Making Science More Better For You on 01/02/08

Headline of the day
Cops seek help finding man in a flowered sundress (The obscure store)


This what happens when everyone is above average

Survey: Most U.S. adults in good health

ATLANTA, Jan. 2 (UPI) -- Sixty-one percent of U.S. adults say they are in excellent or very good health, but 62 percent say they never participate in any type of physical activity.

The 2006 National Health Interview Survey, conducted by the Centers for Disease Control and Prevention's National Center for Health Statistics, provides national estimates for a broad range of health measures for the U.S. civilian non-institutionalized adults.

The survey also found that 16 percent of adults did not have a usual place of healthcare, 11 percent had been told by a doctor or health professional that they had heart disease and 23 percent had been told on two or more visits that they had hypertension.

Twenty-one percent of all adults were current smokers and 21 percent were former smokers. Based on estimates of body mass index, 35 percent of adults were overweight and 26 percent were obese, the survey said.

The sample for the NHIS is redesigned and redrawn about every 10 years to better measure the changing U.S. population and to meet new survey objectives. A new sample was implemented in 2006 and data were collected for 24,275 adults.


Is that what they mean by sweet dreams?

Lack Of Deep Sleep May Increase Risk Of Type 2 Diabetes

ScienceDaily (Jan. 2, 2008) — Suppression of slow-wave sleep in healthy young adults significantly decreases their ability to regulate blood-sugar levels and increases the risk of type 2 diabetes, report researchers at the University of Chicago Medical Center.

Deep sleep, also called "slow-wave sleep," is thought to be the most restorative sleep stage, but its significance for physical well-being has not been demonstrated. This study found that after only three nights of selective slow-wave sleep suppression, young healthy subjects became less sensitive to insulin. Although they needed more insulin to dispose of the same amount of glucose, their insulin secretion did not increase to compensate for the reduced sensitivity, resulting in reduced tolerance to glucose and increased risk for type 2 diabetes. The decrease in insulin sensitivity was comparable to that caused by gaining 20 to 30 pounds.

Previous studies have demonstrated that reduced sleep quantity can impair glucose metabolism and appetite regulation resulting in increased risk of obesity and diabetes. This current study provides the first evidence linking poor sleep quality to increased diabetes risk.

"These findings demonstrate a clear role for slow-wave sleep in maintaining normal glucose control," said the study's lead author, Esra Tasali, MD, assistant professor of medicine at the University of Chicago Medical Center. "A profound decrease in slow-wave sleep had an immediate and significant adverse effect on insulin sensitivity and glucose tolerance."

"Since reduced amounts of deep sleep are typical of aging and of common obesity-related sleep disorders, such as obstructive sleep apnea these results suggest that strategies to improve sleep quality, as well as quantity, may help to prevent or delay the onset of type 2 diabetes in populations at risk," said Eve Van Cauter, PhD, professor of medicine at the University of Chicago and senior author of the study.

The researchers studied nine lean, healthy volunteers, five men and four women between the ages of 20 and 31. The subjects spent two consecutive nights in the sleep laboratory, where they went to bed at 11 P.M., slept undisturbed but carefully monitored, and got out of bed 8.5 hours later, at 7:30 A.M.

The same subjects were also studied for three consecutive nights during which they followed identical nighttime routines. During this session, however, when their brain waves indicated that they were drifting into slow-wave sleep they were subtly disturbed by sounds administered through speakers beside the bed.

These sounds were loud enough to disrupt deep sleep but not so loud as to cause a full awakening. This technique enabled the researchers to decrease slow-wave sleep by about 90 percent, shifting the subjects from the onset of deep sleep (stage 3 or 4) to a lighter sleep (stage 2) without altering total sleep time.

"Our system proved quite effective," Tasali said. When asked about the sounds the next morning, study subjects vaguely recalled hearing a noise "three or four times," during the night. Some recalled as many as 10 to 15. On average, however, subjects required about 250-300 interventions each night, fewer the first night but more on subsequent nights as "slow-wave pressure," the body's need for deep sleep, accumulated night after night.

