The fact that insufficient sleep can harm your heart has been understood for some time. Now, scientists are learning more about how exactly that happens.
A recent study from Uppsala University in Sweden looked at what happens inside the body when sleep is limited. The researchers found that sleeping only about four hours a night for three nights caused changes in the blood that could increase the risk of heart problems.
The team focused on special proteins in the blood called inflammatory markers. These proteins are part of the body’s defense system and are usually released when we’re stressed or sick. But if they stay high for too long, they can harm the blood vessels and lead to serious conditions like heart disease, heart failure or an irregular heartbeat.
The study included 16 healthy young men who stayed in a lab where everything including their food, activities and lighting was carefully controlled. Each participant followed two different sleep routines. For three nights, one group got a normal amount of sleep (8.5 hours), while the other group only slept about half as much (4.25 hours).
After each sleep period, the men did a short but intense cycling workout. Blood samples were collected before and after the workout.
The researchers tested about 90 different proteins in each blood sample. They discovered that harmful inflammatory proteins increased when the men slept less.
Normally, exercise boosts good proteins like interleukin-6 and BDNF, which help the heart and brain. But after the men were sleep-deprived, the levels of these good proteins didn’t increase as much as usual.
That these changes happened in healthy young men after only a few nights of bad sleep is surprising. That’s concerning especially since many people experience short-term sleep loss or work shifts that mess up their sleep schedule.
Another interesting finding was that the time of day the blood was taken mattered. The protein levels changed between morning and evening and those changes were even more noticeable when the men hadn’t slept well. This means sleep doesn’t just change what’s in your blood, but also affects when those changes show up.
In today’s world, it’s easy to skip sleep to work longer, stay out late, or scroll through your phone.
However this study shows that the body doesn’t ignore the lack of rest. It responds in quiet but serious ways, making changes that could lead to health problems later on.
Getting enough sleep is not just about feeling rested, it’s also about keeping your heart and body healthy. So next time you’re tempted to cut back on sleep, remember that even a few bad nights can have lasting effects.
