People with diabetes are at increased risk of carpal tunnel syndrome >Not only are people with diabetes are at increased risk of carpal tunnel syndrome, but the testing commonly used to diagnose the painful condition may not be accurate in diabetics, researchers report.
Due to the difficulty of diagnosing carpal tunnel syndrome in people with diabetes, doctors should rely more on symptoms when examining diabetics, according to the investigators.
Carpal tunnel syndrome occurs when one of the nerves that passes through the wrist becomes compressed. Symptoms include numbness, weakness, tingling and pain in the fingers and hand.
People with diabetes are at risk for several different kinds of nerve problems, the most common being a type of nerve injury called diabetic polyneuropathy, says Dr. Vera Bril of the University of Toronto. Bril noted that people with diabetes often develop carpal tunnel syndrome, too.
The usual way to diagnose the disorder is a noninvasive test called nerve conduction study. However, the criteria for interpreting the results of this testing were developed without including patients who have both diabetic polyneuropathy and carpal tunnel syndrome. So the accuracy of the criteria for diagnosing carpal tunnel syndrome in people with diabetes is uncertain, Bril and co-author Dr. Bruce A. Perkins of Harvard Medical School in Boston, Massachusetts, note in the March issue of the journal Diabetes Care.
To see how often carpal tunnel syndrome occurs in diabetics as well as to determine the accuracy of the conventional diagnostic test, Bril and Perkins evaluated 478 people for the condition. The study included people with diabetes who had mild, moderate or severe neuropathy or none at all.
Based on clinical symptoms, the researchers determined that 2% of the reference group had carpal tunnel syndrome, compared with 14% of diabetics who did not have neuropathy and 30% who did. But among diabetics, electrodiagnostic testing used to diagnose carpal tunnel syndrome did not accurately distinguish between those with carpal tunnel syndrome and those without it, the report indicates.
The study shows that conventional diagnostic testing "does not seem to apply in those with diabetes," according to Bril. Calling the diagnosis of diabetes "tricky," she said, "The results of this study suggest that doctors should put more weight on the symptoms that people describe rather than sophisticated lab tests."
Bril advised people with diabetes "to pay attention to symptoms of numbness, tingling, weakness or pain in their hands and tell their doctors about these symptoms."
Diabetes Care 2002;25:565-569.