Zinc and Copper in Oral Submucous Fibrosis

Abstract

Oral Submucous Fibrosis (OSMF) is a precancerous condition of the oral cavity that is characterized by inflammation and progressive fibrosis of the submucosal tissues. This chronic condition is more prevalent among South Asian population, but cases have also been identified in Europe and North America. The trace elements zinc (Zn) and copper (Cu), act as cofactors of antioxidant enzymes that are protective against free radicals. Studies have reported altered Zn and Cu in the body fluids of OSMF subjects; but findings are inconsistent. The objective of this research is to perform a meta‐analysis to summarize studies that report Zn and Cu status in subjects with and without OSMF. A literature search of Embase, PubMed, Cochrane library and Web of Science electronic databases was conducted for cross sectional, case‐controlled and prospective studies investigating the trace element concentrations in OSMF subjects up to November 2016. Values for these trace elements for control and patient groups were extracted. A total of 22 reports met the inclusion criteria, amounting to 44 effect sizes. Standardized mean difference, the bias corrected Hedges' g, was utilized as the effect size for the meta‐analysis. Robust Variance Estimation (RVE) method was chosen to handle dependency of multiple related outcomes in meta‐analysis. No publication bias was found from the funnel plot. Results suggested a significant increase in the levels of Cu (effect size= 2.70, p‐value <0.05, 95% Confidence Interval (CI): 0.371 — 5.032) and a significant decrease in levels of Zn (effect size= −1.57, p‐value <0.01, 95% CI: −2.676 — −0.459) in OSMF patients as compared to controls. The estimation of zinc and copper status may serve as an additional tool to understand OSMF along with the clinical features.Support or Funding InformationThe Bess Heflin Centennial Professorship