Association between Homocysteine Levels and Psoriasis: A Meta-Analysis

BACKGROUND: Psoriasis is a multifactorial disease associated with an increased risk for metabolic syndrome and cardiovascular diseases. Elevated levels of homocysteine (Hcy) are a marker of cardiovascular risk. Several studies have evaluated the associations between psoriasis and Hcy levels; however, the results remain inconclusive. OBJECTIVE: We performed a systematic review of the literature and a meta-analysis to better understand the relationship between psoriasis and Hcy. METHODS: Five scientific databases (MEDLINE, Embase, Cochrane Library, Scopus, and Web of Science) were searched to identify relevant studies. A review of 307 publications identified 16 studies that directly assessed plasma levels of Hcy in psoriasis patients. RESULTS: A total of 16 studies including 2,091 subjects were included in the meta-analysis. Hcy levels were significantly higher in psoriasis patients relative to healthy controls (weighted mean difference [WMD], 3.30; 95% confidence interval [CI], 1.58∼5.02; I(2)=82.1%). Subgroup analyses revealed that patients with higher mean psoriasis area severity index (PASI) scores (PASI>10) had significantly higher Hcy levels compared to healthy controls (WMD, 4.17; 95% CI, 1.18∼7.16; I(2)=88.3%), whereas patients with lower mean PASI scores (PASI ≤10) had not (WMD, 0.76; 95% CI, −1.84∼3.35; I(2)=72.2%). CONCLUSION: This meta-analysis found that psoriasis patients, in particular those with PASI >10, had significantly higher Hcy levels compared to healthy controls. Further research is needed to determine the association between Hcy levels and psoriasis severity.