Urinary excretion of non-dialysable conjugates of glucose and galactose in normal people and diabetic patients.

Urine contains non-dialysable conjugates of glucose and galactose from which the free sugars are released by acid hydrolysis. In 14 non-diabetic subjects the 24-h outputs (mean +/- SEM) were 25 +/- 3 mumol/24 h (glucose) and 109 +/- 15 mumol/l (galactose). In collections from 23 diabetic patients output of conjugated glucose was increased to 177 +/- 96 mumol/24 h but conjugated galactose was unchanged (119 +/- 10 mumol/24 h). The concentration ratio of glucosyl/galactosyl allows relative 24-h outputs of conjugated glucose to be estimated on random samples. The ratio (mean +/- SEM) was 0.24 +/- 0.01 in 27 normal men and 0.37 +/- 0.04 in 30 normal women. The mean ratio was increased to 0.72 +/- 0.20 in 56 male and to 0.51 +/- 0.07 in 17 female diabetic patients. In individual diabetic patients, the ratio was increased significantly in 28 out of 56 men and in 5 out of 30 women. In male diabetic patients the ratio was increased in 17 out of 23 Type 1 (insulin-dependent) but in only 3 out of 15 Type 2 (non-insulin-dependent) diabetic patients. There was no correlation between the glucosyl/galactosyl ratio and patient age, known duration of diabetes, or urinary excretion of free glucose or protein. Urine samples showing increased glucosyl/galactosyl ratios did not yield bacteria on culture and were negative for Candida albicans cell-wall mannan antigen. It is concluded that 80% of male Type 1 diabetic patients show increased urinary excretion of non-dialysable conjugated glucose. In women, there is much greater variation in non-diabetic subjects which may obscure an increased excretion in diabetic patients.