(Courtesy Daniel P Urban DDS) 

More than 12,000 people were interviewed in their homes and questioned about snoring.

It is estimated that about 40% of adult males and 24% of adult females are habitual snorers.  For several years now, scientists have been aware of a relationship between snoring and cardiovascular disease.  However a team of Hungarian scientists interviewed 12,000 patients to assess any correlation.

The research discovered that compared to the rest of the population, loud snorers had a 34% increased risk of having a heart attack, and a 67% greater chance of suffering a stroke.

The researchers say that loud snoring with breathing pauses could be used to help identify people at risk from these diseases.

The data also highlighted the fact that people who snore quietly had no increase in their risk of cardiovascular illness.

Elaine Warburton  www.geneticsandhealth.com

Caenorhabditis elegans (C.elegans)

I’m sure like all of you with young kids, I don’t get enough sleep. I don’t need much naturally but an extra hour or so here and there would be great!  The roundworm C. elegans, a staple of laboratory research, may be key in unlocking one of the central biological mysteries: why do we sleep?

Researchers at the University of Pennsylvania School of Medicine report in this week’s advanced online edition of Nature that the round worm has a sleep-like state, joining most of the animal kingdom in displaying this physiology. This research has implications for explaining the evolution and purpose of sleep and sleep-like states in animals.

In addition, genetic work associated with the study provides new prospects for the use of C. elegans to identify sleep-regulatory genes and drug targets for sleep disorders.

The research showed that there is a period of behavioral quiescence during the worm’s development called lethargus that has sleep-like properties. “Just as humans are less responsive during sleep, so is the worm during lethargus,” explains lead author David M Raizen. “And, just as humans fall asleep faster and sleep deeper following sleep deprivation, so does the worm.”

By demonstrating that worms sleep, Raizen and colleagues have not only demonstrated the need for sleep in nature, but also propose a compelling hypothesis for the purpose for sleep.  The time of lethargus coincides with a time in the round worms’ life cycle when synaptic changes occur in the nervous system.  In other words, in order for the nervous system to grow and change, there must be down time of active behavior. Other researchers at Pennsylvania have shown that, in mammals, synaptic changes occur during sleep and that deprivation of sleep results in a disruption of these synaptic changes - often resulting in changes to mood and normal behavior.

In addition, the research team used C. elegans as a model system to identify a gene that regulates sleep. This gene, which encodes a protein kinase and is regulated by a small molecule called cyclic GMP, has been previously studied but not suspected to play a role in sleep regulation. The findings suggest a potential role for this gene in regulating human sleep and may provide an avenue for developing new drugs for sleep disorders.

Elaine Warburton

Earlier this week, the National Sleep Foundation reported that more than half of American women are suffering from sleep deprivation. These women are too tired to have a good work and personal life and are completely stressed out. (I’m sure many of us can identify!) And if they also happen to have the long version of the PER3 gene, they’d also have issues with cognitive function.

A small study of 24 people, half of whom carried two copies of the long version of PER3 and the other half with two copies of the short version, found that those with the long version performed poorly on cognitive function tests after being deprived of sleep for 24 hours. People with the long version of PER3 also spend more of their sleep time in deep sleep suggesting that they need more of this type of restorative sleep than others.

It’s estimated that 10% of people in the UK have two copies of the long version of PER3. They’re probably more susceptible to sleep deprivation and have trouble working odd hours. Worst of all, bad moods have a lot to do with how little sleep a person gets. So combined with the serotonin receptor 2C gene, mood swings are inevitable in our household.

New Scientist, March 8, 2007

A study of one-year-olds has found that children of parents who snore are three times as likely to snore as well. What’s the biggie? Children who suffer from severe snoring tend to have:

• Poor school performance
• Cardiovascular problems
• Daytime behavioral problems, e.g., attention-deficit hyperactivity disorder

Does this finding warrant this opening salvo from The New York Times?

Title: In the Genes: When the Littlest Family Member Snores, Too

Opening Sentence: Snoring may be genetic.

May I remind everyone that just because a family tends to have a particular trait like snoring doesn’t mean that it’s mainly due to genetics. As the article later goes on to point out, allergies play an important role as well; a positive allergy test almost doubled the risk for snoring. No definitive sleep disorder examination in a sleep laboratory was performed in this study and neither were any candidate genes identified.

Time to review genetics quiz #1: Genetic = Inherited?