Could diabetes/obesity GLP1 receptor agonist medications treat Alzheimer's or Parkinson's diseases?

As blogged previously, existing data suggests that GLP1 receptor agonists (GLP1RAs) may protect against vascular dementia/cognitive impairment.

Early stage research suggests a possible benefit in Alzheimer’s or Parkinson’s diseases. What do we know so far?

A small study with exenatide in people with Parkinson’s disease demostrated positive effects on motor scores that persisted after medication was stopped, as well as improvement in mood and well being (not sustained after treatment was stopped). A small study of liraglutide (Victoza) has suggested improvement in non-motor symptoms and activities of daily living in people with Parkinson’s disease.

While animal studies have been promising, early studies in people with Alzheimer’s disease have shown mixed results. A small 6 month study of 38 participants suggested that liraglutide improved glucose transport across the blood-brain barrier, though did not improve cognition vs placebo. An 18 month pilot study of exenatide vs placebo in 21 people did not show improvement in clinical or cognitive measures. The GLP1 receptor agonist (GLP1RA) semaglutide (Ozempic) is currently being studied on a much larger scale in people with early Alzheimer’s disease (see here and here), and is under consideration for study in Parkinson’s disease.

Postulated mechanism of benefit of GLP1RAs for Alzheimer’s and/or Parkinson’s disease include anti-inflammatory, neurotropic and neuroprotective effects, and reduction in insulin resistance. These medications also cause weight loss, which may be a good thing for people with obesity and Alzheimer’s or Parkisons, but would be undesired in people without obesity, or who are already unintentionally losing weight (as can be the case in people with dementia). As always, it is important to consider each individual holistically, to determine the best treatment approach. It will be very interesting to see what evidence may evolve in this area, and whether GLP1RAs may prove to be of benefit in Alzheimer’s and/or Parkinson’s diseases.

Disclaimer: I am/have been an investigator in clinical trials of semaglutide and liraglutide. I receive honoraria as a continuing medical education speaker and consultant from the makers of semaglutide and liraglutide (Novo Nordisk).

Share this blog post using your favorite social media link below!

Follow me on twitter! @drsuepedersen