Postprandial Serum Bile Acid Concentrations Research Articles

Resting and postprandial serum bile acid concentrations in dogs with liver disease.

BackgroundSerum bile acids (SBAs) are frequently measured in dogs. However, there is limited data comparing SBAs in different liver diseases diagnosed according to standardized histological criteria.ObjectivesTo compare resting and postprandial SBAs, and determine their sensitivity and specificity, for various liver diseases in dogs.AnimalsThree hundred and forty‐one client‐owned dogs with suspected liver disease that had a liver biopsy and SBAs measured.MethodsMulticenter retrospective study. Cases were classified according to standardized histological criteria. The sensitivity and specificity of resting and postprandial SBAs for the diagnosis of each liver disease, and all liver diseases combined, were calculated.ResultsThe median resting SBAs were highest in dogs with cirrhosis (98.8 μmol/L; range, 6‐135) and congenital circulatory anomalies (CCa; 79.45 μmol/L; 0.3‐705). The highest median postprandial concentrations were found in CCa (126 μmol/L; 0‐726) and chronic hepatitis (CH; 54.3 μmol/L; 0‐260). Using the cut‐off value of 10 μmol/L, the highest sensitivities of resting SBAs were recorded in dogs with CCa (87.5%; 95% confidence interval, 76.8‐94.4) and CH (81.1%; 71.5‐88.6). The sensitivities of postprandial SBAs were the highest in cholangitis (100%; 47.8‐100.0) and CCa (91.1%; 78.8‐97.5). The specificities of resting and postprandial SBAs for all diseases were 49.3% (37.6‐61.1) and 29.7% (15.9‐47.0), respectively.Conclusions and Clinical ImportancePostprandial SBAs are more sensitive but less specific than resting SBAs for the diagnosis of liver disease. There were dogs in all categories of liver disease with resting SBAs <10 and >90 μmol/L. Therefore, careful interpretation of both normal and elevated values is required.

Long-term serum bile acid concentrations in 51 dogs after complete extrahepatic congenital portosystemic shunt ligation.

To report the long-term bile acid stimulation test results for dogs that have undergone complete suture ligation of a single congenital extrahepatic portosystemic shunt. Data were collected from the hospital records of all dogs that had undergone a complete suture ligation of a single congenital extrahepatic portosystemic shunt. Owners were invited to return to the referral centre or their local veterinarian for repeat serum bile acid measurement. Dogs diagnosed with idiopathic epilepsy and undergoing bile acid stimulation tests were used as a comparison population. Fifty-one study dogs were included, with a mean follow-up time of 62 months. 48 dogs had no evidence of multiple acquired shunts and a significant reduction in the pre- and post-prandial serum bile acid concentrations at long-term follow-up compared with pre-operative measurements. Pre- and post-prandial serum bile acids were statistically significantly greater for dogs that had undergone a full ligation (with no evidence of multiple acquired shunts) at all time points compared to the control dogs (P<0·001 for all comparisons). The results suggest that in dogs treated with complete suture ligation mild increases in serum bile acids are not clinically relevant if there are no physical examination abnormalities, a normal body condition score and no relapse in clinical signs.

PS-116 - Post-prandial serum bile acid concentration change after bariatric surgery and is associated with weight loss and glucose metabolism improvement in obese human subjects

PS-116 - Post-prandial serum bile acid concentration change after bariatric surgery and is associated with weight loss and glucose metabolism improvement in obese human subjects

The inheritance of extra‐hepatic portosystemic shunts and elevated bile acid concentrations in Maltese dogs

To determine the heritability of extra-hepatic portosystemic shunts and elevated post-prandial serum bile acid concentrations in Maltese dogs. Maltese dogs were recruited and investigated by a variable combination of procedures including dynamic bile acid testing, rectal ammonia tolerance testing, ultrasonography, portal venography, surgical inspection or necropsy. In addition, nine test matings were carried out between affected and affected dogs, and affected and unaffected dogs. In 135 variably related Maltese, shunt status could be confirmed in 113, including 19 with an extra-hepatic portosystemic shunt (17 confirmed at surgery, 2 at necropsy). Rectal ammonia tolerance testing results and post-prandial serum bile acid concentrations were retrievable for 50 and 88 dogs, respectively. Pedigree information was available for these 135 and an additional 164 related dogs. Two consecutive test matings were carried out between two affected animals (whose shunts had been attenuated), with 2 of 8 (25%) of offspring having an extra-hepatic portosystemic shunt. Six test matings were carried out between an affected and an unaffected animal, with 2 of 22 (9%) offspring affected. Heritability of extra-hepatic portosystemic shunt was 0·61 calculated using variance components analysis [95% confidence interval (CI) 0·14 to 1·0, P=0·001]. The best fitting model from segregation analysis was a common, partially penetrant, recessive model (allele frequency 0·34, penetrance 0·99, CI 0·09 to 1·0). The heritability of elevated post-prandial serum bile acid (and thus likely portal vein hypoplasia) was 0·81 (CI 0·43 to 1·0, P=0·2) after logarithmic transformation of post-prandial serum bile acid concentrations. There is strong support for extra-hepatic portosystemic shunts and elevated post-prandial serum bile acid concentrations both being inherited conditions in Maltese.

