Quantitative analysis of single stool samples using a continuous marker

Peripheral Vascular Disease and Carotid Artery Disease Are Associated with Decreased Bile Acid Excretion

Low bile acid excretion (BAE) is associated with a higher risk of coronary artery disease (CAD) and cerebrovascular disease (stroke). This study investigated BAE in patients with peripheral vascular disease (PVD) and carotid artery disease (CA) and those without these diseases, compared to patients with CAD, stroke, or no evidence of atherosclerosis. Patients with complaints of chest pain-suspected CAD, syncope, stroke/TIA, severe headache, intermittent claudication, or falls were enrolled. All received a 4-day standard diet with 490 mg of cholesterol and internal standard copper thiocyanate. Fecal BAE was measured using gas-liquid chromatography. One hundred and three patients, sixty-eight (66%) men and thirty-five women (34%), mean age range 60.9 ± 8.9 years, were enrolled in this prospective, 22-year follow-up study. Regression analysis showed that advanced age, total BAE, and excretion of the main fractions were the only significant independent factors that predicted prolonged survival (p < 0.001). Twenty-two years' follow-up revealed only 15% of those with BAE <262.4 mg/24 h survived, compared to >60% of participants without atherosclerosis and a mean BAE of 676 mg/24 h. BAE was lower in patients with polyvascular atherosclerosis than in those with involvement of 1-3 vascular beds. Pearson correlations were found between total BAE and various fractions of BA, as well as HDL cholesterol. BAE and short-term survival were decreased among patients with PVD compared to those with CAD or stroke. Low BAE should be considered a valuable and independent risk factor for PVD.

Diminished bile acids excretion is a risk factor for coronary artery disease: 20-year follow up and long-term outcome

BACKGROUND

Patients with coronary artery disease (CAD) had significantly lower bile acid excretion (BAE) compared with non-CAD patients, leading to the hypothesis that the inability to efficiently excrete bile acids leads to coronary atherosclerosis development. We investigated the long-term role of BAE in CAD development and related mortality in 50 patients with proven CAD compared with that of 50 patients with chest pain and no CAD (controls) matched for clinical and laboratory characteristics.

METHODS

All subjects received a 4-day standard diet that included ~500 mg of cholesterol. Fecal bile acids from 24-h stool collections were measured by gas liquid chromatography.

RESULTS

CAD patients excreted lower amounts of total bile acids than controls (p < 0.001), less deoxycholic acid (p < 0.0001) and less lithocholic acid (p < 0.01). BAE was the best significant independent laboratory factor that predicted CAD (p < 0.05). Mortality and CAD development rates were significantly lower for the controls at the 20-year follow up.

CONCLUSIONS

These results showed that CAD patients had markedly decreased BAE levels compared with non-CAD controls. BAE <415 mg/day was associated with increased CAD long-term mortality. Impaired ability to excrete cholesterol might be considered an additional independent risk factor for CAD development.

The association of bile acid excretion and atherosclerotic coronary artery disease

BACKGROUND

Excess cholesterol is usually eliminated from the body by conversion to bile acids excreted in feces as bile salts. The excretion of large amounts of bile protects against atherosclerosis, while diminished excretion may lead to coronary artery disease (CAD).

OBJECTIVE

To investigate a relationship between CAD and bile acid excretion.

METHODS

Bile acid excretion was compared between 36 patients with proven CAD and 37 CAD-free individuals (controls). The groups were comparable for demographics and selected risk factors. All subjects received a 4-day standard diet that included ∼500 mg of cholesterol. Fecal bile acids from 24-hour stool collections were measured by gas liquid chromatography.

RESULTS

CAD patients excreted lower amounts of total bile acids (358 ± 156 mg) than controls (617 ± 293 mg; p < 0.01) and less deoxycholic acid (188.29 ± 98.12 mg versus 325.96 ± 198.57 mg; p < 0.0001) and less lithocholic acid (115.43 ± 71.89 mg versus 197.27 ± 126.87 mg; p < 0.01). Advanced age, male gender, left ventricular ejection fraction and total bile acid levels were significant independent factors that predicted CAD (p < 0.05). Mortality, CAD and cerebrovascular accident development rates were significantly lower for the controls at the 13-year follow up.

CONCLUSION

CAD patients have significantly decreased bile acid excretion levels than non-CAD patients. An impaired ability to excrete cholesterol may be an additional risk factor for CAD development.

Assessment of titrimetric and photometric methods for the determination of chymotrypsin catalytic activity in stool

In this report a method for the spectrophotometric measurement of stool chymotrypsin (CT) is presented and compared to the more commonly used titrimetric method. Homogenisation of specimen and dissolution of CT is examined in detail. The advantages of the photometric method lie in the small size of sample required, and its easy adaptation to manual or automated analysis with a CT-specific amide substrate.