title: Serum urate and probability of dopaminergic deficit in early "Parkinson's disease".
abstract: The objective of this study was to investigate whether higher levels of urate, an antioxidant linked to a lower likelihood of developing Parkinson's disease, is also a predictor of having a dopamine transporter brain scan without evidence of dopaminergic deficit. In a cross-sectional study of 797 mildly affected, untreated parkinsonian subjects diagnosed with early Parkinson's disease in the Parkinson Research Examination of CEP-1347 Trial, we investigated the relationship at baseline between serum urate and striatal dopamine transporter density, determined by single-photon emission computed tomography of iodine-123-labeled 2-β-carboxymethoxy-3-β-(4-iodophenyl)tropane uptake. A scan without evidence of dopaminergic deficit was defined as lowest putamen iodine-123-labeled 2-β-carboxymethoxy-3-β-(4-iodophenyl)tropane > 80% age-expected putamen dopamine transporter density. The odds of having a scan without evidence of dopaminergic deficit rose across increasing quintiles of urate level, with an age- and sex-adjusted odds ratio of 3.2 comparing the highest to the lowest urate quintile (95% confidence interval, 1.5-7.2; P for trend = .0003), and remained significant after adjusting for potential confounding factors. The association was significant in men but not women, regardless of whether common or sex-specific quintiles of urate were used. Higher levels of urate were associated with a greater likelihood of a scan without evidence of dopaminergic deficit among subjects with early untreated parkinsonism in the Parkinson Research Examination of CEP-1347 Trial. The findings support the diagnostic utility of urate in combination with other determinants.
authors.affiliation: Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Schwarzschild
authors.forename: Kenneth
authors.initials: K
authors.lastname: Marek
authors.forename: Shirley
authors.initials: S
authors.lastname: Eberly
authors.forename: David
authors.initials: D
authors.lastname: Oakes
authors.forename: Ira
authors.initials: I
authors.lastname: Shoulson
authors.forename: Danna
authors.initials: D
authors.lastname: Jennings
authors.forename: John
authors.initials: J
authors.lastname: Seibyl
authors.forename: Alberto
authors.initials: A
authors.lastname: Ascherio
mesh_terms: D000328:Adult; D000368:Aged; D004298:Dopamine / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins / Q000172:deficiency*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010300:Parkinson Disease / Q000097:blood* / Q000000981:diagnostic imaging / Q000378:metabolism*; D011336:Probability; D012189:Retrospective Studies; D012737:Sex Factors; D015899:Tomography, Emission-Computed, Single-Photon; D014326:Tropanes; D014527:Uric Acid / Q000097:blood*
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane; D014527:Uric Acid; D004298:Dopamine