The Association of Vitamin B-12 Plasma Concentration with Stroke Incidence According to Sex.

BACKGROUND

Previous studies reported that vitamin B-12 deficiency is associated with an increased risk of stroke. However, studies examining the association between excessive vitamin B-12 and stroke risk are limited. Our study aimed to investigate the relationship between excessive vitamin B-12 concentrations and risk of stroke and explore whether this association varies according to sex.

METHODS

Utilizing the Korean Genome Epidemiology Study (KoGES) prospective cohort data, our primary exposure variables were vitamin B-12 plasma concentration and sex. The occurrence of stroke served as the main outcome of interest. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regression analysis. An interaction analysis was conducted to assess the interaction effect of vitamin B-12 and sex on stroke incidence.

RESULTS

Cox proportional logistic regression analysis, adjusting for confounders, showed that excessive vitamin B-12 did not significantly alter stroke risk (HR: 1.22, 95% CI: 0.82, 1.71) and revealed no significant sex-based differences in stroke risk (HR: 0.90, 95% CI: 0.75, 1.04). However, interaction analysis indicated that excessive vitamin B-12 was linked to a significant increase in stroke risk in males (HR: 1.81, 95% CI: 1.10, 2.99) but not in females (HR: 1.04, 95% CI: 0.66, 1.60), with statistically significant interaction effect (P < 0.01).

CONCLUSIONS

Our study demonstrated that although excessive vitamin B-12 alone does not significantly increase stroke risk, it increases risk in males when considering the interaction with sex.