Low serum uric acid levels in chronic insomnia patients: A case-control study.

Recent studies have demonstrated the presence of oxidative stress in insomnia patients. Uric acid (UA) is regarded as one of the most important antioxidants that may attenuate oxidative stress. The aim of our study was to investigate whether there is an alteration of serum UA levels in chronic insomnia patients. The association between sleep quality and serum UA in chronic insomnia patients was also investigated. We recruited 300 chronic insomnia patients and 300 age- and gender-matched normal controls. The uricase-PAP method was used to measure the concentration of UA both in patient and normal control subjects. The Pittsburgh Sleep Quality Index (PSQI) was used to assess the sleep quality of chronic insomniac participants. As a result, significantly lower serum UA levels were observed in patients with chronic insomnia when compared with normal control subjects (279.56±65.80 vs. 299.10±61.17μmol/L, t=-3.991, p<0.001). Low serum UA levels were correlated with high PSQI scores in multiple linear regression models (β=-0.322, p<0.001). Our results suggested that low serum UA levels were associated with the presence and severity of chronic insomnia.