Alcohol Consumption and Plasma Iron-Related Biomarkers, Including the Iron-Regulatory Hormone Hepcidin: A Cross-Sectional Study in a Japanese Population.

BACKGROUND

Although individuals who consume alcohol tend to exhibit increased iron stores, the potential suppression of plasma hepcidin by habitual alcohol consumption in the general population has not been epidemiologically investigated.

OBJECTIVES

We aimed to investigate the cross-sectional association between alcohol consumption and the plasma iron-related biomarkers iron, ferritin, and hepcidin in a Japanese population-based cohort.

METHODS

A total of 1396 men, 538 premenopausal women, and 1753 postmenopausal women aged 40-69 y in 1990-1994 were examined for plasma biomarker measurement and alcohol consumption through a self-administered questionnaire. Alcohol consumption was categorized as nondrinking (<1 d/mo), occasional drinking (1-3 d/mo), and regular drinking (men: <150, 150-300, ≥300 g ethanol/wk; women: <150, ≥150). A generalized linear model was applied to estimate geometric mean values [95% confidence intervals (CIs)] of each biomarker according to alcohol consumption group and ratio of geometric values (95% CIs) relative to the nondrinking group with adjustment for age, body mass index, smoking, high-sensitivity C-reactive protein, and blood sampling time.

RESULTS

Both men and postmenopausal women showed significant increases in plasma iron and ferritin levels with higher alcohol consumption (P for trend < 0.01). The hepcidin-to-ferritin ratio, used as a marker of hepcidin levels relative to iron stores, was significantly decreased with increasing alcohol intake (P < 0.001), at 25% (95% CIs: 14%, 34%) lower than the fully adjusted geometric mean for regular drinking of 150-300 g ethanol/wk, and 36% (27%-44%) lower for ≥300 g in men and 43% (22%-58%) lower for ≥150 g in postmenopausal women. No significant association was observed among premenopausal women.

CONCLUSIONS

While body iron stores increased with greater alcohol consumption, the plasma hepcidin-to-ferritin ratio significantly decreased in men and postmenopausal women. This finding may provide epidemiological support for the mechanism whereby habitual alcohol consumption suppresses hepcidin expression, leading to elevated iron stores.