Medical briefs

SLEEP GOOD FOR ARTERIES

Participants in a study who slept an average of one hour longer each night than other participants had a lower incidence of coronary artery calcification, thought to predict future heart disease, according to a study in JAMA (Journal of the American Medical Association).

Coronary artery calcification is the buildup of calcified plaques, visible by computed tomography. Risk factors associated with it have included the male gender, older age, glucose intolerance, tobacco use, high cholesterol, high blood pressure and obesity, among others. Sleep quality and quantity has been connected to several of those factors.

Researchers at the University of Chicago tested whether objectively measured sleep duration predicted development of calcification over five years of follow-up. They included 495 men and women, 35-47, who had no detectable calcification at the beginning of the study, using CT scans. They also measured factors that could influence the results.

The incidence of calcification at five years was 12.3 percent. Adjusting for other risk factors, they found that an extra hour of sleep each night decreased the estimated odds of calcification by 33 percent.

MRI DIAGNOSES ALZHEIMER'S

MRI scans can be used to diagnose Alzheimer's disease even before the onset of symptoms, according to researchers from the Florida Alzheimer's Disease Research Center.

The disease is currently diagnosed using a process of elimination as other diseases cause similar symptoms. The diagnosis is not confirmable until after the patient's death, at autopsy, where changes to the brain can be seen. But results of the Florida study add to a growing body of evidence that suggests that MRI scans of the brain can be used to diagnose the neurodegenerative disease.

The researchers used a visual rating system to evaluate the extent of shrinkage shown on MRI scans in three parts of the medial temporal lobe of the brain, which are vital for conscious memory. They then compared the MRI brain scans of 260 people, including those with probable Alzheimer's, those with varying degrees of mild cognitive impairment, and a control group of elderly with no symptoms of memory loss.