Patients with Alzheimer’s disease and their families are often surprised when they read Dr. Hamid Okhravi’s notes in their file and see the words “probable Alzheimer’s.”
They ask what that means, because they thought the diagnosis was definite, said Okhravi, medical director of the memory consultation clinic at Eastern Virginia Medical School, now part of Old Dominion University. But he said Alzheimer’s, the most common cause of dementia, can’t be diagnosed definitively without a brain biopsy — which typically only happens after death.
Almost 120 years after Dr. Alois Alzheimer first identified, via autopsy, the characteristic ways Alzheimer’s changes the brain, many aspects of the disease remain a mystery. But Okhravi hopes to find a few more clues in a study of whether a common diabetes drug can help prevent dementia due to Alzheimer’s. EVMS recently joined the nationwide research effort, which is recruiting participants in Hampton Roads.
The study, led by Columbia University and sponsored by the National Institutes on Aging, attempts to determine whether metformin, the most common drug prescribed for diabetes, could help prevent early memory loss. Researchers believe there is a potential link between insulin resistance and neurodegenerative disorders. Metformin lowers glucose, the main blood sugar found in the human body, and increases sensitivity to insulin, a hormone that regulates blood sugar levels.
Those effects may help prevent mild cognitive impairment, Okhravi said.
“MCI is really a stage between normal age-related memory loss you see in people when they get older and the serious decline of dementia,” he said. “About 1 to 2 out of 10 people with MCI probably progress to a stage of dementia in a one-year period. But this number actually goes up to 60% five years after developing mild cognitive impairment.”
Mild cognitive impairment can be hard to recognize. In an Alzheimer’s Association survey, more than 50% of Americans thought a description of it sounded like “normal aging.”
Symptoms include losing things like eyeglasses, keys, cell phones and remote controls, forgetting to go to important appointments and events and having more trouble coming up with names and phrases than other people the same age, Okhravi said. Diagnosis usually requires separate clinical interviews with the patient and with a spouse or close family member and a standardized memory test.
“Essentially, we can figure out if this is a different trajectory from age-related memory issues,” Okhravi said.
The earlier Alzheimer’s is caught, the better the chances of delaying the progression of the disease, he said, and in some cases, it can be caught very early — up to 20 years before any symptoms develop.
That information comes from a separate research effort in which Okhravi participates, called the Ahead Study, run by a consortium of leading academic Alzheimer’s research centers. It has found that a buildup of amyloids, a protein in the brain, may begin up to two decades before people notice symptoms like memory impairment.
This kind of study is particularly important because although mild cognitive impairment can be determined clinically fairly well, Alzheimer’s is very hard to diagnose based on clinical evaluation alone.
“Even the best people in the field, there is a 36% chance that we may make a mistake or a not accurate diagnosis,” Okhravi said. “When we think a person has Alzheimer’s, 36% of the time they did not have Alzheimer’s.”
PET scans, imaging used to build 3D images of internal tissue, can accurately diagnose Alzheimer’s over 90% of the time, he added.
Given a potential two-decade window of time to fight progression of the disease, the opportunity to slow it down with metformin — which is widely available and inexpensive — could present a major breakthrough.
“Right now, there aren’t many options for preventing Alzheimer’s,” he said. “This study could lead to new ways to keep people healthy and improve quality of life as they age.”
Learn more about the study at evms.edu/research/current_clinical_trials/.
Have a health care or science story, question or concern? Contact Katrina Dix, 757-222-5155, katrina.dix@virginiamedia.com.
