STUDY: HIGH BLOOD SUGAR INCREASES ALZHEIMER’S RISK
Diabetes is considered to be a risk factor for Alzheimer’s disease (AD), but researchers wondered whether having blood sugar levels that are high, but still within the normal range, might increase a person’s risk for AD as well. To find out, the scientists focused on 124 participants in a larger AD study with median age of 64 and a family history of AD. All participants were cognitively normal and free of diabetes. The researchers assessed study participants’ blood sugar levels, and used brain scans to examine the metabolic activity in their brains. The scientists found that study participants with high-normal blood sugar levels showed reduced brain metabolism in the same regions of the brain where reduced metabolism is seen in people with AD, whether or not they carried the APOE4 genetic variant associated with increased vulnerability to AD. The findings, which were published in the April 23, 2013 issue of the journal Neurology, may lead to new ways to diagnose and treat AD while it is still in its very early stages.
HOPES RAISED FOR A VACCINE AGAINST HEROIN ADDICTION
After decades of frustration on the part of addiction researchers, a team of scientists has finally succeeded in developing a vaccine that eliminates addiction to heroin in laboratory rats—raising hopes that a similar vaccine might be available for humans sometime in the future. According to a report published May 6, 2013 in the Proceedings of the National Academy of Sciences (PNAS), the vaccine prevents heroin from reaching the brain by interacting with the drug and its metabolites while they are still in the bloodstream. Essentially, the body mounts an immune response against the heroin itself, treating it as a foreign pathogen and creating antibodies against it. Animals that were previously addicted to heroin and usually desperate to use the drug lost interest in it following vaccination, reported the researchers, who hope to secure funding for human clinical trials.
STROKE RISK DOUBLES FOR WOMEN WITH DEPRESSION
Depression may be a preventable risk factor for stroke in middle-aged women, according to a study published in the May 16, 2013 issue of Stroke: Journal of the American Heart Association. Using data from a long-running study in Australia in which women were surveyed about their mental and physical health once every three years, the researchers looked at the interaction between a history of depression and stroke incidence in 10,547 women ranging in age from 47 to 52. About 24 percent of participants in this age group reported being depressed over the 12-year period covered by the study, and medical data suggested that 177 had suffered first-time strokes. The researchers found that depressed participants had 2.4 times the risk of stroke as those who weren’t depressed. After controlling for stroke risk factors such as age, smoking, high blood pressure and diabetes, the depressed women were still 1.9 times more likely to have a stroke. The study’s lead author advised treating depression to help reduce stroke risk.
SCIENTISTS BLOCK GENE BEHIND STRESS-RELATED DAMAGE TO BRAIN
Researchers have found a way to block the actions of a gene responsible for harmful stress-related changes in the hippocampus, a key memory region of the brain. Working with human stem cells that are the source of new cells in the brain, the researchers exposed the cells to cortisol, a stress hormone that has a negative effect on neurogenesis, the creation of new brain cells. They discovered that a protein called SGK1 prolonged cortisol’s harmful effects, and that blocking SGK1 with a drug known to obstruct the protein significantly reduced the brain changes caused by stress hormones, promoting neurogenesis. Subsequent studies in animals and human blood samples confirmed these findings, according to a report published May 6, 2013 in PNAS. Because a reduction of neurogenesis is considered part of the process leading to depression, the researchers believe that developing pharmacological agents designed to reduce levels of SGK1 in depressed patients might be a potential strategy for future antidepressant treatments.