Serum ferritin level is positively associated with insulin resistance and metabolic syndrome in postmenopausal women: A nationwide population-based study

Objective Serum ferritin, a marker of iron metabolism, has recently emerged as a biomarker of chronic low-grade inflammation. After menopause, there is a remarkable increase in insulin resistance (IR) and metabolic syndrome (MetS), which is increasingly being viewed as an inflammatory disease. Thus, we examined the associations of serum ferritin with insulin resistance and MetS in postmenopausal women. Methods A nationwide cross-sectional study was conducted to examine the relationship between serum ferritin and IR and MetS in 2734 postmenopausal women using data from the 2010–2012 Korean National Health and Nutrition Examination Survey. The odds ratios (ORs) and 95% confidence intervals (CIs) for insulin resistance (HOMA-IR ≥ 75th percentile, 3.04) and MetS were calculated using multiple logistic regression analyses across serum ferritin quartiles (Q1, ≤ 36.25; Q2, 36.56–56.56; Q3, 56.57–85.98; and Q4 ≥ 85.99 ng/ml). Results The mean values of most cardiometabolic variables tended to increase proportionally with serum ferritin quartiles. The proportion of women with IR and MetS significantly increased in accordance with serum ferritin quartiles. Compared to individuals in the lowest quartile, the ORs (95% CIs) in the highest quartile were 2.06 (1.23–3.45) for IR and 1.92 (1.44–2.55) for MetS after adjusting for age, cigarette smoking, alcohol intake, and regular exercise. Conclusion Serum ferritin levels were positively and independently associated with IR and MetS in postmenopausal women. These findings suggest that serum ferritin level in postmenopausal women may help to identify the presence of IR and MetS.