Fasting and postprandial serum bile acid concentrations in 10 healthy female red-eared terrapins (Trachemys scripta elegans)

The fasting and postprandial serum concentrations of bile acids and other blood constituents were measured in a group of 10 clinically healthy, female, six-year-old captive red-eared terrapins (Trachemys scripta elegans)....

The effect of colestipol dose on postprandial serum bile acid concentration: assessment by an enzymic bioluminescence procedure

A dose-response study was performed with three doses of colestipol, using postprandial serum bile acid levels to assess bile acid sequestering activity in 40 volunteers with asymptomatic hyperlipidaemia. Subjects who entered the study had total serum cholesterol concentrations greater than 220 mg/dl and triglyceride concentrations less than 200 mg/dl. They were randomly assigned to one of four parallel treatment groups: (a) placebo b.d., (b) colestipol (as Colestid hydrochloride granules) 2.5 g b.d., (c) colestipol 5 g b.d., and (d) colestipol 7.5 g b.d. Subjects were maintained on a constant repeating solid diet throughout the 6-day study period, and colestipol was ingested 30 min before breakfast and dinner. No drug was administered on Days 1-3; baseline (pre-treatment) serum bile acid concentration profiles were determined on Day 3. The above treatments were given on Days 4-6, and total serum bile acid concentrations were determined at 30- or 60-min intervals for 10 h on Days 4 and 6. Serum bile acids were measured using a bioluminescence procedure which enzymically measures total 3 alpha hydroxy bile acids. Serum bile acid concentrations were significantly decreased from the pretreatment period by 5.0 and 7.5 g/day as compared to 2.5 g/day or placebo. Differences from the pre-treatment period in the area under the serum bile acid time curve revealed the same trends in the data as analysis of percentage difference (Day 6 vs pre-treatment period) in serum bile acid concentrations. These results indicate that postprandial serum bile acid concentrations are influenced by colestipol in a dose-related manner, with doses of 5 and 7.5 g b.d. having a significantly greater effect than 2.5 g b.d. The dose of 7.5 g b.d. had an identical effect on serum bile acid patterns as a dose of 5.0 g t.d.s., which was previously reported. Our findings also show that changes in serum bile acid concentrations may be used to follow the immediate effects of bile acid sequestration in hypercholes terolaemic subjects, and that the bioluminescence enzyme technique is sufficiently sensitive to detect such changes.

Effect of oral ursodeoxycholic acid on bile acids tolerance tests in healthy dogs

To determine whether oral administration of ursodeoxycholic acid (UDCA) to healthy dogs alters the results of the bile acids tolerance test. UDCA (15 mg/kg once daily) was administered to 16 healthy dogs for 7 days. Health of the dogs was assessed by clinical examination, haematology, serum biochemistry and a bile acids tolerance test. Normal liver structure was confirmed by histopathology at the end of the study. Bile acids tolerance tests were performed before and at the end of the treatment period, with each dog serving as its own control. For the posttreatment bile acids tolerance test, UDCA was administered at the time of feeding. Pretreatment, the fasted serum total bile acid concentrations ranged between 0 and 9 micromol/L. In the majority of dogs, the postprandial total bile acid concentration was greater than the preprandial value, with a range of 0 to 16 micromol/L. The fasted total bile acid concentration was 0 micromol/L in most dogs (93.75%) after treatment with UDCA. Postprandial serum bile acids also remained within the reference range for the majority of dogs (93.75%) after UDCA treatment. A single dog had a postprandial bile acid concentration above the reference range, but the concentration was within the reference range when the assay was repeated the following day without concurrent administration of UDCA. The pre- and postprandial total serum bile acid concentrations were not significantly affected by UDCA treatment. The administration of UDCA does not alter the bile acids tolerance test of normal healthy dogs.

