Previous research has suggested that diabetes may be a risk factor for Alzheimer's, but University of Arizona researchers wanted to examine if high blood sugar levels in people without diabetes may also increase the chances of developing Alzheimer's.
The study included 124 people, aged 47 to 68, who were diabetes-free and had normal brain function, but did have a family history of Alzheimer's. The participants underwent scans that revealed metabolic activity in the brain.
People with Alzheimer's disease show reduced brain metabolism in certain brain regions. A similar pattern of lower metabolism in these same brain regions was seen in study participants with high blood sugar levels.
Study author Christine Burns, a pre-doctoral student in psychology, said she hopes the findings will be useful in ongoing work designed to develop early Alzheimer's interventions.
"A lot of valuable research is focused on treatment and slowing decline in Alzheimer's patients," she said. "I'm interested in complementing this work with interventions that can be implemented earlier on, perhaps at middle age."
The findings were published in the journal Neurology.
About 5 percent of Americans aged 65 to 74 have Alzheimer's, and nearly half of those aged 85 and older may have the progressive brain disease, according to the U.S. Centers for Disease Control and Prevention. Known factors that contribute to the disease include age and genetics, but it is also believed that high blood pressure, high cholesterol and diabetes may increase risk.
The study found an association between Alzheimer's disease and high blood sugar. It didn't show a cause-and-effect relationship.