Study links impaired glucose metabolism in the brain to Alzheimers disease

A new study shows connections between disruptions in brain glucose metabolism and early Alzheimer’s disease symptoms.
Research increasingly suggests that Alzheimer’s disease and type 2 diabetes may stem from the same metabolic dysregulatio, as they share common roots such as problems with insulin and glucose metabolism.
In this study, researchers at the National Institute on Aging (NIA) performed autopsies on Alzheimer’s patients involved in the decades-long Baltimore Longitudinal Study of Aging (BLSA).
They analysed brain tissue samples from three groups of participants: those with visible Alzheimer’s symptoms and tangles and amyloid plaques in their brain, those who lacked symptoms but had plaques and tangles, and a control group without Alzheimer’s disease.
Glucose metabolism and brain glucose levels were measured in different areas of the brain including some that are more vulnerable to Alzheimer’s, such as the frontal and temporal cortex.
There were abnormalities in the mechanism of glucose breakdown (glycolysis) in the brains of people affected with Alzheimer’s, and this poorer ability of the brain to process glucose affected the course of the disease.
Researchers found that lower rates of glycolysis and subsequent higher brain glucose levels correlated to an increased formation of beta amyloid plaques and neurofibrillary tangles, in those with the disease.
According to researchers, reductions in brain glycolysis may be linked to the development of Alzheimer’s symptoms, like memory problems and declining cognitive abilities.
In addition to this, researchers saw a decreased activity of certain enzymes controlling glycolysis, and lower levels of glucose transporters GLUT3, in brains with Alzheimer’s disease compared to normal brains.
The research team also checked blood glucose levels in study participants years before they died and found that greater increases in blood glucose levels were associated with greater brain glucose levels at death.
Further research is however needed to determine whether these abnormalities in brain glucose metabolism are definitively connected with the severity of symptoms of Alzheimer’s or disease progression speed.
The findings were published in the journal Alzheimer’s and Dementia.