Altered bile acid profiles in duodenal bile and urine in diabetic subjects

The bile acid composition in duodenal bile was analysed in 22 diet-treated and 11 insulin-treated middle-aged patients with diabetes mellitus and in 20 normoglycaemic controls. In 10 subjects with diabetes mellitus the bile acid profile in urine was also investigated. In the non-insulin-dependent diabetic patients the percentage of cholic acid was reduced and that of deoxycholic acid increased. As a highly significant finding there was a three-fold increase of the percentage of 12-ketolithocholic acid in duodenal bile in non-insulin-dependent diabetics, whereas the bile acid composition in insulin-dependent diabetics was similar to that in a control group. The percentage of 12-ketolithocholic acid in duodenal bile was positively correlated to the percentage in urine. In nine of the subjects studied, 12-ketolithocholic acid was the major individual bile acid in urine. It constituted 36.3 +/- 4.4% of the bile acids analysed and the excretion was 6.1 +/- 2.3 mumol 24 h-1. Together with 3 alpha, 12 beta-dihydroxy-5 beta-cholanoic acid it was predominantly present in the glycine conjugate fraction, whereas in bile its conjugation was similar to that of the other bile acids. The results may reflect an increased formation of secondary bile acids from cholic acid combined with a metabolic disturbance in non-insulin-dependent diabetics affecting the oxidoreduction of bile acids at C-12.