A high intake of conjugated linoleic acid does not affect liver and kidney function tests in healthy human subjects.

Conjugated linoleic acid (CLA) is consumed widely as a supplement. It causes hepatomegaly in animals, but toxicological data in humans are limited. We therefore studied the effect of a high daily intake of CLA on liver and kidney function in healthy subjects. Twenty subjects received 14.6 g cis-9,trans-11 CLA and 4.7 g trans-10,cis-12 CLA isomers a day for 3 weeks. Liver and kidney function was measured at 0, 3, 7, 10, 16, and 21 days. Mean values of all tests remained within normal limits. Lactate dehydrogenase (mean+/-SD) increased from 290.9+/-43.6 to 322.5+/-60.7 U/L (p=0.04) on day 21. One subject exceeded the upper limit of normal of 450 U/L on day 21, to 472 U/L and another showed an isolated elevation to 555 U/L on day 7. Gamma-glutamyltranspeptidase increased from 12.1+/-5.9 to 13.5+/-6.2U/L (p=0.002). No one exceeded the upper limit of 50 U/L for men and 40 U/L for women. A daily intake of 19.3 g CLA for 3 weeks does not produce clinically relevant effects on markers of liver and kidney function in healthy volunteers.

The effect of different treatment regimens in reducing fasting and postmethionine-load homocysteine concentrations.

OBJECTIVES: To determine the homocysteine-lowering effect of different treatment regimens on both fasting and postmethionine-load plasma total homocysteine (tHcy) concentrations. DESIGN: Descriptive study of consecutive hyperhomocysteinaemic subjects per treatment regimen. Homocysteine was measured in the fasting state and 6 h after methionine loading, both before and after 8 weeks of vitamin therapy. Hyperhomocysteinaemia was defined as a fasting tHcy and/or increase in tHcy (postmethionine-load minus fasting tHcy concentration) exceeding the 95th percentile of local controls. SETTING: Outpatient clinic of internal medicine of a large non-academic teaching hospital. SUBJECTS: One hundred and seventeen hyperhomocysteinaemic subjects (vascular patients and first-degree relatives). INTERVENTIONS: There were four regimens: pyridoxine, 200 mg; folic acid, 5 mg; combination of folic acid 0.5 mg and pyridoxine 100 mg; and folic acid, 0.5 mg daily. RESULTS: All regimens, except pyridoxine 200 mg, significantly reduced fasting tHcy without differences in the percentage reduction (32-38%). All regimens produced a significant reduction in the increase in tHcy and postmethionine-load tHcy. The reduction in postmethionine-load tHcy was smaller for pyridoxine 200 mg than for combination therapy. No differences were found in the percentage reduction (for both increase in tHcy and postmethionine-load tHcy) between folic acid 5 mg and folic acid 0.5 mg. CONCLUSIONS: Monotherapy folic acid (0.5 mg daily) is the lowest effective therapy for reducing both fasting and postmethionine-load tHcy concentrations, with the same results as high-dose folic acid (5 mg daily). Pyridoxine has no additional value.

Hyperhomocysteinaemia as a cardiovascular risk factor: an update.

There is overwhelming epidemiological evidence that hyperhomocysteinaemia is an independent and graded cardiovascular risk factor, although a cause-and-effect relationship is still unproven. Acquired causes of hyperhomocysteinaemia include B-vitamin deficiencies and renal insufficiency. The most important inherited cause is a point mutation in methylenetetrahydrofolate reductase gene, which is, remarkably, not associated with an increased cardiovascular risk. A methionine loading test identifies substantially more subjects with hyperhomocysteinaemia compared with a fasting homocysteine determination alone. Repeated blood sampling is necessary due to an intra-individual variability in homocysteine concentrations up to 25%. A conservative reference value for fasting homocysteine is 15 micromol/l, although there seems to be no definite threshold in the presumed linear relation between homocysteine concentration and cardiovascular risk. The pathophysiological mechanism of homocysteine-induced cardiovascular disease is still not elucidated. The concept of endothelial dysfunction, demonstrated by impaired endothelium-dependent vasodilation, by oxidant damage has been confirmed in hyperhomocysteinaemic healthy adults. Folic acid supplementation (0.5 mg daily) can be considered the optimum homocysteine lowering therapy, with the exception of renal failure patients. Ongoing large prospective, randomised controlled clinical trials are investigating the potential beneficial effect of homocysteine lowering therapy on cardiovascular morbidity and mortality in subjects with hyperhomocysteinaemia.

Comparing subcutaneous danaparoid with intravenous unfractionated heparin for the treatment of venous thromboembolism. A randomized controlled trial.

OBJECTIVE: To compare the efficacy and safety of two subcutaneous doses of danaparoid with that of continuous intravenous administration of unfractionated heparin in the treatment of venous thromboembolism. DESIGN: An open-label, randomized, multicenter clinical trial. SETTING: One university hospital and two university-affiliated hospitals. PATIENTS: 209 patients suspected to have venous thromboembolism. Of these, 188 had a confirmed diagnosis (by ventilation-perfusion lung scan and ultrasonography or contrast venography of the leg) and received study medication. INTERVENTIONS: Patients were randomly assigned to either low-dose danaparoid (intravenous loading dose of 1250 U followed by 1250 U administered subcutaneously twice daily [n = 65]); high-dose danaparoid (intravenous loading dose of 2000 U followed by 2000 U administered subcutaneously twice daily [n = 63]); or unfractionated heparin (intravenous loading dose of 2500 U followed by dose-adjusted continuous infusion [n = 60]). Treatment lasted at least 5 days and was continued until anticoagulation (achieved with acenocoumarol) was adequate. MEASUREMENTS: Efficacy determined clinically and by repeated imaging tests on treatment days 5 to 8; safety determined by daily assessment for bleeding. RESULTS: Two lung scans were done in each of 179 patients; ultrasonography or venography of the leg was done twice in each of 173 patients; and both repeated leg and lung tests were done in 166 patients. A significant reduction in recurrence or extension of venous thromboembolism was seen in patients receiving high-dose danaparoid (8 of 63 [13%]) compared with patients receiving intravenous unfractionated heparin (17 of 60 [28%]; relative risk, 0.45 [95% CI, 0.21 to 0.96]). Four of 61 patients receiving high-dose danaparoid (7%) and 14 of 58 patients receiving unfractionated heparin (24%) had recurrence of pulmonary embolism (relative risk, 0.27 [CI, 0.09 to 0.78]); 3 of 58 patients receiving high-dose danaparoid (5%) and 6 of 54 patients receiving unfractionated heparin (11%) had recurrence of deep venous thrombosis (relative risk, 0.47 [CI, 0.12 to 1.77]). Occurrence of major and minor bleeding was similar in the three groups; major bleeding occurred in 1 patient receiving low-dose danaparoid, 1 patient receiving high-dose danaparoid, and 2 patients receiving heparin. CONCLUSIONS: Our results suggest that high-dose danaparoid is safer and more effective than unfractionated heparin for the treatment of venous thromboembolism.