Abstract

Background
Hyperglycemia and diabetes mellitus have been recognized as poor prognostic factors for motor and nonmotor outcomes in patients with Parkinson’s disease (PD), although there is some controversy. In the present study, we investigated the effects of fasting plasma glucose (FPG) level on longitudinal motor and cognitive outcomes in PD patients.
Methods
We included a total of 201 patients diagnosed with PD between January 2015 and January 2020. The patients were categorized based on FPG level: euglycemia (70< FPG <100 mg/dL), intermediate glycemia (100≤ FPG <126 mg/dL), and hyperglycemia (FPG ≥126 mg/dL), and longitudinal FPG trajectories were analyzed using group-based trajectory modeling. Survival analysis was conducted to determine the time until motor outcome (Hoehn and Yahr stage≥2) and the conversion from normal cognition to mild cognitive impairment.
Results
Among the patients studied, 82 had euglycemia, 93 had intermediate glycemia, and 26 had hyperglycemia. Intermediate glycemia (HR 1.75, 95% CI 1.08-2.81, p=0.022) and hyperglycemia (HR 3.86, 95% CI 2.00-7.48, p<0.01) emerged as significant predictors of worsening motor symptoms. However, neither intermediate glycemia (HR 1.245, 95% CI 0.764-2.029, p=0.3789) nor hyperglycemia (HR 1.602, 95% CI 0.763-3.362, p=0.2129) demonstrated associations with longitudinal progression of cognitive impairment. Diabetes mellitus defined by self-reported medical history was not related to poor motor or cognitive impairment outcomes.
Conclusions
Our results support that both impaired glucose tolerance and hyperglycemia could be associated with motor progression in PD.

• Keywords: Parkinson’s disease, Fasting plasma glucose, Motor outcome, Cognitive impairment, Predictor;