OBJECTIVE: The primary study objective was to evaluate the postprandial fate of tocotrienols and alpha-tocopherol in human plasma and lipoproteins.
DESIGN: Seven healthy volunteers (4 males, 3 females) were administered a single dose of vitamin E [1011 mg palm tocotrienol-rich fraction (TRF) or 1074 mg alpha-tocopherol] after a 7-d conditioning period with a tocotrienol-free diet. Blood was sampled at baseline (fasted) and 2, 4, 5, 6, 8, and 24 h after supplementation. Concentrations of tocopherol and tocotrienol isomers in plasma, triacylglycerol-rich particles (TRPs), LDLs, and HDLs were measured at each interval.
RESULTS: After intervention with TRF, plasma tocotrienols peaked at 4 h (4.79 +/- 1.2 microg/mL), whereas alpha-tocopherol peaked at 6 h (13.46 +/- 1.68 microg/mL). Although tocotrienols were similarly detected in TRPs, LDLs, and HDLs, tocotrienol concentrations were significantly lower than alpha-tocopherol concentrations. In comparison, plasma alpha-tocopherol peaked at 8 h (24.3 +/- 5.22 microg/mL) during the alpha-tocopherol treatment and emerged as the major vitamin E isomer detected in plasma and lipoproteins during both the TRF and the alpha-tocopherol treatments.
CONCLUSIONS: Tocotrienols are detected in postprandial plasma, albeit in significantly lower concentrations than is alpha-tocopherol. This finding confirms previous observations that, in the fasted state, tocotrienols are not detected in plasma. Tocotrienol transport in lipoproteins appears to follow complex biochemically mediated pathways within the lipoprotein cascade.
OBJECTIVE: To determine (i) proportions of patients with CHD in Singapore who achieved goals for serum low-density lipoprotein-cholesterol (LDL-C); and (ii) factors influencing goal attainment.
METHODS: A historical cohort study was conducted using records from the Singapore Cardiac Databank, a national registry of CHD patients. Serum LDL-C goal attainment was assessed in 5174 survivors of acute myocardial infarction or coronary revascularization (i.e. coronary artery bypass graft surgery or percutaneous coronary interventions), of whom 3811 (73.7%) were at very high risk.
RESULTS: At baseline, the mean patient age was 60.3 years, mean serum value of total cholesterol was 228 mg/dL, and mean LDL-C was 163 mg/dL. Of all CHD patients, approximately 70% did not achieve a serum LDL-C target of <100 mg/dL. Most patients receiving HMG-CoA reductase inhibitor (statin) regimens were treated initially with low- to medium-equipotency regimens and were never titrated to stronger regimens. The vast majority (approximately 94%) of patients at very high risk did not achieve the stringent serum LDL-C target of <70 mg/dL. Patients receiving higher potency statins were significantly more likely to achieve LDL-C goals, whereas those with higher baseline LDL-C levels or Malaysian ethnicity were less likely to achieve LDL-C goals.
CONCLUSIONS: Most CHD patients in the large group of Singapore residents with CHD in the present study did not achieve recommended LDL-C targets. A more effective disease-management approach, including patient education concerning lifestyle modification (e.g. diet, physical activity), efforts to enhance medication adherence, and more effective, well tolerated therapies such as high-equipotency or high-dose statins and statin combination regimens, may be needed to improve achievement of consensus cholesterol targets. This is the first study of cholesterol goal attainment in a large group of Southeast Asians and serves as a baseline for future evaluations in Asian populations.