A study from Uppsala University found that just three nights of limited sleep—about four hours a night—can change blood markers linked to a higher risk of heart disease.
They measured inflammatory proteins the body releases during stress or illness. When these proteins stay elevated, they can damage blood vessels and raise the risk of heart failure, coronary artery disease, and atrial fibrillation (an irregular heartbeat).
What Did the Scientists Find?
The team studied 16 healthy young men. They spent several days in a controlled laboratory environment where researchers monitored their diet, activity levels, light exposure, and other factors. During the experiment, the volunteers followed two sleep patterns: three nights of normal sleep (8.5 hours) and three nights of restricted sleep (4.25 hours). After each sleep phase, the men performed a short high-intensity workout on a stationary bike. Researchers analyzed blood samples at each stage, according to ScienceAlert.
Overall, the researchers measured about 90 different proteins in the blood samples. They found that sleep deprivation led to a significant increase in inflammatory markers linked to heart disease.
Normally, exercise raises levels of beneficial proteins such as interleukin-6 and BDNF, which support brain and heart health. But after poor sleep, that boost was diminished.
Even Young Hearts Are Not Immune
Surprisingly, the changes showed up even in young, healthy men who didn’t get enough quality sleep. That’s worrying because many adults report poor or restless sleep, and nearly one in four people work shifts that disrupt sleep patterns.
They also found the time of day mattered. Protein levels varied in the morning and evening, but they fluctuated most when participants were sleep-deprived. That suggests sleep affects not only which proteins are in the blood but also when those changes peak.
Modern life often pushes us to sacrifice quality nighttime rest. This study is a reminder that those sacrifices don’t go unnoticed by the body.
