Higher Triacylglycerol Concentrations Research Articles

Seasonal variation in chemical composition and contaminants in European plaice (Pleuronectes Platessa) originated from the west-coast of Norway

The seasonal effect on chemical composition and contaminants in European plaice (Pleuronectes platessa) captured in Norwegian waters was investigated in three seasons (September, December, April). Fillets were compared by analysing proximate composition, lipid and protein profile, including fatty acids, lipid class distribution, free and total amino acids. Trace elements and polychlorinated biphenyls (PCB) were determined to assess the potential health risk of consumption. Results on proximate composition reveal differences in water, ash, lipid, and protein content between the seasons. Beneficial levels of n3 fatty acids, including a sufficient n3/n6 ratio (6.1–8.7), were observed. Phospholipids and cholesterol were negatively correlated with total lipid content, adding to high triacylglycerol concentrations observed in December samples. No elevated levels for toxic trace elements, yet detrimental concentrations of dioxin-like PCB-118 were found. Results show that European plaice is highly nutritious with desirable amino and fatty acid profile throughout the year, and with few potential risks.

Cross-sectional association of meal skipping with lipid profiles and blood glucose in Chinese adults

ObjectivesThere is an increasing trend of skipping meals, especially breakfast and dinner, in China. Previous studies on the association of meal skipping with lipid profiles and blood glucose have yielded inconsistent results. MethodsA national representative survey of 47 841 adults (age ≥ 45 y) was conducted in China. Frequency of breakfast, lunch, and dinner consumption were assessed with a questionnaire. Blood triacylglycerols, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and fasting blood glucose were measured using standard methods. Generalized linear models were used to estimate relative concentrations and 95% confidence intervals (CIs). ResultsOf 37 355 participants included in the analysis, the prevalence of skipping breakfast, lunch, and dinner was 9.06%, 0.67%, and 0.67%, respectively. Breakfast skippers are more likely to reside in rural areas, while lunch and dinner skippers tend to be urban residents. Compared with regular breakfast consumption, skipping breakfast was associated with 10.6% (95% CI, 8.3–12.9%) higher concentrations of triacylglycerols, 5.5% (95% CI, 4.7–6.3%) higher total cholesterol, 7.7% (95% CI, 6.5–8.9%) higher low-density lipoprotein cholesterol, 2.4% (95% CI, 1.5–3.4%) lower high-density lipoprotein cholesterol, and 1.6% (95% CI, 1.0–2.1%) lower fasting blood glucose. Significant linear trends were observed for days of skipping breakfast per week and biomarker concentrations. No association was found for lunch or dinner skipping. The higher triacylglycerols and lower high-density lipoprotein cholesterol associated with skipping breakfast were more evident in participants who were overweight or obese, and those who were physically inactive. ConclusionsOur findings suggest a worse lipid profile of breakfast skippers. Not skipping breakfast might benefit cardiovascular disease prevention in Chinese adults.

Postprandial Dried Blood Spot–Based Nutritional Metabolomic Analysis Discriminates a High-Fat, High-Protein Meat-Based Diet from a High Carbohydrate Vegan Diet: A Randomized Controlled Crossover Trial

BackgroundDue to the challenges associated with accurate monitoring of dietary intake in humans, nutritional metabolomics (including food intake biomarkers) analysis as a complementary tool to traditional dietary assessment methods has been explored. Food intake biomarker assessment using postprandial dried blood spot (DBS) collection can be a convenient and accurate means of monitoring dietary intake vs 24-hour urine collection. ObjectiveThe objective of this study was to use nutritional metabolomics analysis to differentiate a high-fat, high-protein meat (HFPM) diet from a high-carbohydrate vegan (HCV) diet in postprandial DBS and 24-hour urine. DesignThis was a randomized controlled crossover feeding trial. Participants/settingParticipants were healthy young adult volunteers (n = 8) in California. The study was completed in August 2019. InterventionThe standardized isocaloric diet interventions included an HFPM and an HCV diet. Participants attended 2 intervention days, separated by a 2-week washout. Main outcome measuresDuring each intervention day, a finger-prick blood sample was collected in the fasting state, 3 hours post breakfast, and 3 hours post lunch. Participants also collected their urine for 24 hours. DBS and urine samples were analyzed by ultra-performance liquid chromatography mass spectrometry to identify potential food intake biomarkers. Statistical analyses performedPrincipal component analysis for discriminatory analysis and univariate analysis using paired t tests were performed. ResultsPrincipal component analysis found no discrimination of baseline DBS samples. In both the postprandial DBS and 24-hour urine, post-HFPM consumption had higher (P < 0.05) levels of acylcarnitines, creatine, and cis-trans hydroxyproline, and the HCV diet was associated with elevated sorbitol (P < 0.05). The HFPM diet had higher concentrations of triacylglycerols with fewer than 54 total carbons in DBS, and 24-hour urine had higher nucleoside mono- and di-phosphates (P < 0.05). ConclusionsNutritional metabolomics profiles of postprandial DBS and 24-hour urine collections were capable of differentiating the HFPM and HCV diets. The potential use of postprandial DBS-based metabolomic analysis deserves further investigation for dietary intake monitoring.

