Insulin-dependent diabetes mellitus and glycosaminoglycans

The influence of diabetic nephropathy on urinary glycosaminoglycan distribution was assessed in 96 patients with insulin-dependent diabetes mellitus (IDDM, 49 female, age: 1664 yrs, median 35; duration of IDDM: 0-43 yrs, median 13 yrs) in comparison to 103 healthy controls (57 female, 17 - 82 yrs, median 40 yrs). Glycosaminoglycan concentration in 24 h urine samples was determined by means of precipitation with cethylpyridinium chloride and potassium acetate in ethanol followed by a colorimetric test with carbazole. A marked difference (p=0.0008) in urinary glycosaminoglycan excretion between patients (19.0, 12.4, 35.6 mg/24 h, median, 25th, 75th percentile) and controls (15.8, 10.4, 21.6 mg/24h) could be detected. In patients with insulin-dependent diabetes mellitus of longer duration, glycosaminoglycan excretion was increased (<10 years: 17.3, 10.8, 30.5 mg/24h; > 10 yrs: 23.3, 16.0, 39.1 mg/24 h; p = 0.03). Furthermore, diabetic patients with manifest nephropathy and retinopathy exhibited a significantly higher glycosaminoglycan excretion compared to patients without nephropathy (40.8, 23.3, 42.2 versus 18.2, 11.4, 31.0 mg/24 h, p = 0.005) or retinopathy (31.9, 16.6, 41.6 versus 17.6, 11.2, 26.7 mg/24 h, p = 0.009). Thus, the results of this study demonstrate a close relationship between diabetic nephropathy and the renal glycosaminoglycan excretion.