BACKGROUND Several studies have described increased oxidative stress (OxS) parameters and imbalance of antioxidant enzymes in Bipolar Disorder (BD) but few is know about the impact of treatment at these targets. However, no study has evaluated OxS parameters in unmedicated early stage BD and their association with lithium treatment in bipolar depression. METHODS Patients with BD I or II (n = 29) in a depressive episode were treated for 6 weeks with lithium. Plasma samples were collected at baseline and endpoint, and were also compared to age-matched controls (n = 28). The thiobarbituric acid reactive substances (TBARS), and the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities were measured. RESULTS Subjects with BD depression at baseline presented a significant increase in CAT (p = 0.005) and GPx (p < 0.001) levels, with lower SOD/CAT ratio (p = 0.001) and no changes on SOD or TBARS compared to healthy controls. Regarding therapeutics, lithium only induced a decrease in TBARS (p = 0.023) and SOD (p = 0.029) levels, especially in BDII. Finally, TBARS levels were significantly lower at endpoint in lithium responders compared to non-responders (p = 0.018) with no difference in any biomarker regarding remission. CONCLUSION The present findings suggest a reactive increase in antioxidant enzymes levels during depressive episodes in early stage BD with minimal prior treatment. Also, decreased lipid peroxidation (TBARS) levels were observed, associated with lithium's clinical efficacy. Overall, these results reinforce the role for altered oxidative stress in the pathophysiology of BD and the presence of antioxidant effects of lithium in the prevention of illness progression and clinical efficacy.

中文翻译：

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早期双相情感障碍的氧化应激及其与锂反应的关联。

背景 一些研究已经描述了双相情感障碍 (BD) 中氧化应激 (OxS) 参数增加和抗氧化酶失衡，但很少有人知道治疗对这些目标的影响。然而，没有研究评估未经药物治疗的早期 BD 中的 OxS 参数及其与双相抑郁症中锂治疗的关联。方法 患有抑郁症的 BD I 或 II 患者（n = 29）接受锂治疗 6 周。在基线和终点收集血浆样本，并与年龄匹配的对照 (n = 28) 进行比较。测量了硫代巴比妥酸反应性物质 (TBARS) 和抗氧化酶超氧化物歧化酶 (SOD)、过氧化氢酶 (CAT) 和谷胱甘肽过氧化物酶 (GPx) 的活性。结果 基线时患有 BD 抑郁症的受试者的 CAT 显着增加（p = 0. 005) 和 GPx (p < 0.001) 水平，与健康对照相比，SOD/CAT 比率较低（p = 0.001）并且 SOD 或 TBARS 没有变化。在治疗方面，锂仅导致 TBARS (p = 0.023) 和 SOD (p = 0.029) 水平降低，尤其是在 BDII 中。最后，与无反应者相比，锂反应者在终点时的 TBARS 水平显着降低（p = 0.018），关于缓解的任何生物标志物均无差异。结论 目前的研究结果表明，在 BD 早期抑郁发作期间，抗氧化酶水平反应性增加，而先前的治疗最少。此外，还观察到脂质过氧化 (TBARS) 水平降低，这与锂的临床疗效有关。总体，