Towards Integrated Multi-Trophic Aquaculture: Lessons from Caprellids (Crustacea: Amphipoda).

The search for alternative live feed organisms and the progression of Integrative Multi-Trophic Aquaculture (IMTA) are currently being highly prioritised in EU strategies. Caprellids could potentially be an important exploitable resource in aquaculture due to their high levels of beneficial polyunsaturated fatty acids, fast growing nature and widespread distribution. Furthermore, since they are mainly detritivorous, they could be excellent candidates for integration into IMTA systems, potentially benefitting from uneaten feed pellets and faeces released by cultured fish in fish farms and sea-cage structures. Despite this, there is a lack of experimental studies to: (i) test inexpensive diets for caprellids, such as detritus, (ii) develop sustainable caprellid culture techniques and (iii) include caprellids in IMTA systems. The main aim of this study was to determine whether detritus (D) in the form of fish faeces provided an adequate diet for caprellids in comparison to other traditional diets, such as Artemia nauplii (A) or phytoplankton (P). Adult survival rate was shown to be significantly higher for caprellids fed with D. Conversely, hatchlings had the highest survival rate with A, although the juvenile growth rate and number of moults was similar in the three diets. With regard to lipid composition, caprellids fed with A had higher concentrations of Triacylglycerols (TAG) and Phosphatidylcholine (PC) while those fed with P or D were richer in polyunsaturated fatty acids, especially 22:6(n-3) (DHA). Interestingly, caprellids fed with D were also a rich source of 18:2(n-6) (LA), considered to be an essential fatty acid in vertebrates. It was found that detritus based mainly on fish faeces and uneaten feed pellets can be considered an adequate feed for adult caprellids, providing a source of both omega-3 (DHA) and omega-6 (LA) fatty acids. Hatchlings however seem to require an additional input of TAG and PC during juvenile stages to properly grow.

Prevention of hyperphagia prevents ovariectomy-induced triacylglycerol accumulation in liver, but not plasma

Menopause is associated with higher plasma and liver triacylglycerol (TAG) and increased risk for cardiovascular disease. Lowering TAG in menopause may be beneficial; however, the mechanism underlying menopause-induced TAG accumulation is not clear. Ovariectomy is a model for menopause and is associated with metabolic alterations and hyperphagia. This study investigated the role of hyperphagia in ovariectomy-induced increases in blood and tissue TAG, as well as differences in lipid metabolism enzymes and resting metabolic measures. It was hypothesized that prevention of hyperphagia would restore blood and tissue TAG, enzyme expression, and metabolic measures to eugonadal levels. Ovariectomized rats were fed ad libitum (OVX + AL) or pair-fed (OVX + PF) relative to sham-operated rats (SHAM) to prevent hyperphagia. OVX + AL had higher TAG concentrations in liver and plasma than SHAM (60% and 50%, respectively), and prevention of hyperphagia in OVX + PF normalized TAG concentrations to SHAM levels in liver, but not plasma. OVX + AL also had 141% higher hepatic stearoyl-CoA desaturase 1 which was almost completely normalized to SHAM levels by pair-feeding, suggesting normalization of hepatic lipid storage. In contrast, skeletal muscle carnitine palmitoyl transferase 1 was 40% lower in OVX + AL than SHAM and was intermediate in OVX + PF, suggesting lower muscle fatty acid oxidation that may underlie the higher plasma TAG in OVX. No differences were seen in energy expenditure, VO2, or VCO2. Overall, this study indicates that prevention of hyperphagia resulting from ovarian hormone withdrawal normalizes hepatic TAG to eugonadal levels but has no effect on ovariectomy-induced increases in plasma TAG.

