Friday, March 16, 2012

Obesity Raises Death Risk Tied To Sleeping Pills

Obesity appears to significantly increase the risk of death tied to sleeping pills, nearly doubling the rate of mortality even among those prescribed 18 or fewer pills in a year, researchers reported Friday. New findings delivered at American Heart Association meeting also show heightened risk in men and young adults

"Obesity emerged as a marker of increased vulnerability," said Robert Langer, M.D., M.P.H., at the annual American Heart Association's Epidemiology and Prevention | Nutrition, Physical Activity and Metabolism 2012 Scientific Sessions in San Diego.

"The associations between sleeping pills and increased mortality were present, and relatively stronger, even in people aged 18 to 54," said Dr. Langer, a family physician and epidemiologist with the Jackson Hole Center for Preventive Medicine in Jackson, Wyo.

"Obese patients appear particularly vulnerable, perhaps through interaction with sleep apnea," said study co-author Daniel Kripke, M.D., a psychiatrist with Scripps Clinic's Viterbi Family Sleep Center in San Diego.

He noted that sleeping pills were previously associated with more and longer pauses in breathing in people with sleep apnea.

Among obese patients, use of sleeping pills was associated with about one extra death per year for every 100 people who were prescribed the medications, Dr. Langer said.

Additionally, men who took sleeping pills were about twice as likely to die as women who received the medications, after accounting for other factors, he said.

Friday's findings were the latest to emerge from a Scripps Clinic-led study of almost 40,000 patients, which was initially published in late February in the open-access online journal BMJ Open.

(View the paper here: http://bmjopen.bmj.com/content/2/1/e000850.full)

The research was the first to show that eight of the most commonly used hypnotic drugs were associated with increased hazards of mortality and cancer, including the popularly prescribed medications zolpidem (known by the brand name Ambien) and temazepam (also known as Restoril), Dr. Kripke said.

Those drugs had been thought to be safer than older hypnotics because of their shorter duration of action but were found to have associations with excess deaths no different from the older drugs they have largely replaced.

In order to eliminate the possibility that other factors led to the results, study participants who were prescribed sleeping pills were matched with control patients of similar ages, gender and health who did not receive hypnotics.

The newest findings were delivered by Dr. Langer during an oral session at the American Heart Association conference that focused on drug safety.

For obese patients in the study who had an average body mass index of 38.8, the risk of death was 8.1 times higher on average among those who were prescribed the smallest number of pills (18 or fewer annually) when compared with similar study participants who did not take the medications. The mortality rate was 9.3 times higher on average among obese patients receiving the largest number of pills (132 or more annually).

Death was 4.6 times more likely on average among all patients who received any amount of sleeping pills.

The study cast a shadow over a growing segment of the pharmaceutical industry that expanded by 23 percent in the United States from 2006 to 2010 and generated about $2 billion in annual sales.

Using data stored in an electronic medical record that has been in place for more than a decade, the researchers obtained information on almost 40,000 patients cared for by a large integrated health system in the northeastern United States.

The research included 10,531 sleeping pill users who were prescribed the medications for an average of 2.5 years and 23,674 control participants who were not prescribed the drugs. Information came from outpatient clinic visits conducted between Jan. 1, 2002, and Sept. 30, 2006.

"It is important to note that our results are based on observational data, so even though we did everything we could to ensure their validity, it's still possible that other factors explain the associations," said co-author Lawrence E. Kline, D.O., who is medical director of the Viterbi Family Sleep Center. "We hope our work will spur additional research in this area using information from other populations."

Funding for the study came from the Scripps Health Foundation and other philanthropic sources.

The research should prompt physicians to consider alternatives to hypnotic medications, Dr. Kline said.

Clinicians at the Viterbi Family Sleep Center focus on cognitive therapy that teaches patients to better understand the nature of sleep. For example, some people suffering from insomnia might require less than the eight hours of sleep commonly recommended for each night.

Patients also can benefit from practicing good sleeping habits and relaxation, as well as taking advantage of the body's natural clock, which is driven by the rising and setting of the sun, Dr. Kline said. "Understanding how to use the circadian rhythm is a very powerful tool that doesn't require a prescription," he said.

When insomnia results from emotional problems such as depression, doctors should treat the psychological disorder rather than prescribe sleeping pills that could prove to be harmful, Dr. Kripke said.

Contacts and sources: 

Nano Rescues Skin: Shrimp Shell Nanotech For Wound Healing And Anti-Aging Face Cream


Shrimp shell nanotech for wound healing and anti-aging face cream

Nanoparticles containing chitosan have been shown to have effective antimicrobial activity against Staphylococcus saprophyticus and Escherichia coli. The materials could be used as a protective wound-healing material to avoid opportunistic infection as well as working to facilitate wound healing.

