WEDNESDAY, Jan. 7 (HealthDay News) -- Researchers have identified nine genes that might make people more likely to develop Alzheimer's disease.

In addition, they confirmed earlier reports that a variation in the vitamin D3 receptor gene, on chromosome 12, might also increase risk for Alzheimer's. Low levels of vitamin D have been found in people with Alzheimer's and other dementias, leading researchers to suspect a link.

"The vitamin D3 receptor finding on chromosome 12 is really exciting, because it implicates a potential biological pathway that has been of interest in neurological disorders," researcher Jonathan L. Haines, of Vanderbilt University Medical Center, said in a news release from the University of Miami Miller School of Medicine. Researchers from the university's Miami Institute for Human Genomics collaborated on the study with colleagues from Vanderbilt's Center for Human Genetics Research.

In their study, the researchers compared 550,000 genetic variations in about 500 people with Alzheimer's and 500 people without the disease

Their findings, published in the January issue of The American Journal of Human Genetics, "open the door for increased understanding of this important neurological disorder," researcher Margaret A. Pericak-Vance, of the Miami institute, said in the news release.

"We now have exciting new directions to explore," she said.

The identification of new Alzheimer's genes could lead to a better understanding of the causes of Alzheimer's, the most common type of dementia among older people. Currently, doctors and scientists remain uncertain about what starts the irreversible and progressive brain disease.

More information

To learn more about Alzheimer's disease, visit the U.S. National Institute of Neurological Disorders and Stroke.

TUESDAY, Jan. 6 (HealthDay News) -- Implanted cardioverter defibrillators (ICDs), which deliver an electric shock to prevent sudden death when a heart stops beating properly, improve survival in people 75 and older, new research suggests.

The finding contradicts several earlier studies, notably a 2007 report from Canada that said the benefits of ICDs were limited for older people.

"Their discussion looked at defibrillators in patients who were older and sicker," said Dr. Paul Chan, an assistant professor of medicine at the University of Missouri in Kansas City, and lead author of the new report. "It found use of defibrillators was limited, because they were more likely to die. But there was no control group, no comparison with a group of similar patients who did not get defibrillators."

The new study did have such a control group. It looked at results for 500 people who got ICDs because their left ventricles, which pump blood to the body, were functioning at no more than 35 percent of capacity. The study compared those results to those for a similar number of people with the same condition who did not get ICDs.

"We found that older people were more likely to die," Chan said, "but in this older group of patients, we still found they got a benefit from the defibrillator, similar to that seen in the other age groups."

Over the course of the six-year study, the overall death rate was 26.7 percent for the non-ICD group and 21.6 percent for the ICD group. This 30 percent reduction in deaths was the same for people 75 and older as well as younger recipients.

The results, published in the Jan. 7 issue of the journal Circulation: Cardiovascular Quality and Outcomes , indicate that "we shouldn't be denying defibrillators that may be life-saving specifically because of age," Chan said.

He acknowledged that the finding "needs to be validated in other studies with larger populations."

Another factor that must be considered is whether the potential recipient has already experienced a life-threatening heart arrhythmia (irregular heartbeat) or similar event, said Dr. Gordon F. Tomaselli, a professor of medicine at Johns Hopkins University School of Medicine, and a spokesman for the American Heart Association.

"If there has been a life-threatening arrhythmia, and the patient is otherwise healthy, I would be much more inclined to recommend a defibrillator," Tomaselli said. "For primary prevention, when no such event has yet occurred, I would be a lot more cautious about people in their eighth and ninth decades of life, and would carefully consider their comorbidities (more than one illness)".

"Age and comorbidities are the key factors I consider when a patient might require a defibrillator," he said.

More information

Learn more about implanted defibrillators at the American Heart Association  .

TUESDAY, Jan. 6 (HealthDay News) -- The largest study of its kind finds that deep brain stimulation improves both physical function and quality of life after six months in patients with Parkinson's disease.

Deep brain stimulation (DBS) performed better than currently available drug treatments, but it did carry some risks, including one death, according to a study in the Jan. 7 issue of the Journal of the American Medical Association.

"This basically corroborates what has largely emerged over the last decade from literature and clinical experience showing pretty dramatically the potential benefit of DBS for Parkinson's," said Dr. Fred Marshall, medical director of the deep brain stimulation program at the University of Rochester Medical Center, in New York.

Despite abundant clinical experience, there have been few controlled trials on the topic, added colleague Dr. Irene Richard, an associate professor of neurology and psychiatry at the University of Rochester Medical Center. "This is corroborative, that surgery is helpful, but it is associated with more risk."

Deep brain stimulation, approved for Parkinson's by the U.S. Food and Drug Administration in 2002, is relatively widely used in patients with advanced Parkinson's who are no longer being helped by drugs.

"First-line medication works quite well for some window of time, occasionally one's whole life, but typically, a patient takes more and more medications more often. Their life is ruled by medication to maintain a decent function," said study co-author Dr. William J. Marks Jr., an associate professor of neurology at the University of California, San Francisco, and director of the San Francisco VA Parkinson's Disease Research, Education & Clinical Center.

