However, few studies have investigated the relationship between TG and IgM in human populations. We designed a cross-sectional and prospective cohort study to evaluate how serum TG levels are related to IgM concentration. Participants were recruited from Tianjin Medical University General Hospital-Health Management Centre. Both a baseline cross-sectional (n = 10,808) and a prospective assessment (n = 2,615) were performed. Analysis of covariance was used in the cross-sectional analysis. After multiple adjustments for confounding factors, serum IgM level in the highest quartile of TG in males was significantly higher than levels in lower quartiles (P <0.05). There was no significant difference between the four quartiles in females (P = 0.91). In follow-up analysis, a multiple linear regression model showed a significant and positive correlation between changes in IgM levels and changes of TG concentration in males (P = 0.04, standard β coefficient = 0.882). This cross-sectional and cohort study is the first to show that serum concentration of IgM varies with TG levels in adult male populations. Further research is needed to explore the mechanism by which TG leads to increased IgM concentration.