Review Question - QID 103510

This patient with diabetes mellitus, loss of sensation in the feet, and a erythema over the fifth metatarsal likely has diabetic neuropathy, a microvascular complication of diabetes. Tight glycemic control is critical for preventing microvascular complications of diabetes including diabetic neuropathy and retinopathy.

Elevated glucose levels can affect the osmotic gradient across neurons and retinal cells through several mechanisms, leading to cell swelling and ultimately damage, particularly in Schwann cells of the peripheral nerves. The resulting neuropathy presents with paresthesia that begins distally, such as in the feet, and will progress proximally. Due to loss of sensation in proprioception , patients may be unaware of injuries to the feet. The concomitant microvascular damage can lead to the development of non-healing ulcers that may ultimately progress to osteomyelitis. The most effective strategy to slow progression of neuropathy and other microvascular complications associated with diabetes is tight glycemic control. In this patient with a hemoglobin A1c of 9.5%, this may mean the addition of insulin or an additional oral hypoglycemic agent. The American Diabetes Association recommends a goal hemoglobin A1c target of < 7% to reduce microvascular complications of diabetes in adults. Symptoms of neuropathy that are bothersome or painful may be treated with gabapentin, though this does not address

Feldman et. al review the diagnosis and management of diabetic neuropathy. They discuss the associated complications including non-healing ulcers and osteomyelitis. They recommend tight glycemic control as the preferred strategy in management.

Illustration A shows a diabetic foot ulcer. Note that it is more severe than the ulcer described in the question stem and may require limb amputation.

Incorrect Answers:
Answer 1: Atorvastatin will help decrease the patient’s serum cholesterol, which will may reduce the patient’s risk of vascular disease. However, it will not address this patient's diabetic neuropathy.

Answer 2: Gabapentin may reduce the subjective paresthesias or pain related to diabetic neuropathy, but it will not address the underlying cause or prevent progression.

Answer 3: Sertraline is a selective serotonin reuptake inhibitor and is not likely to be contributing to this patient's neuropathic symptoms.

Answer 5: Right-sided femoral popliteal bypass would be indicated for sever lower extremity vascular disease, which may also lead to the development of foot ulcers. However, this patient's presentation is more suggestive of diabetic neuropathy as the etiology of her condition.

Bullet Summary
Diabetic neuropathy is a microvascular complication of diabetes mellitus that presents with paresthesias, and is best managed with tight glycemic control.