Metabolic effects of a high‐fat diet post‐weaning after low maternal dietary folate during pregnancy and lactation

Investigate the influence of low-folate supply during pregnancy and lactation on obesity and markers of the metabolic syndrome in offspring, and how provision of a high-fat diet post weaning may exacerbate the resultant phenotype. Female C57Bl/6 mice were randomized to low or normal folate diets (0.4 or 2 mg folic acid/kg diet) prior to and during pregnancy and lactation. At 4 wk of age, offspring were randomized to high- or low-fat diets, weighed weekly and food intake assessed at 9 and 18 wk old. Adiposity was measured at 3 and 6 months. Plasma glucose and triacylglycerol (TAG) concentrations were measured at 6 months. Maternal folate supply did not influence adult offspring body weight or adiposity. High-fat feeding post weaning increased body weight and adiposity at 3 and 6 months (p > 0.001). Maternal low folate lowered plasma glucose (p = 0.010) but increased plasma TAG (p = 0.048). High-fat feeding post weaning increased plasma glucose and TAG (p = 0.023, p = 0.049 respectively). Offspring from folate-depleted (but not folate-adequate) dams had 30% higher TAG concentration when fed the high-fat diet from weaning (p = 0.005 for interaction). Inadequate maternal folate intake has long-term effects on offspring metabolism, manifested as increased circulating TAG, particularly in offspring with high-fat intake post weaning.

English

The purpose of this study was to assess the beneficial effect of quercetin, flaxseed and/or in combination as synergetic, in an animal model of metabolic syndrome (MtS), high fructose (HF)-fed rats. Fifty male Sprague-Dawley rats, 3 months old, weighing between 110 to 120 g were randomly divided into 5 groups. Rats were given drinking water (negative (-ve) control rats) or 10% fructose in drinking water (HF; fructose-fed rats) with standard chow for 8 weeks. After 4 weeks of HF feeding, rats were further divided into matched 4 subgroups. Different groups of animals (n = 10, each group) were administered 10% HF (5 mg/kg, +ve control), flaxseed (F; 50 mg/kg), quercetin (Q; 50 mg/kg), flaxseed + quercetin, (FQ; 25 mg/kg each), respectively. All ingredients were given orally, once daily and subsequently for 4 weeks. Serum glucose, insulin, lipids profile, leptin, and adiponectin were estimated. After 4 weeks of feeding, a significant increase in blood glucose level was observed in HF fed rats compared to normal rats, but this was significantly decreased after administration of F, Q and FQ. The serum insulin level in HF fed rats was significantly decreased after administration of F and FQ groups. Significantly, higher concentrations of triacylglycerols (TG), total cholesterol and low density lipoprotein cholesterol (LDL- C) were observed in HF fed rats, and these increases were lower after administration of F, Q and FQ. There was a significant increase in serum high density lipoprotein cholesterol (HDL-C) in FQ group. The increase of serum leptin level was decreased significantly in F, Q and FQ groups. Whereas, the reduction of serum adiponectin level in HF fed rats was increased in F, Q and FQ groups. These data suggests that protective effect of flaxseed and quercetin consumption as functional foods could be less risky for people with decreased insulin sensitivity and increased oxidative stress, such as those with the metabolic syndrome or type 2 diabetes. Key words: Flaxseed, protective effect, quercetin, insulin sensitivity, metabolic syndrome, type 2 diabetes.

