United Press International
08-05-10
Staying up until 2 a.m. and upsetting the body's internal clock might come with serious consequences for lipid metabolism, a U.S. researcher suggests.
M. Mahmood Hussain of the State University of New York Downstate Medical Center says circadian rhythm gets thrown off by staying up late or by traveling it may result in high triglycerides -- fatty acids in the blood -- a risk factor for heart disease.
Plasma triglycerides double or triple during the course of the day, reaching their lowest point at night when nocturnal animals eat and are most active.
In a study using normal mice and mice with altered circadian rhythms, the researchers found the normal mice had triglycerides reach a high once a day, while the altered mice had high triglycerides all the time, Hussain says.
"Metabolic syndrome and obesity are major metabolic disorders characterized by high plasma lipid concentrations," the researchers say in a statement. "Plasma lipids are tightly controlled by mechanisms regulating their production and clearance. Here, we show that light-entrained mechanisms involving clock genes also play a role in regulating plasma triglyceride."
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