UK Prospective Diabetes Study (UKPDS). IX: Relationships of urinary albumin and N-acetylglucosaminidase to glycemia and hypertension at diagnosis of type 2 (non-insulin-dependent) diabetes mellitus and after 3 months diet therapy

In 672 newly-diagnosed, Type 2 (non-insulin-dependent) diabetic patients without urinary infection, aged 51 (9) years, mean (1 SD), 28% of patients had raised albuminuria, defined as albumin excretion greater than 25 mg/l and 66 % raised urinary N-acetylglucosaminidase excretion defined as greater than 300 μmol·h−1·l−1 (both urinary analytes corrected by linear regression on urinary creatinine to 10 mmol/l). In a univariate analysis, urinary N-acetylglucosaminidase and albumin excretion correlated with each other (rs=0.42, p<0.001), and with fasting plasma glucose (rs= 0.46 and rs=0.27, p<0.001, respectively). The association of urinary albumin and N-acetylglucosaminidase remained significant after taking the fasting plasma glucose levels into account, partial rs=0.34, p<0.001. After 3 months of dietary therapy BMI decreased from 29.7 (5.9) kg/m2 to 28.8 (5.8) kg/m2, fasting plasma glucose levels from 12.2 (3.8) mmol/l to 9.8 (3.8) mmol/l, and systolic blood pressure from 143 (21.8) mmHg to 131 (20.3) mm Hg, p<0.001 for each variable. There were concomitant decreases in urinary N-acetylglucosaminidase, geometric mean (1 SD interval), 397 μmol·h−1·l−1 (216 to 728) to 291 μmol · h−1 · l−1 (160 to 528), p<0.001 and in albumin excretion 16 mg/l (5 to 51) to 13 mg/l (4 to 40), p<0.001. The decrease in urinary N-acetylglucosaminidase, but not the decrease in urinary albumin excretion, was associated with the initial degree of glycaemia and the decrease in glycaemia in response to diet. Urinary albumin excretion correlated with systolic blood pressure at diagnosis (rs=0.23, p<0.001) and was higher in both treated and untreated patients with hypertension, p<0.001, whereas urinary N-acetylglucosaminidase excretion was only slightly raised in patients with hypertension on therapy, p<0.05. In conclusion, urinary albumin excretion was associated with hyperglycaemia and hypertension, whereas urinary N-acetylglucosaminidase was primarily associated with hyperglycaemia.

UKPDS Study Group. Diabetologia 1993; 36: 835–842. doi: 10.1007/BF00400359