Association of serum copper, zinc and selenium levels with risk of metabolic syndrome: A nested case-control study of middle-aged and older Chinese adults

Abstract Trace elements, such as copper, zinc and selenium, have been linked to the development of metabolic syndrome. However, previous studies concerning these trace elements in association with metabolic syndrome have presented conflicting results in different countries. The aim of this study was to analyse the association between serum copper, zinc and selenium concentrations and the risk of metabolic syndrome among middle-aged and older Chinese adults. We performed a nested case-control study that included 349 individuals who developed metabolic syndrome (125 males and 224 females) during a 3-year follow-up and 349 controls matched by baseline age (±1 years), sex and area. Serum trace element concentrations were measured using atomic absorption spectrometry. The median serum selenium levels in males and females in the metabolic syndrome group were 82.2 (13.4) μg/L and 82.6 (11.1) μg/L, respectively, which were significantly higher than the serum selenium levels in the control group (p = 0.001 and p