Abnormal Serum Copper and Zinc Levels in Patients with Psoriasis: A Meta-Analysis

BACKGROUND: Copper and zinc are important trace elements involved in the development of psoriasis. However, reports regarding changes in serum copper and zinc levels in patients with psoriasis have been inconsistent. AIMS: This meta-analysis was designed to analyze changes in serum copper and zinc levels between patients with psoriasis and a healthy population. MATERIALS AND METHODS: English and Chinese literature from international and national electronic databases from 1988 to May 2016 was analyzed. Studies that performed a comparative analysis of serum copper and zinc levels between patients with psoriasis and healthy controls were included in the meta-analysis. The random-effects model was used to calculate the overall combined estimates of serum copper and zinc levels between patients with psoriasis and healthy individuals. Results: Fifteen references were included in this study, including 1324 patients with psoriasis and 1324 healthy controls. Compared with healthy controls, serum copper levels were significantly increased (Z = 4.02, P < 0.0001; standardized mean difference [SMD], 1.23; 95% confidence interval [CI], 0.63 to 1.82), and serum zinc levels were significantly decreased (Z = 2.95, P < 0.0001; SMD, −1.35; 95% CI, −2.25 to − 0.45) in patients with psoriasis. CONCLUSIONS: In conclusion, increased serum copper and decreased serum zinc levels were generally observed in patients with psoriasis. Treatments to normalize the serum copper and zinc levels may improve the outcome of psoriasis patients.