Association between zinc level and the risk of preeclampsia: a meta-analysis.

ABSTRACT

BACKGROUND: Epidemiological studies evaluating the association between zinc level and the risk of preeclampsia have produced inconsistent results. We therefore conducted a meta-analysis to summarize the evidence for them. METHODS: Pertinent studies were identified by a search in PubMed and Web of Knowledge up to April 2015. Standardized mean difference (SMD) was performed to combine the results. Random-effect model was used. Publication bias was estimated using Egger's regression asymmetry test. RESULTS: Thirteen articles (11 case-control studies and 2 cross-sectional studies) involving 445 preeclampsia cases and 568 healthy controls were included in this meta-analysis. Our pooled results suggested that preeclampsia patients had a lower zinc level as compared with healthy, pregnant controls (summary SMD = -0.61, 95 % CI = -0.74, -0.48, I (2) = 88.5 %). The association was also significant in Asia (SMD = -0.73, 95 % CI = -0.88, -0.58), but not in Europe. No publication biases were found. CONCLUSIONS: Our analysis indicated that zinc level in preeclampsia patients was significantly lower than that of healthy, pregnant women, especially among the Asian population.