The effect of ploidy and temporal changes in the biochemical profile of gibel carp (Carassius gibelio): a cyprinid fish species with dual reproductive strategies

The basic biochemical profile of gibel carp (Carassius gibelio), diploid-triploid cyprinid species complex with dual reproduction modes, was investigated. The aim of the study was to test for the effect of fish group (which combines the effects of ploidy and sex) and temporal changes on indicators of the biochemical profile of blood in gibel carp. We showed that the basic biochemical profile of blood is significantly influenced by season and fish group. Triploid gynogenetic females had a better condition measured by total protein concentration than sexual diploids. The higher concentrations of triacylglycerols and cholesterol in triploid females when compared to diploids indicate a higher metabolic rate and higher energy intake during the whole year, which may represent a disadvantage for triploids. Differences in the concentrations of blood biochemical analytes between triploid females and diploids suggest a potential difference in the regulation of a wide range of physiological and biochemical processes in which these analytes participate. The biochemical profiles of two forms of C. gibelio could at least partially explain the changes of character of its naturally occurring populations.

Lipid abnormalities predict progression of renal disease in patients with type 1 diabetes

We studied the impact of baseline lipid variables on the progression of renal disease in a large nationwide prospective cohort of patients with type 1 diabetes. A total of 2,304 adult patients with type 1 diabetes and available lipid profiles participating in the Finnish Diabetic Nephropathy Study (FinnDiane) were evaluated. Data on progression of renal disease were verified from medical files and patients were followed for 5.4 +/- 2.0 (mean +/- SD) years. High triacylglycerol, apolipoprotein (Apo) B, ApoA-II and HDL(3)-cholesterol concentrations predicted incident microalbuminuria. Progression to macroalbuminuria was predicted by high triacylglycerol and ApoB. When AER was entered into the model, triacylglycerol was no longer an independent predictor, but when patients with normal AER and microalbuminuria at baseline were pooled, triacylglycerol, HbA(1c), male sex and AER were all independent predictors of renal disease. High total cholesterol, LDL-cholesterol, non-HDL-cholesterol and triacylglycerol as well as low HDL-cholesterol, HDL(2)-cholesterol, ApoA-I and ApoA-II concentrations were predictive of progression to end-stage renal disease. However, when estimated GFR was entered into the model, only total cholesterol remained an independent predictor of progression. Lipid abnormalities, particularly high triacylglycerol concentrations, increase the risk of progression of renal disease.

Serum selenium and serum lipids in US adults

BackgroundSelenium, an essential micronutrient, has received considerable attention for its antioxidant properties. In addition, selenium may affect several cardiometabolic risk factors, such as glucose homeostasis and lipid concentrations. However, the effects of selenium intake on the lipid profile in selenium-replete populations, such as the United States, are largely unknown. ObjectiveWe examined the relation of serum selenium concentrations with serum lipids in a representative sample of US adults. DesignThis was a cross-sectional analysis of 5452 men and women aged ≥ 20 y participating in the third National Health and Nutrition Examination survey. Serum selenium was measured by atomic absorption spectrometry. ResultsThe multivariable adjusted differences in total cholesterol, LDL cholesterol, HDL cholesterol, apolipoprotein B (apo B), and apolipoprotein A-I (apo A-I) comparing the highest with the lowest quartile of serum selenium were 16.6 mg/dL (95% CI: 11.6, 21.4 mg/dL), 10.9 mg/dL (95% CI: 6.4, 15.4 mg/dL), 3.2 mg/dL (95% CI: 1.6, 5.0 mg/dL), 8.9 mg/dL (95% CI: 5.6, 12.2 mg/dL), and 6.9 mg/dL (95% CI: 1.7, 12.1 mg/dL), respectively. Participants in the highest quartile of serum selenium had 10% higher concentrations of triacylglycerols than did participants in the lowest quartile (ratio of triacylglycerol concentrations: 1.10; 95% CI: 1.05, 1.17). The difference in the ratios of LDL cholesterol to HDL cholesterol and apo B to apo A-I that compared the highest with the lowest selenium quartiles were 0.11 (95% CI: −0.02, 0.25) and 0.03 (95% CI: 0.00, 0.06), respectively. ConclusionElevated serum selenium was associated with elevated serum concentrations of total cholesterol, LDL cholesterol, HDL cholesterol, triacylglycerols, apo B, and apo A-I among US adults, a selenium-replete population. Experimental studies are needed to determine cause and effect relations and the potential mechanisms underlying these associations.

