Changes of serum trace elements level in patients with alopecia areata: A meta-analysis

Abnormalities of serum trace elements are involved in the etiology and pathogenesis of alopecia areata (AA); however, the results of published studies are controversial. The purpose of the present study is to investigate the alterations of serum level of trace elements and AA using a meta-analysis approach. We searched all articles indexed in PubMed, Embase and Science Citation Index published up to 30 April 2016 concerning the association between serum level of zinc, copper, iron/ferritin, selenium or magnesium and AA. Ten eligible articles involving 764 subjects were identified. Overall, pooled analysis indicated that patients with AA had a lower serum level of zinc (P < 10^-4 ) and selenium (P < 10^-4 ) than the healthy controls. However, there was no significant difference between the AA patients and controls in the levels of serum copper (P = 0.81), serum iron (P = 0.36), serum ferritin (P = 0.37) and serum magnesium (P = 0.07). This meta-analysis suggests that low serum levels of zinc and selenium seem to be important risk factors for AA.