A study from Taiwan published in the April issue of the journal Stroke titled Insomnia Subtypes and the Subsequent Risks of Stroke, Report From a Nationally Representative Cohort demonstrates the relationship between insomnia and stroke. Over a four-year period, 21,438 subjects with insomnia and 64,314 matched subjects without insomnia were followed.
The results were very interesting and potentially of great importance. The authors found that the incidence of stroke was 54% more likely to occur in those with insomnia as opposed to good sleepers. However, even more astonishing, subjects age 18 to 34 with insomnia had an eight-fold greater risk of stroke. Additionally, when those with insomnia were broken down by chronicity, the rate was considerably higher in those with persistent insomnia.
The authors concluded that the evidence seems to indicate that those with insomnia have a higher risk of stroke than as compared to non-insomniacs. They urge that health education about insomnia should be promoted, especially among the young who seem to be most vulnerable to stroke as a result of poor quality sleep.
This is the first study to show a significant relationship between insomnia and stroke. Several prior studies have demonstrated that short sleep duration can predispose one to stroke. In fact, a study I mentioned in a previous blog titled Sleepless in Stroke-ville demonstrated a four-fold increase of stroke in people who slept less than six hours.
Why would insomnia and sleep deprivation increase one’s risk of stroke? I suspect, as do the authors, that it is multifactorial. They both can negatively affect cardiovascular health through inflammation and metabolic dysregulation, as evidenced by diabetes and increased release of stress hormones. In addition, the over-activity of the sympathetic nervous system results in increased blood pressure. Taken together, these factors put a great deal of stress on the vascular system and over time can destroy its integrity. Thus, we see the high incidence of stroke noted in this study and the increase in heart attacks observed in others.
The take home message is that we need to become more aware of the relationship of sleep to health. If you chronically limit yourself to less than six hours of sleep, you need to do things to increase the duration. Such things as going to bed earlier, establishing a set sleep-wake schedule, turning off the computers and cell phones, and avoiding caffeine after noon can make a big difference. If you suffer from insomnia as defined by the fact that you try to sleep longer but cannot, then talk to your health care provider. There are excellent therapies, many of them non-pharmacological such as CBT (cognitive behavioral therapy) available to deal with insomnia. Remember, in most cases a stroke causes irreversible damage, so be proactive.