Glucose levels in the body rise, the pancreas detects these rising levels and produces more insulin in an attempt to reduce glucose levels. When glucose levels start building up in the blood, this is referred to as glucose intolerance.
Is there a link between diabetes and Parkinson’s?
The fact is we don’t really know, but the incidence of glucose intolerance in people with Parkinson’s has led researchers to begin investigating the association between Parkinson’s and diabetes. Insulin is present in the brain, where it has been shown to impact dopamine levels. Here, insulin controls glucose levels and importantly, it helps cognitive functions, particularly memory. Notably, defects in insulin actions in the brain may contribute to neurodegenerative disorders.
Previous research has suggested that people with diabetes are 2-3 times more likely to develop Parkinson’s than those without diabetes. In addition, individuals with Parkinson’s who are diabetic often have a more rapid progression of symptoms, so careful management of both conditions is important. Recently research, supported by Cure Parkinson’s, has demonstrated that some classes of diabetes medications can reduce the risk of developing Parkinson’s.
Currently, one in 15 people in the UK has Type 2 diabetes, and that number is increasing; the risk of developing Parkinson’s in a person’s lifetime is also growing. Therefore, it is important to try to understand the relationship between the two conditions, and whether Type-2 diabetes medications might, in turn, be able to slow the progression of Parkinson’s.
A significant proportion of people with Parkinson’s have glucose intolerance, and some also live with the added burden of diabetes. That said, it should be noted the vast majority of people with diabetes do not develop Parkinson’s and similarly, the majority of people with Parkinson’s do not have a diagnosis of diabetes.
The research targets
Cure Parkinson’s is focused on funding clinical trials of certain Type 2 diabetes drugs, to determine if glucose intolerant people with Parkinson’s have a better or worse response to the drug being tested, as well as assessing the efficacy of these drugs for the Parkinson’s community as a whole.
The liraglutide trial results
Researchers from Cedars Sinai Hospital, Los Angeles have presented their initial top line results of the liraglutide trial, funded by Van Andel Institute and Cure Parkinson’s, at the recent American Association of Neurology annual meeting. The results are encouraging and indicate that liraglutide improves aspects of daily living and non-motor symptoms in people with Parkinson’s.Read more here
Dual agonists for Parkinson’s
Glucagon-like peptide 1 receptor (or GLP-1R) agonists are a frontline treatment for diabetes; and gastric inhibitory polypeptide (GIP) agonists are the next generation of treatment for diabetes. Now, Dr Dilan Athauda is testing a combination of these two drugs in the laboratory to determine whether used together, they offer potential as a treatment for Parkinson’s.Find out more here
The exenatide PD3 trial
The Exenatide-PD3 trial has been designed to confirm whether exenatide can slow the progression of Parkinson’s, and to check that the results of the phase 2 study can be replicated across more participants at multiple research centres.Read more here
The lixisenatide trial
Another clinical trial in the promising diabetes drug cohort in repurposing for Parkinson’s is evaluating the effect of lixisenatide on the progression of Parkinson’s. This trial is co-funded by Cure Parkinson’s and Van Andel Institute, through the International Linked Clinical Trials programme.Read more here
Diabetes data to inform future Parkinson’s clinical trials
Cure Parkinson’s is funding researchers to analyse real-world data to identify the best clinical and biomarker outcomes for use in future clinical trials of Type 2 diabetes drugs for Parkinson’s.Read more here