Modeling of the kinetic for the acidolysis of different triacylglycerols and caprylic acid catalyzed by Lipozyme IM immobilized in packed bed reactor

This work proposes a lumped kinetic model for the acidolysis of a triacylglycerol (TAG) and an odd free fatty acid (FFA) in a non-aqueous medium, catalyzed by a 1,3 specific lipase immobilized on a solid support. This model is based on the mechanism of the acidolysis reaction by considering the following hypothesis: (1) only the fatty acids in positions 1 and 3 of TAG are exchanged and these two positions in the glycerol backbone are equivalent and (2) the only intermediate of appreciable lifespan in which the enzyme participates is the acyl-enzyme complex. The kinetic equation obtained for the rate of incorporation of an odd fatty acid to TAG has been applied to the results obtained in the acidolysis of three oils (commercial triolein, cod liver oil (CLO) and a commercial oil enriched in eicosapentaenoic acid (EPA), EPAX 4510TG) with caprylic acid (CA), catalyzed by the immobilized lipase Lipozyme IM contained in a packed bed reactor (PBR). The acidolysis has been carried out by recirculating the reaction mixture through the PBR until the reaction equilibrium was reached. In these conditions it has been proved that the PBR behaves as a perfect mixed dispersion reactor and the experimental results obtained at low TAG concentrations ( < 100 mol / m 3 ) have been acceptably fitted to the kinetic expression obtained from the proposed model, with only two fitting parameters. However, for TAG concentrations higher than 100 mol / m 3 , an appreciable reduction of the reaction rate was observed. This result was due to the decrease of the effective diffusivity of reactants within the pores of the support where the lipase is immobilized, since the viscosity of the reaction mixture increases appreciably when the reactant concentration also does. When this phenomenon is included in the developed kinetic model, the experimental results obtained at high TAG concentrations could also be explained, even in absence of the organic solvent ( n -hexane). It is observed that the influence of diffusion into the pores increases with the degree of CA incorporation to TAG, which was due to the increase of TAG and native fatty acid concentrations in the particle pores, which determines a continuous decrease in the effective diffusivity of CA.

Plasma triacylglycerol and coagulation factor concentrations predict the anticoagulant effect of dietary fish oil in overweight subjects.

Fish oil, containing (n-3) PUFA, is associated with a moderate reduction in cardiovascular disease through a multifactorial mechanism involving a decrease in plasma lipids and anticoagulant activity. Two intervention studies on subjects at risk were performed to determine the relation of these 2 fish-oil effects. In study 1, 54 overweight subjects consumed 3.1 g (n-3) PUFA daily. In study 2, which involved 42 overweight patients with type 2 diabetes, 20 subjects consumed (n-3) PUFA, whereas 22 others ingested a preparation rich in (n-6) PUFA. Tissue factor-induced thrombin generation (thrombin potential) was determined as an integrated measure of plasma coagulant activity. In both studies, multivariate analysis indicated a strong clustering of fasting concentrations of triacylglycerols, prothrombin, factor V, factor VII, and factor X with one another at baseline. This cluster of factors determined partly the interindividual variation in thrombin generation, of which prothrombin and triacylglycerol concentrations were the main determinants. In both healthy subjects and diabetes patients, high triacylglycerol concentrations (>1.69 mmol/L) at baseline were closely linked to a strong fish oil-induced lowering of triacylglycerol and coagulation factor V, VII, and X concentrations, and thrombin generation. We conclude that high fasting triacylglycerol concentrations predict high procoagulant activity and a lowering of thrombin potential with dietary fish oil.

Decreases in Serum Triacylglycerol and Visceral Fat Mediated by Dietary Soybean .BETA.-conglycinin

Soy protein isolate (SPI) is known to reduce the risk of heart disease by lowering serum cholesterol and triacylglycerol (TG) levels. Soybean beta-conglycinin, which is a component of SPI, might be the active ingredient that prevents and/or ameliorates lifestyle-related diseases, such as hyperlipidemia and obesity. This study aimed to determine the efficacy of soybean beta-conglycinin for lowering the human serum TG level and visceral fat. Randomized double-blind placebo-controlled designs were used to test the effect of dietary beta-conglycinin, which was taken in the form of candy. [Test 1]In order to examine the serum TG level, 138 volunteers aged 26 to 69 years with TG concentrations above 1.69 mmol/L participated in the study. The subjects were divided at random into two different groups: the test group only consumed the experimental candy containing beta-conglycinin and the placebo group only consumed the placebo candy containing casein. The test period consisted of a 2-wk pre-evaluation phase to screen the participants, a 12-wk consumption period and a 4-wk post-evaluation phase. The serum TG concentrations were significantly reduced in the test group, compared with the placebo group, after consuming the experimental candy. [Test 2]In order to measure visceral fat by means of CT scanning, 102 volunteers aged 26 to 69 years with body mass indices (BMI) between 25 and 30 participated in the study. The subjects were divided at random into two different groups as for Test 1. The test period consisted of a 2-wk pre-evaluation phase to screen the participants, a 20-wk consumption period and a 4-wk post-evaluation phase. A significant reduction in visceral fat only occurred in the beta-conglycinin group. This study showed that beta-conglycinin is an effective food ingredient that will be of use to reduce high serum TG concentrations and to prevent obesity.