Chitosan is a natural, non-toxic and biodegradable, polysaccharide readily obtained from chitin, the main component of the shells of shrimp, lobster and the beak of the octopus and squid. Its antimicrobial activity is well known and has been exploited in dentistry to prevent caries and as preservative applications in food packaging. It has even been tested as an additive for antimicrobial textiles used in clothing for healthcare and other workers.

Now, Mihaela Leonida of Fairleigh Dickinson University, in Teaneck, New Jersey and colleagues writing in the International Journal of Nano and Biomaterials describe how they have prepared nanoparticles of chitosan that could have potential in preventing infection in wounds as well as enhancing the wound-healing process itself by stimulating skin cell growth.

The team made their chitosan nanoparticles (CNP) using an ionic gelation process with sodium tripolyphosphate. This process involves the formation of bonds between polymers strands, a so-called cross-linking process. Conducted in these conditions it precludes the need for complex preparative chemistry or toxic solvents. CNP can also be made in the presence of copper and silver ions, known antimicrobial agents. The researchers' preliminary tests show the composite materials to have enhanced activity against two representative types of bacteria.

Understanding the mechanism of inhibition of bacteria by these particles may lead to the preparation of more effective antibacterial agents. The team has also demonstrated that the CNP have skin regenerative properties in tests on skin cell fibroblasts and keratinocytes, in the laboratory, which might even have implications for anti-aging skin care products.

Contacts and sources:
Mihaela D. Leonida
Inderscience Publishers

"Nanocomposite materials with antimicrobial activity based on chitosan" in Int. J. Nano and Biomaterials, 2012, 3, 316-334

Lyme Disease Surge Predicted For The Northeastern US

Boom-and-bust acorn crops and a decline in mice leave humans vulnerable to infected ticks

Millbrook, NY – The northeastern U.S. should prepare for a surge in Lyme disease this spring. And we can blame fluctuations in acorns and mouse populations, not the mild winter. So reports Dr. Richard S. Ostfeld, a disease ecologist at the Cary Institute of Ecosystem Studies in Millbrook, NY.

What do acorns have to do with illness? Acorn crops vary from year-to-year, with boom-and-bust cycles influencing the winter survival and breeding success of white-footed mice. These small mammals pack a one-two punch: they are preferred hosts for black-legged ticks and they are very effective at transmitting Borrelia burgdorferi, the bacterium that causes Lyme disease.

Acorns  
Photo by Lori Quillen 

“We had a boom in acorns, followed by a boom in mice. And now, on the heels of one of the smallest acorn crops we’ve ever seen, the mouse population is crashing,” Ostfeld explains. Adding, “This spring, there will be a lot of Borrelia burgdorferi-infected black-legged ticks in our forests looking for a blood meal. And instead of finding a white-footed mouse, they are going to find other mammals—like us.”

For more than two decades, Ostfeld, Cary Institute forest ecologist Dr. Charles D. Canham, and their research team have been investigating connections among acorn abundance, white-footed mice, black-legged ticks, and Lyme disease. In 2010, acorn crops were the heaviest recorded at their Millbrook-based research site. And in 2011, mouse populations followed suit, peaking in the summer months. The scarcity of acorns in the fall of 2011 set up a perfect storm for human Lyme disease risk.


White-footed mouse  
mouse 
Photo by Rick Ostfeld 

Black-legged ticks take three bloodmeals—as larvae, as nymphs, and as adults. Larval ticks that fed on 2011’s booming mouse population will soon be in need of a nymphal meal. These tiny ticks—as small as poppy seeds—are very effective at transmitting Lyme to people. The last time Ostfeld’s research site experienced a heavy acorn crop (2006) followed by a sparse acorn crop (2007), nymphal black-legged ticks reached a 20-year high.

The May-July nymph season will be dangerous, and Ostfeld urges people to be aware when outdoors. Unlike white-footed mice, who can be infected with Lyme with minimal cost, the disease is debilitating to humans. Left undiagnosed, it can cause chronic fatigue, joint pain, and neurological problems. It is the most prevalent vector-borne illness in the U.S., with the majority of cases occurring in the Northeast.

Ostfeld says that mild winter weather does not cause a rise in tick populations, although it can change tick behavior. Adult ticks, which are slightly larger than a sesame seed, are normally dormant in winter but can seek a host whenever temperatures rise several degrees above freezing. The warm winter of 2011-2012 induced earlier than normal activity. While adult ticks can transmit Lyme, they are responsible for a small fraction of tick-borne disease, with spring-summer nymphs posing more of a human health threat.

Past research by Ostfeld and colleagues has highlighted the role that intact forest habitat and animal diversity play in buffering Lyme disease risks. He is currently working with health departments in impacted areas to educate citizens and physicians about the impending surge in Lyme disease.

For more information and how environmental conditions set the stage for disease risk:


Contacts and sources:
Lori M. Quillen
Cary Institute of Ecosystem Studies