Differential timing of maximal postprandial concentrations of plasma chenodeoxycholate and cholate: its variability and implications.

The concentrations of conjugated chenodeoxycholate and cholate in serum have been measured in 26 controls and 19 patients with liver disease before and after taking a fat-containing meal. The times at which maximum bile salt concentrations occurred varied considerably between individuals. In the majority of cases maximal concentrations of the two bile salts occurred simultaneously but in 3 subjects maximal concentrations of chenodeoxycholate were found 15-60 min prior to maximal cholate concentrations. The measurement of bile salt concentration in a single sample taken 2 h after the fatty test meal would have produced two false-negative results in the patients with liver disease. It is concluded that the jejunal absorption of dihydroxylated bile salts may not be significant in the majority of individuals and that the protocol for assessment of liver function by postprandial bile salt analysis should include at least two blood samples collected at 1.5 and 2 h after ingestion of the test meal.