A recent meta-analysis found that metformin significantly reduces dementia risk. Other research also suggests that the drug reduces dementia risk in patients with diabetes. At the same time, however, other studies report that metformin may increase the risk of Alzheimer’s disease and that it may aggravate dementia symptoms in mice.
In the current study, researchers set out to understand more about the link between metformin and dementia in obese patients. To do so, they analyzed electronic health record data from over 450,000 adult patients with varying degrees of overweight and obesity. Over a ten-year period, 35,784 people developed dementia and there were 76,048 mortalities.
Ultimately, the researchers found that patients using metformin were significantly less likely to be affected by dementia or all-cause mortality than non-users. The benefits were apparent across all categories of overweight, obesity, and severe obesity; experiencing an 8-12% lower risk of dementia and a 26-28% lower risk of death.
In their paper, the researchers wrote that the findings are noteworthy as dementia and atherosclerotic cardiovascular disease share risk factors such as BMI, plasma triglycerides, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, hypertension, and diabetes. These overlaps, they wrote, suggest that obesity also contributes to dementia.
The researchers added that dementia as a contributing factor to all-cause mortality may partially explain the drug’s effects on all-cause mortality. They acknowledged, however, that further research is needed to understand other mechanisms through which metformin reduces all-cause mortality.
“Although our study results are promising for metformin’s effects on dementia and mortality, further research is required to explore the mechanisms involved,” said co-corresponding author Chiehfeng Chen, MD, Professor at the Department of Public Health at Taipei Medical University, Taiwan, in a press release.
Sources: Diabetes, Obesity and Metabolism, EurekAlert