Relation between elevated serum alanine aminotransferase and metabolic syndrome in Korean adolescents

Concern is growing about nonalcoholic fatty liver disease, not only because it is a common liver disorder but also because it is one of the leading causes of chronic liver disease. Unexplained elevations in aminotransferase concentrations have been strongly associated with adiposity and thus may represent nonalcoholic fatty liver disease. We investigated the relation between nonviral or nonalcoholic elevations in alanine aminotransferase (ALT) and the metabolic syndrome in Korean adolescents. Data were obtained from 1594 subjects aged 10-19 y from the Korean National Health and Nutrition Examination Survey 1998, a cross-sectional health survey of a nationally representative sample of noninstitutionalized civilian South Koreans. Body mass index, waist circumference, blood pressure, fasting glucose, lipid profiles, and serum ALT were measured. The prevalence of elevated ALT (> 40 U/L) was 3.6% in boys and 2.8% in girls. The prevalence of metabolic syndrome was 3.3% in both boys and girls. The components of the metabolic syndrome were significantly worse in the group with elevated ALT concentrations than in the group with normal ALT concentrations. The odds ratios (95% CIs) for elevated ALT were 6.6 (3.7, 11.8), 2.3 (1.2, 4.6), and 3.0 (1.6, 5.8) in the adolescents with abdominal obesity, high triacylglycerol concentrations, and low HDL-cholesterol concentrations, respectively. The odds ratios for elevated ALT were 1.5 (0.7, 3.1), 2.6 (1.1, 6.2), and 6.2 (2.3, 16.8) in the adolescents with 1, 2, and > or = 3 risk factors (metabolic syndrome), respectively. The metabolic syndrome was strongly associated with elevated ALT concentrations in Korean adolescents, and this association existed in a graded fashion across the number of metabolic components.

Dietary and antismoking advice and ischemic heart disease mortality in men with normal or high fasting triacylglycerol concentrations: a 23-y follow-up study

In the Oslo Diet and Antismoking Trial, 1232 high-risk men aged 40-49 y were randomly assigned to either a lifestyle intervention group or a control group for 5 y. The study showed a significant reduction in ischemic heart disease (IHD) events in the intervention group. Our objective was to examine this cohort 23 y after the start of the trial. We examined the effect of group assignment on IHD mortality in subjects with a normal (below the median; range: 0.69-2.00 mmol/L; n = 615) or a high (at or above the median; range: 2.01-13.80 mmol/L; n = 617) fasting triacylglycerol concentration in 1972-1973 (at inclusion into the study). We recorded vital status on 31 December 1996 and ascertained causes of death by linkage to Statistics Norway. In the men with a high triacylglycerol concentration, IHD death occurred in 25 (8.13%) subjects in the intervention group and in 44 (14.2%) subjects in the control group (relative risk: 0.57; 95% CI: 0.36, 0.91; P = 0.02). An adjusted Cox proportional hazards model yielded a hazard ratio of 0.56 (95% CI: 0.34, 0.93; P = 0.027). In the men with a normal triacylglycerol concentration, the intervention had no detectable effect on IHD mortality (adjusted hazard ratio: 1.10; 95% CI: 0.66, 1.83; P = 0.7). These data suggest that advice to change diet and smoking habits reduced the relative risk of IHD mortality after 23 y in men with high triacylglycerol concentrations. Men with normal triacylglycerol concentrations did not appear to achieve this long-term benefit of lifestyle intervention.

