Daijiworld Media Network – Helsinki
Helsinki, May 7: Frequently going to bed at different times during midlife could significantly increase the risk of serious heart problems later in life, according to a new study conducted by researchers at the University of Oulu in Finland.
The study found that people with highly irregular bedtimes, particularly those spending less than eight hours in bed, faced nearly double the risk of major cardiovascular events compared to individuals with more stable sleep schedules.
Researchers noted that irregular wake-up times, however, did not show a strong link with heart-related complications.
The cardiovascular events examined in the study included serious medical conditions such as myocardial infarction and cerebral infarction that require specialised treatment and hospital care.
“Previous research has linked irregular sleep patterns to heart health risks, but this is the first time we've looked separately at variability in bedtime, wake-up time and the midpoint of the sleep period — and their independent associations with major cardiac events,” said postdoctoral researcher Laura Nauha from the University of Oulu.
The researchers monitored sleep patterns using activity trackers that recorded the amount of time participants spent in bed and their sleep timing habits.
According to the findings, maintaining a consistent bedtime appeared to play a particularly important role in long-term heart health.
“Our findings suggest that the regularity of bedtime, in particular, may be important for heart health. It reflects the rhythms of everyday life — and how much they fluctuate,” Nauha explained.
The long-term study tracked 3,231 people born in Northern Finland in 1966. Participants’ sleep habits were recorded over a one-week period when they were 46 years old, and their health outcomes were then monitored for more than a decade using healthcare registry data.
Researchers said the findings highlight how daily routines and lifestyle habits can significantly influence cardiovascular health over time.
“Maintaining a regular sleep schedule is one factor that most of us can influence,” Nauha added.