Xiao-Min Lu, Ji-Ping Zhu, Xian-Mei Zhou

Insomnia is a common comorbidity associated with COPD. Although benzodiazepines (BZDs) can have adverse effects on respiratory response in COPD patients, these are the most common hypnotics. The aim of this study was to examine by meta-analysis the efficacy and safety of BZD to treat insomnia in COPD patients. Electronic databases (PubMed, China National Knowledge Infrastructure, Cochrane clinical trials database) were searched. Studies were eligible if they compared the effects of BZD versus placebo on insomnia in COPD patients. Two reviewers extracted data independently. Disagreements were resolved by discussion with another reviewer until a consensus was achieved. Data that included objective and subjective sleep evaluation and respiratory function variables were extracted. Data were analyzed by the methods recommended by Review Manager 5.3 software. A total of 233 records were identified through the initial search; of these, five studies were included in the meta-analysis. When BZD was compared with placebo, objective sleep quality was significantly improved, including total sleep time (95% confidence interval [CI] 0.54-1.14, P<0.00001), sleep efficiency (95% CI 0.48-1.16, P<0.00001), sleep latency (95% CI -18.24 to -4.46, P=0.001), and number of arousals/hour of sleep (95% CI -0.72 to -0.07, P=0.02). Otherwise, subjective sleep quality was not improved remarkably. Apart from maximum transcutaneous carbon dioxide pressure increase during sleep (95% CI 0.05-0.28, P=0.006), BZD administration had no effect on respiratory assessment. In this meta-analysis, the results suggested BZDs might be efficient and safe hypnotics. Compared with placebo, BZD improved sleep quality partly, and significantly increased maximum transcutaneous carbon dioxide pressure during sleep. More randomized controlled trials are necessary to determine the potential effect of BZD in COPD patients with insomnia.