Diabetic foot, characterized by a pronounced inflammatory reaction, decreased
collagen content and biosynthesis and accelerated degradation are crucial in wound healing.
Cathepsin D, an
aspartic endopeptidases implicated in cell growth, apoptosis, and its inhibitor has been reported to reverse the inhibition of
collagen biosynthesis in wounded rat skin with diabetes. To date, the increased proteolytic activity of
Cathepsin D in
diabetic foot has not been evaluated and the pathogenic significance of the
inflammation has received little attention. Of the patients [with
ulcer (n=211) and without
ulcer (n=208)], 89.73% had
type 2 diabetes. Subjects with
diabetic foot ulcer showed higher median plasma level of
Cathepsin D [556.3 (312.6-587.3) RFC/ml vs 306.3 (92.6-337.3) RFC/ml], TNF-α [96.6 (79.9-121.5) ng/ml vs 8.4 (7.1-9.20) ng/ml],
IL-6 [32.2 (8.52-48.4) ng/ml vs 4.9 (4.5-5.6) ng/ml],
hsCRP [12.6 (11.2-14.1) mg/ml vs 3.90 (3.50-4.60) mg/ml] and lower median plasma levels of
adiponectin [8.50 (7.10-9.5) ng/ml vs 13.3 (12.1-14.2) ng/ml]. A positive correlation was found between grades of
ulcer, BMI, A1c and retinopathy for
Cathepsin D, for
adiponectin, between grades of
ulcer, BMI, retinopathy, nephropathy & smoking, for
IL-6, between grades of
ulcer, BMI, nephropathy, CAD & smoking, for
hsCRP, grades of
ulcer, BMI,
LDL-C, nephropathy & smoking, while total
cholesterol, nephropathy, PAD, smoking and neuropathy for TNF-α.