Brief report Impaired activity of serum alpha-1-antitrypsin in diabetes mellitus

Alpha-1-antitrypsin (AAT) is the prototypic member of the serine protease inhibitor (serpin) superfamily of proteins, which has a major role in inactivating neutrophil elastase and other proteases to maintain protease–antiprotease balance. In this study, the serum AAT was measured using enzymatic assay in diabetic patients. The serum trypsin inhibitory capacity (s-TIC) was determined in 144 outpatients with uncontrolled insulin-dependent diabetes mellitus (n = 47) and non-insulin dependent diabetes mellitus (n = 97). The s-TIC values were 1.960 0.399, 2.002 0.4304 and 2.867 0.395 mmol/min/ml in IDDM, NIDDM and healthy subjects, respectively. The diabetics individual had a significantly lower s-TIC than controls (P < 0.0001). It was found that there was a negative correlation between the s-TIC and the duration of diabetes (r = 0.5420; P < 0.0001). There was no correlation between s-TIC and age of patients (P = 0.865). Thus, diabetes is associated with reduced trypsin inhibitory capacity of plasma. # 2006 Elsevier Ireland Ltd. All rights reserved.