Scientists from the University of Southern California (USC) have found that patients on medication for type 2 diabetes have a slower progression of dementia and Alzheimer’s disease. The study found that those patients with untreated diabetes developed signs of Alzheimer’s disease 1.6 times faster than people who did not have diabetes.
The paper on the study was published on March 4 in the international journal Diabetes Care.
“Our findings emphasize the importance of catching diabetes or other metabolic diseases in adults as early as you can,” said Daniel A. Nation, a psychologist at USC Dornsife College of Letters, Arts and Sciences. “Among people with diabetes, the difference in their rate of developing the signs of dementia and Alzheimer’s is clearly tied somehow to whether or not they are on medication for it.”
For the study, the scientists were comparing the “tau pathology” — the progression of the brain tangles that are the hallmark of Alzheimer’s disease. When the tangles combine with sticky beta-amyloid plaques — a toxic protein — they disrupt signals between brain cells, impairing memory and other functions.
Nation mentioned that this study may be the first to compare the rate of developing the pathology for Alzheimer’s disease and dementia among people with normal glucose levels, with prediabetes, or people with type 2 diabetes — both treated and untreated.
Nation along with Elissa McIntosh, a USC Dornsife Ph.D. candidate in psychology, analyzed data collected by the Alzheimer’s Disease Neuroimaging Initiative on 1,289 people age 55 and older. Data included biomarkers for diabetes and vascular disease, brain scans and a range of health indicators, including performance on memory tests. For some participants, they were able to analyze 10 years’ worth of data, while for others, they had one or four years.
Among 900 of those patients, 54 had type 2 diabetes but were not being treated, while 67 were receiving treatment.
Most people in the study — 530 — had normal blood sugar levels while 250 had prediabetes (hyperglycemia).
The researchers compared, among the different diabetic patient categories, the brain and spinal fluid test results that can indicate signs of amyloid plaques and the brain tangles.
“It is possible that the medicines for treating diabetes might make a difference in the progression of brain degeneration. But it’s unclear how exactly those medications might slow or prevent the onset of Alzheimer’s disease, so that is something we need to investigate,” said Nation.
Scientists are now regarding Alzheimer’s disease as the result of multiple problems, instead of being caused by only one or two. The compounding factors range from pollution exposure and genetics to heart disease and metabolic disease.