Thrombomodulin levels in insulin-dependent diabetic patients with microalbuminuria

Thrombomodulin (TM) plays an important role in the regulation of blood coagulation at the endothelial surface. TM is also present in plasma, where an increase of its level seems to reflect endothelial damage. Since microalbuminuria is associated with an increased atherothrombotic risk and is considered an expression of widespread vascular damage, we evaluated plasma thrombomodulin levels, blood pressure, and plasma lipid values in Type 1 diabetic patients with micro- and normoalbuminuria. Thrombomodulin was measured in 12 microalbuminuric (albumin excretion rate 20-200 micrograms min-1 in 2 of 3 overnight urine collections) and in 12 normoalbuminuric (albumin excretion rate < 20 micrograms min-1) Type 1 diabetic patients matched for age, sex, body mass index, smoking habits, diabetes duration, and glycated haemoglobin. Mean thrombomodulin was significantly higher in micro- than in normalbuminuric group (59.34 +/- 3.58 vs 43.56 +/- 3.52 ng ml-1 p < 0.01). Systolic and diastolic blood pressure were significantly higher in micro- than in normoalbuminuric group (p < 0.05). There was a positive correlation between plasma thrombomodulin and albumin excretion rate (p = 0.013, r = 0.49), and between thrombomodulin and diastolic blood pressure (p = 0.023, r = 0.46) in diabetic patients as a whole but not in the individual groups. These findings suggest the presence of an endothelial injury in microalbuminuric patients.