Diabetes Increases the Incidence of Levodopa-Induced Dyskinesia in Parkinson’s Disease; A Case-Control Study

Background and Objective: Dyskinesia is a debilitating complication of Parkinsonchr('39')s disease (PD), which appears due to some known risk factors. The effect of diabetes and high plasma glucose on the manifestation of dyskinesia has been evaluated in just a few previous reports. The current study aimed to assess the mentioned correlation. Materials and Methods: In this case-control study, 88 patients with PD were enrolled and categorized into two equal groups of diabetic and non-diabetic patients. They were selected from the movement disorder clinic in Rasoul Akram Hospital, Tehran, Iran. Patients were evaluated regarding the presence of dyskinesia and its characteristics, besides the assessment of other clinical parameters.  Results: The prevalence of dyskinesia in diabetics, compared to non-diabetics, showed a higher rate (P=0.033). Baseline parameter equality was confirmed to exclude the confounding bias effect. Simultaneous involvement of upper and lower extremities (right after drug intake) was the most prevalent sign of dyskensia in diabetic patients with PD. Conclusion: The comorbidity of PD and diabetes showed a higher prevalence of levodopa-induced dyskinesia (LID) in PD; this result was obtained based on homogeneity of the two groups in manners of age, disease, treatment duration and the dosage of levodopa.