MUNICH – A combined eye, foot, and renal screening clinic identified undiagnosed painful diabetic neuropathy in 12% of diabetic patients who attended.

The clinic in Sheffield, England, was well attended and well liked, with 85% patient approval. The patients appreciated that the visit assured attention to their feet and also let them combine several individual clinic visits for diabetes complications screening, Solomon Tesfaye, MD, said at the annual meeting of the European Association for the Study of Diabetes.

“Twenty percent of our attendants said they had never even had a foot exam before,” said Dr. Tesfaye, an endocrinologist at the University of Sheffield. “And almost half had never had any kind of diabetic foot education.”

Dr. Tesfaye said this lack of attention to foot care in diabetes patients in the United Kingdom is “completely unacceptable.” The country is facing an epidemic of diabetes-related foot amputations, he said.

“We have unacceptable numbers of amputations, on the order of 135 each week, and unfortunately that number is rising. Why is that? Because in the U.K., we tend to diagnose diabetic neuropathy mainly with the 10-g monofilament test, because that is reimbursed. And while it’s a good way of screening for foot ulceration risk, it’s not a good model of diagnosing neuropathy early. So we are now unfortunately diagnosing it late, when it’s advanced and completely irreversible.”

The consequences of foot damage are far-reaching, Dr. Tesfaye said. “Patients who have to be referred into a foot clinic have very high mortality, approaching 50% at 5 years. In the U.K., we’re adding more and more foot clinics every year, and this is not a measure of success. It’s a measure of failure.”

Diabetic retinopathy, however, is the country’s good news story. More than 90% of people – diabetic or not – attend an annual eye screening as part of their wellness visits. As a result, diabetic eye disease is no longer the leading cause of blindness in adults in the United Kingdom.

“Everyone attends this annual eye screening, which uses retinal photography, and anyone with early changes is referred to specialist care,” Dr. Tesfaye said. “This has resulted in a paradigm shift in blindness, and that’s fantastic news.”

It just made sense, he said, to use the popular eye screening visit as a chance to also intervene early in undiagnosed diabetic neuropathy. A recent German study underscored the importance of early intervention (Diabetes 2014 Jul;63[7]:2454-63).

This study demonstrated that intraepidermal nerve fibers were already significantly reduced in 20% of patients within a year of their diabetes diagnosis. Nerve conduction values and amplitude were already impacted as well.

“The neuropathic process starts early, but we are using very insensitive measures to diagnose it,” Dr. Tesfaye said.

The combination clinic used several devices to test nerve function in feet, in addition to the 10-g monofilament test:

• A handheld device called DPN-Check, which measures sural nerve conduction velocity and response amplitude.

• Sudoscan, which measures sudomotor dysfunction – one of the earliest neurophysiologic changes in distal small fiber neuropathies.

• The Toronto Clinical Scoring System, a clinical tool that assesses symptoms, reflexes, and sensory function.

The entire foot exam takes 15 minutes and is done after the patient receives the eyedrops necessary for the ocular exam. The renal screening consists of a blood draw for tests of renal function.

The study group comprised 180 patients, with a mean age of 64 years. Type 1 diabetes was present in 6%; the rest had type 2 disease.

The Toronto score was 5 or higher, indicating the presence of diabetic neuropathy, in almost 32%.

The Sudoscan identified small nerve dysfunction consistent with neuropathy in 40%. The DPN-Check score identified neuropathy in 55%. However, the monofilament test was positive in 12%.

In addition to the increased number of neuropathy patients identified, “we also had new diagnoses of painful diabetic neuropathy in about 12% of the group,” Dr. Tesfaye said.

The devices had very good individual diagnostic accuracy, and when the devices were combined, the results were “really staggering,” he said. The Sudoscan alone had a sensitivity of 79% and a specificity of 60%; the DPN-Check alone, a sensitivity of 91% and a specificity of 73%. But when combined, the two diagnostic tools yielded an overall sensitivity of 94% and specificity of 63%. This correlated very well with the Toronto Clinical Scoring System, he added.

“It’s obvious that the 10-g monofilament test grossly underestimated the true presence of diabetic neuropathy. But using these combined point-of-care devices, we were able to detect it with an extremely high sensitivity. This service enables our patients to be referred early to podiatric services. Whether this early referral will result in the reversal of these neuropathic changes is yet to be determined.”

Dr. Tesfaye reported relationships with NeuroMetrix, Impeto Medical, Eli Lilly, Pfizer, Worwag Pharma, and TRIGOcare International.

msullivan@frontlinemedcom.com

Adding foot screening to eye clinic catches diabetic neuropathy