In Alzheimer research, glucose metabolism moves to center stage

Researchers suspect that reduced glucose metabolism, often present in brain scans of patients with Alzheimer disease (AD) and other dementias, may have a bigger role in dementia pathology than previously thought.

Researchers suspect that reduced glucose metabolism, often present in brain scans of patients with Alzheimer disease (AD) and other dementias, may have a bigger role in dementia pathology than previously thought. "We're starting to try to understand how [brain glucose metabolism] could be more of a causal player in the disease, and a modifiable player," says Shannon Macauley, PhD, with the Alzheimer's Disease Research Center at Wake Forest School of Medicine in Winston-Salem, NC. The possibilities are many, including that AD could be a brain-specific "type 3" diabetes. Other theories hinge on diabetic traits—ranging from insulin resistance in the brain to sleep loss to increased stroke risk—that, in turn, may contribute to an AD diagnosis. "At the very least, diabetes creates a hit that makes the brain more susceptible to other conditions of aging, such as Alzheimer disease or neurodegeneration in general," says Jose Luchsinger, MD, MPH, of Columbia University Irving Medical Center in New York City. With that in mind, researchers are turning their focus to possible ways to slow or prevent dementia using metformin and other drugs typically used to treat conditions such as diabetes or obesity. They also are tinkering with metabolism-boosting lifestyle interventions, including dietary modifications and exercise, as a way to deflect cognitive impairments. Study results have been mixed so far.