The Impact of Immunoglobulins on Cardiovascular Diseases and Lipid Profiles in Elderly and Middle‐Aged Chinese Individuals: A 15‐Year Retrospective Study

Background Humoral immunity defends via immunoglobulins. This study aimed to evaluate the association between immunoglobulins and CVDs and lipid profiles in a cohort of individuals aged 45 years and older. Methods Data from 982 subjects were analyzed. The cohort had a median age of 61 years (IQR 56–72), was predominantly male (84.8%), and had a high prevalence of CVDs at baseline, including hypertension (30.3%), dyslipidemia (20.7%), arrhythmia (22.3%), coronary heart disease (12.1%), and atrial fibrillation (4.5%). Logistic regression analysis was used to examine the association between baseline and time‐varying serum levels of IgG, IgA, and IgM and the presence of five CVDs: coronary heart disease, atrial fibrillation, arrhythmia, hypertension, and dyslipidemia. We additionally explored the relationship between these immunoglobulin levels and lipid profiles. Results No significant differences in immunoglobulin levels were found between CVD and non‐CVD groups at baseline, and baseline immunoglobulin levels were not associated with any CVD. However, longitudinal changes in IgG and IgA levels were positively associated with changes in free fatty acids (FFAs). Intriguingly, longitudinal increases in IgM levels were positively associated with total cholesterol, LDL‐C, non‐HDL‐C, and HDL‐C. Conclusions This study provides longitudinal evidence that increases in IgG and IgA levels are associated with elevated FFA levels, while increases in IgM are associated with an adverse lipid profile characterized by higher total cholesterol, LDL‐C, and non‐HDL‐C, and lower HDL‐C. These findings suggest a link between humoral immunity and lipid metabolism that warrants further investigation, with potential implications for cardiovascular risk assessment.