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Query: UMLS:C0020473 (hyperlipidemia)
 15,891 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Splanchnic metabolism was studied to quantify changes underlying the fatty liver, hyperlipemia, and hypoglycemia produced by ethanol. Four subjects fasted for 15 h were compared with five subjects fasted for 69 h under basal conditions and during continuous intravenous infusion of sufficient ethanol to give a concentration of 3-5 mM in arterial blood plasma. Splanchnic storage of fatty acids was estimated from the difference between uptake of FFA and secretion of derived products. Basal values for splanchnic uptake of FFA were twofold higher after the 69-h fast while splanchnic storage of fatty acids and production of ketone bodies increased threefold. Values for basal secreation into the blood of triglycerides derived from FFA were similar in the two groups. In both nutritional states, the fraction of FFA taken up in the splanchnic region oxidized to ketone bodies and to CO2 fell when ethanol was given because of preferential oxidation of ethanol to acetate, and the fraction esterified rose. However, systemic transport and splanchnic uptake of FFA fell with ethanol in subjects fasted 15 h, so that neither storage of triglycerides in splanchnic tissues nor secretion into the blood increased. In subjects fasted 69 h, ethanol increased transport of FFA and splanchnic storage of fat. In all but one subject it also increased secretion of triglycerides into the blood. The concentration of glucose in blood fell during ethanol infusion in all five subjects undergoing the 69-h fast. Mean splanchnic glucose production was maintained at about one-half of the pre-ethanol value, despite virtual cessation of splanchnic uptake of lactate and of those amino acids that are metabolized via malate. Quantitative estimates of extrasplanchnic metabolism suggest that enhanced formation of alpha-glycerophosphate from glucose, in addition to impaired hepatic gluconeogenesis, may contribute to ethanol-induced hypoglycemia in man.
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PMID:Effects of a 3-day fast and of ethanol on splanchnic metabolism of FFA, amino acids, and carbohydrates in healthy young men. 17 79

After healthy persons, aged between 20 and 35 years, had consumed either ethanol or ethanol and fructose, triglycerides, free glycerol, FFA, phospholipids and total cholesterol were determined. After a basic dosage of 0.5 g ethanol/kg body weight, each person received a maeintenance dosage of 0.1 g ethanol/kg body weight and hour. Control experiments were carried out on persons receiving only fructose and on fasting persons who consumed no ethanol. After 8 hrs, triglycerides rose in the ethanol group by 107 %, in the ethanol-fructose group by 63 %. FFA exhibited in both ethanol and ethanol-fructose groups an initial decrease, with a secondary increase in the ethanol group. The initial decrease was greater in the ethanol-fructose group. A significant rise in free glycerol by 419 % was observed 30 min after the intake of combined ethanol/fructose. Free glycerol rose under ethanol alone by 144%. The ohospholipids exhibited a slight rise in the ethanol group; no significant changes occured in the cholesterol. The blood ethanol level was lower under ethanol-fructose than under ethanol alone. The addition of fructose diminishes the ethanol-induced hypertriglyceridemia. Our investigations give further proof that, under short-term ethanol load, the fatty acids necessary for the increased triglyceride synthesis in the liver, originate predominantly from a peripheral lipolysis, and that changes in liver metabolism depending on the oxidation of ethanol are not of less importance for the development of the acute ethanol-induced hyperlipidemia.
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PMID:Alteration of plasma lipids and intermediates of lipid metabolism in healthy fasting volunteers by ethanol and fructose. 18 75

Human growth hormone (HGH) response to arginine (25 gm IV in 30 min) and to insulin (0.1 U/kg B.W.) was studied in 12 male patients (mean age 36 +/- 2 years), with normal glucose tolerance and normal body weight, affected with Fredrickson's Type IV primary hyperlipemia. The patients were examined both when plasma triglycerides (TG) were elevated and following clofibrate (2 gm/die for 30-60 days) induced TG reduction. No variations in glucose or FFA behaviour or in body weight were observed after clofibrate. HGH response to arginine was absent, while that to insulin was only inhibited, when plasma TG were elevated. A significant increase in HGH peaks after arginine (from 1.99 +/- 0.59 to 9.34 +/- 1.58 ng/ml) and a slight increment in HGH peaks after insulin (from 23.09 +/- 7.19 to 31.46 +/- 7.95 ng/ml) were observed following reduction in plasma TG. Arginine test was carried out in 7 normal subjects during saline infusion and at the 3rd hour of lipid infusion (Intralipid 20%). HGH response to arginine was absent in all of the subjects during lipid infusion. The HGH response to insulin test, carried out in 9 other normal subjects during saline infusion and at the 3rd hour of lipid infusion (Lipiphysan 15%) was significantly inhibited during lipid infusion. Since lipid infusion provoked an increment, not only in plasma TG but also in FFA, the inhibition of HGH release could be correlated with the elevated plasma levels of both TG and FFA. The results obtained in both spontaneous and experimental hyperlipemia not only confirm the role played by FFA in the regulation of HGH secretion, but also support the hypothesis that elevated TG levels could inhibit HGH response to some stimuli.
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PMID:The influence of plasma triglycerides on human growth hormone response to arginine and insulin: a study in hyperlipemics and normal subjects. 118 14

