Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “triglycerides”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 973 records · Page 54Linked to original sources
PubMed2006

Preclinical investigations of a medium-chain triglyceride:fish oil emulsion. I. Effects of bovine milk lipoprotein lipase on lipid composition.

The bolus intravenous injection of a novel medium-chain triglyceride:fish oil emulsion (MCT:FO, 8:2, w:w) was recently found to increase within 60 min the leucocyte and platelet phospholipid content of long-chain polyunsaturated omega3 fatty acids. The present report deals with the effects of bovine milk lipoprotein lipase on the lipid composition of this emulsion. The results are compared to those obtained with either a pure fish oil emulsion or a medium-chain triglyceride: long-chain triglyceride:fish oil emulsion (MLF, 5:4:1). Emphasis is placed on i) differences in the fate of distinct fatty acids initially present in the triglycerides, di glycerides and phospholipids, ii) the generation of unesterified fatty acids relative to their initial content in each emulsion, and iii) the time course for these various events. The comparison between the three emulsions under consideration also provides information relevant to their respective sensitivity to lipoprotein lipase and suitability in terms of the generation of distinct unesterified fatty acids, including long-chain polyunsaturated omega3 fatty acids. Furthermore, attention is drawn to the greater efficiency for the hydrolysis of fatty acids from diglycerides as compared to triglycerides and a transient increase in the paired C8:0/C10:0 ratio in the diglycerides generated from the MCT:FO or MLF emulsion. The present study thus affords novel information relevant to the possible use of the MCT:FO emulsion in human subjects.

Animals↗
PubMed1976

Measurement of two plasma triglyceride lipases by an immunochemical method: studies in patients with hypertriglyceridemia.

Postheparin plasma lipolytic activity consists of two hydrolytic activities, hepatic triglyceride lipase and lipoprotein lipase. These two enzymes were separated and partially purified by means of ammonium sulfate precipitation and affinity chromatography using Sepharose with covalently linked heparin and concanavalin A, respectively. Antibodies were produced against hepatic triglyceride lipase and they did not cross react with lipoprotein lipase. Optimal conditions for selective precipitation of hepatic lipase and specific measurement of these two lipases were investigated. This method was applied to the study of 15 patients with hypertriglyceridemia and 8 patients with familial lecithin-cholesterol-acyltransferase deficiency of whom 6 also had a marked elevated plasma triglyceride concentration. All patients had normal values of hepatic plasma lipase. All 8 patients with Type I and 2 of 4 patients with Type V hyperlipoproteinemia had lipoprotein lipase activities that were markedly reduced. The patients with Type III hyperlipoproteinemia and all 8 patients with lecithin-cholesterol-acyltransferase deficiency also had normal lipoprotein lipase values. These studies emphasize the necessity for differentiating between triglyceride lipase activity of hepatic and extrahepatic origin in evaluating patients with impaired triglyceride metabolism.

Acyltransferases↗
PubMed1990

[Determination of potentially atherogenic triglyceride-rich lipoprotein particles].

Hypertriglyceridemia is a common disorder of lipid transport occurring either as a primary or secondary manifestation of the underlying metabolic derangement. Although most prospective studies have provided no evidence for the independent contribution of plasma triglycerides to atherosclerosis, results of several clinical and metabolic studies have indicated that some modified triglyceride-rich lipoproteins may be as atherogenic as the typical cholesterol-rich low density lipoproteins. Our studies on the sequential fractionation of apolipoprotein B-containing lipoproteins have identified five major apolipoprotein-defined lipoprotein families including cholesterol-rich lipoprotein B and triglyceride-rich lipoproteins B:C, B:C:E, B:E and A-II:B:C:D:E. The evaluation of the results of Cholesterol Lowering Atherosclerosis Study has shown that some triglyceride-rich lipoproteins play an important role in the progression of atherosclerosis. The combined niacin-colestipol treatment resulted in a 40-50% decrease in the levels of cholesterol-rich lipoprotein B but had no effect on triglyceride-rich lipoproteins. Patients who had increased levels of latter lipoproteins, as demonstrated by decreased levels of apolipoprotein C-III in heparin-Mn++ supernates, showed progression of atherosclerotic lesions. On the other hand, in the Helsinki Heart Study, despite minimal reduction in the levels of LDL-cholesterol, patients with phenotypes IIB and IV had higher reduction rates in coronary end points than patients with phenotype IIA.(ABSTRACT TRUNCATED AT 250 WORDS)

Apolipoproteins↗
PubMed1990

[Triglyceride-rich lipoproteins as risk factors for atherosclerosis].

