Differential scanning calorimetry, biochemical, and biomechanical analysisof human skin from individuals with diabetes mellitus

The aim of this work was to compare biochemical, two-dimensional biomechani cal and calorimetric parameters of diabetic skin vs. control skin. Skin spe cimens taken from the palms and backs of the hands of aged persons with non -insulin-dependent diabetes mellitus (NIDDM) and of controls (CO) were comp ared (age range 68-85 years). Only skin specimens from individuals with dia betes mellitus (DM) showed an increased fluorescence specific for the forma tion of advanced glycation end-products (AGEs) and the presence of tissue A GEs, such as N-e-(Carboxymethyl)lysine (CML). Differential scanning calorim etry (DSC) revealed an elevation of the heat flow per unit mass during coll agen denaturation in diabetic skin samples. However, the temperatures of th e heat flow maximum and the onset of the phase transformation were not unif ormly altered. Young's moduli were found to be increased in diabetic skin a nd correlated with AGE-fluorescence and tissue AGEs. The ratio between the Young's moduli, which defines a measure for the degree of anisotropy, was h igher for dorsal skins from hands. In dorsal skin specimens from diabetic s ubjects the degree of anisotropy was more pronounced than in healthy contro ls. In general, neither of the measured parameters showed any correlation w ith age. However, E-1 moduli were clearly associated with the duration of d iabetes. Anat Rec 259:327-333, 2000. (C) 2000 Wiley-Liss, Inc.