title: Low serum levels of zinc, copper, and iron as risk factors for osteoporosis: a meta-analysis.
abstract: Zinc (Zn), copper (Cu), and iron (Fe) are essential trace elements for the growth, development, and maintenance of healthy bones. However, there are conflicting reports as to the relationship between serum level of Zn, Cu, or Fe and osteoporosis (OP). The purpose of the present study is to clarify the relationship between serum Zn, Cu, or Fe and OP using a meta-analysis approach. We searched all articles indexed in PubMed published up to May 2014 concerning the association between serum level of Zn, Cu, or Fe and OP. Eight eligible articles involving 2,188 subjects were identified. Overall, pooled analysis indicated that patients with OP had a lower serum level of Zn, Cu, or Fe than the healthy controls (Zn standardized mean difference (SMD) = -1.396, 95% confidence interval (CI) = [-2.129, -0.663]; Cu SMD = -0.386, 95% CI = [-0.538, -0.234]; Fe SMD = -0.22, 95% CI = [-0.30, -0.13]). Further subgroup analysis found that geographical location and gender had an influence on the serum level of Zn in OP and healthy controls, but not on the serum level of Cu or Fe. No evidence of publication bias was observed. In conclusion, this meta-analysis suggests that low serum levels of Zn, Cu, and Fe seem to be important risk factors for OP and well-designed studies with adequate control for confounding factors are required in future investigations.
authors.affiliation: Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Affiliated Stomatological Hospital, Sun Yat-sen University, Guangzhou, Guangdong, 510055, China.
authors.forename: Jianmao
authors.initials: J
authors.lastname: Zheng
authors.forename: Xueli
authors.initials: X
authors.lastname: Mao
authors.forename: Junqi
authors.initials: J
authors.lastname: Ling
authors.forename: Qun
authors.initials: Q
authors.lastname: He
authors.forename: Jingjing
authors.initials: J
authors.lastname: Quan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003300:Copper / Q000097:blood* / Q000172:deficiency*; D005260:Female; D006801:Humans; D007501:Iron / Q000097:blood*; D000090463:Iron Deficiencies; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000097:blood* / Q000453:epidemiology*; D012307:Risk Factors; D015032:Zinc / Q000097:blood* / Q000172:deficiency*
chemical_list: D003300:Copper; D007501:Iron; D015032:Zinc