There is more and more epidemiological evidence elevated plasma triglyceride concentrations increase the risk for atherosclerosis especially for coronary heart disease. Since triglyceride-rich lipoprotein fractions also contain different concentrations of cholesterol and since the metabolism of triglyceride-rich lipoproteins is not independent from the metabolism of HDL, the variables HDL-cholesterol and LDL-cholesterol (respectively total-cholesterol) must be taken into account when evaluating the atherosclerotic risk of triglyceride-rich lipoproteins. This epidemiological evidence is underlined by clinical observations about the high incidence of atherosclerosis and coronary heart disease in relation to abnormalities in the triglyceride-rich lipoprotein metabolism as in patients with diabetes mellitus, familial dysbetalipoproteinemia and familial combined hyperlipidemia. Very low density lipoproteins (VLDL), low density lipoproteins (LDL) and high density lipoproteins (HDL) from patients with hypertriglyceridemia are enriched in free and esterified cholesterol. This changed composition of these lipoprotein fractions leads to an increased elimination from the circulation via atherogenic macrophages and smooth muscles cell pathways. Successful treatment of hypertriglyceridemic states obviously normalizes the changed composition of the lipoprotein fractions and in consequence effects also the atherogenicity.

Arteriosclerosis↗
PubMed1990

[Triglyceride-rich lipoproteins and risk of atherosclerotic cardiovascular diseases in various European populations].

High serum levels of triglycerides have been found associated with increased risk for atherosclerotic cardiovascular disease. Cross cultural comparisons between populations with different cardiovascular mortality do not demonstrate significant differences in serum triglycerides. Lipoprotein analysis however suggests that higher levels of intermediate density lipoproteins might be associated with higher coronary mortality in spite of the same levels in total serum triglycerides. A case-control study in Italy has demonstrated an association between premature development of coronary heart disease (before age 40) and higher concentrations of LDL cholesterol or triglycerides, whereas no difference was detected in LDL apo B. This finding suggested an accumulation of bigger and less dense LDL particles, including also intermediate density lipoproteins. Another case-control study evaluated forty pairs of hypercholesterolemic patient matched for sex and age, but differing for the presence or absence of hypertriglyceridemia. Patients with hypercholesterolemia plus hypertriglyceridemia had a significantly more abnormal condition in the arterial district of the lower limbs in comparison to their normotriglyceridemic counterparts. Studies performed in the Mediterranean area support the idea that high serum levels of triglyceride-rich lipoproteins are associated with an increased occurrence of cardiovascular diseases.

Cholesterol↗
PubMed1990

Do enzymatic analyses of serum triglycerides really need blanking for free glycerol?

Distributions of concentrations of free glycerol in clinical plasma obtained for triglyceride assay were compiled to determine the frequency with which increased concentrations of free glycerol posed a potential problem for clinical interpretation of triglyceride results. Clinical histories were studied in patients with increased concentrations of free glycerol to ascertain possible reasons for the increase and to assess the relative clinical importance of glycerol-blank-corrected triglyceride results. Significant increases in free glycerol were very uncommon, usually occurring in patients receiving glycerol-containing hyperalimentation fluids, those receiving heparin (which causes both in vivo and in vitro increases in free glycerol), or those critically ill. Free glycerol was never increased significantly in a large outpatient population. Monitoring lipid metabolism in critically ill patients, or measuring true triglyceride concentrations in patients receiving glycerol-containing fluids, may represent rare exceptions for which glycerol-blank correction is necessary for accurate clinical diagnosis and management. We conclude that there is insufficient justification for the routine expenditure of extra time and reagents to correct most analytical enzymatic triglyceride methods for free glycerol.

Adolescent↗
PubMed1990

Prediction of fatty liver from serum triglyceride levels and body weight indexes.

