Background: Pioglitazone may be beneficial in the treatment of psoriasis. However, based on the effectiveness and safety considerations, it has not been widely used. To fully evaluate the strength of evidence supporting psoriasis treatment with pioglitazone, we conducted a meta-analysis of existing published studies.
Methods: PubMed, Ovid, Cochrane Library, Google Scholar, and Web of Science databases were systematically searched before February 2019. Randomized controlled trials (RCTs) of pioglitazone administration compared with placebo, administered to patients with psoriasis for at least 10 weeks, and published in English were included. Quality of the included RCTs was identified by the modified Jadad scale. The quality of evidence for each outcome was evaluated using the GRADEpro Guideline Development Tool online software. Primary outcomes were proportion of patients showing psoriasis area and severity index (PASI) score improvement (>75%) and the mean percent change in PASI score from baseline to the end of treatment. Dichotomous data were analyzed using odds ratios (ORs) corresponding to the 95% confidence interval (CI), whereas continuous variables, expressed as mean and standard deviation, were analyzed using the mean differences (MD) with the 95% CI.
Results: Six RCTs were analyzed. Meta-analysis showed that pioglitazone reduced the PASI scores in patients with psoriasis compared with the control group when administered at 30 mg per day (P < 0.001, MD = -3.82, 95% CI = -5.70, -1.93) and at 15 mg per day (P = 0.04, MD = -3.53, 95% CI = -6.86, -0.20). The PASI-75 of the pioglitazone group was significantly higher than that of the control group at 30 mg per day (P < 0.001, OR = 8.30, 95% CI = 3.99, 17.27) and at 15 mg per day (P = 0.03, OR = 2.96, 95% CI = 1.08, 8.06). No statistically significant differences in total adverse events were observed between the groups. There were no significant differences in common adverse reactions such as weight gain and elevated liver enzymes between the two pioglitazone groups.
Conclusions: Use of pioglitazone in the current treatment of psoriasis is beneficial. The therapeutic effect of the daily 30 mg dose may be greater than that of the 15 mg dose per day with no significant change in the frequency of adverse reactions.