Outcomes after extrahepatic portosystemic shunt ligation in 49 dogs.

To evaluate outcomes after attenuation of extrahepatic portosystemic shunts in dogs using surgical silk. Retrospective study. Case records were reviewed for degree of surgical attenuation, experience of the primary surgeon, perioperative mortality and problems related to persistent portosystemic shunting or shunt ligation. Presence of portosystemic shunting after surgery was evaluated by ammonia tolerance testing, measurement of postprandial serum bile acid, plasma urea and cholesterol concentrations and liver enzyme activity. The influence of age, postocclusion portal pressure, primary surgeon, degree of attenuation and postoperative biochemical findings on the occurrence of postoperative problems was assessed. The mortality rate was 2.1%. Shunt attenuation was complete in 34% and partial in 66% of dogs. Portal hypertension necessitating ligature removal was encountered in only one dog. Five dogs experienced neurological abnormalities (seizures or ataxia), possibly as a manifestation of 'postligation seizure syndrome'. Postoperative liver function was normal in 78% of dogs, including 70% with partial shunt attenuation. Experience of the surgeon was related positively to outcome after partial attenuation (P = 0.002). Postoperative biochemical evidence of abnormal liver function was the most sensitive predictor of recurrence of clinical signs referable to persistent portosystemic shunting. In the hands of an experienced surgeon, surgical attenuation of single extrahepatic shunts was safe and effective, even in animals with partial attenuation. Most dogs with biochemical evidence of persistent shunting suffer relapse of clinical signs within 18 months of surgery. Postligation neurological syndromes of variable intensity may be more common than previously thought.

Clinicopathologic features of dogs with hepatic microvascular dysplasia with and without portosystemic shunts: 42 cases (1991–1996)

Objective To identify and compare clinicopathologic features between dogs with hepatic microvascular dysplasia (HMD) and confirmed portosystemic shunts (PSS) and dogs with HMD alone and to determine whether any discriminating variables can be identified to differentiate the conditions. Design Retrospective study. Animals 42 dogs with HMD. Procedure Medical records of dogs with HMD examined between January 1991 and October 1996 at 3 veterinary hospitals were reviewed. Results Compared with dogs with PSS and HMD, dogs with HMD alone were older and had higher values for mean corpuscular volume (MCV) and serum total protein, albumin, creatinine, cholesterol, BUN, and blood glucose concentrations. Compared with dogs with HMD alone, dogs with PSS and HMD had higher values for pre- and postprandial serum bile acid concentrations, WBC, and serum alkaline phosphatase and aspartate aminotransferase activities. The most discriminating variables for the 2 conditions were serum postprandial bile acid concentrations, MCV, and serum albumin and cholesterol concentrations. Clinical Implications The discriminant variables of postprandial serum bile acid concentrations, MCV, and serum albumin and cholesterol concentrations may be useful in distinguishing between dogs with HMD alone and dogs with PSS and HMD. (J Am Vet Med Assoc 1999;214:218–220)

Characterization of hepatoportal microvascular dysplasia in a kindred of cairn terriers.

Hepatoportal microvascular dysplasia (MVD), a congenital disorder of the hepatic vasculature, is described in a kindred of Cairn Terrier dogs. Cairn Terrier dogs (n = 165) were evaluated using the serum bile acid test. Affected dogs, identified by abnormal fasting or postprandial serum bile acid concentrations, were divided into 2 groups. Group 1 dogs (n = 147) were used for pedigree analysis. Group 2 dogs (n = 18) were characterized on the basis of history, physical examination, clinicopathologic studies, diagnostic imaging of the liver and portal circulation, and hepatic histopathology. Group 2 contained control dogs (n = 2), dogs with hepatoportal MVD (n = 11), and dogs with macroscopic portosystemic vascular anomalies (PVSA) (n = 5). With the exception of high serum bile acid concentrations, dogs with hepatoportal MVD were indistinguishable from control dogs on the basis of history, physical examination, clinicopathologic findings, survey abdominal radiography, abdominal ultrasound, or transcolonic scintigraphy. Contrast portography in dogs with MVD revealed abnormalities of terminal twigs of the portal vasculature with out large intrahepatic or extrahepatic shunting vessels. Histopathologic abnormalities in dogs with hepatoportal MVD were similar to those reported for dogs with PSVA. Pedigree analysis suggested an autosomal inheritance for MVD. Dogs with MVD had high serum bile acid concentrations, abnormal indocyanine green clearance, and hepatic pathology suggestive of PSVA, but they lacked characteristic clinical findings of PSVA. The clinical significance of MVD is unclear. Dogs with MVD were clinically normal when evaluated but long-term follow-up is not yet available. Dogs with hepatoportal MVD should be identified at an early age to avoid confusion in future diagnostic evaluations.

