10.19.2012
Too little sleep can harm your fat cells, study finds
>
A new study finds that not getting enough sleep wreaks havoc with your fat cells, reducing their ability to respond to insulin by about 30 per cent.
Research has already linked lack of sleep with not only crankiness and cognitive impairment but overeating and weight gain.
“We found that fat cells need sleep to function properly,” says study author Matthew Brady of the University of Chicago in the US. “Many people think of fat as a problem, but it serves a vital function,” he adds.
Body fat stores and releases energy. In storage mode, fat cells remove fatty acids and lipids that can damage other tissues, but this process gets disrupted when fat cells cannot respond well to insulin.
In the study, Brady and his team recruited seven volunteers, all young and healthy, who agreed to sleep for eight nights in a sleep lab. For four nights, each volunteer slept 8.5 hours a night. Four weeks later, they returned for a second round, but this time sleeping only 4.5 hours for four nights. After the fourth night in both sessions, each volunteer took an intravenous glucose tolerance test, which measures total-body insulin sensitivity. The researchers also took fat samples.
After four nights of short sleep, total-body insulin response decreased by an average of 16 pe rcent, with the fat cells reducing their ability to respond to insulin by 30 per cent — a reduction, the researchers noted, comparable to the difference between cells from obese versus lean people.
“Sleeping four to five hours a night, at least on work days, is now a common behaviour,” said study author and sleep specialist Esra Tasali. Over the long term, this could put a person at risk for type 2 diabetes, fatty liver disease and weight gain.
Their findings were published in the journal Annals of Internal Medicine on Tuesday.
Labels: matthew-brady, university-of-chicago
