## 2 Results
### Principal Component Analysis  
MetaboAnalyst and Compound Discoverer 3.3 were both used to generate a visual representation of the overall positive and negative mode dataset from all samples via a principal component analysis (PCA) (Figures 1 and 2, respectively). Figure 1A was created by importing positive mode data processed from Compound Discoverer 3.3 into MetaboAnalyst. Figure 1B utilizes the same positive mode dataset, but was created within Compound Discoverer 3.3. Figure 2 is analogous to Figure 1, but uses negative mode data. The PCA was used to identify any differences between patients classified by PASI. The quality of data were also assessed via the spread and location of pooled QCs in the PCA plots. Their tight clustering indicates strong instrumental stability during data acquisition. However, the low-, moderate-, and high-PASI groups were not separated in Figures 1 and 2. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \multirow{2}{*}{**Group**} & **Sex (No. of** & \begin{tabular}{c} **Mean Age** \\ **Patients** \\ \end{tabular} & \begin{tabular}{c} **Mean BMI** \\ **Standard Orientation** \\ **(Age Range)** \\ \end{tabular} & \begin{tabular}{c} **PASI Score Mean** \\ **Standard Deviation** \\ **(BMI Range)** \\ \end{tabular} & \begin{tabular}{c} **Dur. Porviasis Mean** \\ **Standard Deviation** \\ **(Range) \\ \end{tabular} & \begin{tabular}{c} **Dur. Porviasis Mean** \\ **Standard Deviation** \\ **(Range) \\ \end{tabular} & \begin{tabular}{c} **Treatment (No.** \\ **Range) \\ \end{tabular} & \begin{tabular}{c} **Conorbidities (No.** \\ **Patients** \\ \end{tabular} \\ \hline \begin{tabular}{c} PNA \\ (Low) \\ \end{tabular} & M (28) & 44.4 & 27.6 & 2.0 & 17.6 & 9.3 & NSAIDs (17) & Hypertension (5) \\  & & 15.4 & 5.4 & 1.3 & 17.5 & 9.1 & DMARDs (9) & Depression (1) \\  & & (0.81-74.6) & (0.62-42.6) & (0.3-4.8) & (0.5–53.6) & (0.0–25.9) & Steroids (1) & Hyperlipidemia (6) \\  & & & & & & & Diabetes (3) \\ \hline \multirow{7}{*}{(Moderate)} & F (28) & 47.9 & 28.5 & 1.8 & 22.1 & 9.5 & NSAIDs (19) & Hypertension (2) \\  & & 10.0 & _7.4_ & 1.4 & 13.6 & 8.5 & DMARDs (10) & Depression (3) \\  & & (0.06-6.6) & (0.98-49.3) & (0.1-4.8) & (0.5–46.8) & (0.5–28.8) & Steroids (1) & Hyperlipidemia (6) \\ \hline \
\begin{tabular}{c} PNA \\ (Moderate) \\ \end{tabular} & M (27) & 51.0 & 28.5 & 6.4 & 22.5 & 13.6 & NSAIDs (19) & Hypertension (1) \\  & & 10.1 & 6.9 & 1.4 & 12.7 & 10.5 & DMARDs (11) & Depression (2) \\  & & (28.9-73.7) & (0.98-52.1) & (0.5-9.8) & (3.1–50.1) & (0.6–34.7) & Hyperlipidemia (3) \\ \hline \multirow{7}{*}{(PNA \\ (High) \\ \end{tabular} } & F (27) & 47.1 & 29.1 & 7.2 & 23.7 & 10.2 & NSAIDs (15) & Hypertension (1) \\  & & 12.1 & 6.6 & 1.4 & 11.0 & 10.0 & DMARDs (14) & Depression (3) \\  & & (0.93-71.6) & (18.2-41.7) & (5.1-9.4) & (3.3-44.6) & (0.2–3.7) & Steroids (1) & Hyperlipidemia (3) \\ \hline
\begin{tabular}{c} PNA \\ (High) \\ \end{tabular} & M (28) & 46.5 & 27.7 & 21.1 & 18.8 & 7.9 & NSAIDs (15) & Hypertension (3) \\  & & 13.5 & 4.6 & 9.6 & 11.0 & 9.7 & DMARDs (11) & Depression (2) \\  & & (22.5-81.2) & (0.88-34.3) & (0.1-40.7) & (5.5–45.2) & (0.0–37.3) & Steroids (1) & Diabetes (3) \\  & & & & & & Hyperlipidemia (5) \\ \hline \multirow{7}{*}{(PNA \\ (High) \\ \end{tabular} } & F (12) & 48.0 & 31.0 & 22.5 & 19.4 & 14.0 & NSAIDs (3) & Hyperlipidemia (2) \\  & & 12.7 & 6.6 & 13.3 & 17.4 & 12.6 & DMARDs (7) & Diabetes (3) \\  & & (27.2–71.7) & (0.91-40.1) & (10.2–54.6) & (0.4–36.5) & (0.2–32.2) & Steroids (2) \\ \hline \end{tabular}
\end{table} 
Table 1: Summary of demographics and disease information of patients participating in study. Figure 1: Principal component analysis (PCA) of metabolite data from psoriatic arthritis (PsA) patients from positive mode data acquisition. (**A**) PCA—PC1: 32.9%, PC2: 6.4%, PC3: 5.6% of patients with PsA, and pooled quality control (PooledQC). High-skin-disease-activity PsA, low-disease-activity PsA, moderate-disease-activity PsA, and PooledQC are represented in green, dark blue, light blue, and red, respectively.