The role of apolipoprotein E polymorphisms in levodopa-induced dyskinesia

Objectives - To determine the relationship between apolipoprotein E (APOE) polymorphisms to the time to appearance of levodopa-induced dyskinesia (LID) in patients with Parkinson's disease. Methods - The APOE genotype of 155 consecutive patients treated with levodopa was determined and its effect on the time of onset of LID was examined using Cox regression model, controlling for gender, age of disease onset, time to initiation of levodopa treatment and history of smoking. Results - Two patients were homozygous for the APOE epsilon 2 allele, 7 had epsilon 2/epsilon 3, 1 had epsilon 2/epsilon 4, 130 had epsilon 3/epsilon 3, 12 had epsilon 3/epsilon 4 and 3 had epsilon 4/epsilon 4; LID appeared in 57.4% of the patients, appearing 4.1 +/- 3.5 years after the initiation of levodopa treatment. The survival curve for LID was not affected by the APOE genotype (P = 0.34). Conclusion - APOE polymorphisms were found not to be associated with either the occurrence or the time to development of LID.