Short Sleep Adds to Colon Cancer Risk

A new study shows sleeping less than six hours per night may increase your risk to develop a key sign of early colon cancer by about 50 percent. Patients who reported short sleep durations are far more likely to be diagnosed with colorectal adenomas, a precursor to cancer tumors.

The study involved 1,240 patients scheduled for colonoscopies. The screening results found about 350 of the patients had colorectal adenomas.

Prior to the screening, each patient answered questions about sleep habits from the Pittsburg Sleep Quality Index. Patients reported their overall sleep quality during the past month, frequency of insomnia and other details related to sleep.

Study results show colorectal adenomas appeared more frequently among patients who said they slept fewer than six hours each night. The findings were adjusted for other risk factors for colon cancer, such as family history, smoking and obesity.

It’s still not known why short sleep duration may increase the risk for colon cancer. The lead author of the study speculates it may be because of the decrease in melatonin production or the increase in insulin resistance from sleep deprivation.

Colon cancer isn’t the only serious health risk related to sleeplessness. Short sleepers have a higher risk of obesity, diabetes and heart disease. Last year a study found men with chronic insomnia have four times the risk of death compared to men who slept more than six hours per night.

The latest findings clearly demonstrate the importance of sleep to your overall health. Do your body a favor and make sleep a health priority, along with diet and exercise.

Irregular Sleep in Early Pregnancy Linked to Hypertension Later

Adopt healthy sleep habits early in pregnancy and your body will thank you later. Research shows too much or too little sleep during near the beginning of pregnancy can lead to hypertension and potentially serious complications during the third trimester.

Women who sleep about nine hours night have significantly lower systolic and diastolic blood pressure compared to pregnant women with unhealthy sleep habits, researchers at the University of Washington report.

Abnormal sleep duration is also associated with preeclampsia, a condition linked to pregnancy induced hypertension and excess protein in urine. Preeclampsia can lead to serious or fatal complications if left untreated.

The study published in the October 2010 issue of the journal SLEEP measured the blood pressure of more than 1,200 healthy, pregnant women immediately after childbirth. During early pregnancy, each answered the question, “since becoming pregnant, how many hours per night do you sleep?”

About 1 in 5 women said they slept nine hours per night - the normal sleep duration for pregnant women. More than half the women slept seven to eight hours per night. About 14 percent of women slept less than six hours, and around 10 percent of women slept 10 hours or more.

Short sleepers and long sleepers had an average systolic blood pressure of 118.05 mm Hg and 118.90 mm Hg, respectively. Healthy sleeping pregnant women had much lower average blood pressure, at 114 mm Hg. The National Heart, Lung, and Blood Institute reports a systolic blood pressure reading of 140 mm Hg or more is considered high.

Short sleepers also had a 10 times higher preeclampsia rate. Overall, about 6.3 percent of study participants were diagnosed with preeclampsia or pregnancy induced-hypertension.

Sleep patterns tend to change throughout pregnancy due to shifting hormone levels. Pregnant women tend to sleep longer than normal adults.

Read more about Sleep & Pregnancy at Sleepeducation.com.

Photo by Bethykae

Work & Sleep: Are Adults Sleeping Less in the U.S.?

Have adults in the U.S. been getting less sleep over the past three decades? A new study examined time-use surveys to find out. The results were published in the Jan. 1 issue of the journal Sleep.

The study analyzed data from eight time-use surveys. The earliest survey was conducted in 1975. The most recent data came from the 2006 American Time Use Survey.

Surveys were completed by more than 73,000 adults. They were at least 18 years of age. “Short sleep” was defined as less than six hours of sleep, nap or rest in a 24-hour period.

Results show that the overall odds of being a short sleeper have not increased over the past 31 years. The highest proportion of short sleepers was 11.8 percent in the 1998-99 survey. The lowest proportion was 7.5 percent in the 1992-94 survey. The proportion was 9.3 percent in the 2006 survey.

“The assertion that sleep durations have declined drastically in the U.S. population in general over the past 30 years may be inaccurate,” wrote the authors.

But the study did find a significant trend for full-time workers. Their odds ratio for short sleep was increased by 19 percent.

“Longer work times seem to be the most important cofactor for short sleep,” the authors concluded.

Unmarried adults, those with some college education, and African Americans also had higher odds of short sleep. Women, older adults, Asians, Hispanics and married people were less likely to be short sleepers.

The authors noted that the 24-hour time-use surveys split the sleep period. They combined the end of one night of sleep with the beginning of the second night of sleep. Daytime sleep also was added to the total.

And time categorized as “sleep” included activities such as “resting” and “getting up.” Thus the time-use surveys may have overestimated true sleep time.

Dr. Mathias Basner wrote a commentary on the study in the same issue of Sleep. He noted that chronic, partial sleep deprivation remains an important public health issue.

Why do millions of Americans put their health at risk by failing to get enough sleep? One reason may be that short sleepers simply adjust to regular sleep loss.

“Those who do need more sleep simply may have habituated to feeling sleepy,” Basner wrote. “Many of the short sleepers may have ‘forgot­ten’ how well they could feel and perform if they satisfied their individual sleep need.”

In October the Sleep Education Blog reported on new survey data about the sleep of people in the U.S. In May it took a closer look at time-use survey data.

The “Short Sleep” Gene: When Six Hours is Enough

A new study reports the discovery of the first gene involved in regulating the length of human sleep. A rare mutation in the “DEC2” gene enables some people to function well on only six hours of sleep per night.

“Subjects with the mutation are able to live unaffected by shorter amounts of sleep throughout their lives,” senior author Ying-Hui Fu, PhD, said in a UC San Francisco statement.

Researchers identified the gene mutation in a mother and daughter; both women go to bed around 10 or 10:30 p.m. and wake up at 4 or 4:30 a.m. without an alarm, reports the New York Times.

"It's not like they have sleep problems, they just don't sleep as much," Fu told NPR.

But do people with the mutated gene really need less sleep? Or does the mutation prevent them from getting enough sleep?

“Right now all we can say is that they sleep less,” Fu told Science News. “Whether they need less, we don’t know.”

We also don’t know if the effect of the gene mutation could be replicated by a drug. Could there be a “short sleep” drug in the future? And would it be safe? It could be decades before we know, reports WebMD.

How common is the “short sleep” gene? USA Today reports that it is found in less than three percent of people.

In contrast, the CDC estimates that from 2004 to 2006, about 21 percent of U.S. adults usually slept for only six hours in a 24-hour period; about 8 percent reported sleeping less than 6 hours.

This means that most of the people who try to get by on six hours of shut-eye are depriving themselves of the sleep they need. This is called behaviorally induced insufficient sleep syndrome. The sleep loss produces daytime symptoms such as fatigue, irritability and poor concentration.

“Many people get only six hours of sleep a night, but we drink coffee and tea to make ourselves stay up,” Fu told the New York Times. “That’s a very different thing.”

The AASM reports that a true short sleeper will function well on five hours of sleep or less; there will be no daytime impairment. There also will be no need to “catch-up” on sleep during the weekend.

Most adults need about seven to eight hours of sleep per night. In 2008 people in the U.S. reported sleeping an average of 8.6 hours in a 24-hour period.

Learn more about the study on SleepEducation.com.