The sleep, diabetes link
Pancreatic cells have melatonin receptor
Scientists find a surprisingly clear connection between sleep and a healthy body: the regulation of sugar levels in the blood.
Three large genomic studies, all online December 7 in Nature Genetics, describe the first genetic link between sleep and type 2 diabetes, a disease marked by high blood sugar levels (SN: 1/3/09, p. 5). The research places bodily rhythms, including the clock that sets human sleep cycles, squarely in the blood sugar business.
Melatonin is a major regulator of the body’s sleep clock, best known for its sleep-inducing properties. People with a single-letter change in the gene encoding a molecule that senses melatonin are more likely to develop diabetes, the studies show. One of the studies also showed that the sensing molecule, known to be expressed in the brain, also sits on the outside of insulin-producing pancreatic cells.
The results identify the melatonin system as a “fascinating new target” for diabetes treatments, says endocrinologist Leif Groop of Lund University in Malmö, Sweden, who coauthored two of the new reports. These data link two trends in the United States — rising diabetes rates and falling sleep levels.
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Same brain map Months after receiving a right-hand transplant, a man displays a partial sense of touch in the new hand, activating the same brain areas that would have controlled his original hand (SN: 11/8/08, p. 18).
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Statin ups and downs Older people taking cholesterol-lowering statin drugs seem less likely to develop dementia (SN Online: 7/28/08). A variant form of the gene SLCO1B1 may be responsible for muscle pain that statins sometimes cause (SN: 8/16/08, p. 9).
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