Potential mechanisms for low uric acid in Parkinson disease

Abstract

Several epidemiologic studies have described an association between low serum uric acid (UA) and Parkinson disease (PD). Uric acid is a known antioxidant, and one proposed mechanism of neurodegeneration in PD is oxidative damage of dopamine neurons. However, other complex metabolic pathways may contribute. The purpose of this study is to elucidate potential mechanisms of low serum UA in PD. Subjects who met diagnostic criteria for definite or probable PD (n = 20) and controls (n = 20) aged 55–80 years were recruited. Twenty-four hour urine samples were collected from all participants, and both uric acid and allantoin were measured and corrected for body mass index (BMI). Urinary metabolites were compared using a twoway ANOVA with diagnosis and sex as the explanatory variables. There were no significant differences between PD and controls for total UA (p = 0.60), UA corrected for BMI (p = 0.37), or in the interaction of diagnosis and sex on UA (p = 0.24). Similarly, there were no significant differences between PD and controls for allantoin (p = 0.47), allantoin corrected for BMI (p = 0.57), or in the interaction of diagnosis and sex on allantoin (p = 0.78). Allantoin/UA ratios also did not significantly differ by diagnosis (p = 0.99). Our results imply that low serum UA in PD may be due to an intrinsic mechanism that alters the homeostatic set point for serum UA in PD, and may contribute to relatively lower protection against oxidative damage. These findings provide indirect support for neuroprotection trials aimed at raising serum UA.

The significance of uric acid in the diagnosis and treatment of Parkinson disease

“…They speculated that the chronically lower levels of UA may contribute to relatively lower protection against damage from oxidative stress in PD. [ 56 ] Although several studies assumed an association between UA and oxidative stress in PD, they do not prove directly and sample size was relatively small. Moreover, results may be interfered by variety of inflammatory and neurodegenerative diseases.…”

Level of uric acid and uric acid/creatinine ratios in correlation with stage of Parkinson disease

“…Thus, we can speculate that lower UA may be a potential risk factor for PD. [ 17 ] At the same time, foreign scholars have found that higher UA could reduce the risk of PD. [ 18 , 19 ] Furthermore, recent studies have found that in addition to antioxidative stress effects, other mechanisms exist between UA and PD.…”

Uric Acid in Parkinson′s Disease: What Is the Connection?

“…In this situation, low UA in PD may reflect an innocent bystander effect. This possibility was tested in 20 PD subjects and 20 controls by measuring the 24‐hour urinary accumulation of allantoin, the oxidative product of UA 73 . This study showed no evidence for low urinary UA in PD and no evidence for increased oxidation of UA in PD.…”