Homocysteine and cognitive function in Parkinson's disease

Nicole Licking, Charles Murchison, Brenna Cholerton, Cyrus P. Zabetian, Shu Ching Hu, Thomas J. Montine, Amie Peterson, Kathryn (Kathy) Chung, Karen Edwards, James B. Leverenz, Joseph Quinn

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Introduction: Increased plasma homocysteine (HC) is a risk factor for dementia in the general population. Levodopa therapy causes increased plasma HC, but it remains unclear whether elevated plasma HC is associated with cognitive impairment in Parkinson's disease (PD). Methods: The study population includes all participants in the Pacific Northwest Udall Center (PANUC) Clinical cohort at the time of the study, consisting of 294 individuals with PD who had a standardized neuropsychological assessment and plasma collection for HC measurement. We tested the hypothesis that elevated plasma HC is inversely related to cognitive function in patients with PD. Results: As expected, plasma HC was positively associated with age, disease duration, disease severity, and levodopa usage, while cognitive function was associated with age, education, gender, and APOE genotype, so subsequent analyses controlled for these covariates. When plasma HC was dichotomized as normal (<14 μmol/L) or elevated (≥14 μmol/L), subjects with hyper-homocysteinemia had lower scores on Digit Symbol (p = 0.031), Hopkins Verbal Learning Task (HVLT) Delayed Recall (p = 0.004), and semantic verbal fluency (p = 0.049). When examined as a continuous variable, plasma HC was inversely associated with HVLT Delayed Recall (p = 0.009)) and semantic verbal fluency (p = 0.004), but was not significantly related to Digit symbol, Trail-making test, Judgment of Line Orientation, phonemic verbal fluency, MMSE, or MOCA. When analysis was restricted to non-demented subjects (n = 231), the findings were unchanged. Conclusions: We conclude that plasma HC is significantly associated with some aspects of cognitive function in PD, and may represent a treatable risk factor for cognitive decline in PD.

Original languageEnglish (US)
JournalParkinsonism and Related Disorders
DOIs
StateAccepted/In press - 2017

Fingerprint

Homocysteine
Cognition
Parkinson Disease
Verbal Learning
Levodopa
Semantics
Methylenebis(chloroaniline)
Northwestern United States
Trail Making Test
Time and Motion Studies
Population
Dementia
Genotype
Education

Keywords

  • Cognition
  • Dementia
  • Movement disorders
  • Parkinson's disease

ASJC Scopus subject areas

  • Neurology
  • Geriatrics and Gerontology
  • Clinical Neurology

Cite this

Licking, N., Murchison, C., Cholerton, B., Zabetian, C. P., Hu, S. C., Montine, T. J., ... Quinn, J. (Accepted/In press). Homocysteine and cognitive function in Parkinson's disease. Parkinsonism and Related Disorders. https://doi.org/10.1016/j.parkreldis.2017.08.005

Homocysteine and cognitive function in Parkinson's disease. / Licking, Nicole; Murchison, Charles; Cholerton, Brenna; Zabetian, Cyrus P.; Hu, Shu Ching; Montine, Thomas J.; Peterson, Amie; Chung, Kathryn (Kathy); Edwards, Karen; Leverenz, James B.; Quinn, Joseph.

In: Parkinsonism and Related Disorders, 2017.

Research output: Contribution to journalArticle

Licking, Nicole ; Murchison, Charles ; Cholerton, Brenna ; Zabetian, Cyrus P. ; Hu, Shu Ching ; Montine, Thomas J. ; Peterson, Amie ; Chung, Kathryn (Kathy) ; Edwards, Karen ; Leverenz, James B. ; Quinn, Joseph. / Homocysteine and cognitive function in Parkinson's disease. In: Parkinsonism and Related Disorders. 2017.
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abstract = "Introduction: Increased plasma homocysteine (HC) is a risk factor for dementia in the general population. Levodopa therapy causes increased plasma HC, but it remains unclear whether elevated plasma HC is associated with cognitive impairment in Parkinson's disease (PD). Methods: The study population includes all participants in the Pacific Northwest Udall Center (PANUC) Clinical cohort at the time of the study, consisting of 294 individuals with PD who had a standardized neuropsychological assessment and plasma collection for HC measurement. We tested the hypothesis that elevated plasma HC is inversely related to cognitive function in patients with PD. Results: As expected, plasma HC was positively associated with age, disease duration, disease severity, and levodopa usage, while cognitive function was associated with age, education, gender, and APOE genotype, so subsequent analyses controlled for these covariates. When plasma HC was dichotomized as normal (<14 μmol/L) or elevated (≥14 μmol/L), subjects with hyper-homocysteinemia had lower scores on Digit Symbol (p = 0.031), Hopkins Verbal Learning Task (HVLT) Delayed Recall (p = 0.004), and semantic verbal fluency (p = 0.049). When examined as a continuous variable, plasma HC was inversely associated with HVLT Delayed Recall (p = 0.009)) and semantic verbal fluency (p = 0.004), but was not significantly related to Digit symbol, Trail-making test, Judgment of Line Orientation, phonemic verbal fluency, MMSE, or MOCA. When analysis was restricted to non-demented subjects (n = 231), the findings were unchanged. Conclusions: We conclude that plasma HC is significantly associated with some aspects of cognitive function in PD, and may represent a treatable risk factor for cognitive decline in PD.",
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T1 - Homocysteine and cognitive function in Parkinson's disease

