Length-dependent polyneuropathy has long been recognized as a frequent complication of diabetes. A decade of observational
and epidemiologic studies support the concept that intermittent hyperglycemia or insulin resistance associated with prediabetes
may be sufficient to damage distal nerves. Features of the metabolic syndrome have been implicated as independent neuropathy
risk factors in large population-based studies of diabetic patients. Preferential injury to small unmyelinated nerves is suggested
by prominent neuropathic pain, predominant sensory injury, and early autonomic dysfunction. Small uncontrolled trials suggest
that diet and exercise may transiently improve distal nerve function and neuropathy symptoms in these patients. Patients with
prediabetes neuropathy may permit greater insight into the balance between distal axonal injury and nerve regenerative capacity
that determines neuropathy progression, and will be good candidates for evaluation of rational therapy based on known pathophysiology
of hyperglycemic neuropathy.