Chronic insomnia and increased inflammation and mortality are linked according to a new study, with people who suffer from persistent insomnia being at greater risk than those who experience intermittent insomnia. Researchers from the University of Arizona showed that there is a 58 percent greater risk of dying for those who can’t sleep well for long periods of time.
In the United States, 20 percent of the adults are affected by insomnia and half of them suffer from persistent (or chronic) insomnia. The findings show that the mortality for the latter category is cardiovascular, rather than cancer-related.
“We hypothesized that insomnia that was persistent over eight years, rather than intermittent insomnia, was associated with death independent of the effects of sedatives, opportunity for sleep (to distinguish it from sleep deprivation), and other confounding factors in a representative sample of the general adult community,” explained lead investigator Sairam Parthasarathy, MD, associate professor of medicine at the University of Arizona College of Medicine.
After adjusting for age, sex, body weight, smoking, hypnotics, and physical activity, researchers found that subjects with persistent insomnia were 58% more likely to die during the study and had higher levels of serum C-reactive protein (CRP), an independent risk factor for mortality. But even after taking out the CRP levels, the mortality risk remained at 36% for subjects with persistent insomnia.
In case of intermittent insomnia, the risk was eliminated after adjustments for body mass index, smoking status, and regular physical activity.
Researchers looked for the effects of insomnia in 1409 adult participants from the Tucson Epidemiological Study of Airway Obstructive Disease. The study started in 1972 with multiple follow-up surveys to 1996 and continuous mortality follow-up data to 2011 for a total of 38 years. Questions about sleep and related habits were inserted in two surveys completed between 1984 and 1985 and between 1990 and 1992. The persistence of insomnia was assessed based upon whether insomnia was present in both the 1984-1985 and 1990-1992 surveys.