Having peripheral nerve function problems — that is, sensory or motor impairment in the lower legs — was linked to a higher risk of developing dementia among older adults, according to a new analysis published in the journal Neurology.
People with diabetes are at greater risk for cognitive impairment and dementia, especially if they have a history of poor blood glucose control. In addition to optimizing your blood glucose levels, there are many steps you can take to potentially reduce your risk for dementia — including following a plant-based diet, getting enough fiber in your diet, avoiding inflammatory foods, and engaging in moderate physical activity on a daily basis. But even if you do everything right, there are still no guarantees that you won’t develop dementia. That’s why researchers are studying ways to predict who will develop dementia, which may lead to new treatment or monitoring protocols to ensure that people get the care they need if they experience cognitive decline.
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For the latest analysis, researchers looked at data from 2,174 participants in a study called the Health, Aging, and Body Composition Study, who were all ages 70-79 and didn’t have dementia at the time of enrollment. Participants had their lower extremity sensory and motor function measured four years into the study. Then over the next 11 years, the researchers tracked who developed a number of different health conditions, including dementia. A dementia diagnosis was confirmed through medical records, cognitive testing scores, or taking a prescription medication for dementia.
At the time of their lower extremity evaluation, 45% of participants could not detect a monofilament (very thin fiber) with 1.4 grams of pressure on their foot or leg. Another 9% could not detect a monofilament with 10 grams of pressure, and 6% could not feel vibration. When it came to motor function, 10% of participants scored low in what’s known as CMAP amplitude (a measure of muscle function) and 24% had slow conduction velocity (a measure of nerve function).
Nerve problems linked to increased risk of developing dementia
The researchers found that after adjusting for certain differences among participants — including age and certain health conditions — being insensitive to a 10-gram monofilament was linked to a 35% higher risk of developing dementia over the next 11 years, while being insensitive to vibration was linked to a 73% higher risk for dementia. For each of the other measures of peripheral nerve health, the link to dementia was too small to be considered statistically significant. But the researchers found that having more than one measure of nerve impairment was strongly linked to the risk for dementia — so that participants who scored poorly in three or more areas were 137% more likely to develop dementia over the next 11 years.
The researchers concluded that the link between peripheral nerve function and risk for dementia may reflect “a shared susceptibility to nervous system degeneration” in more than one area of the body. Such a link could mean that people with diabetes who develop peripheral neuropathy — nerve damage that typically affects the legs and feet — might be at greater risk for dementia, even after controlling for differences in blood glucose control. But more research is needed to confirm any such link specifically in people with diabetes.
Want to learn more about maintaining cognitive health with diabetes? Read “Nine Tips to Keep Your Memory With Diabetes,” “Keeping Your Brain Strong With Diabetes” and “Memory Fitness: How to Get It, How to Keep It.”