Blood glucose, free fatty acid and insulin responses to oral glucose and the fasting serum lipids were measured in 3 groups: 32 non-obese (mean age: 47.5 years) and 9 obese (mean age: 84.5 years), male patients with coronary heart disease and 12 non-obese male controls (mean age: 46.5 years). The oral glucose tolerance tests were repeated after 3 years in 16 of the non-obese patients with coronary heart disease. The results were as follows: 1) Glucose tolerance was impaired in 19 of 32 non-obese patients (59.4%). There was a significant correlation between impaired glucose tolerance and hyperlipidemia (hypercholesterolemia and/or hypertriglyceridemia). 2) In obese patients FFA levels at 30, 60, and 120 min after oral glucose administration were significantly elevated and FFA decrease was delayed with a drop to minimum levels at 180 min. 3) The insulin response after oral glucose administration in the group of non-obese patients with normal glucose tolerance was similar to that of non-obese controls. In the group of non-obese patients with impaired glucose tolerance, serum insulin levels went up to normal levels, but the peak was delayed. The serum insulin levels in obese patients were significantly higher than those of controls of 0, 60, 120, and 180 min. After 3 years the change in insulin response to oral glucose was not related to anginal symptoms or ECG findings, but was related to body weight change in patients with minor changes in glucose tolerance. 4) The metabolic pattern in the non-obese group with impaired glucose tolerance resembled that of "mild diabetes" in delayed response of insulin and FFA, and mild hyperlipidemia. These findings suggest that obesity may contribute to hyperinsulinemia in patients with coronary heart disease and that impaired glucose tolerance observed in patients with coronary heart disease is in part due to "latent diabetes".
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PMID:Glucose tolerance, serum insulin and lipid abnormalities in patients with coronary heart disease. 118 89

Abdominal obesity is closely associated with risk factors for cardiocerebrovascular disease and NIDDM and the precipitation of these diseases. Together, they seem to constitute a metabolic syndrome where hyperinsulinaemia, insulin resistance, hyperlipidaemia, hypertension, visceral fat accumulation, cardiocerebrovascular disease and NIDDM are the individual constituents. The background to this syndrome might be a primary aberration expressing itself as an increased sensitivity of the hypothalamo-adrenal axis, and subsequent inhibition of sex steroid hormone secretions. This in turn will probably be followed by metabolic derangements, primarily peripheral insulin resistance, as well as by visceral fat accumulation by mechanisms which are partially visualized by recent work in the field. Visceral fat accumulation may then amplify the metabolic aberrations via hepatic effects of excessive concentrations of portal FFA, producing hyperproteinaemia, hyperglycaemia, hyperinsulinaemia and, perhaps, hypertension. The background to the central endocrine aberration remains more speculative, but factors leading to increased cortisol production, including specific stress reactions, tobacco smoking and alcohol may turn out to be important. The tentative conclusion provides a hypothesis for further work, and has recently obtained considerable support from further observations in humans in other than the endocrine and metabolic areas, as well as from studies in experimental animal models, where such factors can be studied under fully controlled conditions, which is not possible in humans for ethical reasons.
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PMID:Regional fat distribution--implications for type II diabetes. 133 83

