A prospective, non-randomized controlled open trial in psoriasis patients with metabolic syndrome was conducted between January 2019 and May 2020. Inclusion criteria were age ≥ 18 years, being affected by moderate to severe chronic plaque psoriasis and concomitant metabolic syndrome and being candidate to systemic treatment with methotrexate or secukinumab according to the Italian guideline for psoriasis. Psoriasis was diagnosed on clinical base, and it was classified as moderate to severe if PASI ≥ 10, Investigator Global Assessment (IGA) score≥ 3 and/or Dermatology Life Quality Index ≥ 10%. Metabolic syndrome was diagnosed according to criteria of the National Cholesterol Education Programme Adult Treatment Panel III (NCEP ATP III) and The American Heart Association and the National Heart, Lung, and Blood Institute (AHA/NHLB).3 In particular, metabolic syndrome was confirmed in presence of at least three of the following components: abdominal obesity (waist circumference ≥ 102 cm for men or ≥ 88 cm for women), triglycerides ≥ 150 mg/dL, HDL cholesterol ≤ 40 mg/dL for men or 50 mg/dL for women, systolic/diastolic blood pressure ≥ 130/85 mmHg or receiving drug treatment, and fasting plasma glucose ≥ 100 mg/dL. Exclusion criteria were being affected by psoriatic arthritis, pregnancy, breast feeding, having initiated a systemic treatment for psoriasis in the previous 3 months and having a clinical condition that could affect the metabolic parameters other than metabolic syndrome. After having signed the informed consent for the participation in the study, eligible patients were consecutively assigned in a 1:1 ratio to secukinumab (standard dose) or methotrexate 15 mg/week by subcutaneous administration and folic acid supplementation 5 mg given 24 hours after methotrexate. The primary endpoint was investigating any variation in waist circumference, body mass index (BMI), blood pressure, fasting glucose, total cholesterol, low density lipoprotein (LDL)-cholesterol, high density lipoprotein (HDL)-cholesterol, triglycerides, aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine levels at month-6. Any other adverse events related to the treatments and the proportion of patients who discontinued the treatment because of adverse reactions were also reported. The secondary endpoints were assessing the PASI 75 and PASI 90 proportion of responders in the two groups at 6 and 12 months follow-up. Clinical and laboratory data were evaluated at the baseline and every 3 months up to month 12.

Statistical Methods A descriptive statistic was conducted using proportions for categorical and mean and standard deviation (SD) for quantitative variables. The categorical variables were compared between the groups using the chi-squared test, while the quantitative variables were compared using the Student's T test. Variations in waist circumference, BMI, blood pressure, fasting glucose, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, AST, ALT, creatinine levels between baseline and month-6 or 12 were assessed by paired t-test in patient receiving methotrexate or secukinumab, respectively. PASI 75 and PASI 90 proportion of responders at month -6 or 12 in the two cohorts' were compared by the chi-squared test. The normal distribution of data was confirmed using the one-sample Kolmogorov-Smirnov Test. A value of p\< 0.05 was considered statistically significant. Statistical analysis was performed using the STATA (version 13 StataCorp, College Station, TX, U.S.A.).