Sleep disturbances have a strong negative impact on the immune system of people who have recently lost a spouse, reports a new study from Northwestern Medicine and Rice University.
The overactivated immune system of the bereaved triggered by sleep disturbances — and resulting chronic inflammation — may make them more susceptible to heart disease or cancer, the study authors said. Grieving spouses have a higher risk of developing heart disease or dying within a year of their loved one’s death.
The study, Project Heart, compared recent widows or widowers with sleep disturbances such as insomnia to married or single individuals with sleep disturbances. The association between sleep disturbances and inflammation was two to three times higher in the grieving spouses.
“We think these individuals are more vulnerable to the negative effects of poor sleep,” said corresponding author Dr. Diana Chirinos, research assistant professor of preventive medicine at Northwestern University Feinberg School of Medicine. “They have been hit twice. The death of a spouse is an acutely stressful event, and they have to adapt to living without the support of the spouse. Add sleep disturbance to their already stressful situation, and you double the stressor. As a result, their immune system is more overactivated.”
Dr. Chirinos conducted the study, published recently in Psychosomatic Medicine, when she was a researcher at Rice. It adds to previously published research showing individuals who have lost a spouse within the past three months have higher levels of pro-inflammatory cytokines (immune markers that indicate inflammation in the bloodstream) and lower heart rate variability. Both increase an individual’s risk for cardiac events, including death. Heart rate variability is the variation in time between each heartbeat.