Abstract：
BACKGROUND: N-acetylcysteine (NAC) is a mucolytic agent with antioxidant properties. Oxidative stress is a key pathogenic mechanism in chronic respiratory conditions such as COPD and chronic bronchitis (CB). In these meta-analyses we investigated the efficacy of NAC in subjects with COPD or CB, the latter being a potential pre-COPD condition (CB/pre-COPD).
METHODS: The meta-analyses were conducted according to PRISMA guidelines. Exacerbations were assessed using total number of exacerbations. Improvement in patients\' respiratory symptoms and/or patients quality of life (QoL) were measured by validated tools or assessed at the end of the study.
RESULTS: Twenty studies were included, of which seven evaluated NAC in patients with symptoms of CB/pre-COPD as entry criterion. NAC treated patients showed a significant reduction of the incidence of exacerbations as compared to placebo both in COPD (IRR=0.76; 95% confidence interval (CI) 0.59-0.99) and CB/pre-COPD (IRR=0.81; 95% CI 0.69-0.95). Sensitivity analyses in studies with duration higher than 5 months, confirmed the overall results. CB/pre-COPD patients treated with NAC were significantly more likely to experience an improvement in symptoms and/or QoL compared to placebo (odds ratio (OR)=3.47; 95% CI 1.92-6.26). A similar trend was observed in the few COPD studies evaluable. Sensitivity analyses showed a significant association of NAC with improvement in symptoms and/or QoL both in CB/pre-COPD and COPD patients.
CONCLUSIONS: These findings provide novel data of NAC on the improvement in symptoms and QoL in addition to prevention of exacerbations in COPD and CB/pre-COPD. PROSPERO registry no. CRD42023468154.
METHODS: The meta-analyses were conducted according to PRISMA guidelines. Exacerbations were assessed using total number of exacerbations. Improvement in patients\' respiratory symptoms and/or patients quality of life (QoL) were measured by validated tools or assessed at the end of the study.
RESULTS: Twenty studies were included, of which seven evaluated NAC in patients with symptoms of CB/pre-COPD as entry criterion. NAC treated patients showed a significant reduction of the incidence of exacerbations as compared to placebo both in COPD (IRR=0.76; 95% confidence interval (CI) 0.59-0.99) and CB/pre-COPD (IRR=0.81; 95% CI 0.69-0.95). Sensitivity analyses in studies with duration higher than 5 months, confirmed the overall results. CB/pre-COPD patients treated with NAC were significantly more likely to experience an improvement in symptoms and/or QoL compared to placebo (odds ratio (OR)=3.47; 95% CI 1.92-6.26). A similar trend was observed in the few COPD studies evaluable. Sensitivity analyses showed a significant association of NAC with improvement in symptoms and/or QoL both in CB/pre-COPD and COPD patients.
CONCLUSIONS: These findings provide novel data of NAC on the improvement in symptoms and QoL in addition to prevention of exacerbations in COPD and CB/pre-COPD. PROSPERO registry no. CRD42023468154.
摘要：
背景：N-乙酰半胱氨酸（NAC）是一种具有抗氧化特性的粘液溶解剂。氧化应激是慢性呼吸系统疾病如COPD和慢性支气管炎(CB)的关键致病机制。在这些荟萃分析中，我们调查了NAC在COPD或CB受试者中的疗效，后者是潜在的COPD前疾病（CB/pre-COPD）。
方法：根据PRISMA指南进行meta分析。使用加重总数评估加重。患者呼吸道症状和/或患者生活质量(QoL)的改善通过验证工具进行测量或在研究结束时进行评估。
结果：纳入了20项研究，其中7人评估了以CB/COPD前症状为进入标准的患者的NAC。与安慰剂相比，NAC治疗的患者在COPD（IRR=0.76；95％置信区间（CI）0.59-0.99）和CB/COPD前（IRR=0.81；95％CI0.69-0.95）中的加重发生率均显着降低。持续时间超过5个月的研究的敏感性分析，确认了总体结果。与安慰剂相比，接受NAC治疗的CB/COPD前期患者的症状和/或QoL明显改善（比值比（OR）=3.47；95％CI1.92-6.26）。在少数可评估的COPD研究中观察到类似的趋势。敏感性分析显示，在CB/COPD前期和COPD患者中，NAC与症状和/或QoL的改善显著相关。
结论：这些研究结果为NAC提供了新的数据，可以改善COPD和CB/pre-COPD的症状和生活质量。PROSPERO注册表编号CRD42023468154。
方法：根据PRISMA指南进行meta分析。使用加重总数评估加重。患者呼吸道症状和/或患者生活质量(QoL)的改善通过验证工具进行测量或在研究结束时进行评估。
结果：纳入了20项研究，其中7人评估了以CB/COPD前症状为进入标准的患者的NAC。与安慰剂相比，NAC治疗的患者在COPD（IRR=0.76；95％置信区间（CI）0.59-0.99）和CB/COPD前（IRR=0.81；95％CI0.69-0.95）中的加重发生率均显着降低。持续时间超过5个月的研究的敏感性分析，确认了总体结果。与安慰剂相比，接受NAC治疗的CB/COPD前期患者的症状和/或QoL明显改善（比值比（OR）=3.47；95％CI1.92-6.26）。在少数可评估的COPD研究中观察到类似的趋势。敏感性分析显示，在CB/COPD前期和COPD患者中，NAC与症状和/或QoL的改善显著相关。
结论：这些研究结果为NAC提供了新的数据，可以改善COPD和CB/pre-COPD的症状和生活质量。PROSPERO注册表编号CRD42023468154。
