Background: Zinc, a co-factor of antioxidant enzymes, may be involved in the pathophysiology of metabolic syndrome (MetS).

Aim: To determine the association between serum zinc concentration and MetS in a population-based study.

Subjects and methods: In the Tehran Lipid and Glucose Study, serum zinc concentration was measured by flame atomic absorption spectrometry in 2626 adult participants. After removal of outliers, usable data was available for 2401 participants. Dietary zinc was assessed by a validated semi-quantitative food frequency questionnaire.

Results: Compared to those without the MetS, serum zinc concentration was significantly higher in men with syndrome (17.1 ± 4.9 vs 16.5 ± 4.6 μみゅーmol/L, p = 0.035); however, values were comparable in females (16.1 ± 4.8 vs 15.8 ± 4.4, p = 0.460). Men in tertile 3 of serum zinc had significantly higher chances of having MetS, even after multivariate adjustment (OR = 1.48, 95% confidence interval (CI) = 1.07–2.06, p = 0.020). Women in tertile 2 of serum zinc had significantly lower chances of having MetS, which remained significant after multivariate adjustment (OR = 0.68, 95% CI = 0.47–0.99, p = 0.046).

Conclusion: This study observed a gender difference between serum zinc and MetS, with higher levels being positively associated with MetS in men and having a protective effect in women. Further studies are needed to elucidate the role of zinc status in the development of MetS.