Marks has served as a consultant to Medtronic, the manufacturer of the DBS device, as have other members of the study team. The trial was funded by the VA, the U.S. National Institute of Neurological Disorders and Stroke, and Medtronic.

As Parkinson's advances, motor symptoms are often accompanied by anxiety, depression and other non-motor symptoms.

Generally, DBS, a procedure which involves placing a thin wire that can carry electrical currents deep within the brain, is performed after patients are already failing on their medications.

For this study, 255 Parkinson's patients were randomized to receive either DBS or "best medical therapy." One-quarter of the participants were 70 or older, a population underrepresented in previous trials.

DBS was targeted either to the subthalamic nucleus (same as current practice) or to the globus pallidus; results of that comparison are forthcoming.

After six months, participants in the DBS arm gained about 4.6 hours per day of "on time," meaning time without troubling movement problems, compared with no gain for patients on best medical therapy.

Seventy-one percent of DBS patients, and only 32 percent of patients in the control group, experienced "clinically meaningful motor function improvements." Those receiving DBS also reported improvements in quality of life.

However, at least one serious adverse event occurred in 49 of the DBS patients vs. 15 in the other group.

Those receiving DBS also experienced small problems with cognitive functioning similar to patterns seen in previous studies and had more falls resulting in fractures and other injuries.

Although both younger and older patients gleaned similar benefits from DBS, older patients were more prone to adverse effects.

This "landmark" study, said Marks, "proved superior for such patients, rather than a tweak-and-adjustment [of medications] approach."

Hopefully, he added, the findings will encourage more neurologists to consider DBS for appropriate patients.

"I think this is going to spur those people who have still been on the fence about DBS to feel comfortable with it," Marshall said.

"This study, to me, confirms the tremendous usefulness of the procedure in spite of the warning, of course, that there were certain adverse effects," said Dr. Carlos Singer, director of the Parkinson's Disease Center and a professor of neurology at the University of Miami Miller School of Medicine. "It means that we have to continue refining our selection of patients. You don't want to be overzealous in picking up patients . . . take into account that the surgery was not effective for everybody."

More information

Visit the U.S. National Institute of Neurological Disorders and Stroke for more on Parkinson's disease.

MONDAY, Jan. 5 (HealthDay News) -- More and more people with diabetes are living to older ages, thanks to medical advances. But the long-term facilities, such as nursing homes, that care for aging Americans may not be ready for the additional challenges that come with treating patients with diabetes.

"We need to spend appropriate time to think of a way to successfully provide care for people with diabetes as they enter their elder years, and we're just beginning to understand how to do that," said Dr. Paul Strumph, vice president and chief medical officer for the Juvenile Diabetes Research Foundation.

Although as many as one in four nursing home residents has diabetes, not all are getting care that meets the American Diabetes Association's goals for community-dwelling adults, according to a recent study.

The study, published in Diabetes Care, found that while 98 percent of nursing home residents with diabetes had their blood glucose levels monitored, only 38 percent met short-term glucose goals.

The better news from the study was that 67 percent of the nursing home residents with diabetes met their long-term glucose control goals, which meant they scored less than 7 percent on their A1C tests. A1C is a measure of long-term blood sugar control.

"One of the key differences in managing diabetes in a nursing home is that it's often not the condition of primary importance," said Helaine Resnick, director of research at the Institute for the Future of Aging Services for the American Association of Homes and Services for the Aging.

Resnick said one of the concerns she had with the study findings was that no one has yet to come up with specific guidelines for caring for elderly people with diabetes. Glucose control goals for someone who's 40 and living at home may well be different than for someone who's 85, cognitively impaired, and living in a long-term care facility, she said.

"Diabetes medications are designed to lower glucose levels, which can prevent complications from developing in diabetic people. But, when you take medicines to lower blood glucose, it can go too low, which can be extremely dangerous, especially for older adults," Resnick said, noting that it's difficult to find "the appropriate balance between keeping sugars low with the risk of keeping it too low."

Strumph pointed out that the needs of older people with diabetes may be different as well. People with type 1 diabetes and people with type 2 diabetes who need insulin often choose to use an insulin pump when they're younger, but pumps may not be the best choice for someone who's older and not as aware, he said.

"Someone in a nursing home could pull out a pump site and not know. In that case, you may want to be on a longer-acting insulin instead. We haven't yet defined what the ideal insulin [regimen] is for someone in a facility with a fairly predictable schedule," Strumph said.

Both Strumph and Resnick said it's important for family members, the nursing home resident, and the staff to come up with a realistic care plan.

"Families need to become more actively involved in working with care teams, and that's true for diabetes and for other conditions. Ensure that the facility understands the family's and the resident's preferences. Is your mother more interested in keeping her blood glucose control tight and risk [low blood sugar]? Or is it better for her to ease up on glucose control and work more on quality-of-life issues? Resnick said.

"Families have to be very involved, and the communication needs to be ongoing, because people's values can change," she added.

More information

For tips on selecting a nursing home, visit the AARP Web site  .