Sex differences in iron stores and associations of body iron with cardiovascular risk factors in the middle-aged general population.

BACKGROUND

Men and women exhibit clear differences in both atherosclerotic cardiovascular disease and iron metabolism, although specific cardiovascular risk factors associated with body iron stores remain unclear. This study investigates if there are sex-specific differences in ferritin or total body iron (TBI) and their associations with cardiovascular risk factors and the metabolic syndrome.

METHODS

A total of 1,272 participants (640 men, 632 women) were randomly selected from the Swedish CArdiopulmonary Bioimage Study (SCAPIS). Iron-related biomarkers including ferritin, hemoglobin, soluble transferrin receptor, sTfR/log ferritin index, and TBI were analyzed in relation to conventional cardiovascular risk factors.

RESULTS

Men had higher iron stores than both premenopausal and postmenopausal women. They also demonstrated a more adverse cardiovascular risk profile with higher body mass index (BMI), a higher prevalence of hypertension, hyperlipidemia, diabetes, and prior myocardial infarction and a more atherogenic lipid profile than women. The prevalence of hyperferritinemia was 21.6% in men versus 12.0% in women (p < 0.01), whereas that of metabolic syndrome was 34.5% in men versus 24.6% in women (p < 0.01). In both sexes, BMI, alcohol consumption, LDL cholesterol, and triglycerides were associated with ferritin levels. Unlike men, women showed a significant association between age or hypertension and ferritin levels. Furthermore, ferritin, TBI, and hyperferritinemia were associated with metabolic syndrome in both sexes.

CONCLUSIONS

This study highlights sex-specific differences in body iron stores, prevalence of cardiovascular disease comorbidity, and cardiovascular metabolic status. Hyperferritinemia or TBI was associated with metabolic syndrome in both sexes. In women, but not in men, age or hypertension was associated with ferritin levels. The findings underscore the importance of considering body iron markers when assessing cardiovascular risk in the middle-aged general population. It may help in developing personalized diagnostic and managing approaches for unhealthy cardiovascular metabolic status.