Figure 4.

Plasma protein carbonyl concentrations relative to cognitive function. Plasma protein carbonyl concentrations in individuals with Parkinson’s disease as per cognitive status subgroups: normal (PD-N, n = 94), mild cognitive impairment (PD-MCI, n = 84), and dementia (PD-D, n = 34). The cognitively impaired group (PD-MCI and PD-D combined, n = 118) was significantly lower than the PD-N group (p = 0.007). Box plots show medians with boundaries set at 25th and 75th percentiles, whiskers at 5th and 95th percentiles, outliers are indicated by symbols (two outliers in the PD-N subgroup are not shown on the figure; 969 and 603 pmol/mg protein).