Menu

Circadian Clock Controls Sugar Metabolism

The body’s circadian rhythm has more of an effect on glucose tolerance than one’s eating and sleeping patterns, a study shows.  

Apr 17, 2015
Anna Azvolinsky

WIKIMEDIA, JACOB TOORNVLIET's 'THE SLEEPING WOMAN' Humans’ 24-hour circadian clock plays a leading role in glucose tolerance, according to a study published Moday (April 13) in PNAS. Researchers in Boston have found that, because of body’s circadian rhythm, human glucose tolerance is reduced during the evening hours, even when “day” and “night” times are experimentally reversed.

“In a prior [human] study, we found that when behavior cycles of feeding and sleeping are not in normal alignment with the internal body clock, that this negatively affects the regulation of blood sugar and especially glucose tolerance,” said neuroscientist Frank Scheer from the Division of Sleep and Circadian Disorders at the Brigham and Women’s Hospital in Boston. People who work night shifts are more prone to type 2 diabetes and obesity, he noted.

In an attempt to understand the independent effects of eating and sleeping behaviors versus the circadian clock on glucose tolerance, Scheer and his colleagues mimicked night-shift work in 14 healthy individuals under controlled laboratory conditions. Participants spent eight days on a typical day-shift schedule, eating breakfast at 8:00 a.m., dinner at 8:00 p.m., and sleeping during the night. Several weeks later, the same individuals had their days reversed: they then ate breakfast at 8:00 p.m., had dinner at 8:00 a.m., and slept during the day.

“We showed that glucose levels after identical meals were 17 percent higher [indicating lower glucose tolerance] in the evening than in the morning, independent of when a participant had slept or had their meals,” study coauthor Christopher Morris, an instructor of medicine at the Division of Sleep and Circadian Disorders at Harvard Medical School, wrote in an e-mail to The Scientist.

The results suggest that, rather than behavioral cycles, the body clock largely dictates the body’s daily glucose tolerance.

“This phenomenon of mistiming of the behavioral cycle relative to the . . . body clock, [called] ‘circadian misalignment,’ may have important implications for shift workers,” Morris added.

November 2018

Intelligent Science

Wrapping our heads around human smarts

Marketplace

Sponsored Product Updates

Slice® Safety Cutters for Lab Work

Slice® Safety Cutters for Lab Work

Slice cutting tools—which feature our patent-pending safety blades—meet many lab-specific requirements. Our scalpels and craft knives are well suited for delicate work, and our utility knives are good for general use.

The Lab of the Future: Alinity Poised to Reinvent Clinical Diagnostic Testing and Help Improve Healthcare

The Lab of the Future: Alinity Poised to Reinvent Clinical Diagnostic Testing and Help Improve Healthcare

Every minute counts when waiting for accurate diagnostic test results to guide critical care decisions, making today's clinical lab more important than ever. In fact, nearly 70 percent of critical care decisions are driven by a diagnostic test.

LGC announces new, integrated, global portfolio brand, Biosearch Technologies, representing genomic tools for mission critical customer applications

LGC announces new, integrated, global portfolio brand, Biosearch Technologies, representing genomic tools for mission critical customer applications

LGC’s Genomics division announced it is transforming its branding under LGC, Biosearch Technologies, a unified portfolio brand integrating optimised genomic analysis technologies and tools to accelerate scientific outcomes.