I saw a review from Medscape about a poster presented at the annual SLEEP meeting in San Antonio last month. In this study, researchers analyzed patients from the Wisconsin Sleep Cohort. The patients were mailed surveys about insomnia symptoms - difficulty starting or staying asleep, for example. After adjusting for other factors that could be contributing to death (age, BMI, chronic conditions, e.g.), the researchers concluded that there was an approximately 2-fold increase risk for all-cause mortality in chronic insomnia patients.
The problem with this study is in the way the researches determined if someone has insomnia, and what type of insomnia they might have. Insomnia is difficult to diagnose off of a mailed survey. Although I did not read the poster because I did not attend this meeting, the review of the poster mentions nothing about whether the patients in this study might have had a coexistent sleep-related breathing disorder. Not all insomnia symptoms are due to primary insomnia - many times, insomnia is due to undiagnosed obstructive sleep apnea, a condition known to increase mortality if left untreated.
This study is misleading in that it implies that patients with primary chronic insomnia have an increased risk of dying. Insomnia is a serious disorder, but it is not life threatening and has not been linked to other physical diseases based on research studies where primary insomnia was diagnosed by an experienced sleep clinician.