Post‐prandial serum bile acid concentrations and ammonia tolerance in Maltese dogs with and without hepatic vascular anomalies

Australian Veterinary JournalVolume 72, Issue 6 p. 238-238 Free Access Post-prandial serum bile acid concentrations and ammonia tolerance in Maltese dogs with and without hepatic vascular anomalies First published: June 1995 https://doi.org/10.1111/j.1751-0813.1995.tb03532.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume72, Issue6June 1995Pages 238-238 RelatedInformation

Post-prandial serum bile acid concentrations and ammonia tolerance in Maltese dogs with and without hepatic vascular anomalies.

Post-prandial serum bile acid concentrations were measured in 200 Maltese dogs in an attempt to identify those with subclinical portosystemic shunts. Five of these were later shown to have hepatic pathology or abnormal liver function. In the other 195 Maltese, bile acid concentrations ranged from 1 to 362 mumol.L-1 (mean +/- SD, 70 +/- 50 mumol.L-1; median, 65.0 mumol.L-1). Of these, 79% were above the reference range (0 to 31 mumol.L-1) established from 23 mixed-breed control dogs. It was therefore not possible to determine the prevalence of subclinical portosystemic shunts on the basis of bile acid determinations. Further investigation of liver function was performed to investigate why bile acid concentrations were increased in these dogs. Rectal ammonia tolerance tests were normal in 102 of 106 Maltese tested and liver samples (11 dogs) and plasma biochemistry profiles (9 dogs) demonstrated no significant hepatic disease or dysfunction. Of 2 Maltese with hyperammonaemia after administration of ammonium chloride, one had a large congenital portosystemic shunt that was confirmed at surgery. In the other there were no macroscopic portosystemic communications, but a liver biopsy showed histological changes consistent with microscopic portovascular dysplasia. Total serum bile acid concentrations were consistently lower when assessed by high-performance liquid chromatography than by an enzymatic spectrophotometric method. This discrepancy was substantially larger in Maltese than in control dogs, suggesting the presence of an additional reacting substance in the serum of Maltese dogs.

The pathophysiology and laboratory diagnosis of congenital portosystemic shunts in dogs

Abstract Congenital portosystemic shunts generally arise as single vascular anomalies that cause the portal blood to bypass the liver and enter the systemic venous circulation directly. The liver is primarily affected, as it is deprived of perfusion by portal hepatotrophic factors such as insulin, glucagon, and amino acids. There is progressive hepatic atrophy, and as a consequence, dysfunction. Hepatic encephalopathy can result from increased levels of ammonia and gamma-aminobutyric acid within the systemic circulation. Variably toxic amines, captans and short chain fatty acids may act as false neurotransmitters. Hypoglycaemia will exacerbate the effects of these substances. Increased concentrations of ammonia and uric acid in the urine predispose to the precipitation of ammonium biurate crystals and the formation of calculi. Haematological changes include anaemia, microcytosis, hypoproteinaemia, leucocytosis, and coagulation abnormalities. Gastrointestinal effects are common. They may be displayed as anorexia, vomiting, ptyalism, pica, diarrhoea, or polyphagia. Most dogs are less than 1 year of age at initial presentation. Diagnosis from a laboratory viewpoint will involve a consideration of the history, clinical findings, haematology, serum biochemistry and urinalysis. If the findings are suggestive of a congenital portosystemic shunt, the demonstration of elevated fasting or, more consistently, post-prandial serum bile acid concentrations, and subsequent histological examination of a liver biopsy will provide a definitive diagnosis.

Serum Bile Acids in Companion Animal - Medicine

Quantification of total serum bile acids is used as a method for appraising liver function and perfusion in contemporary small animal practice. This article provides a historical perspective and a comprehensive review of bile acid physiology, laboratory methodologies for bile acid quantification, and normal values published for total serum bile acids measured using the spectrophotometric enzymatic method and for serum bile acids measured using validated radioimmunoassay procedures. The variables influencing the enterohepatic circulation of bile acids and, consequently, the fasting and postprandial serum bile acid concentrations are discussed with the intent of clarifying the application of test results to clinical patients. A brief discussion of the therapeutic use of dehydrocholate and ursodeoxycholic acid in clinical patients is provided.

