Study Completed

The purpose of this study is to determine whether impaired glucose handling (abnormality in the way the body processes blood sugar) can cause a neuropathy (damage to the nerves).

Neuropathy of undetermined etiology is a common disease that usually starts at the sixth to seventh decades. It can cause significant pain and disability. Previous studies have demonstrated increased prevalence of abnormal glucose handling, when these patients were tested with oral glucose tolerance test (OGTT). On the other hand, many of the neuropathy patients suffer from pain and depression and obesity; and abnormal OGTT in these patients may be the result of these factors. We assume that if abnormal handling of blood sugar is the cause of neuropathy, these patients may have evidence of damage to other organs (like eyes and kidneys) as a result of abnormal blood sugar. In a pilot study, we will determine the incidence of subtle damage to kidneys, eyes and also look for other factors associated with abnormal glucose handling in patients with neuropathy and abnormal OGTT and compare it to age matched controls with normal OGTT.

Inclusion Criteria:

Inclusion criteria (for the subjects) will include peripheral neuropathy, age more than 50 years, and a negative workup for neuropathy (aside from an abnormal OGTT). Age matched controls will have no history of diabetes or baseline retinal disease . A workup to rule out other causes of peripheral neuropathy, and an OGTT, will be performed prior to participation in the study.

Exclusion Criteria:

Patients with abnormal OGTT in the diabetic range will not be included.