Metabolic Responses to Nocturnal Eating in Men Are Affected by Sources of Dietary Energy

Because night work is becoming more prevalent, we studied whether feeding at different times of a 24-h period would elicit different metabolic responses and whether dietary macronutrient composition would affect these responses. Seven men (26-43 y, 19.9-26.6 kg/m(2)) consumed two isocaloric diets, in a crossover design. The diets were a high carbohydrate (HC) diet [65 energy % (E%) carbohydrates, 20E% fat] and a high fat (HF) diet (40E% carbohydrates, 45E% fat). After a 6-d diet-adjustment period, the men were kept awake for 24 h and the food (continuation of respective diet) was provided as six isocaloric meals (i.e., every 4 h). Energy and substrate turnover, heart rate, mean arterial pressure (MAP), blood glucose, triacylglycerol (TAG), nonesterified fatty acid (NEFA) and glycerol were measured throughout the 24-h period. Significantly higher energy expenditure and NEFA concentration, and lower blood glucose and TAG concentrations were observed when the men consumed the HF diet than when they consumed the HC diet. Significant circadian patterns were seen in body and skin temperature (nadir, 0400-0500 h). When the men consumed the HF diet, significant circadian patterns were seen in fat oxidation (nadir, 0800-1200 h; plateau, 1200-0800 h), heat release (nadir, 0800-1200 h; plateau, 1600-0800 h), heart rate (nadir, 0000 h), blood glucose (nadir, 0800-1200 h; peak, 0000-0400 h), NEFA (nadir, 0800-1200 h; peak, 1200-2000 h) and TAG (nadir, 0800-1200 h; peak, 0400-0800 h) concentrations. Energy expenditure, carbohydrate oxidation, MAP and glycerol concentration did not display circadian patterns. Unequal variances eradicated most circadian effects in the HC-diet data. The increased TAG concentration in response to feeding at 0400 h might be involved in the higher TAG concentrations seen in shift workers. Distinct macronutrient/circadian-dependent postprandial responses were seen in most studied variables.

APOE polymorphism and the hypertriglyceridemic effect of dietary sucrose

The E4 allele of the apolipoprotein gene (APOE) is associated with a greater serum cholesterol response to dietary changes in fat and cholesterol. However, less is known about the interaction between APOE polymorphism and other macronutrients in the diet. We evaluated the interaction between APOE polymorphism and dietary fat and carbohydrate, particularly sucrose, in relation to serum lipid concentrations. A total of 284 men and 130 women with coronary artery disease (mean age: 61 y; range: 33-74 y) participated in the cross-sectional EUROASPIRE study. Serum lipids and fatty acids in cholesteryl esters (CEs) were measured and APOE genotypes were determined. Dietary intake was examined by using a 4-d food record. Patients were grouped by APOE genotype: E2 (E2/E2 and E2/E3; n = 21), E3 (E3/E3; n = 245), and E4 (E4/E2, E4/E3, and E4/E4; n = 148). Patients with the E2 allele had lower LDL-cholesterol concentrations and tended to have higher triacylglycerol concentrations than did patients with the E3 or E4 allele; concentrations were not significantly different between the last 2 groups. In regression analysis, significant predictors of serum triacylglycerol were the interaction between sucrose intake and the E2 allele, proportion of n-3 fatty acids in CEs, body mass index, and diabetes. A high sucrose intake was associated with high triacylglycerol concentrations only in patients with the E2 allele. Interaction between saturated fat intake and the E2 allele, proportion of linoleic acid in CEs, and fiber intake predicted serum cholesterol. Coronary artery disease patients with the E2 allele will likely have a greater triacylglycerol response to high dietary sucrose intakes than will patients with the E3 or E4 allele.