Clinical chemical diagnosis of diseases assisted by logistic regression illustrated by diagnosis of canine primary and secondary hepatobiliary diseases.

The purpose of the present study was to demonstrate the use of logistic regression models in the prediction of diseases using the prediction of canine primary and secondary hepatobiliary diseases as an example. Briefly, in a logistic regression model independent variables (i.e. the analytical results) are combined in a linear equation that is used to estimate the logarithm of the odds (logit) of an event (i.e. having primary or secondary hepatobiliary disease). From the estimated logit given by the logistic regression model, a conditional probability of the event (i.e. having primary or secondary hepatobiliary disease) can be calculated. Twenty-six dogs with verified primary and secondary hepatobiliary diseases and 19 dogs, initially suspected to have hepatobiliary diseases, but with apparently other diseases, were included in the study. The following clinical chemical parameters were measured: alanine aminotransferase (ALAT), aspartate aminotransferase (ASAT), alkaline phosphatase (AP), bilirubin(Total) (TB), urea, glucose, retention of bromosulphthalein (BSP), fasting and postprandial total serum bile acid concentration (FSBA and PSBA). Logistic regression analysis, using the CATMOD procedure in SAS, was used to select which of the measured parameters should be included in the model, and to derive a logistic regression model using the selected parameters. To observe more closely the potential of the logistic regression model, the model was also used to classify a test group consisting of 13 dogs (6 dogs with hepatobiliary diseases and 7 dogs with other diseases). By logistic regression analysis, ASAT and PSBA were selected to be included in the final model, and the final logistic regression model was Y = -3.194 + 0.044.PSBA + 3.251.ASAT. The logistic regression model classified correctly 38 (84%) of 45 dogs in the present study. Specifically, 21 (81%) of 26 dogs with verified primary or secondary hepatobiliary diseases and 17 (90%) of 19 dogs with various other diseases were correctly classified by the logistic regression model. When the model was used on the test group, 5 (83%) of 6 dogs with hepatobiliary diseases and 7 dogs (100%) of 7 dogs with other diseases were correctly classified. Even though the logistic regression model derived in the present study only serves as an example, thus reducing the practical usefulness of the derived logistic regression model, the present study indicates a great potential of logistic models for the diagnosis of diseases.

Evaluation of diagnostic tests using relative operating characteristic (ROC) curves and the differential positive rate. An example using the total serum bile acid concentration and the alanine aminotransferase activity in the diagnosis of canine hepatobiliary diseases.

The value of a diagnostic test depends on most cases on its ability to discriminate between patients with and without a certain disease. One way of evaluating a diagnostic test is to use the relative operating characteristic curve (ROC curve) and the differential positive rate (DPR). The ROC curve displays the relationship between the true positive ratio and the false positive ratio for a range of cutoff values and it can be used to compare various diagnostic tests under equivalent conditions (equal true positive ratios or false positive ratios) and over the entire range of cutoff values. The DPR is the difference between the true positive ratio and the false positive ratio at various cutoff values and it can be used to obtain the cutoff value associated with the highest sensitivity and specificity. The purpose of this study was to describe the evaluation and comparison of diagnostic tests using ROC curves and DPR. Eventually, the positive and negative predictive values were used to assess the differences between the sensitivity and specificity obtained when the upper limit of the reference interval, or the optimal cutoff value indicated by the DPR, was used as cutoff value. To illustrate the methods, the 2 h post-prandial total serum bile acid concentration (PSBA) and the alanine aminotransferase activity (ALAT) in the diagnosis of primary or secondary hepatobiliary diseases in dogs were used. The ROC curves showed, as expected from previous studies, that PSBA was superior to ALAT in diagnosing dogs with hepatobiliary diseases. Using DPR, the optimal cutoff value for PSBA was suggested to be 15.48 mumol/l. Compared to the traditionally used cutoff value of 22.24 mumol/l, no decisive difference in the positive predictive values were observed. However, the cutoff value of 15.48 mumol/l appeared to produce higher negative predictive values compared to a cutoff value of 22.24 mumol/l. Seemingly, ROC curves and DPR are simple methods useful to the evaluation of diagnostic tests and due to the simplicity, there seems to be a great potential for these methods in the evaluation of diagnostic tests in veterinary medicine.