Fatty liver is a common disease in Taiwan. In this study, we tried to evaluate the validity of predicting the presence of fatty liver from clinical data instead of liver biopsy or sonography. From a community survey in Putai, a total of 873 adults older than 30 years and quantified as to triglyceride level, body height, body weight, and the results of the oral glucose tolerance test and upper abdominal sonography were recruited for analysis. Using a receiver operating characteristic (ROC) curve, the best 'cutoff values' for determination of fatty liver were predicted from body weight index and serum triglyceride level in 8 clusters grouped by sex, age and presence or absence of diabetes mellitus. The best cutoff values of triglyceride in the 8 clusters varied from 100 to 170 mg/dl with worse validity. Most of the values were 130 and 140 mg/dl. The cutoff values of body weight index were constant in all clusters and showed greater validity than those for triglyceride. They were 115% or 120%. Their accuracy for the prediction of fatty liver was positively correlated with its prevalence. However, their accuracy was lower than 70% in non-diabetic females. We conclude that body weight index is a good parameter for prediction of fatty liver especially in the high risk groups and we recommend that health-determining cutoff values of serum triglyceride and body weight index should be set at 130 mg/dl and 115%, respectively.

Adult↗
PubMed1990

Effects of fish oil on VLDL triglyceride kinetics in humans.

Dietary n-3 fatty acids (FAs) found in fish oils markedly lower plasma triglyceride (TG) and very low density lipoprotein (VLDL) levels in both normal and hypertriglyceridemic subjects. The present study examined the mechanism of this effect. Ten subjects with widely different plasma triglyceride levels (82 to 1002 mg/dl) were fed metabolically controlled diets containing 20% fat. The control diet contained a blend of cocoa butter and peanut oil (P/S = 0.8). The test diet contained fish oil (P/S = 1.1) and provided 10-17 g of n-3 FAs per day (depending on calorie intake). After 3 to 5 weeks of each diet, the kinetics of VLDL-TG were determined over a 48-h period after the injection of [3H]glycerol. The fish oil diet reduced the VLDL-TG synthetic rate from 23 +/- 14.3 (mean +/- SD) to 12.6 +/- 7.5 mg/h per kg ideal weight (P less than 0.005) and increased the fractional catabolic rate (FCR) for VLDL-TG from 0.23 +/- 0.12 to 0.38 +/- 0.16 h -1 (P less than 0.005). At the same time, there was a 66% reduction of plasma triglyceride levels, resulting largely from a 78% decrease in VLDL-TG levels (398 +/- 317 to 87 +/- 77 mg/dl; P less than 0.005). There was a strong correlation (r = 0.83; P less than 0.01) between the change in synthetic rates and pool sizes, but there was no correlation (r = 0.24; NS) between changes in FCRs and pool sizes. The VLDL cholesterol: triglyceride ratio increased during the n-3 diet suggesting that smaller VLDL particles were present. These particles would be expected to leave the VLDL fraction more rapidly than larger particles producing a higher FCR. We conclude that the hypotriglyceridemic effect of fish oil appears to be caused primarily by an inhibition of very low density lipoprotein-triglyceride synthesis, but an additional, independent effect upon VLDL catabolism cannot be ruled out.

Dietary Fats, Unsaturated↗
PubMed1979

Triglyceride and cholesterol concentrations in whole serum and in serum lipoproteins in Reye syndrome.

Triglyceride and cholesterol concentrations in whole serum and in the serum lipoprotein fractions were measured during the course of hospitalization in six patients with Reye syndrome, four of whom survived. Very low density lipoprotein (VLDL) triglycerides were significantly lower on admission than on the last day of hospitalization. However, no VLDL triglyceride value was below the normal range. Triglyceride transport was increased in low density lipoprotein (LDL) and high density lipoprotein (HDL) fractions. LDL and HDL cholesterol concentrations were low on admission and decreased further during hospitalization. The changes in LDL and HDL cholesterol concentrations were more severe among nonsurvivors. No HDL cholesterol was detected in nonsurvivors on the last day of hospitalization. These results suggest that decreased VLDL triglycerides may not play an important role in the development of fatty liver and that decreased LDL and HDL cholesterol concentrations may be of prognostic value in Reye syndrome.

Adolescent↗
PubMed1979

Role of lipoprotein lipase in plasma triglyceride removal.

