Neurologist to endocrinologists: Listen to your patients’ feet
AT THE ADA ANNUAL SCIENTIFIC SESSIONS
SAN DIEGO – Listen to the feet of your patients, and don’t just focus on glucose control as a way to combat diabetic neuropathy, according to Eva L. Feldman, MD, PhD.
Regular foot exams are crucial for patients with diabetes because of the high risk of diabetic neuropathy (DN), Dr. Feldman, professor of neurology and director of the Program for Neurology Research and Discovery at University of Michigan, Ann Arbor, said in a presentation at the annual scientific sessions of the American Diabetes Association. 
“Diabetic neuropathy has some important clinical consequences in a patient’s life. There’s clearly impaired function, a lower quality of life, and increased mortality. There’s also a high association between DN and cardiovascular disease and a high risk of amputation,” said Dr. Feldman, coauthor of the ADA’s new clinical guidelines for diabetic neuropathy (Diabetes Care. 2017;40[1]:136-54).
And in patients with type 2 diabetes, “diabetic neuropathy is not just hyperglycemia, which is what we’ve focused all our efforts on up until the past 5 years. There is also a role for dyslipidemia and other metabolic impairments,” she said.
In a follow-up interview, Dr. Feldman elaborated on a common misconception about DN, simple tools for foot exams by endocrinologists, and how to know when it’s time for a referral to a neurologist or podiatrist.
Q: What do you think physicians/endocrinologists misunderstand about diabetic neuropathy?
A: Commonly, physicians think if patients with diabetes do not complain of pain or numbness, they do not have DN. This simply isn’t correct. Over 80% of patients with DN have insensate feet – they simply do not have feeling in their feet. Physicians must examine a patient’s foot at least once a year to ensure the patient has not developed DN.
Q: What should endocrinologists understand about how diabetic neuropathy develops?
A: We know that excellent glucose control has a significant impact on DN in patients with type 1 diabetes. In patients with type 2 diabetes, we know that excellent glucose control plays a much less significant role. While it’s important, it must be coupled with control of other components of metabolic syndrome – elevated blood lipids, obesity, and hypertension.
A: Take a 126 Hz tuning fork and determine if the patient can feel vibration on the joint of the great toe for at least 10 seconds. Then take a 10-gram filament and a pin and determine if the patient can feel both of these instruments when they are applied to the joint of the great toe. Some physicians also take a 10-gram filament and apply it to the sole of the foot. I would not suggest using a pin on the sole of the foot.
Q: What else should they look for when they inspect feet? And how often would you recommend that endocrinologists do this per patient?
A: Inspection for callous formation, fissure formation, and fungal infections is important, and a foot exam should be done once yearly.
Q: What about testing whether patents can feel temperature?
A: The pin tests the same class of nerve fibers so this is routinely not done in an endocrinologist’s office.
Q: When should endocrinologists refer out for neuropathy?
A: Endocrinologists can treat DN by treating the diabetic condition and, in type 2 diabetes, the metabolic syndrome. Referral to a neurologist is indicated if there are atypical symptoms or signs, such as motor impairment that’s greater than sensory impairment, a significant asymmetry, or a very rapid onset. All patients with severe DN should be under the care of a podiatrist to prevent the development of nonhealing wounds and ulcers.
Q: What have you learned about how diabetic neuropathy affects the lives of patients?
A: DN definitely affects the quality of a patient’s life, not only in terms of work productivity and ability to perform activities of daily living. Quality of life and general enjoyment of life can frequently be adversely affected.
Q: How successful is treatment for diabetic neuropathy?
A: Treatment for pain can be very successful, and we have outlined a protocol in our recent ADA guidelines. For patients with uncontrollable pain, frequently a referral to a pain clinic is in order.
Dr. Feldman reports no relevant disclosures.