Multiple cytokines induce a number of alterations in lipid metabolism which can produce hyperlipidemia. Recent studies have demonstrated that tumor necrosis factor (TNF) increases lipolysis, resulting in an increase in circulating FFA levels, which stimulates hepatic triglyceride production, thereby contributing to the hyperlipidemia induced by TNF. In the present investigation we have determined the effects of a variety of cytokines on lipolysis in cultured 3T3-F442A adipocytes. TNF increased lipolysis approximately 3-fold with a maximal effect at 100 ng/ml and a half-maximal increase at 5-10 ng/ml. This increase was first observed 8 h after incubation with TNF. Interleukin-1 (IL-1) and interferon-alpha (IFN), -beta, and -gamma also stimulated lipolysis in cultured adipocytes. The half-maximal increase in lipolysis occurred at approximately 10 ng/ml IL-1, 5 ng/ml IFN alpha, 10 ng/ml IFN beta, and 8 ng/ml of IFN gamma. Maximal lipolysis was observed at approximately 100 ng/ml for each of these cytokines, with the exception of IFN beta, for which maximal stimulation was observed at 1000 ng/ml. Neither platelet-activating factor nor IL-6 stimulated lipolysis; therefore, it is unlikely that these compounds mediate the increase in lipolysis induced by cytokines. However, indomethacin, a well known inhibitor of prostaglandin synthesis, prevented the increase in lipolysis induced by TNF, IL-1, IFN alpha, IFN beta, or IFN gamma. Indomethacin did not affect basal lipolysis or the acute stimulation of lipolysis induced by epinephrine. These results demonstrate that multiple cytokines can increase lipolysis and that this increase is mediated by cytokine-induced stimulation of prostaglandin synthesis.
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PMID:Stimulation of lipolysis in cultured fat cells by tumor necrosis factor, interleukin-1, and the interferons is blocked by inhibition of prostaglandin synthesis. 137 Jan 49

Short- and long-term effects of hyperlipidemia with elevated FFA on insulin secretion were investigated. Male Sprague-Dawley rats were fed ad libitum and additionally infused with Intralipid 10%, 1.0 ml/h. After 3 h of Intralipid the response to 27 mM glucose in isolated perfused pancreas was enhanced by 86%, P less than 0.02. After 6 h of Intralipid enhancement had subsided. After 48 h of Intralipid glucose-induced insulin release was inhibited by 49%, from 1950 +/- 177 microU/min after saline to 1003 +/- 232 microU/min after Intralipid, P less than 0.02. Inhibition was glucose-selective since responses to other secretagogues (1 mM 3-isobutyl-1 methylxanthine, 10 mM octanoate, or 5 mM alpha-ketoisocaproic acid) were unaffected as were pancreatic contents of insulin (2284 +/- 111 mU/pancreas after saline, 2566 +/- 131 mU/pancreas after Intralipid). In isolated islets from 48 h lipid infused rats production of [14-C]CO2 from D[U-14-C]glucose was decreased (P less than 0.02) in parallel with the insulin response to 27 mM glucose. Glucose-induced secretion was partially normalized by in vitro exposure to a carnitine palmitoyl-transferase I inhibitor (Etomoxir). Effects of a 48 h lipid infusion were also tested during hyperglycemia. Rats were infused with glucose, and hyperglycemia was enhanced by dexamethasone (25 micrograms/24 h). Hyperglycemia depressed glucose-induced secretion from perfused pancreas from 2072 +/- 22 microU/min after saline + dexamethasone to 1185 +/- 155 microU/min after glucose + dexamethasone, P less than 0.01). Intralipid, added to the latter protocol, further inhibited glucose-induced secretion to 437 +/- 87 microU/min, P less than 0.005. Hyperlipidemia is concluded to be associated with short term stimulation but long term inhibition of glucose-induced insulin secretion. Evidence indicates that inhibition depends on fatty acid oxidation, is coupled to decreased glucose oxidation and operates both during normo- and hyperglycemia.
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PMID:A 48-hour lipid infusion in the rat time-dependently inhibits glucose-induced insulin secretion and B cell oxidation through a process likely coupled to fatty acid oxidation. 169 43

