Serum uric acid level is associated with the prevalence but not with survival of amyotrophic lateral sclerosis in a Chinese population

Oxidative stress is involved in the pathogenesis of amyotrophic lateral sclerosis (ALS). Serum uric acid (UA) has anti-oxidative effect. To clarify the associations between UA and sporadic ALS (SALS) in Chinese population. A total of 512 SALS patients and 501 age- and gender- matched healthy controls were included, with fasting serum UA evaluated. The ALS functional rating scale-Revised was used to assess disease severity, and the mean change of ALSFRS-R per month (a-(3)ALS-FRS-R/m) to assess its progression. Four hundred forty-five patients were followed up. Survival and progression were estimated according to quartiles and gender-specific quartiles of UA. The mean age of SALS patients was 53.3 +/- 11.7 years. UA level of SALS was significantly lower than controls (p = 0.001). Male SALS had higher UA than female (p = 0.001). The occurrence of SALS was increased in the lowest, second and third quartiles compared with the highest quartile (p = 0.001). In the gender-specific analysis, increased occurrence was found in the lowest and second quartiles compared with third and fourth quartiles in both males and females SALS (p (f) = 0.001 and p (m) < 0.05). No correlation was found between a-(3)ALS-FRS-R/m and UA (p > 0.05), nor between SALS survival and UA. SALS patients have low level of serum UA than controls. Low level of uric acid may be associated with increased occurrence of SALS in Chinese population. Uric acid level may not contribute to the survival or progression of SALS.