Association between metabolic syndrome and psoriasis: a meta-analysis of observational studies with non-psoriasis control groups

INTRODUCTION: Psoriasis is a highly prevalent condition that affects the quality of life of affected individuals. Several studies have indicated an association between psoriasis and metabolic syndrome (MS). However, the results were inconsistent. The objective of this study was to evaluate the relationship between psoriasis and MS. MATERIAL AND METHODS: Electronic databases (PubMed, EBSCO, Elsevier, Springer, Wiley, and Cochrane) were searched systematically for published studies up to November 2, 2018. Odds ratio (OR) and 95% confidence interval (CI) were used to evaluate the association between psoriasis and MS. The heterogeneity of the study was estimated with the I(2) statistic and analyzed by meta-regression and subgroup analyses. RESULTS: Twenty-two studies with a total of 137,053 participants were included in this meta-analysis. Psoriasis was associated with MS and the combined OR (95% CI) was 2.02 (1.67–2.43). The results showed high heterogeneity (I(2) = 83.60%, p < 0.001) and no publication bias among the included studies (p = 0.119). The source of controls may have influenced the heterogeneity according to the meta-regression. There was no heterogeneity in studies with matched non-psoriasis control groups according to the subgroup analysis. CONCLUSIONS: Psoriasis was associated with MS. The source of the control group was an influencing factor on heterogeneity in this study. Treating for MS in patients with psoriasis might improve psoriasis and reduce the risk of cardiovascular disease.