Stimulated saliva flow rate was affected by Parkinson’s disease (The Wilcoxon rank-sum test, Z = 2.02, P = 0.04) and methyldopa (The Wilcoxon rank-sum test, Z = 2.02, P = 0.04), and the IgA concentration was affected antihypertensive agents (The Wilcoxon rank-sum test, Z = 2.03, P = 0.04). This evidence concerns the gene CD79A and Parkinson disease.