OBJECTIVES: The objectives of this study were to evaluate whether a 1-time measurement of non-HDL-C or LDL-C in a young adult can predict cumulative exposure to these lipids during early adulthood, and to quantify the association between cumulative exposure to non-HDL-C or LDL-C during early adulthood and the risk of ASCVD after age 40 years.
METHODS: We included CARDIA (Coronary Artery Risk Development in Young Adults Study) participants who were free of cardiovascular disease before age 40 years, were not taking lipid-lowering medications, and had ≥3 measurements of LDL-C and non-HDL-C before age 40 years. First, we assessed the ability of a 1-time measurement of LDL-C or non-HDL-C obtained between age 18 and 30 years to predict the quartile of cumulative lipid exposure from ages 18 to 40 years. Second, we assessed the associations between quartiles of cumulative lipid exposure from ages 18 to 40 years with ASCVD events (fatal and nonfatal myocardial infarction and stroke) after age 40 years.
RESULTS: Of 4,104 CARDIA participants who had multiple lipid measurements before and after age 30 years, 3,995 participants met our inclusion criteria and were in the final analysis set. A 1-time measure of non-HDL-C and LDL-C had excellent discrimination for predicting membership in the top or bottom quartiles of cumulative exposure (AUC: 0.93 for the 4 models). The absolute values of non-HDL-C and LDL-C that predicted membership in the top quartiles with the highest simultaneous sensitivity and specificity (highest Youden's Index) were >135 mg/dL for non-HDL-C and >118 mg/dL for LDL-C; the values that predicted membership in the bottom quartiles were <107 mg/dL for non-HDL-C and <96 mg/dL for LDL-C. Individuals in the top quartile of non-HDL-C and LDL-C exposure had demographic-adjusted HRs of 4.6 (95% CI: 2.84-7.29) and 4.0 (95% CI: 2.50-6.33) for ASCVD events after age 40 years, respectively, when compared with each bottom quartile.
CONCLUSIONS: Single measures of non-HDL-C and LDL-C obtained between ages 18 and 30 years are highly predictive of cumulative exposure before age 40 years, which in turn strongly predicts later-life ASCVD events.
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.
Purpose: This study aimed to investigate the relationships between dietary nutrient intake and lipid levels with functional MRI (fMRI) brain activation in DLPFC among older adults with mild cognitive impairment.
Participants and methods: A total of 15 community-dwelling older adults with mild cognitive impairment, aged ≥60 years, participated in this cross-sectional study at selected senior citizen clubs in Klang Valley, Malaysia. The 7-day recall Diet History Questionnaire was used to assess participants' dietary nutrient intake. Fasting blood samples were also collected for lipid profile assessment. All participants performed N-back (0- and 1-back) working memory tasks during fMRI scanning. DLPFC (Brodmann's areas 9 and 46, and inferior, middle, and superior frontal gyrus) was identified as a region of interest for analysis.
Results: Positive associations were observed between dietary intake of energy, protein, cholesterol, vitamins B6 and B12, potassium, iron, phosphorus, magnesium, and HDL-C with DLPFC activation (P<0.05). Multivariate analysis showed that vitamin B6 intake, β=0.505, t (14)=3.29, P=0.023, and Digit Symbol score, β=0.413, t (14)=2.89, P=0.045; R2=0.748, were positively related to DLPFC activation.
Conclusion: Increased vitamin B6 intake and cognitive processing speed were related to greater activation in the DLPFC region, which was responsible for working memory, executive function, attention, planning, and decision making. Further studies are needed to elucidate the mechanisms underlying the association.