AU - Licking, Nicole

AU - Murchison, Charles

AU - Cholerton, Brenna

AU - Zabetian, Cyrus P.

AU - Hu, Shu Ching

AU - Montine, Thomas J.

AU - Peterson, Amie

AU - Chung, Kathryn (Kathy)

AU - Edwards, Karen

AU - Leverenz, James B.

AU - Quinn, Joseph

PY - 2017

Y1 - 2017

N2 - Introduction: Increased plasma homocysteine (HC) is a risk factor for dementia in the general population. Levodopa therapy causes increased plasma HC, but it remains unclear whether elevated plasma HC is associated with cognitive impairment in Parkinson's disease (PD). Methods: The study population includes all participants in the Pacific Northwest Udall Center (PANUC) Clinical cohort at the time of the study, consisting of 294 individuals with PD who had a standardized neuropsychological assessment and plasma collection for HC measurement. We tested the hypothesis that elevated plasma HC is inversely related to cognitive function in patients with PD. Results: As expected, plasma HC was positively associated with age, disease duration, disease severity, and levodopa usage, while cognitive function was associated with age, education, gender, and APOE genotype, so subsequent analyses controlled for these covariates. When plasma HC was dichotomized as normal (<14 μmol/L) or elevated (≥14 μmol/L), subjects with hyper-homocysteinemia had lower scores on Digit Symbol (p = 0.031), Hopkins Verbal Learning Task (HVLT) Delayed Recall (p = 0.004), and semantic verbal fluency (p = 0.049). When examined as a continuous variable, plasma HC was inversely associated with HVLT Delayed Recall (p = 0.009)) and semantic verbal fluency (p = 0.004), but was not significantly related to Digit symbol, Trail-making test, Judgment of Line Orientation, phonemic verbal fluency, MMSE, or MOCA. When analysis was restricted to non-demented subjects (n = 231), the findings were unchanged. Conclusions: We conclude that plasma HC is significantly associated with some aspects of cognitive function in PD, and may represent a treatable risk factor for cognitive decline in PD.

AB - Introduction: Increased plasma homocysteine (HC) is a risk factor for dementia in the general population. Levodopa therapy causes increased plasma HC, but it remains unclear whether elevated plasma HC is associated with cognitive impairment in Parkinson's disease (PD). Methods: The study population includes all participants in the Pacific Northwest Udall Center (PANUC) Clinical cohort at the time of the study, consisting of 294 individuals with PD who had a standardized neuropsychological assessment and plasma collection for HC measurement. We tested the hypothesis that elevated plasma HC is inversely related to cognitive function in patients with PD. Results: As expected, plasma HC was positively associated with age, disease duration, disease severity, and levodopa usage, while cognitive function was associated with age, education, gender, and APOE genotype, so subsequent analyses controlled for these covariates. When plasma HC was dichotomized as normal (<14 μmol/L) or elevated (≥14 μmol/L), subjects with hyper-homocysteinemia had lower scores on Digit Symbol (p = 0.031), Hopkins Verbal Learning Task (HVLT) Delayed Recall (p = 0.004), and semantic verbal fluency (p = 0.049). When examined as a continuous variable, plasma HC was inversely associated with HVLT Delayed Recall (p = 0.009)) and semantic verbal fluency (p = 0.004), but was not significantly related to Digit symbol, Trail-making test, Judgment of Line Orientation, phonemic verbal fluency, MMSE, or MOCA. When analysis was restricted to non-demented subjects (n = 231), the findings were unchanged. Conclusions: We conclude that plasma HC is significantly associated with some aspects of cognitive function in PD, and may represent a treatable risk factor for cognitive decline in PD.

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KW - Dementia

KW - Movement disorders

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