Intravenous injections of anti-lipoprotein lipase serunis quantitatively block the catabolism of very low density lipoprotein (VLDL) and portomicron triglyceride and specifically inhibit triglyceride transport into ovarian follicles. The immunological studies presented provide information on the site of action of lipoprotein lipase (LPL). In the anti-LPL serum-treated animals initial plasma triglyceride accumulation occurs at the time of antiserum injection. This instantaneous inhibition of triglyceride removal provides direct evidence that the functional LPL responsible for VLDL and portomicron triglyceride hydrolysis is located in sites within the plasma compartment readily accessible to immunoglobulins. In vitro immunological studies show that the adipose, heart, ovarian, and liver LPL share common immunological determinants. Biochemical studies on highly purified heart and adipose LPL suggest that these enzymes have identical protein moieties.

Adipose Tissue↗
PubMed1990

Effects of phorbol 12-myristate 13-acetate on triglyceride and cholesteryl ester synthesis in cultured coronary smooth muscle cells and macrophages.

In cultured pig coronary smooth muscle cells phorbol 12-myristate 13-acetate (PMA) stimulated the conversion of [4-14C]cholesterol into cholesteryl esters and the incorporation of [2-3H]glycerol into triglycerides 6.4- and 4.5-fold, respectively. The maximal effects occurred after 3 h of treatment and there was a return to basal values after 72 h. In the presence of 400 microM oleic acid, PMA stimulated the conversion of [4-14C]cholesterol into cholesteryl esters and that of [2-3H]glycerol into triglycerides 5.3- and 2.3-fold, respectively. The stimulatory effects were more sustained (still significant after 72 h) and their maxima were delayed (peaks after 24 h). PMA was also found to increase 2-fold the amount of triglyceride that accumulated in the cells in the presence of oleic acid after 24 h. In macrophages IC-21, the effects of PMA were observed only in the presence of oleic acid. They consisted of a 1.9-fold stimulation in the conversion of [4-14C]cholesterol into cholesteryl esters after 72 h and of a 1.7-fold stimulation in the incorporation of [2-3H]glycerol into triglycerides after 24 h. PMA also increased the amount of triglyceride that accumulated in the cells 1.9-fold after 72 h. It is concluded that PMA, and possibly growth factors, may promote lipid storage in smooth muscle cells and that fatty acids favor long lasting effects of PMA in smooth muscle cells and are necessary for any effect of PMA in macrophages.

Animals↗
PubMed1990

Effects of glucose ingestion on postprandial lipemia and triglyceride clearance in humans.

To determine whether the metabolism of diet-derived triglycerides (TG) is acutely regulated by the consumption of insulinogenic carbohydrates, we measured the effects of glucose ingestion on oral and intravenous fat tolerance, and on serum triglyceride concentrations obtained during duodenal fat perfusion. Postprandial lipemia was diminished by the ingestion of 50 g (148 +/- 121 mg.dl-1 x 7 h-1 vs 192 +/- 124 mg.dl-1 x 7 h-1, P less than 0.05) and 100 g (104 +/- 106 mg.dl-1 x 7 h-1 vs 171 +/- 104 mg.dl-1 x 7 h-1, P less than 0.05) glucose. Peak postprandial TG concentrations occurred later after meals containing glucose and fat than after meals containing fat alone. This effect could be reproduced when an iso-osmotic quantity of urea was substituted for glucose in the test meal. Starch ingestion had no discernible effect on postprandial lipemia. Intravenous fat tolerance was similar before (4.9 +/- 1.2%.min-1) and 2 h (4.4 +/- 1.3%.min-1) and 4 h (4.8 +/- 1.5%.min-1) after 50 g glucose ingestion. During duodenal fat perfusion, glucose ingestion caused a progressive decrease in plasma triglyceride concentrations. These data suggest that glucose ingestion diminishes postprandial lipemia in a dose-dependent manner, but that this effect is not due to increased clearance of triglyceride from the circulation. The hypotriglyceridemic effects of glucose appear to reflect delayed gastric emptying and decreased hepatic secretion of triglyceride.

Adult↗
PubMedDate not supplied

Detection of pork and lard as adulterants in processed meat: liquid chromatographic analysis of derivatized triglycerides.

