Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran; Students' Scientific Research Center (SSRC), Tehran University of Medical Sciences (TUMS), Tehran, Iran.
Department of Traditional Medicine, School of Persian Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Cytokine. 2020 Nov;135:155239. doi: 10.1016/j.cyto.2020.155239. Epub 2020 Aug 12.
Randomized Clinical Trials (RCTs) have provided varied and conflicting findings regarding the effect of N-acetylcysteine (NAC) on inflammatory biomarkers. This study was conducted to review existing literature to determine whether NAC supplementation can affect inflammatory biomarkers in adults.
Bibliographic databases of Scopus, and PubMed were used for relevant papers published until October 2019. Results were reported as weighted mean differences (WMD) with 95% confidence intervals (CI) using multi-level models. Cochrane's Q and I-squared (I) tests were used to determine heterogeneity among studies.
Twenty-four RCTs which include 1057 sample size were entered to analysis. NAC doses and intervention duration ranged from 400 to 2000 mg/d, and 1 to 80 weeks, respectively. Oral supplementation of NAC reduced serum level of C-reactive protein (CRP) [WMD: -0.61 mg/L, 95% CI: -1.18 to -0.03, P = 0.039, I = 79.6%], and interleukin-6 (IL-6) [WMD: -0.43 pg/mL, 95% CI: -0.69 to -0.17, P = 0.001, I = 89.3%]. However, the effect of oral NAC supplementation on other inflammatory biomarkers was nonsignificant. Dose-response investigation showed a non-linear association between oral NAC supplementation with CRP.
Oral NAC supplementation reduced serum level of CRP and IL-6, but did not affect other inflammatory biomarkers. Nevertheless, more RCTs seems to be required to explore how NAC in different dosage and different routes of administration can affect inflammatory biomarkers.
随机临床试验（RCTs）对于 N-乙酰半胱氨酸（NAC）对炎症生物标志物的影响提供了不同且相互矛盾的发现。本研究旨在回顾现有文献，以确定 NAC 补充剂是否会影响成年人的炎症生物标志物。
使用 Scopus 和 PubMed 书目数据库检索截至 2019 年 10 月发表的相关论文。结果以多水平模型计算的加权均数差值（WMD）和 95%置信区间（CI）表示。使用 Cochrane's Q 和 I 平方（I）检验来确定研究之间的异质性。
共纳入 24 项 RCT，包含 1057 例样本量。NAC 剂量和干预持续时间分别为 400 至 2000mg/d 和 1 至 80 周。口服 NAC 补充剂可降低血清 C 反应蛋白（CRP）水平[WMD：-0.61mg/L，95%CI：-1.18 至 -0.03，P=0.039，I=79.6%]和白细胞介素-6（IL-6）水平[WMD：-0.43pg/mL，95%CI：-0.69 至 -0.17，P=0.001，I=89.3%]。然而，口服 NAC 补充剂对其他炎症生物标志物的影响无统计学意义。剂量反应研究表明，口服 NAC 补充与 CRP 之间存在非线性关联。
口服 NAC 补充剂可降低 CRP 和 IL-6 血清水平，但不影响其他炎症生物标志物。然而，似乎需要更多的 RCT 来探讨不同剂量和不同给药途径的 NAC 如何影响炎症生物标志物。
