Dielectric properties of keratin–water system in diabetic and healthy human fingernails

Dielectric measurements as a function of temperature (22–200 °C) and frequency (100 Hz–100 kHz) are reported for the healthy and the diabetic nail plate. The plots of the relative permittivity versus temperature at the same frequency are higher in the healthy than in the diabetic nail. These results are interpreted as caused by the damage of the polar sites in the keratin–matrix–water system of the diabetic nail. The activation energy of the β-relaxation is higher for the diabetic nail than for the healthy nail, suggests that advanced glycation end products (AGEs) may form cross-links by interaction with keratin. The results of this work indicate that the dielectric measurements of the nail could be used in detection of diabetes.