Anales de la RANM

59 A N A L E S R A N M R E V I S T A F U N D A D A E N 1 8 7 9 SERUM MYELOPEROXIDASE AND PARKINSON´S DISEASE Fernández-Espejo E An RANM. 2022;139(01): 56 - 66 omous variables). Correlations between variables were studied with the Pearson’s test, and values were adjusted for age, gender, and age-at-PD onset. Data normalization was verified with the Shapiro-Wilk test. The patients were classified into subgroups according to the Hoehn-Yahr staging (early disease, stages 1 and 2; moderate-advanced disease, stage 3), and these subgroups were compared. Since many variables were analyzed, the Bonferroni correc- tion was used. Thus, the significance level was set at 0.005 to avoid making Type I errors. Data were analyzed with Minitab19 statistical package (AddLink Software Científico, Spain). 3.1. Demographic and clinical parameters, and MPO concentration First, basic demographic and clinical features in the patients and control participants were compared. Hypertension was found to be signif- icantly more frequent in PD patients than controls (χ α 2 =11.726, p<.001), as shown in Table 1. Serum MPO concentration, not CSF one, was significantly higher in the patients (t=4.9781, p<.0001, Table 1). Serum/CSF ratio of MPO level was found to be significantly higher in PD patients (t=4.5062, p<.0001, Table 1). Individual values of CSF and serum MPO concentration in all participants are shown in Figure 1A. Since hypertension was found to be more frequent in PD patients, the influence of this factor on MPO level was further analyzed. MPO concentration was quantified in patients with or without hypertension, as well as in controls with or without high blood pressure. MPO concentration was found not to be signif- icantly different in patients with hypertension (3,252±1,836 pg/ml) relative to patients without high blood pressure (4,058±2,082 pg/ml), as well as in control participants with hypertension (1,662±305 pg/ml) versus controls without high blood pressure (1,423±690 pg/ml). 3. RESULTS Figure 1. (A) Individual concentration of myeloperoxidase in serum and the cerebrospinal fluid in patients with idiopathic Parkinson’s disease and controls, and (B) serum and CSF MPO concentration in patients with early (Hoehn-Yahr stages 1 and 2) and moderate-advanced disease (Hoehn-Yahr stage 3), and control participants. (A) Serum MPO concentration, not CSF one, was significantly higher in the patients than in control subjects (t=4.9781, **p<.0001). Mean and standard deviation are represented with solid lines. (B) Serum MPO concentration was significantly higher in both PD groups than in controls (early disease, t=4.496, **p<.0001; moderate-advanced disease, t=8.0719, **p<.0001), and patients with moderate-advanced di- sease showed significantly higher serum MPO content relative to patients with early disease (t=4.1533, ## p=.0002). Abbrev.: CSF, cerebrospinal fluid; MPO, myeloperoxidase.