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 qual-ity of life of affected individuals. Several studies have indicated an associa-tion between psoriasis and metabolic syndrome (MS). However, the results were inconsistent. The objective of this study was to evaluate the relation-ship 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 inter-val (CI) were used to evaluate the association between psoriasis and MS. The heterogeneity of the study was estimated with the I2 statistic and ana-lyzed by meta-regression and subgroup analyses. Results: Twenty-two studies with a total of 137,053 participants were in-cluded in this meta-analysis. Psoriasis was associated with MS and the com-bined OR (95% CI) was 2.02 (1.67-2.43). The results showed high heteroge-neity (I2 = 83.60%, p < 0.001) and no publication bias among the included studies (p = 0.119). The source of controls may have influenced the hetero-geneity according to the meta-regression. There was no heterogeneity in studies with matched non-psoriasis control groups according to the sub-group 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.