Research published just this week adds to the growing body of evidence that some medications used to treat type 2 diabetes may also help reduce the occurrence of dementia in those at high risk. An older class of antidiabetic medications was associated with a lower risk of dementia in this study’s elderly participants compared to more recently developed antidiabetic treatments. New clinical studies may be necessary to validate the unrealized potential of these medications, the authors conclude.
Dementia is characterized by a gradual decline in cognitive abilities such as memory and reasoning, and may eventually lead to inability to carry out even the most fundamental of daily activities like eating. Our genetic predisposition is only one of several risk factors for acquiring one of the numerous kinds of dementia. Type 2 diabetes has long been regarded as a key risk factor for dementia. And thus, some scientists have pondered whether or not diabetic medications that are effective in controlling the disease would also protect against dementia.
However, studies have shown conflicting results; some have connected common diabetic medicines like metformin to a reduced risk of dementia, while others have shown no such effect. This study focused on thiazolidinediones (TZDs), a family of diabetic medications that has been understudied in the area of dementia research until now.
Veterans Affairs is the biggest healthcare network in the United States, therefore the researchers looked at data on nearly half a million patients with type 2 diabetes who were 60 or older and received treatment there. Researches compared the long-term effects of TZD use to those of other diabetic medications, such as metformin and sulfonylureas, in a study of patients who had used TZDs for at least a year. They were found to be dementia-free before beginning treatment and were followed for an average of almost seven years. Since metformin is the standard first treatment for type 2 diabetes, and non-diabetic individuals are typically in better health than those who have been diagnosed with the condition but have not yet been given any treatment, those taking just metformin served as the study’s control group.
Individuals with dementia were 22% less likely to be diagnosed when using TZDs alone throughout the research period compared to those with dementia who were on metformin alone. This group also had an 11% lower risk of receiving a diagnosis of Alzheimer’s disease, the most prevalent type of dementia. In addition, the risk of vascular dementia, which accounts for around 10% of all cases, was reduced by 57%. BMJ Open Diabetes Research & Care released the results on Tuesday.
Given the complexity of the underlying disease process, it is unlikely that TZDs or other medications would have a simple preventative impact on dementia. However, experts contend that TZDs may primarily operate to prevent dementia by helping improve better circulation, as poor circulation is frequent among people with diabetes and is a recognized risk factor for vascular dementia and Alzheimer’s.
These findings suggest that TZD usage is associated with a reduced risk of dementia, but they do not establish causation. Even TZDs have their own worries. These medications were introduced in the 1990s and continue to see widespread usage today, although often as a backup plan. The FDA placed a warning label on the TZD medicine rosiglitazone in the middle of the 2000s after some studies revealed that some TZDs could increase the risk of heart attacks. Due to the lack of evidence from further research, the cautionary label was subsequently withdrawn. However, newer studies have reopened this discussion, and the medications are still not advised for those at increased risk of heart failure.
The authors conclude that this study provides sufficient evidence to warrant further investigation into the advantages of these medications for dementia, including the conduct of clinical trials. If these findings hold up to scrutiny, they might change the way physicians manage diabetics who are at high risk for dementia. For instance, the group discovered that those who used sulfonylureas alone were at a higher risk of developing dementia than those who took metformin or TZDs together. Taking metformin or TZDs with these medications may be necessary if they do, as the studies suggest, increase the chance of developing dementia. Patients who are overweight or obese may benefit the most from TZDs because of their potential to reduce the risk of dementia. Dementia prevention with other, more recent diabetes medications is also an area of active research.