A study has explored the relationship between IgM antibodies against phosphorylcholine and cardiovascular disease in women. The findings revealed a significant inverse association between higher anti-PC levels and a lower risk of myocardial infarction and ischemic heart disease, particularly among women.

In the study, published in JACC: Advances, investigators analyzed data from 932 women with a mean age of 66 ± 6 years from the Swedish Mammography Cohort. Over 16 years of follow-up (13,033 person-years), the study identified 113 cases of composite cardiovascular disease (CVD), 69 cases of ischemic heart disease (IHD), 44 cases of myocardial infarction (MI), and 50 cases of ischemic stroke.

IgM anti-PC levels were measured using an enzyme-linked immunosorbent assay (ELISA). The mean baseline level was 70 ± 66 U/mL, with a median of 53 U/mL (5th to 95th percentile = 16–165 U/mL). The Cox proportional hazard regression models adjusted for potential confounders.

Women in the highest tertile of IgM antibodies against phosphorylcholine (anti-PC) levels had a 73% lower risk of MI compared with those in the lowest tertile (hazard ratio [HR] = 0.27, 95% confidence interval [CI] = 0.11–0.68, P trend < .01). The protective associations extended to composite CVD (HR = 0.42, 95% CI = 0.21–0.84, P trend = .06) and IHD (HR = 0.35, 95% CI = 0.14–0.84, P trend = .05) when comparing the highest quintile to the lowest.

Additional study data showed:

• Higher proportions of current and former smokers in the highest quintile of IgM anti-PC levels, and a lower prevalence of hypertension
• Age-standardized characteristics by IgM anti-PC quintiles showed consistent body mass index (BMI), but differences in factors like smoking and hypercholesterolemia.

Restricted cubic spline analyses indicated no deviation from linearity (P nonlinearity ≥ .72) for associations between IgM anti-PC levels and CVD outcomes. However, the association with ischemic stroke was not statistically significant (HR = 0.82, 95% CI = 0.40–1.67, P trend = .61).

The investigators highlighted strengths like the population-based design and detailed covariate data but acknowledged limitations such as sample size and potential residual confounding. Because the study was conducted among postmenopausal women in Sweden, further research is needed to determine if these findings are generalizable across different races and ethnicities.

The investigators reported that they have no relationships relevant to the contents of this paper to disclose except that the lead author is named as inventor on other aspects of anti-PC than associations with any cardiovascular disease studied herein.

Conflict of interest disclosures can be found in the study.