Cushing's syndrome has been recently compared to visceral-type obesity, since it is characterised by the accumulation of adipose tissue at a deep abdominal site, to the detriment of the subcutaneous adipose panniculus, and is associated with insulin-resistance and hyperlipemia. The aim of the present study was to evaluate the influence of glucocorticoid hormones on lipolytic activity (index of FFA mobilisation) and on lipoproteinlipase (LPL) activity (an index of the accumulation of triglycerides) in subcutaneous and perirenal adipose tissue in order to clarify the mechanisms involved in this type of accumulation in Cushing's syndrome. Five patients (4 F and 1 M) were included in the study, mean age 27.8 +/- 3.7 years and BMI 21.3 +/- 1.2 kg/m2; patients were hospitalised in the 2nd Surgical Clinic at the University of Padua and underwent surgery for secondary corticosurrenal hyperplasia with ACTH secreting hypophysial adenoma. Lipolytic activity in subcutaneous adipose tissue in these patients was significantly lower (p less than 0.05) than in control subjects, in particular after noradrenalin stimulation (p less than 0.01). No significant difference was observed when lipolytic activity in subcutaneous adipose tissue was compared to that one in perirenal tissue. LPL activity in subcutaneous adipose tissue did not reveal statistically significant differences compared to control subjects, although values were lower. A further decrease in LPL activity, which was not however significant, was observed in perirenal tissue in comparison to subcutaneous tissues in the same patients. The mean weight of adipocytes (ug) was slightly lower in subcutaneous adipose tissue compared to control subjects and even lower in perineal tissue in comparison to the subcutis in the same patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Lipolytic and lipoprotein lipase activity of subcutaneous and visceral adipose tissue in Cushing's syndrome]. 210 37

An important function of endothelium is to release PGI2, a prostaglandin produced from arachidonic acid that prevents platelet aggregation and causes arterial relaxation. Small amounts of other eicosanoids also are produced, but their role in endothelial function has not been elucidated. Much of the arachidonic acid present in the endothelium is obtained preformed from the plasma, either as FFA or from lipoproteins. Arachidonic acid is efficiently incorporated into endothelial lipids even when only relatively small amounts are available. In response to agonists, arachidonic acid is rapidly released from the endothelial phospholipids and converted to eicosanoids. Small amounts of eicosanoids also are continuously formed due to exposure of the endothelium to free fatty acid and lipoproteins containing arachidonic acid, without the need for any additional stimulus. Although the role of plasma lipid abnormalities has not been systematically investigated, there presently is little indication that hyperlipidemia interferes with endothelial arachidonic acid metabolism or the capacity of the endothelium to produce eicosanoids.
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PMID:Lipid and lipoprotein effects on endothelial eicosanoid formation. 306 Oct 5

Palmitate, glucose, and glycerol oxidation to CO(2) have been investigated in the fasted state in ten normal subjects and nine patients (six hyperlipoproteinemias, one xanthomatosis, and two glycogenosis) after intravenous injection of [1-(14)C]palmitate, [1-(14)C]glucose, or [1-(14)C]glycerol in tracer amounts. The specific activities and concentrations of plasma palmitate, glycerol, or glucose and expired CO(2) were measured at various intervals after the injection for a period of 24 h. All the studies were analyzed in terms of a multicompartment model describing the structure for each of the subsystems, the transfer of carbon label between subsystems, and the oxidation to CO(2). A bicarbonate subsystem was also included in the model to account for its role in shaping the CO(2) curves. All the CO(2) activity following a palmitate injection could be accounted for by a direct oxidative pathway from plasm FFA with the addition of a 20-min delay compartment. The same also applied to glucose, except that the delay compartment had a mean time of about 150 min. Only about a third of the injected glycerol was directly oxidized to CO(2) from plasma; the delay time was about 4 min. Most of the remainder was converted to glucose. In normals about 45% of the FFA is oxidized to CO(2) directly. This constitutes about 30% of the total CO(2) output. In hyperlipemia the CO(2) output is nearly unchanged and the contribution from FFA is nearly the same. There is a considerable increase (factor of 2), however, in FFA mobilization, most of which is probably diverted to triglyceride synthesis. The glucose and glycerol subsystems are roughly the same in normals and hyperlipemics. About 50% of glucose is oxidized by the direct pathways which accounts for about 35% of the CO(2) output. Glycerol accounts for only 1.5% of the CO(2) produced. Major changes occurred in the glycerol and glucose subsystems in glycogenosis. The changes are consistent with the known deficiency in glucose-6-phosphatase in this disorder. There is a considerable reduction (factor of 2 or more) in the release of glucose to plasma (gluconeogenesis) and in the conversion of glycerol to glucose. Despite the integration of the kinetics of the glucose, glycerol, and FFA subsystems over a 24-h period, 36% of the CO(2) production was still unaccounted for in normals and 50% in hyperlipemics. Thus, some of the carbon must wind up in very slowly turning-over pools which supply CO(2) through subsystems not covered in these studies (triglycerides, glycogen, amino acids, etc.). All the modeling was carried out with the aid of the SAAM25 computer program.
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PMID:Interrelations in the oxidative metabolism of free fatty acids, glucose, and glycerol in normal and hyperlipemic patients. A compartmental model. 452 90


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