The Science of Sleep: Your genes determine duration of your sleep, A Mid day nap can help lower blood pressure


How Genes Effect your sleep time

Experiencing problems like insomnia or hypersomnia could be genetic, say researchers who identified 76 new gene regions associated with the time a person sleeps.

It is well known that regularly getting adequate sleep — 7 to 8 hours per night — is important for health, and both insufficient sleep — 6 or fewer hours — and excessive sleep — 9 hours or more — have been linked to significant health problems.

Family studies have suggested that 10 to 40 per cent of variation in sleep duration may be inherited, and previous genetic studies have associated variants in two gene regions with the sleep duration.

The study from the Massachusetts General Hospital (MGH) in Boston, US, analysed genetic data from more than 446,000 participants, who self-reported the amount of sleep they typically received.

The study identified 78 gene regions — including the two previously identified — as associated with sleep duration.

While carrying a single gene variant influenced the average amount of sleep by only a minute, participants carrying the largest number of duration-increasing variants reported an average of 22 more minutes of sleep, compared with those with the fewest.

This was comparable to other well-recognised factors that influenced sleep duration.

“While we spend about a third of our life asleep, we have little knowledge of the specific genes and pathways that regulate the amount of sleep people get,” said Hassan Saeed Dashti from MGH.

“Our study suggests that many of the genes important for sleep in animal models may also influence sleep in humans and opens the door to better understanding of the function and regulation of sleep,” Dashti added.

Beautiful asleep woman lying on her bed

The study, published in Nature Communications journal, also found shared genetic links between both short and long sleep duration.

It also found factors such as higher levels of body fat, depression symptoms and fewer years of schooling, implying negative effects from both too little and too much sleep.

While short sleep duration was genetically linked with insomnia and smoking, long sleep duration was linked with ailments such as schizophrenia, Type-2 diabetes and coronary artery disease.

How Mid-day nap can lower high Blood Pressure

Professional check of blood pressure in a medical study.

Want to lower your high blood pressure? Taking a nap during the day may help reduce hypertension levels, besides increasing your energy levels and improving mood, finds a study.

The findings showed that taking a nap during the day was associated with an average 5 mm Hg drop in blood pressure.

In addition, for every 60 minutes of mid-day sleep, 24-hour average systolic (top number) blood pressure decreased by 3 mm Hg.

“Mid-day sleep appears to lower blood pressure levels at the same magnitude as other lifestyle changes,” said Manolis Kallistratos, cardiologist at the Asklepieion General Hospital in Voula in Greece.

“These findings are important because a drop in blood pressure as small as 2 mm Hg can reduce the risk of cardiovascular events such as heart attack by up to 10 per cent,” said Kallistratos.

Moreover, people who slept during the day had more favourable blood pressure numbers readings (128.7/76.2 versus 134.5/79.5 mm Hg) compared with those who did not.

“We obviously don’t want to encourage people to sleep for hours on end during the day, but on the other hand, they shouldn’t feel guilty if they can take a short nap, given the potential health benefits,” said Kallistratos.

The results will be presented at the American College of Cardiology’s 68th Annual Scientific Session in New Orleans.

For the study, the team included 212 people aged 62 years on average with a mean blood pressure of 129.9 mm Hg.

Further research is needed to validate these findings, the team noted.