[Microalbumin and N-acetyl-beta-D-glucosaminidase in random spot urine samples as predictors of diabetic nephropathy in the elderly non-insulin dependent diabetic patients].

To determine whether urinary albumin to creatinine ratio (Albumin index) and urinary N-acetyl-beta-D-glucosaminidase (NAG) to creatinine ratio (NAG index) in random spot urine samples can be sued to predict the early stage of diabetic nephropathy in the elderly non-insulin dependent diabetic patients, we measured these concentrations in 150 non-diabetics, 61 diabetics without retinopathy and 56 diabetics with retinopathy. All patients with Albustix-positive urine were excluded. Subjects divided into two groups according to whether they were < 60 years (adult group) or > or = 60 years old (old group). Multiple regression analysis was used to investigate the relationship between NAG index or Albumin index (dependent variable) and independent variables (age, systolic blood pressure, duration of diabetes. HbA1c) in diabetic patients. Diabetic patients with retinopathy showed the highest mean Albumin index, followed by diabetic patients without retinopathy and then non-diabetic patients both in adult group and in old group (p < 0.001, p < 0.001, respectively). Diabetic patients with retinopathy showed the highest mean NAG index, followed by diabetic patients without retinopathy and then non-diabetic patients both in adult group and in old group (p < 0.001, p < 0.001, respectively). Albumin index positively correlated with systolic blood pressure, duration of diabetes and HbA1c (r = 0.18, r = 0.35, r = 0.18, respectively). NAG index positively correlated with age, duration of diabetes and HbA1c (r = 0.18, r = 0.25, r = 0.29, respectively). These results suggest that both NAG index and Albumin index in random spot urine samples may serve as early functional indicators of diabetic nephropathy in elderly diabetics.