Can Insomnia and Sleep Apnea Together Cause Heart Disease?
Yes. A massive study of 937,598 U.S. veterans found that having both insomnia and obstructive sleep apnea, a combination called COMISA, was linked to a 3.8-fold increased risk of cardiovascular disease and a 2.4-fold increased risk of developing high blood pressure. These risks were far greater than having either sleep problem alone.
Most doctors treat insomnia and sleep apnea as separate problems. You might get a sleeping pill for one and a CPAP machine for the other. But this study from the Journal of the American Heart Association suggests that when these two conditions overlap, the danger to your heart jumps dramatically. The researchers are now calling for both conditions to be screened together as part of routine cardiovascular risk assessment.
What the Data Show
This was one of the largest studies ever conducted on the relationship between sleep disorders and heart health. Researchers followed 937,598 post-9/11 U.S. veterans and tracked who developed high blood pressure or cardiovascular disease over time. Veterans who had both insomnia and obstructive sleep apnea faced a 2.4-fold increased risk of developing hypertension compared to those without either condition. Even more concerning, their risk of cardiovascular disease was 3.8 times higher.
What makes these numbers striking is the comparison. Having sleep apnea alone or insomnia alone also raised the risk, but not nearly as much. The combination of both conditions created a risk that was much greater than simply adding the two individual risks together. This pattern held true for both men and women veterans in the study, suggesting the findings apply broadly regardless of sex.
Dr. Kumar’s Take
I find this study particularly important because of its sheer size. Nearly a million participants gives us strong confidence in the results. What stands out to me is that COMISA, having both insomnia and sleep apnea, is not just a minor inconvenience. It is a serious cardiovascular risk factor that deserves the same attention we give to high cholesterol or diabetes.
In my view, the biggest takeaway is the call to evaluate these conditions together. Too often in clinical practice, a patient gets diagnosed with sleep apnea and receives a CPAP machine, but nobody asks about insomnia. Or someone complains of insomnia and gets a prescription without being screened for sleep apnea. This study makes a strong case that we need to look at the full picture of a patient’s sleep health when assessing heart risk.
Why COMISA Is Worse Than Either Condition Alone
Sleep apnea causes repeated drops in oxygen levels throughout the night. Your body responds by releasing stress hormones that raise blood pressure and strain your heart. Insomnia, on the other hand, keeps your nervous system in a state of heightened alertness, which also raises blood pressure and increases inflammation. When both conditions are present at the same time, these harmful effects likely feed into each other, creating a cycle that is much harder on the cardiovascular system than either problem would be on its own.
There is also a practical problem. People with both conditions often struggle more with treatment. CPAP machines, the main treatment for sleep apnea, can be harder to use when you already have trouble falling asleep. This means COMISA patients may get less effective treatment overall, leaving their hearts exposed to ongoing damage night after night.
Who Should Be Concerned
The study focused on post-9/11 veterans, a population that tends to have higher rates of sleep problems due to factors like combat stress, irregular schedules, and mental health challenges. However, the researchers note that COMISA affects the general population as well. If you snore loudly, wake up gasping, feel tired during the day, and also have trouble falling or staying asleep, you may have both conditions. Talking to your doctor about a comprehensive sleep evaluation could be an important step for your heart health.
Practical Takeaways
- If you have been diagnosed with sleep apnea, ask your doctor to also screen you for insomnia, since having both conditions together raises your cardiovascular risk far beyond having either one alone.
- If you struggle with insomnia and also snore heavily or wake up feeling exhausted despite spending enough time in bed, request a sleep study to check for obstructive sleep apnea.
- Treating both conditions at the same time, such as combining cognitive behavioral therapy for insomnia with CPAP therapy for sleep apnea, may be more effective than addressing just one.
- Talk to your doctor about monitoring your blood pressure regularly if you have any sleep disorder, given the strong link between poor sleep and hypertension shown in this study.
Related Studies and Research
If you want to learn more about how sleep affects heart health, explore these related articles:
- Sympathetic neural mechanisms in obstructive sleep apnea: cardiovascular impact explains how sleep apnea activates the fight-or-flight response and damages blood vessels over time.
- CPAP reduces blood pressure in sleep apnea patients with resistant hypertension shows how treating sleep apnea can help bring down stubborn high blood pressure.
- Sleep loss increases C-reactive protein: inflammation and heart disease risk looks at how poor sleep drives inflammation, a key factor in cardiovascular disease.
- Irregular sleep patterns increase heart disease risk by 2x in large study explores how inconsistent sleep schedules are linked to higher heart disease risk.
FAQs
What is COMISA and how common is it?
COMISA stands for co-morbid insomnia and sleep apnea, meaning a person has both conditions at the same time. Research suggests it may affect anywhere from 30 to 50 percent of people who have obstructive sleep apnea. Many people with COMISA go undiagnosed because doctors often test for one condition but not the other. Since this study shows that the combination carries far more cardiovascular risk than either disorder alone, getting properly screened for both is important for anyone who has persistent sleep problems.
Does treating insomnia and sleep apnea lower heart disease risk?
While this study did not directly test whether treatment reduces cardiovascular risk, the logic is promising. CPAP therapy has been shown in other research to lower blood pressure in sleep apnea patients, and cognitive behavioral therapy for insomnia is an effective, drug-free way to improve sleep quality. Combining both treatments may address the overlapping damage these conditions cause. However, more research is needed to confirm that treating COMISA leads to measurable reductions in heart attacks, strokes, and other cardiovascular events over time.
Are veterans more at risk for COMISA than the general population?
Veterans, especially those who served after 9/11, tend to have higher rates of both insomnia and sleep apnea. Factors like combat exposure, post-traumatic stress, irregular duty schedules, and the physical demands of military service all contribute to sleep problems. However, COMISA is not limited to veterans. Obesity, aging, chronic stress, and other common risk factors can cause both conditions in anyone. The large veteran population in this study provided strong statistical power, but the biological mechanisms linking COMISA to heart disease apply to the general population as well.
Bottom Line
Having both insomnia and obstructive sleep apnea is far more dangerous for your heart than having either condition alone. In this study of nearly a million U.S. veterans, the combination was linked to a 3.8-fold increase in cardiovascular disease risk and a 2.4-fold increase in hypertension risk. If you have trouble sleeping and also show signs of sleep apnea, do not treat them as separate issues. Ask your doctor for a comprehensive sleep evaluation and discuss treating both conditions together. Your heart health may depend on it.