Predictors of postprandial triacylglycerol response in children: the Columbia University Biomarkers Study

Predictors of postprandial lipemia have not been explored in children. Our objective was to determine whether the postprandial triacylglycerol response is associated with low HDL-cholesterol and high fasting triacylglycerol concentrations and family history of early-onset ischemic heart disease (IHD) in children. We administered a standardized fat load (52.5 g fat/m(2)) to 60 children (mean age: 14.0 y), 20 with and 40 without a family history of early-onset IHD, and to 29 mothers, all recruited from families enrolled in the Columbia University Biomarkers Study. Plasma lipid and retinyl palmitate concentrations were measured in the fasting state and 3, 6, and 8 h after the oral fat load. In children, postprandial lipemia, as indicated by the incremental area under the triacylglycerol response curve, was associated with elevated fasting triacylglycerol concentrations (>/=1.13 mmol/L; P: < 0.01), with low fasting HDL-cholesterol concentrations (</=0.91 mmol/L; P: < 0.01), and with the combination of low HDL-cholesterol and high triacylglycerol concentrations (P: < 0.05). Family history of IHD, baseline LDL-cholesterol concentration, and apolipoprotein E genotype were not associated with the postprandial triacylglycerol or retinyl palmitate response. The mothers had fasting triacylglycerol concentrations similar to those of their children but a more prolonged response with higher triacylglycerol concentrations at 6 and 8 h (P: < 0.01 and P: < 0.05, respectively). In children, a delayed postprandial triacylglycerol response to a fat load is associated with the combination of high fasting triacylglycerol and low HDL-cholesterol concentrations. Predictors of postprandial triacylglycerol concentrations may be similar in children and adults.

Different degrees of moderate iron deficiency modulate lipid metabolism of rats.

Severe iron deficiency affects lipid metabolism. To investigate whether moderate iron depletion also alters lipid variables-including lipid levels in serum and liver, hepatic lipogenesis, and fatty acid composition indicative of an impaired desaturation-we carried out experiments with rats fed 9, 13, and 18 mg iron/kg diet over a total of 5 wk. The study also included three pair-fed control groups and an ad libitum control group, fed with 50 mg iron/kg diet. The iron-depleted rats were classified as iron-deficient on the basis of reduced serum iron, hemoglobin concentration, and hematocrit. All moderately iron-deficient rats had significantly lower cholesterol concentrations in liver and serum lipoproteins than their pair-fed controls. Rats with the lowest dietary iron supply had higher concentrations of hepatic phosphatidylcholine (PC) and phosphatidylethanolamine (PE), lower activities of glucose-6-phosphate dehydrogenase, malic enzyme and fatty acid synthase, and higher triacylglycerol concentrations in serum lipoproteins than the corresponding pair-fed control rats. Moderate iron deficiency also depressed the serum phospholipid level. Moreover, several consistent significant differences in fatty acid composition of hepatic PC and PE occurred within moderate iron deficiency, which indicate impaired desaturation by delta-9 and delta-6 desaturases of saturated and essential fatty acids. We conclude that lipid variables, including cholesterol in liver and serum lipoproteins as well as fatty acid desaturation, reflect the gradations of iron status best and can be used as an indicator of the degree of moderate iron deficiency.

Comparison of the effects of medium-chain triacylglycerols, palm oil, and high oleic acid sunflower oil on plasma triacylglycerol fatty acids and lipid and lipoprotein concentrations in humans

Although medium-chain triacylglycerols (MCTs, composed of medium-chain fatty acids 8:0 and 10:0) have long been described as having neutral effects on serum cholesterol concentrations, experimental evidence supporting this claim is limited. In a randomized, crossover, metabolic-ward study, we compared the lipid effects of a natural food diet supplemented with either MCTs, palm oil, or high oleic acid sunflower oil in nine middle-aged men with mild hypercholesterolemia. Rather than having a neutral effect, MCT oil produced total cholesterol concentrations that were not significantly different from those produced by palm oil (MCT oil: 5.87 +/- 0.75 mmol/L; palm oil: 5.79 +/- 0.72 mmol/L) but significantly higher than that produced by high oleic acid sunflower oil (5.22 +/- 0.52 mmol/L). Low-density-lipoprotein (LDL)-cholesterol concentrations paralleled those of total cholesterol. MCT oil tended to result in higher triacylglycerol concentrations than either palm oil or high oleic acid sunflower oil, but this difference was not significant. There were no differences in high-density-lipoprotein cholesterol concentrations. The palmitic acid and total saturated fatty acid content of plasma triacylglycerols in the MCT-oil diet was not significantly different from that in the palm oil diet. On the basis of percentage of energy, this study suggests that medium-chain fatty acids have one-half the potency that palmitic acid has at raising total and LDL-cholesterol concentrations.