Urinary excretion of beta-thromboglobulin and N-acetyl-beta-D-glucosaminidase in type 1 diabetes: potential indicators of early nephropathy?Diabete Metab 1990 Sep-Oct; 16(5):441-7DM
While microalbuminuria indicates the glomerular damage of early diabetic nephropathy, tubular abnormalities also occur at an early stage of diabetic renal disease. Urinary excretion of beta-thromboglobulin (BTG) and N-acetyl-beta-D-glucosaminidase (NAG) was measured in 132 normotensive Type 1 (insulin-dependent) diabetic patients with no evidence of overt renal disease, of whom 35 had microalbuminuria and the remainder had normal urinary albumin excretion. Of 21 patients in whom there was a detectable urinary BTG concentration, only 8 (38%) had a concurrently abnormal urinary albumin excretion. NAG excretion was elevated in 22 (63%) of the 35 patients with microalbuminuria; significant associations were also identified between urinary NAG excretion and smoking habit (x2 = 12.7, p less than 0.001) and glycated haemoglobin (r = 0.49, p less than 0.01). It is concluded that measurement of urinary BTG is not of sufficient sensitivity to be of value in the detection of early diabetic renal disease, but measurement of urinary NAG may be of value in the detection of diabetic nephropathy at a potentially reversible stage.