Posts Tagged ‘sleep’

New Insights into how sleep deprivation leads to obesity

February 28th, 2013

New research, published in the Proceedings of the National Academy of Science, is shedding light on the interaction of sleep and genes. Researchers at Surrey University took a small group of 26 subjects. Half slept for less than six hours a night; the other for 10. The sleep-deprived group was found to have altered functions in 711 genes, including some involved in metabolism, inflammation, and stress. The body’s normal circadian rhythms were also affected.

Getting fewer than six hours’ sleep per night deactivates genes which play a key role in the body’s constant process of self-repair and replenishment, according to a new study.

Genes produce proteins which are used to replace or repair damaged tissue, but after a week of sleep deprivation some of these ceased functioning.

The subjects’ bodies returned to normal after a period of regular sleep but prolonged deprivation could lead to major problems. The Center for Disease Control reports that 25% of Americans have occasional sleep problems and 10% have chronic sleep disorders.

 

 

Are we looking for answers in the wrong places?

January 23rd, 2010

In a cross-sectional and longitudinal study in Canada, nine known risk factors for overweight and obesity were examined. Only short-sleep duration, low dietary calcium intake and high disinhibited  eating were found to be significantly associated with higher BMI in both men and women. Short sleep duration had a greater effect than parental obesity, television viewing and physical inactivity. Population studies indicate that sleep duration has decreased over recent years. The authors note that affecting obesity by addressing  the traditional risk factors – reduced physical activity, high caloric intake and high fat intake – have not been very successful and that attention to factors which are not caloric per se may be worthwhile.  Risk factors for adult overweight and obesity in t… [Obesity (Silver Spring). 2009] – PubMed result

The Obesity Society Meeting-Day Two

October 26th, 2009

Today’s sessions of the Obesity Society’s annual scientific meeting covered a lot of ground.  I think the most interesting  was the session on the relationship of cancer and obesity organized by Ruth Ballard-Barash of the National Cancer Institute and Ted Adams of the University of Utah School of Medicine. Christine Friedenreich, Ph.D. of the Alberta Health Services presented a comprehensive overview of the association between specific cancers and obesity, reviewing the published literature for each cancer. At the end, she proposed that obesity was responsible for about 20% of all cancers. If (in an ideal world) obesity levels could be resolved to normal BMIs, she speculated 1.6 million deaths due to cancer could be saved, 2.2 million new cancer cases could be avoided and we could avoid having 5 million persons living with cancer.

Other key presentations addressed the powerful influence of sleep and circadian rhythms, or the lack thereof, on rising rates of obesity. This led one presenter to suggest that we should have our biggest meals at breakfast and gradually reduce caloric input throughout the day to a light salad at dinner. Rena Wing reported on the 4 year results of the Look Ahead Trial which provided persuasive information for intensive lifestyle counseling over less intensive interventions in reductions in body fat and related metabolic indicators.

Sometimes these meetings morph into abstract, perhaps irrelevant, discussions of minutia   among researchers.  At other times, you feel you are witnessing an emerging new insight into obesity and its effects. So it was today in a session, Is There Good and Bad Body Fat? chaired by Richard Bergman, editor of Obesity, and including prominent researchers, Tamara Harris, Michael Jensen (who readers may remember from our conference at the 2008 Republican National Convention) and Sam Klein. Their task was to unravel which fat was bad and which was good. Their presentations covered detailed, precise research into these tangled issues.  Why are there some obese individuals who were, nevertheless, metabolically normal? Why did bariatric surgery resolve diabetes in some cases but not others?  Why does weight loss resolve some metabolic disorders but not others? For many in the audience, these are the cutting edge questions – today – to understand the metabolic sequela of weight gain, insulin resistance, diabetes and cardiovascular disease. The presenters provided exciting new data interspersed with a camaraderie and jocularity which is the realm of highly accomplished and competitive scientists who admire each other’s works but are not going to give them an inch. Bottom line: adipose cell build up in the liver may explain many of the inconsistencies in present views of the obesity-insulin resistance-metabolic disorders axis. But, build up of adipose cell in the liver is hard to measure given today’s technology and bio-statistical resources. On the other hand, there may well be another factor, not yet identified (kind of like dark matter in astrophysics), which modulates the effects of obesity, insulin resistance and metabolic disorders. The large, enthusiastic audience no doubt left with many possible research proposals in mind to unravel this conundrum. Stay tuned, as they say, “we wait with bated breath,” for the next insight.