Figure 2.

Salivary total protein and HO-1 levels between groups. A) Normal distribution visually assessed by Q-Q plot of salivary HO-1 protein level residuals and threshold 45°-line y=x B) Linear regression and correlation analyses between salivary HO-1 and total protein of study’s sample population. C) Unadjusted mean salivary total protein measured by BCA assay of non-neurological control group (n=162), degenrative neurological controls (n=37), and non-degenrative neurological controls(n=33) and PD group (n=75). Statistical analysis performed using ANOVA with a=0.05, error bars indicate the mean with SEM.