Association of daytime Sleepiness with COMT polymorphism in patients with Parkinson disease: a pilot study

To evaluate an association between catechol-O-methyltransferase (COMT) genotype and subjective daytime sleepiness in patients with Parkinson disease. Structured questionnaire study. Tertiary Parkinson disease care center and sleep outpatients' department at the university hospital neurology department. All nondemented patients with idiopathic Parkinson disease who had been part of a previous study of D4-receptor polymorphisms in 1997 were eligible to participate. From the original sample of 113 patients, 46 participated in the study, 22 met exclusion criteria, and 43 were not available. Not applicable. In this study, 46 patients were included (27 men, 19 women; 68.4 +/- 9.9 years of age; symptomatic disease duration, 12.2 +/- 5.2 years; Hoehn and Yahr stage in "on" of 2.6 +/- 0.8). Out of the 46 patients, 13 had LL genotype, 22 LH, and 11 HH. The Epworth Sleepiness Scale scores were 9.5 +/- 4.8 in LL, 8.5 +/- 4.7 in LH, and 6.8 +/- 3.1 in HH (mean +/- SD) (NS). LL and LH were grouped together. The Epworth Sleepiness Scale score was 11 or more in 40% of the LL+LH group, compared to 9.1% of the HH group (P = .039). The levodopa or dopamine-agonist doses and types did not differ between the LL+LH group versus the HH group. These preliminary data suggest an association of the Lallele and daytime sleepiness in patients with Parkinson disease.