10.22376/ijpbs.2019.10.1.p1-12 Volume 5 Issue 1 2014 (January - March) Diabetes is shown to have an increased risk for periodontal disease compared to non-diabetes. The present study aimed to evaluate the concentration of serum cathepsin D level in periodontitis subjects with and without type 2 diabetes mellitus. We studied a total of 600 subjects categorized into 4 groups as Group I (150 healthy subjects as control), Group II (150 type 2 diabetes mellitus with periodontitis), Group III (150 type 2 diabetes mellitus without periodontitis) and Group IV (150 non-diabetic patients with periodontitis). Serum concentration of cathepsin D was measured by means of UV absorption spectrophotometer at 280 nm. The activity of cathepsin D was found to be elevated 8 times in non-diabetic periodontitis subjects (group IV) when compared to control and it was 3 times higher when compared to type 2 diabetes mellitus with periodontitis (group III). It gives an evidence for the release of lysosomal enzymes during periodontal tissue damage. D.S.PUSHPARANI AND S. NIRMALA Cathepsin D, Lysosomal enzymes, Oxidative stress, Periodontitis, Type 2 diabetes mellitus. 148-157