Summary: Type 2 diabetes is not only associated with an increased risk of developing Parkinson’s disease, but it’s also associated with an accelerated progression of Parkinson’s symptoms.
Source: Queen Mary’s University of London
Research from Queen Mary University of London has concluded that there is convincing evidence that type 2 diabetes is associated with an increased risk of Parkinson’s disease. The same study found that there was also evidence that type 2 diabetes may contribute to faster disease progression in patients who already have Parkinson’s.
Treating people with drugs already available for type 2 diabetes may reduce the risk and slow the progression of Parkinson’s. Screening for and early treatment of type 2 diabetes in patients with Parkinson’s may be advisable.
Previous systematic reviews and meta-analyses have produced conflicting results around the link between diabetes and the risk of Parkinson’s disease.
This new study, published in the Movement Disorders Journal, used meta-analysis of observational data and meta-analysis of genetic data to evaluate the effect of type 2 diabetes on risk and progression of Parkinson’s disease.
Corresponding author Dr Alastair Noyce from Queen Mary University of London said: “This research brings together the results from many other studies to provide convincing evidence that type 2 diabetes likely affects not only Parkinson’s risk, but also Parkinson’s progression. There are many treatment strategies for type 2 diabetes, including prevention strategies, which may be re-purposed for the treatment of Parkinson’s.”
Funding: The Preventive Neurology Unit is funded by Barts Charity. Funding for co-authors came from the Michael J. Fox Foundation, the Canadian Consortium on Neurodegeneration in Aging (CCNA), the Canada First Research Excellence Fund (CFREF), Parkinson Canada, and the Intramural Research Program of the NIH, National Institute on Aging.
Type 2 diabetes (T2DM) and Parkinson’s disease (PD) are prevalent diseases that affect an aging population. Previous systematic reviews and meta‐analyses have explored the relationship between diabetes and the risk of PD, but the results have been conflicting.
The objective was to investigate T2DM as a determinant of PD through a meta‐analysis of observational and genetic summary data.
A systematic review and meta‐analysis of observational studies was undertaken by searching 6 databases. We selected the highest‐quality studies investigating the association of T2DM with PD risk and progression. We then used Mendelian randomization (MR) to investigate the causal effects of genetic liability toward T2DM on PD risk and progression, using summary data derived from genome‐wide association studies.
In the observational part of the study, pooled effect estimates showed that T2DM was associated with an increased risk of PD (odds ratio [OR] 1.21, 95% confidence interval [CI] 1.07–1.36), and there was some evidence that T2DM was associated with faster progression of motor symptoms (standardized mean difference [SMD] 0.55, 95% CI 0.39–0.72) and cognitive decline (SMD −0.92, 95% CI −1.50 to −0.34). Using MR, we found supportive evidence for a causal effect of diabetes on PD risk (inverse‐variance weighted method [IVW] OR 1.08, 95% CI 1.02–1.14; P = 0.010) and some evidence of an effect on motor progression (IVW OR 1.10, 95% CI 1.01–1.20; P = 0.032) but not on cognitive progression.
Using meta‐analyses of traditional observational studies and genetic data, we observed convincing evidence for an effect of T2DM on PD risk and new evidence to support a role in PD progression.