India, May 23 -- In a striking new study, scientists from Uppsala University in Sweden have found that just three consecutive nights of poor sleep - as little as four hours per night - can trigger biological changes in the body that significantly increase the risk of heart disease. The findings shine a new spotlight on how quickly the body responds to sleep deprivation, even in healthy young adults.

The researchers monitored 16 young men under controlled lab conditions, ensuring uniformity in meals, activity, and light exposure. Each participant experienced two routines: three nights of normal sleep (8.5 hours) and three nights of restricted sleep (4.25 hours). After each phase, blood samples were taken before and after a brief high-inte...