Sleep science has been making new discoveries every day, with most pointing to the importance of getting adequate sleep, the benefits of getting better-than-adequate sleep, and the risks of not getting enough sleep. Sleep disorders and insomnia have gotten special attention as cures are sought for both chronic conditions, and now researchers have found another reason why a cure is needed. A Harvard and Brigham and Women’s Hospital research project has shown that men who self-reported insomnia ran a somewhat higher risk of dying from cardiovascular disease.
The information was gleaned by pulling data from the famous Harvard Health Professionals Follow-Up Study, a project that has been ongoing since 1986. From that data the researchers isolated a six-year period in the lives of the 23,447 men in the study. They focused on answers that the men had given to questions regarding their ability to fall asleep and stay asleep and compared those answers to the incidence of death or cardiovascular disease. What they found was that the risk of death was 25 percent higher in those who had reported insomniac issues than in those who hadn’t. A 55% higher risk of cardiovascular was discovered for the same group.
The risk described is relative risk, which is different from absolute risk – it describes the difference between groups of people rather than an individual’s actual risk. But the number is still significant, as it translates into an eight percentage point increase in absolute risk. What’s the reason for the increased potential for cardiovascular disease? According to Harvard epidemiologist Xiang Gao, who took party in the study, “Poor sleep has influence on endocrine function. It can increase chronic inflammation and also it can change circadian patterns.”
Interestingly, a similar but much larger study was conducted in Norway and the results were very similar. That research pulled data from over 54,000 male and female patients, and also reported a significant risk association between insomnia and heart failure, with a 27 to 66% greater risk in those who reported having a hard time falling asleep nearly every night. Their conclusion discussed the impact that the stress of not sleeping had on the body.
Because of the structure of both studies, the connection between insomnia and cardiovascular disease is said to be an association – there is no cause and effect that can be interpreted, as there could be other factors at play in the men’s deaths, though factors such as depression, age and related illnesses such as diabetes were taken into account. Additional studies would need to be done to create a more certain link between the two. Additionally, the study would need to utilize a more accurate method of measuring the men’s sleep patterns than relying on self-reporting, which is highly subjective. Though sleep studies are expensive and would be cumbersome or impossible to utilize over an extended period of time, the advent of applications that monitor sleep and wristbands that measure movement may be helpful for future studies.