Low levels of serum total antioxidant capacity and presence at admission and absence at discharge of a day/night change as a marker of acute paranoid schizophrenia relapse

Abstract

Background: An oxidant-antioxidant system dysregulation has been described as a schizophrenia pathophysiological base. The total antioxidant capacity (TAC) is one measure of the antioxidant capacity of a system. Day/night concentration changes is a biological characteristic of hormones such as melatonin or cortisol. There is no information about TAC day/night changes in schizophrenia.

Aims: Studying the existence of a day/night TAC change in schizophrenia.

Method: Forty-three DSM-IV paranoid schizophrenia inpatients participated in the study. Thirty healthy subjects matched by age and gender acted as control group. Blood was sampled at 12:00 and 00:00h the day after admission and the day before discharge. Serum TAC was measured by the ABTS radical cation technique and expressed in Trolox mmol/L.

Results: Patients had significantly lower TAC levels at admission and discharge (12:00 and 00:00) than controls. At admission patients had a TAC day/night change, with higher day-time than night-time levels (0.66±0.14 vs 0.60±0.15) as well as healthy subjects (0.83±0.07 vs 0.77±0.11). At discharge patients had a similar TAC level at 12:00 and 00:00 (0.64±0.15 vs 0.63±0.14).

Conclusion: Schizophrenic patients present a deficit of the antioxidant system. The initial presence and the later absence of a day/night change deserves future studies.

Keywords: Acute relapse; Biological markers; Day/night changes; Methodology; Oxidant-antioxidant system; Schizophrenia; Total antioxidant capacity.