Not just how much you sleep, your bedtime is important too

Not just how much you sleep, your bedtime is important too

More Heart Ailments In Those Who Sleep Before 10pm, After 12am

Pushpa.Narayan@timesgroup.com

19.02.2021 

Going to bed early can indicate an underlying heart ailment while going to bed late can trigger a series of metabolic diseases and lifestyle disorders, according to a study.

There was a 9% increase in incidence of heart ailments among those sleeping before 10pm, compared to those who went to bed between 10pm and midnight, scientists wrote in medical journal Sleep Medicine, after screening 5,633 deaths and 4,346 deaths from more than 21 countries. Among people who sleep past midnight, the incidence increases by nearly 10%.

“We know sleeping six to eight hours is important. This study shows sleeping at the right time matters too,” said senior diabetologist Dr V Mohan, who was a part of the study. “We saw a Ushaped association between bedtime and medical events. The incidence was lower when the sleep time was between 10pm and midnight. The score went up for people in both early and late bedtime groups. While it may not be very different for those who slept at 9pm or 1am, the graph showed that those who slept after 3am or before 7pm were more likely to have health problems,” he said.

Canada-based scientist Dr Salim Yusuf from McMaster University, Hamilton, who is also the corresponding author of the study, concluded that “those going to bed between 10pm and 12am experienced the lowest incidence of events, while early or late bedtimes were associated with a modest detrimental effect on health, suggesting that early or late bedtimes could be an indicator or risk of adverse health outcomes”.

Experts say sleeping early or late tampers with circadian rhythms. These rhythms are 24-hour cycles that are part of the body’s internal clock, running in the background to carry out essential functions. Different systems of the body follow circadian rhythms that are synchronized with a master clock in the brain. This master clock is directly influenced by environmental cues, such as day and night. This rhythm promotes consistent and restorative sleep. But when this circadian rhythm is thrown off, it can create significant sleeping problems. “While sleeping late can trigger a series of diseases including heart attacks and death, sleeping early is an indication of an underlying disease. A person who has hyperthyroidism, diabetes or obesity usually tends to sleep more,” Mohan said.

The study found that early sleepers were slightly older, less educated, more likely to be women, lived in rural areas, slept more, smoked and drank less, consumed less energy and had a lower BMI. People with hypertension were more in this group compared to late sleepers, but there were fewer people with diabetes or depression.

While an individual may not have complete control over time of sleep, doctors say the body can be trained to follow the rhythm with exposure to natural light, exercise, low intake of stimulants like caffeine. The key message is it’s important to consult a doctor if you are hitting the bed too early, sleeping for more than eight hours or waking up early.