Homocysteine and cognitive function in Parkinson's disease

Area of Science:

• Neuroscience
• Neurology
• Biochemistry

Background:

• Elevated plasma homocysteine (HC) is a known dementia risk factor in the general population.
• Levodopa treatment in Parkinson's disease (PD) increases plasma HC, but its association with cognitive impairment in PD is unclear.

Purpose of the Study:

• To investigate the relationship between plasma HC levels and cognitive function in individuals with PD.
• To determine if elevated plasma HC is associated with cognitive impairment in PD patients.

Main Methods:

• A cohort of 294 PD participants from the Pacific Northwest Udall Center (PANUC) Clinical cohort were analyzed.
• Standardized neuropsychological assessments and plasma HC measurements were conducted.
• Statistical analyses controlled for age, education, gender, and APOE genotype.

Main Results:

• Higher plasma HC levels correlated with lower scores in Digit Symbol, HVLT Delayed Recall, and semantic verbal fluency.
• Plasma HC was inversely associated with HVLT Delayed Recall and semantic verbal fluency when treated as a continuous variable.
• These associations remained significant even when the analysis was restricted to non-demented subjects.

Conclusions:

• Plasma HC is significantly associated with specific cognitive functions in PD patients.
• Elevated plasma HC may represent a modifiable risk factor for cognitive decline in PD.
• Further research into HC-lowering interventions for PD cognitive health is warranted.