Type 2 diabetes (T2D) and Alzheimer disease are linked.
People with T2D, a chronic condition characterized by high blood sugar levels, are at a higher risk of developing Alzheimer disease than those who don’t have it. Moreover, high blood sugar levels have been implicated in brain dysfunction—such as deficits in attention, memory and information processing—which are hallmarks of Alzheimer disease and other forms of dementia.
Several clinical studies suggest that some anti-diabetic medications, which lower blood sugar levels, might improve brain function in Alzheimer disease and slow its progression. However, it’s unclear which of the approximately 20 anti-diabetic medications currently available would be most effective.
To begin to narrow down this list, a team led by Krembil Clinician Investigator Dr. Roger McIntyre performed a study that examined relevant clinical trials completed within the past 13 years. Dr. McIntyre was named one of ‘the world’s most influential scientific minds’ by Clarivate Analytics/Thomson Reuters in 2014, 2015, 2016 and 2017.
The researchers identified 19 clinical trials that evaluated the effect of six different diabetes medications in patients with either Alzheimer disease or mild forms of dementia.
By performing a comprehensive analysis of the studies’ findings, the researchers found that all six diabetes medications produced significant improvements in the mental function of participants. The two drugs that produced the most improvement—pioglitazone and rosiglitazone—lower blood sugar through the same mechanism: by stimulating cells to absorb more sugar and use it as a source of energy.
“Our study provides compelling evidence that anti-diabetic drugs, especially piglitazone, help protect brain function in Alzheimer disease. However, before these findings can be applied in the clinic, they need to be replicated and confirmed in large-scale clinical trials,” says Dr. McIntyre.
This work was supported by the China Scholarship Council and the Toronto General & Western Hospital Foundation.
Cao B, Rosenblat JD, Brietzke E, Park C, Lee Y, Musial N, Pan Z, Mansur RB, McIntyre RS. Comparative efficacy and acceptability of antidiabetic agents for Alzheimer's disease and mild cognitive impairment: A systematic review and network meta-analysis. Diabetes Obes Metab. 2018 May 23. doi: 10.1111/dom.13373.
Dr. Roger McIntyre, Clinician Investigator, Krembil Research Institute