A new method is described for detection of pork and lard as adulterants in processed beef and mutton mixtures. The unsaturated triglycerides in the fat are ozonized and then derivatized. The mixture of derivatized and saturated triglycerides is analyzed by liquid chromatography using a reverse-phase column and a UV detector. Pork fat has larger amounts of triglyceride containing saturated fatty acid at the C-2 position than does the fat of other meat. The ratio of triglyceride containing saturated fatty acid vs triglyceride containing unsaturated fatty acid at the same (C-2) position (SSU/SUS) in a sample is compared with those of pure meats. The presence of pork in the sample causes the ratio to increase compared with ratios for pure beef or mutton. The increase in the SSU/SUS ratio is significant for the addition of 1% pork in beef. In the case of mutton, the addition of 3% pork causes a noticeable change. The method is reliable and is also applicable to samples containing only fat. Processing (heating or cooking) does not affect the ratios.

Animals↗
PubMed1989

Cholesterol guidelines, lipoprotein cholesterol levels, and triglyceride levels: potential for misclassification of coronary heart disease risk.

By using National Cholesterol Education Program guidelines for serum cholesterol (less than 200 mg/dl is designated "desirable," and 200 to 239 mg/dl is designated "borderline-high," and greater than or equal to 240 mg/dl is designated "high"), low-density and high-density lipoprotein (LDL, HDL) cholesterol levels and triglyceride levels were quantitated in 897 self-referred fasting subjects to assess the potential for coronary risk misclassification. With cholesterol less than 200 mg/dl, misclassification was arbitrarily identified by an LDL level greater than or equal to the 75th percentile, a triglyceride level greater than or equal to the 90th percentile, or an HDL level less than or equal to the 10th percentile. With the cholesterol level in the 200 to 239 mg/dl range, misclassification was identified by an LDL level greater than or equal to the 75th percentile, a triglyceride level greater than or equal to the 90th percentile, and an HDL level less than or equal to the 10th percentile or greater than or equal to the 90th percentile (or both). With a cholesterol level greater than or equal to 240 mg/dl, misclassification was identified by an HDL level less than or equal to the 10th percentile, or greater than or equal to the 90th percentile. With the cholesterol level less than 200 mg/dl, misclassification is rare, occurring in 14.5% of the subjects. With the cholesterol level in the 200 to 239 mg/dl range, and greater than or equal to 240 mg/dl, misclassification occurred in 46.7% and 17.6% of the subjects, respectively. The importance of routine lipoprotein analysis when the cholesterol level is greater than or equal to 240 mg/dl is emphasized by the finding that 65% of the subjects in this category had top quartile LDL levels, 8% had bottom decile HDL levels, and 30% had top decile triglyceride levels. To avoid misclassification, fasting HDL, LDL, and triglyceride levels should probably be measured in all subjects with screening cholesterol levels greater than or equal to 200. There is remarkably little misclassification with top quartile LDL or bottom decile HDL levels (or both) when the cholesterol level is less than 200 mg/dl.

Adolescent↗
PubMed1986

Effect of saturated and unsaturated lipid on the composition of mesenteric triglyceride-rich lipoproteins in the rat.

The effect of saturated and unsaturated lipids on the composition of mesenteric lymph triglyceride-rich lipoproteins was studied in rats. A short-term steady-state infusion model was developed in mesenteric lymph fistula rats. Micellar solutions of linoleate, oleate, or palmitate were infused intraduodenally. Steady-state conditions of lymph flow, triglyceride, and apoA-I and apoB secretion rates were achieved in hours 3-5 after the start of the infusion. During this steady-state period, triglyceride-rich lipoproteins were prepared and characterized. With lipid infusion there were the expected increases in secretion rates of triglyceride, apoB, and apoA-I both in whole lymph and in the d less than 1.006 g/ml lipoproteins. Compositional analysis of d less than 1.006 g/ml lipoproteins revealed no difference in the ratios of phospholipid or apoA-I (surface) to triglyceride (core) constituents between saturated and unsaturated lipids, suggesting a similar particle size. This was directly verified by agarose gel filtration and electron microscopy carried out at 27 degrees C, which showed no difference in particle size between linoleate and palmitate chylomicrons. When these lipoproteins were prepared at 4 degrees C, palmitate lipoproteins exhibited dramatically changed gel filtration elution profiles, suggesting a shift to smaller or at least distorted particles and questioning earlier results suggesting a smaller size for saturated fat d less than 1.006 g/ml lipoproteins. Despite the similarity of size between saturated and unsaturated chylomicrons, the apoB content of unsaturated linoleate chylomicrons was significantly lower than that of palmitate chylomicrons. This difference was present whether chylomicrons were prepared by centrifugation or by gel filtration. The clearance of palmitate chylomicrons from the circulation of recipient rats was slightly more rapid than that of linoleate chylomicrons. The mechanism for this apparently selective increase in the apoB content of saturated fat chylomicrons is unknown but the present studies suggest that these changes may be of physiologic significance, perhaps relating to the potential atherogenicity of saturated lipids.

