Serum sodium and chloride are inversely associated with dyskinesia in Parkinson's disease patients

Objective We aim to report and evaluate the associations between serum sodium and chloride and dyskinesia in patients with Parkinson's disease. One hundred and two patients with Parkinson's disease were enrolled in this study. Methods Patients’ serum electrolytes including sodium, calcium, potassium, magnesium, and chloride were measured. Other demographic information was collected, and Unified Parkinson's disease rating scale and Hoehn and Yahr stage scale were also performed. Results Patients with dyskinesia tended to have longer duration of disease, higher daily levodopa-equivalent dose, and Hoehn–Yahr stage, with lower serum sodium than those without dyskinesia. Spearman correlation analyses showed that serum sodium inversely correlated with duration of disease (r = −.218, p = .028), and positively correlated with serum chloride levels (r = .565, p < .001). Univariate logistic regression analysis found that duration of disease, daily levodopa-equivalent dose, serum sodium, and serum chloride were associated with dyskinesia in Parkinson's disease patients (p < .05 for all). After adjusting for age, sex, age at onset of Parkinson's disease, medical history, and other covariates, serum sodium and chloride were still associated with dyskinesia, with corresponding Odd ratios 0.783 (95% confidence intervals, 0.642–0.955) and 0.796 (95% confidence intervals, 0.652–0.972), respectively. Conclusion Our findings indicated that serum sodium and chloride levels were inversely associated with dyskinesia in patients with Parkinson's disease. Further studies with large samples and range of serum sodium and chloride are needed.