Neuropathy, or nerve damage, is one of the most common diabetic complications, affecting up to 70% of people who have diabetes. Now, new research from the University of Michigan shows that many people with the condition are receiving a less effective — and more expensive — test to diagnose the condition, instead of a more accurate diagnostic test.
In people who have diabetes, neuropathy is believed to be caused in large part by excess glucose in the blood infiltrating the nerves and interfering with their electrical signals. Sensory neuropathy impacts the nerves responsible for sensation, and typically affects the feet, legs, hands, and arms. Symptoms include pain, numbness, loss of sensation, tingling, coldness, and sensitivity to touch. (Another type of neuropathy, autonomic neuropathy, impacts nerves that control the functions of internal organs, and may cause complications ranging from gastroparesis to sexual dysfunction.)
Along with diabetes, other causes of neuropathy include shingles, vitamin deficiency (particularly of vitamin B12), autoimmune diseases such as lupus and rheumatoid arthritis, exposure to toxins, use of certain cancer medicines, and more. Diabetes is the most common cause of peripheral neuropathy, or neuropathy that affects the arms, legs, hands, and feet.
In an effort to make diagnosis of peripheral neuropathy more efficient, researchers used the 1996–2007 Health and Retirement Study to determine how this condition is typically diagnosed. They identified 1,031 people who had been diagnosed with neuropathy and met the study’s criteria. The researchers then focused on 15 diagnostic tests for the condition, studying the pattern of testing six months before and after the participants’ diagnoses.
The researchers found that the low-cost glucose tolerance test — the test measures a person’s blood glucose response to the consumption of a glucose-rich drink after at least eight hours without food or drink — which could detect undiagnosed diabetes in people experiencing neuropathy symptoms, was ordered in only 1.0% of people. Expensive magnetic resonance imaging, or MRI, tests of the spine or brain (which cannot identify diabetes), on the other hand, were ordered in 23.2% of people.
“Our findings, that MRIs were frequently ordered by physicians, but a lower-cost glucose tolerance test was rarely ordered, show that there is substantial opportunity to improve efficiency in the evaluation of peripheral neuropathy,” noted lead researcher Brian Callaghan, MD. “Currently no standard approach to the evaluation of peripheral neuropathy exists. We need more research to determine an optimal approach. We do a lot of tests that cost a lot of money, and there’s no agreement on what we’re doing.”
For more information, read the article “Neuropathy Patients More Likely to Receive High-Cost, Low-Yield Screening Instead of More Effective Tests” or see the study’s abstract in the Archives of Internal Medicine. And to learn more about controlling pain from neuropathy, see the articles “Coping With Painful Neuropathy” and “Controlling Neuropathic Pain.”