Animals↗
PubMed1987

Insulin increases triglyceride secretion rate in rats in vivo.

To investigate whether insulin regulates triglyceride secretion from the liver in vivo, triglyceride secretion rate (TGSR) and serum insulin were measured in the following three experiments: in rats 12 weeks after ventromedial hypothalamic (VMH) lesions (Exp. 1), in rats 12 weeks after a high fat diet-feeding (Exp. 2), and in rats 10 days after streptozotocin treatment (65 mg/kg) (Exp. 3). Under hexobarbital anesthesia, overnight fasted rats were bled for measuring insulin and triglyceride. Rats were again bled 45 and 90 minutes after Triton WR 1339 (120 mg) injection, for measuring triglyceride. TGSR was calculated from serum triglyceride values measured before and after Triton injection. In Exp. 1, VMH obese rats had higher serum insulin concentrations and TGSR than control rats. There was a significantly positive correlation between serum insulin concentrations and TGSR in VMH lesioned rats alone (r = 0.939, P less than 0.001) and in VMH lesioned and control rats combined (r = 0.958, P less than 0.001). In Exp. 2, high fat diet-fed rats gained more weight than control rats, but they had the same levels of serum insulin concentrations and TGSR as those of control rats. In Exp. 3, streptozotocin treated rats had lower serum insulin concentrations and TGSR than control rats. There was a significantly positive correlation between serum insulin concentrations and TGSR in the two groups of rats combined (r = 0.680, P less than 0.05). From the results of these three sets of in vivo studies, we conclude that insulin increases TGSR in vivo.

Animals↗
PubMed1988

Decreased stability of triglycerides and increased free glycerol in serum from heparin-treated patients.

Triglycerides usually are stable in serum. However, for a few patients, we noted marked decreases in measured triglycerides when the same serum specimen was analyzed on successive days. This was found to be ascribable to intravenous administration of heparin. Measured triglyceride in serum of 11 patients being treated with heparin decreased 34% (SD 17%) in samples stored for one day at room temperature. Triglyceride values for sera from control patients remained unchanged. Increases in free glycerol corresponded to the observed decreased in triglycerides. Measurement of free glycerol thus provides a means of recognizing this problem.

Dose-Response Relationship, Drug↗
PubMed1987

Maintenance of plasma triglyceride-lowering through use of low-dose fish oils in the diet.

The ingestion of large doses of fish oil may be associated with a marked reduction in plasma triglyceride concentrations. The present study was a preliminary evaluation of whether a lower maintenance dose of fish oils in hyperlipidemic patients would be sufficient to sustain therapeutic effects already achieved on higher dosage over a prior period of three months or longer. For the purposes of this study, 10 or 16g/day of fish oil (LipitacR) was defined as high dosage, 6g/day as medium dosage and 3g/day as low dosage. Five subjects entered on high dosage and were subsequently evaluated on medium and then on low dosage at intervals of six weeks. Five subjects entered on medium dosage and were evaluated after six weeks on low dosage. Seven of the subjects entered with a significant degree of hypertriglyceridemia while the remainder had hypercholesterolemia. Subjects entering with background triglyceride concentrations in excess of 2mmol/l showed reduced triglyceride concentrations at all dose levels, while two subjects with entry triglycerides in excess of 10mmmol/l experienced further improvement in plasma triglycerides when comparing medium with low dosage, or high with medium dosage. Low dose fish oil appears to have potential as a form of maintenance therapy in the management of moderate degrees of hypertriglyceridemia.

Adult↗