Introduction: Statin use might be associated with an increased risk of sleep disturbances including insomnia, but the evidence regarding sleep changes following statin therapy has not been conclusive. Therefore we assessed the impact of statin therapy on sleep changes through a systematic review and meta-analysis of available randomized controlled trials (RCTs).
Material and methods: We searched MEDLINE and SCOPUS up to October 1, 2014 to identify placebo-controlled RCTs investigating the effect of statin therapy on sleep changes. A meta-analysis was performed using either a fixed-effects or a random-effect model according to the I2 statistic. Effect size was expressed as weighted mean difference (WMD) and 95% confidence interval (CI).
Results: Overall, the impact of statin therapy on polysomnography (PSG) indices of sleep was reported in 5 trials comprising 9 treatment arms. Overall, statin therapy had no significant effect on total sleep duration (WMD: -7.75 min, 95% CI: -18.98, 3.48, p = 0.176), sleep efficiency (WMD: 0.09%, 95% CI: -2.27, 2.46, p = 0.940), entries to stage I (WMD: 0.36, 95% CI: -0.91, 1.63, p = 0.580), or latency to stage I (WMD: -1.92 min, 95% CI: -4.74, 0.89, p = 0.181). In contrast, statin therapy significantly reduced wake time (WMD: -4.43 min, 95% CI: -7.77, -0.88, p = 0.014) and number of awakenings (WMD: -0.40, 95% CI: -0.46, -0.33, p < 0.001). Meta-regression did not suggest any correlation between changes in wake time and awakening episodes with duration of treatment and LDL-lowering effect of statins.
Conclusions: The results indicated that statins have no significant adverse effect on sleep duration and efficiency, entry to stage I, or latency to stage I sleep, but significantly reduce wake time and number of awakenings.
Keywords: meta-analysis; polysomnography; sleep; stain therapy; statins.