Insomnia is a common sleep disorder - some studies suggest it is the most common one, even more so than sleep apnea. COPD is a lung disease more commonly known as emphysema. Dr. Budhiraja and others published a paper in the March edition of the Journal Sleep about the prevalence of COPD and insomnia. They studied patients with COPD with home sleep studies called actigraphy and had them fill out sleep diaries. No laboratory sleep studies were done, which could be an important limitation to interpreting the study's results.
The results showed that insomnia occurred in 27.3% of the study participants, almost three times the prevalence in the general population (estimated to be 10%). Insomnia was more common in those that were currently smoking, and in those that reported feelings of sadness or anxiety. Insomnia was less common in those receiving oxygen, whether continuously or intermittently. Excessive daytime sleepiness was higher in patients with insomnia. Interestingly, there was no association between COPD severity and insomnia. Some studies have shown that insomnia is more common when COPD patients use their inhalers. However, the results of this study showed that insomnia was not more common in those that used inhalers for their COPD.
In discussing the results, the study authors noted that the insomnia prevalence would have been even higher in those with COPD had they included more females (the patients were all at a VA, which is mostly men), and if they allowed patients with depression to enter the study. Another issue that could be affecting insomnia is that sleep apnea and periodic limb movement disorder can cause insomnia, but would be missed by the home studies used in this study. A lab-based sleep study would have picked that up.
Currently, it is difficult to improve the quality of life in patients with COPD, but improving sleep quality may help. Quitting smoking and using oxygen at night may improve sleep quality enough to boost quality of life.