title: Selenium and Iodine Levels in Subjects with Kashin-Beck Disease: a Meta-analysis.
abstract: Kashin-Beck disease (KBD) is an endemic, degenerative osteoarthropathy, and particularly seen in China. A deficiency of selenium and iodine is implicated as the main etiological factor for KBD. This meta-analysis aimed to evaluate the differences in the selenium and iodine levels between patients with KBD and healthy individuals. Eligible articles published before March 6, 2015 were searched from four electronic databases. Data extraction and quality assessment of included studies were performed by two independent reviewers. Results were summarized as standardized mean difference (SMD) with 95 % confidence intervals (CIs). Cohen's d test was used to estimate the difference of the effect size between patients with KBD and healthy controls. A total of 26 cross-sectional studies were included in the meta-analysis. The pooled SMD showed that the whole blood selenium (Cohen's d = 4.39, P < 0.001), serum selenium (Cohen's d = 2.42, P = 0.015), hair selenium (Cohen's d = 5.46, P < 0.001), and urinary selenium (Cohen's d = 4.16, P < 0.001) levels were significantly lower in patients with KBD than that in healthy controls. There was no significant difference of plasma selenium (Cohen's d = 0.08, P = 0.936) and urinary iodine (Cohen's d = 0.33, P = 0.744) levels between subjects with KBD and healthy controls. In conclusion, the levels of selenium, but not iodine were significantly lower in subjects with KBD than that in healthy controls. Selenium deficiency might be associated with the risk of KBD.
authors.affiliation: School of Public Health, Health Science Center, Xi'an Jiaotong University, Key Laboratory of Trace Elements and Endemic Diseases of National Health and Family Planning Commission, Xi'an, Shaanxi, 710061, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
authors.affiliation: Hong Hui Hospital, Health Science Center, Xi'an Jiaotong University, Xi'an, Shaanxi, 710054, People's Republic of China.
authors.forename: Guang-hui
authors.initials: GH
authors.lastname: Zhao
authors.affiliation: School of Public Health, Health Science Center, Xi'an Jiaotong University, Key Laboratory of Trace Elements and Endemic Diseases of National Health and Family Planning Commission, Xi'an, Shaanxi, 710061, People's Republic of China.
authors.forename: Fang-fang
authors.initials: FF
authors.lastname: Yu
authors.affiliation: School of Public Health, Health Science Center, Xi'an Jiaotong University, Key Laboratory of Trace Elements and Endemic Diseases of National Health and Family Planning Commission, Xi'an, Shaanxi, 710061, People's Republic of China.
authors.forename: Rong-qiang
authors.initials: RQ
authors.lastname: Zhang
authors.affiliation: School of Public Health, Health Science Center, Xi'an Jiaotong University, Key Laboratory of Trace Elements and Endemic Diseases of National Health and Family Planning Commission, Xi'an, Shaanxi, 710061, People's Republic of China. guox@mail.xjtu.edu.cn.
authors.forename: Xiong
authors.initials: X
authors.lastname: Guo
mesh_terms: D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D006801:Humans; D007455:Iodine / Q000097:blood*; D057767:Kashin-Beck Disease / Q000097:blood*; D012643:Selenium / Q000097:blood*
chemical_list: D007455:Iodine; D012643:Selenium
keywords: Iodine; Kashin-Beck disease; Meta-analysis; Selenium