Thursday, August 12, 2021 (HealthDay News) — Older adults who take certain diabetes medications may see a slower decline in their memory and thinking skills, a new study suggests.
Researchers in South Korea found that among older adults with memory problems, those using diabetes drugs called DDP-4 inhibitors typically showed slower progression of those symptoms over the next few years. This was compared with both older adults without diabetes and those taking other diabetes medications.
People taking DDP-4 inhibitors also showed smaller amounts of “plaques” building up in the brains of people with Alzheimer’s disease.
Experts cautioned that the results do not prove that the drugs can prevent or delay mental illness.
To do this, researchers will need to conduct Clinical trials Testing drugs are straightforward, said Dr. Howard Villette, chief scientific officer of the Alzheimer’s Drug Discovery Foundation in New York City.
But, he said, the study adds to the evidence that some existing drugs — including some for diabetes or… high blood pressure They can be ‘redirected’ to protect the aging brain.
In fact, other diabetes drugs, such as metformin And GLP-1 agonists, they are already being studied to slow the decline in memory and thinking skills.
Villette said there is little research on DDP-4 inhibitors — which include oral medications such as sitagliptin (Januvia), linagliptin (Tradjenta), saxagliptin (Onglyza) and alogliptin (Nesina). They share similarities with GLP-1 agonists, in that they act on the same “path” in the body.
Villette explained that DDP-4 inhibitors work by increasing blood levels of GLP-1, the gut hormone that stimulates insulin secretion. Insulin is a hormone that regulates Blood sugar.
People with diabetes are resistant to InsulinThis leads to chronically elevated blood sugar levels. Some studies have found that people with Alzheimer’s disease also have problems with insulin resistance – and researchers have speculated that this may contribute to the brain degeneration seen in the disease.
But Villette said diabetes medications may have effects beyond improving insulin resistance.
Animal research has suggested that DDP-4 inhibitors can reduce brain inflammation and protect brain cells from Alzheimer’s-like injury.
For the current study, researchers led by Dr. Phil Heo Lee of Yonsei University School of Medicine in Seoul reviewed 282 patients who came to their clinic with complaints about their memory and thinking abilities. Brain scans showed that they all contained evidence of amyloid – the protein that makes up the plaques associated with Alzheimer’s disease.
Of these patients, half had diabetes: 70 were taking a DDP-4 inhibitor, and 71 were using other diabetes medications, often metformin and a sulfonylurea.
On average, the researchers found that patients taking DDP-4 inhibitors had less amyloid buildup than patients without diabetes or those taking other diabetes medications. And over the next few years, they also showed slower declines on tests of memory and reasoning.
The results were published online August 11 in the journal Neurology.
Maria Carrillo, chief scientific officer of the Alzheimer’s Association, stressed that the study cannot prove that DDP-4 inhibitors slow the dementia process.
One limitation of the study, she noted, was that patients’ amyloid levels were only initially measured. So it is not clear whether those taking DDP-4 inhibitors have a slower accumulation of brain plaques over time.
It’s well known that people with diabetes are more likely to develop Alzheimer’s disease than non-diabetics – although the reasons aren’t entirely clear, Carrillo added.
According to the Alzheimer’s Association, insulin resistance, as well as high blood sugar, may explain this in part. Carrillo noted that this study did not look at the patients’ long-term blood sugar control — and whether that had any role in their rates of decline over time.
“There are some rationales for considering these diabetes drugs in people with Alzheimer’s disease,” Carrillo said.
But like Villette, she said only randomized clinical trials — where patients are randomly assigned to take a DDP-4 inhibitor or not — can prove whether there are benefits.
One question for future studies, Villette said, is whether DDP-4 inhibitors can slow mental decline in people who don’t have diabetes, or those who only have the disease.
Because Alzheimer’s disease is so complex, Villette said drug combinations that target different mechanisms behind the disease are likely to be more effective in treating or preventing the disease.
Both nonprofits encourage people to eat a healthy diet, exercise, avoid smoking, and engage in mentally stimulating activities to help keep their bodies and minds in good shape as they age.
Alzheimer’s Drug Discovery Foundation Has More Protecting brain health.
SOURCES: Maria Carrillo, Ph.D., chief science officer, Alzheimer’s Association, Chicago; Howard Villette, MD, chief scientific officer, Alzheimer’s Drug Discovery Foundation, New York City; NeurologyOnline, Aug. 11, 2021