Increased serum ferritin predicts the development of hypertension among middle-aged men

Background: We aimed to examine the relationship between iron status and hypertension as few studies have addressed this. Methods: We analyzed the association between ferritin/total iron-binding capacity (TIBC) and the subsequent development of hypertension. A total of 8,580 men who visited the Health Promotion Center for a medical checkup in 2005 were followed-up after 4 years. Results: Of the 8,580 men who were not hypertensive at baseline, 818 were found to be hypertensive at the 4-year follow-up. Compared with those who remained normotensive, these hypertensive subjects had higher levels of ferritin and TIBC at baseline, but had no significant difference in iron levels. After adjustment for age and body mass index (BMI), the odds ratios (OR) was substantially higher for new hypertension (OR 1.54, 95% confidence intervals (CIs) 1.26-1.88; P for trend <0.001) in subjects with the highest ferritin quartiles compared with those in the lowest quartiles. The association of serum ferritin levels with the incidence of hypertension was unchanged after adjustment for baseline blood pressure (BP). Adjustment for insulin resistance as measured by the homeostasis model assessment and the presence of a fatty liver reduced the magnitude of the OR for hypertension (first quartile reference, fourth quartiles OR 1.24, 95% CI 1.01-1.53, P for trend = 0.012), but did not affect their statistical significance. Conclusion: Serum ferritin, but not iron level, was a significant predictor of hypertension in middle-aged Korean men. Fatty liver disease and insulin resistance may be mediators of this high ferritin-hypertension association.