Official websites use. Share sensitive information only on official, secure websites. Corresponding author: Rayaz A. Malik, ram qatar-med. Impaired glucose tolerance IGT through to type 2 diabetes is thought to confer a continuum of risk for neuropathy. Identification of subjects at high risk of developing type 2 diabetes and, hence, worsening neuropathy would allow identification and risk stratification for more aggressive management.
Thirty subjects with IGT and 17 age-matched control subjects underwent an oral glucose tolerance test, assessment of neuropathic symptoms and deficits, quantitative sensory testing, neurophysiology, skin biopsy, and corneal confocal microscopy CCM to quantify corneal nerve fiber density CNFD , branch density CNBD , and fiber length CNFL at baseline and annually for 3 years. CCM and skin biopsy detect a small-fiber neuropathy in subjects with IGT who develop type 2 diabetes and also show a dynamic worsening or improvement in corneal and intraepidermal nerve morphology in relation to change in glucose tolerance status.
The International Diabetes Federation states that there are currently million people with impaired glucose tolerance IGT , which will increase to million people by 1. There is considerable debate as to whether these subjects should be considered to have a medical problem 2. However, in subjects with IGT, the risk of developing type 2 diabetes ranges from 3.
Furthermore, IGT is also independently associated with the traditional microvascular complications of diabetes, including retinopathy, microalbuminuria, and neuropathy 4. There appears to be a good rationale for identifying subjects with IGT, but there are limited data identifying subjects with IGT who may be at greatest risk for developing diabetes and its complications. However, there is debate as to whether IGT is associated with neuropathy, with some studies showing evidence of neuropathy 8 β 12 , while others do not 13 β We recently showed that a significant small-fiber neuropathy occurred in Interestingly, a recent study evaluating electrochemical sweat conductance, a proxy for small-fiber neuropathy, has shown that healthy subjects with an abnormal response have a significantly increased odds ratio for the development of IGT over 2 years Of relevance, lifestyle modification has been shown to improve intraepidermal nerve fiber density IENFD 11 and to improve after chemical axotomy We previously showed an improvement in corneal nerve morphology after an improvement in glycemic control, lipids, and blood pressure 19 after simultaneous pancreas and kidney transplantation 20 and more recently in patients on continuous subcutaneous insulin infusion 21 , suggesting a dynamic regenerative capacity of the small fibers in relation to metabolic change.
We have undertaken a longitudinal study in subjects with IGT to assess whether baseline and follow-up measures of neuropathy, particularly small-fiber neuropathy, relate to changes in glucose tolerance over 3 years.
