Background Parkinson’s disease (PD) is a late-life neurodegenerative disease. evaluation start time was 11:00 AM both for PD cases and controls (Mann Whitney = 1.02 p = 0.31). PD symptom duration levodopa dosage and Hoehn & Yahr score are shown (Table 1). Thirty-five (31.0%) PD cases were TP PD 13 (11.5%) were PIGD PD and the remainder (57.5%) were intermediate. Table 1 Demographic and Clinical Characteristics of 113 PD cases vs. 101 PIK-293 controls Using controls we examined the correlates of log blood [HA]. Log blood [HA] was not associated with age in years (r = 0.13 p = 0.21) education (r = ?0.13 p = 0.20) body mass index (r = 0.08 p = 0.45) or Cumulative Illness Rating Score (r = 0.07 p = 0.48). Log blood [HA] did not differ by gender (0.27 ± 0.70 g ?10/ml for men and 0.27 ± 0.57 g ?10/ml for women Rabbit Polyclonal to SUPT16H. t = 0.00 p = 1.00). The log blood [HA] was similar in current smokers and nonsmokers (0.03 ± 0.40 g ?10/ml for smokers and 0.28 ± 0.63 g ?10/ml for nonsmokers t = 0.76 p = 0.45). Log blood [HA] was not associated with white vs. non-white race (t = 0.72 p = 0.47); and it was not associated with current use of any of the 19 classes of medications (data not shown) or evaluation start time (i.e. time of day that evaluation began) (Spearman’s r = 0.06 p = 0.57). Mean log blood [HA] in PD cases was approximately double that of controls (0.59 ± 0.63 g ?10/ml vs. 0.27 ± 0.63 g?10/ml t = 3.77 p <0.001). Although the ranges overlapped the distribution of data points for cases and controls differed (Figures 1 and ?and2).2). A non-parametric test (Mann Whitney U) on non-transformed data (median harmane = 3.31 g ?10/ml in PD cases and 1.44 g ?10/ml in controls) also showed this case-control difference (z = 3.90 p < 0.001). We stratified log blood [HA] based on the median value in the controls (0.24 g ?10/ml); 78 (69.0%) PD cases vs. 50 (49.5%) controls had a high log blood [HA] based on this median split (odds ratio [OR] = 2.27 95 confidence interval [CI] = 1.30 - 3.97 p = 0.004). Figure 1 Log blood harmane concentration in controls (left) and PD cases (right). The central point represents the mean and the bars represent the 95% confidence interval. Figure 2 Scatter plot of log blood harmane concentration in controls (left) and PD cases PIK-293 (right). The lines represent the means for the respective groups. In an unadjusted logistic regression analysis log blood [HA] was associated with the outcome (diagnosis of PD vs. normal) (OR = PIK-293 2.31 95 CI = 1.46 – 3.67 p <0.001) (i.e. for every doubling of the [HA] the odds of PD increased by 131%). In logistic regression analyses that adjusted for each one of the following variables individually and then in combination the association remained unchanged: age in years gender body mass index current smoker Cumulative PIK-293 Illness Rating Scale score (e.g. in a model that adjusted for each of these variables in combination OR = 2.54 95 CI = 1.55 - 4.16 p < 0.001). In a model that adjusted for each of the variables listed above and which further included a covariate for evaluation start time OR = 2.61 95 CI = 1.58 PIK-293 - 4.33 p <0.001. In another model that adjusted for each of the variables listed above and which further included a series of 19 variables for use/non-use of each of the 19 classes of medications OR = 2.69 95 CI = 1.60 - 4.54 p < 0.001. Among PD cases there was a marginal and weak inverse correlation between symptom duration and log blood [HA] (Spearman's r = ?0.18 p = 0.09) but no correlation of log blood [HA] with Hoehn & Yahr score (Spearman's r = 0.15 p = 0.22) or with daily dose of levodopa (Pearson's r = ?0.12 p = 0.30). Log blood [HA] was similar in the 35 TP PD cases and 13 PIGD PD cases (0.80 ± 0.65 g?10/ml vs. 0.72 ± 0.64 g?10/ml t = 0.36 p = 0.72). In PD log blood [HA] PIK-293 covaried with family history: 0.54 ± 0.60 g?10/ml in 80 PD cases with no family history 0.66 ± 0.71 g?10/ml in 16 PD cases with a family history of PD 0.83 ± 0.70 g?10/ml in 6 PD cases with a family history of ET and 0.84 ± 0.68 g?10/ml in 5 PD cases with a family history of both ET and PD (Figure 3). In a linear regression analysis with log blood.