Hepatotoxicity of phenobarbital in dogs: 18 cases (1985-1989)

Summary The medical records of 18 dogs that had hepatic disease and received phenobarbital as an anticonvulsant for 5 to 82 months were reviewed. Clinical signs included sedation and ataxia in all dogs, 5 dogs were also anorectic, 2 had coagulopathy, 3 were icteric, and 5 had ascites. Serum biochemical analysis revealed serum albumin concentration ≤ 2.2 g/dl in 12 dogs, serum alkaline phosphatase activity ≥ 169 U/L in 18 dogs, serum alanine transaminase activity ≥ 57 U/L in 15 dogs, and total bilirubin concentration ≥ 1 mg/dl (in the absence of lipemia) in 7 dogs. Serum phenobarbital concentration was ≥ 40 μg/ml in 12 of 17 dogs. Sulfobromophthalein excretion was prolonged in 8 of 10 dogs. Preprandial serum bile acid concentrations were high in 8 of 10 dogs, and 2-hour postprandial serum bile acid concentrations were high in 9 of 10 dogs. Two of 4 dogs tested had resting plasma ammonia concentrations &gt; 200 mg/dl. An ammonia tolerance test was performed on 2 other dogs; both had ammonia concentration ≥ 200 mg/dl in the plasma 30 minutes after receiving 100 mg of ammonium chloride/kg of body weight, po. Nine dogs died, 1 was euthanatized, and necropsies were performed on these 10 dogs. Biopsies and necropsies of 6 dogs revealed chronic hepatic fibrosis with nodular regeneration (cirrhosis). One dog had hepatocellular carcinoma and mild cirrhosis. In 1 dog, after phenobarbital had been withheld, necropsy revealed complete recovery of the previously observed lesions.

Evaluation of Fasting and Postprandial Total Serum Bile Acid Concentration in Dogs with Hepatobiliary Disorders

The fasting and 2 h postprandial total serum bile acid concentrations (FSBA and PSBA), alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, bilirubin (Total), and retention of bromosulphthalein were determined in a group of dogs with various hepatobiliary disorders as well as in a group of dogs with other diseases than hepatobiliary disorders. Although FSBA and PSBA were generally elevated in cases of hepatobiliary disorders, no distinction between different disease groups could be made based solely on FSBA and PSBA. FSBA and PSBA were found to be relatively sensitive and specific parameters compared to the other hepatic tests. PSBA tended to be superior to the other parameters investigated in terms of sensitivity, specificity, positive predictive value, and negative predictive value.

Fasting and postprandial serum bile acid concentration with special reference to variations in the conjugate profile.

Serum bile acids were group-separated by ion exchange chromatography on diethylaminohydroxypropyl Sephadex LH-20 into unconjugated bile acids and bile acids conjugated with either glycine, taurine, glucuronic acid or sulphuric acid. The conjugate moiety was hydrolysed by treatment with a combination of Helix pomatia and cholylglycine hydrolase and the released bile acids analysed by gas liquid chromatography/mass spectrometry. Analysis of fasting and postprandial serum from six healthy subjects showed that, in addition to the primary bile acids, cholic (C) and chenodeoxycholic acid (CDC), secondary bile acids were present to varying extents. Unconjugated serum bile acids were found in four of the six subjects. Glycine and taurine conjugates of C and CDC and their glucuronides and sulphates were found in all subjects. The postprandial increase of serum bile acids was mainly due to increase of the glycine conjugates of C and CDC. After the meal, the ratio C:CDC in glycine and taurine conjugates shifted to lower values.

Diagnostic Values of Fasting and Postprandial Concentrations in Serum of 3α-Hydroxy-Bile Acids and Gamma-Glutamyl Transferase in Hepatobiliary Disease

Fasting and postprandial concentrations in serum of 3 alpha-hydroxy-bile acids and gamma-glutamyl transferase were measured in 138 consecutive patients, 62 with (D) and 76 without (D) hepatobiliary disease. The maximum efficiencies of the three tests--that is, the fractions of patients allocated correctly to the D or D group at the optimum discrimination values--were 0.85, 0.84, and 0.83, respectively. Furthermore, the predictive values and nosographic sensitivities and specificities were rather similar. When the three tests were combined, the nosographic sensitivity increased significantly to a value of 0.84, and the corresponding specificity was 0.91. The diagnostic value of the absolute postprandial increase in serum bile acid concentration was slightly inferior to the diagnostic values of the fasting and postprandial serum bile acid concentrations and, finally, the relative postprandial serum bile acid increase was of no diagnostic value at all.