"This decrease in slow-wave sleep resembles the changes in sleep patterns caused by 40 years of aging," Tasali said. Young adults spend 80 to 100 minutes per night in slow-wave sleep, while people over age 60 generally have less than 20 minutes. "In this experiment," she said, "we gave people in their 20s the sleep of those in their 60s."

At the end of each study, the researchers gave intravenous glucose (a sugar solution) to each subject, then took blood samples every few minutes to measure the levels of glucose and insulin, the hormone that controls glucose uptake.

They found that when slow-wave sleep was suppressed for only three nights, young healthy subjects became about 25 percent less sensitive to insulin. As insulin sensitivity decreased, subjects needed more insulin to dispose of the same amount of glucose. But for eight of the nine subjects, insulin secretion did not go up to compensate for reduced effects. The result was a 23 percent increase in blood-glucose levels, comparable to older adults with impaired glucose tolerance.

Those with low baseline levels of slow-wave sleep had the lowest levels after having their sleep patterns disrupted and the greatest decrease in insulin sensitivity.

The alarming rise in the prevalence of type 2 diabetes is generally attributed to the epidemic of obesity combined with the aging of the population. "Previous studies from our lab have demonstrated many connections between chronic, partial, sleep deprivation, changes in appetite, metabolic abnormalities, obesity, and diabetes risk," said Van Cauter. "These results solidify those links and add a new wrinkle, the role of poor sleep quality, which is also associated with aging."



Parental bias and sibling rivalry. Pretty interesting stuff, considering the research focused on beetles.


Parents Show Bias In Sibling Rivalry, Says Study

ScienceDaily (Jan. 2, 2008) — Most parents would hotly deny favouring one child over another but new research suggests they may have little choice in the matter.

Biologists studying a unique species of beetle that raises and cares for its young have found that parents instinctively favour the oldest offspring.

The University of Manchester research -- published in Ecology this month -- supports the findings of studies carried out on human families but is significant in that it suggests a wholly natural tendency towards older siblings.

"The burying beetle Nicrophorus vespilloides has a similar family structure to that of a human family unit in that there are two parents, a number of offspring and interactions between parents and their young," said Dr Per Smiseth, who led the research in the University's Faculty of Life Sciences.

"Of course human families are more complex and parent-child relationships are much more sophisticated. However, studying this beetle can help us understand the basic biological principles of how family relationships work.

"Our study looked at how the parent beetles mediate competition between different aged offspring compared to what happens when the young were left to fend for themselves and indicates that parental decisions are important in determining the outcome of competition between offspring."

The beetles, which are native to Britain, give birth to a batch of about 20 young in the carcass of a dead animal over a period of 30 hours. The parents feed the young grubs on regurgitated flesh from the carcass.

The young beetles are able to feed themselves but they grow more quickly and become larger when fed by their parents. By generating experimental broods comprising two sets of offspring, one set of older grubs and one younger set, the scientists were able to study their development, first with the parents present and then when left to fend for themselves.

"When both sets of grubs were left to fend for themselves they grew at the same rate and matured to an equal size," said Dr Smiseth, whose research is funded by the Natural Environment Research Council and the Medical Research Council.

"However, when we allow the parents to remain with the offspring, there is clear favouritism towards the older siblings, which grow at a faster rate as they take the lion's share of their parents' offerings."

The team believes there are two explanations for the behaviour: the first is that the parents attach more value to the older offspring as their maturity gives them a better chance of survival than their younger siblings.

The second explanation is that the older grubs, being stronger, are able to dominate their younger rivals and, in doing so, better attract the attention of the parents when begging for food.

"Even if this second theory is true, the parents are still complicit in the bias towards the older siblings," said Dr Smiseth. "However, the true answer is probably some combination of the two explanations.

"The research tells us something about the relationships within families. We have this view that families are harmonious and that the overriding concern is to help one another. This is true to an extent but it's not to say that families are not without conflict, especially