Glycated nail proteins: a new approach for detecting diabetes in developing countries.

OBJECTIVE To assess glycation of nail proteins as a tool in the diagnosis of diabetes. METHODS Glycation of nail proteins was assessed using a modified photometric nitroblue tetrazolium-based assay, which provides information about average glucose values of the last 6-9 months. Analysis is possible on 10 mg of nail clippings with a within-run coefficient of variation (CV) of 11%. The analyte is extremely stable. The reference range for glycated nail protein (0.55-3.60 μmol/g nail) increases upon ageing. RESULTS In diabetics (n = 112), values for glycated nail protein are significantly higher (median: 4.07 μmol/g nail, IQR: 2.37-6.89 μmol/g nail, P < 0.0001) than in non-diabetics (n = 116). ROC analysis shows an AUC of 0.848 (specificity 93.1%; sensitivity 68.9%). CONCLUSION This affordable method is a simple alternative for diagnosing diabetes in remote areas as the pre-analytical phase (including all processes from the time a laboratory request is made by a physician until the sample is ready for testing) is extremely robust.