Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0242339 (dyslipidemia)
13,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Absent hepatic lipase (HL) activity results in dyslipidemia and premature atherosclerosis. DNA sequencing of the HL gene from subjects with heritable HL deficiency identified a new C to T substitution within exon 8 that in the mature enzyme caused a threonine to methionine change at position 383 (T383M). With a rapid DNA detection method we observed that all 6 individuals with complete HL deficiency from 2 families had the T383M mutation. None of 50 random unrelated unaffected subjects had this mutation. We propose that T383M is specific to families with heritable HL deficiency. Furthermore, structural variation at the HL gene, possibly in combination with other factors, appears to be etiologic in HL deficiency.
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PMID:A hepatic lipase gene mutation associated with heritable lipolytic deficiency. 167 86

Dyslipidemia of chronic renal failure is of multifactorial origin. Decreased activity of lipoprotein lipase and hepatic triglyceride lipase, peripheral insulin resistance, hyperparathyroidism and L-carnitine deficiency are the contributing factors. This results in a disturbed catabolism of chylomicron, accumulation of very-low-density (VLDL) and intermediate-density (IDL) lipoproteins as well as incompletely cleared remnant particles, whereas low-density lipoprotein (LDL) levels are diminished. There is current debate as to whether cardiovascular disease is accelerated and whether hyperlipidemia should specifically be treated. In addition, there have been few means of influencing these metabolic alterations. Drug incompatibility and consequently side effects render treatment difficult. The drugs that have been most tested for lipid lowering in chronic renal failure are the fibric acids. By their mode of action, they are the logical choice. Dose reduction overcomes major side effects such as myopathy and rhabdomyolysis. The second generation of fibric acid derivatives (gemfibrozil and beclobrate) show several advantages over formerly used derivatives. Treatment with lovastatin and simvastatin appears to be safe and is recommended in a minority of patients with predominantly elevations of LDL. HMG-CoA reductase inhibitors also lower remnant particles effectively in hemodialysis (HD) patients. L-Carnitine and low-molecular-weight heparin have been shown to influence VLDL rich in triglycerides in a subset of patients on HD. In posttransplant hyperlipidemia, diet remains the first course of action in all patients. When this approach fails, the new lipid-lowering agents, especially fibric acids, appear to be safe in short-term studies in azathioprine- and ciclosporin-treated patients. Lovastatin has been shown to be safe in stable renal transplant patients. Its toxicity seems to depend mainly on high ciclosporin whole blood through or plasma levels.
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PMID:Hyperlipoproteinemia in chronic renal failure: pathophysiological and therapeutic aspects. 186 98

Abnormalities of plasma lipid and lipoprotein concentrations are common in both insulin-dependent (IDDM) and non-insulin-dependent (NIDDM) diabetes mellitus. In general, individuals with IDDM who are untreated or inadequately treated have elevations in both postprandial and fasting triglyceride levels in association with reduced activity of lipoprotein lipase. Low-density lipoprotein (LDL) cholesterol levels can rise when insulin deficiency impacts on LDL-receptor function. When patients with IDDM are treated and plasma glucose levels well controlled, plasma very-low-density lipoprotein (VLDL) triglyceride and LDL cholesterol levels are usually normal. In addition, plasma high-density lipoprotein (HDL) cholesterol levels are normal or elevated in well-controlled IDDM subjects. In NIDDM, increased VLDL triglyceride and reduced HDL cholesterol concentrations are common and are only partially related to glycemic control. Overproduction of VLDL leads to hypertriglyceridemia, which can be exacerbated if lipoprotein lipase activity is also reduced. The regulation of LDL levels is complex; catabolism can be reduced if significant insulin deficiency exists or increased if significant hypertriglyceridemia is present. The reduced levels of HDL cholesterol in NIDDM appear to be related to increased exchange of HDL cholesteryl esters for VLDL triglycerides, although other mechanisms may exist. The roles of insulin resistance, obesity, and independently inherited abnormalities of lipoprotein metabolism in the etiology of dyslipidemia of NIDDM are complex and require further investigation. Finally, the effects of diabetes on glycosylation of apoproteins; on other lipid enzymes, particularly hepatic triglyceride lipase; on lipoprotein surface lipids; and on hepatic uptake of remnants have only just begun to be defined. In view of the marked increase in atherosclerotic cardiovascular disease in individuals with diabetes mellitus, prompt attention to and aggressive therapy for dyslipidemia should be a central component of care for these patients.
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PMID:Lipoprotein physiology in nondiabetic and diabetic states. Relationship to atherogenesis. 195 76

Elevated plasma intermediate density lipoprotein (IDL) is one of the features of uremic dyslipidemia which is potentially atherogenic. We examined the effects of pravastatin, an HMG-CoA reductase inhibitor, on IDL levels as well as other lipoprotein parameters in 19 uremic patients treated with hemodialysis (HD, n = 11) or continuous ambulatory peritoneal dialysis (CAPD, n = 8). The patients were administered 5 mg/day pravastatin for the initial 4 weeks and 10 mg/day for the subsequent 12 weeks. In the analysis of the total subjects, IDL-cholesterol was reduced by 31% as well as low density lipoprotein (LDL)-cholesterol. Cholesterol in very low density lipoprotein (VLDL) also decreased whereas that in high density lipoprotein (HDL) did not. Significant decrease of serum triglycerides was due mainly to reduced IDL- and LDL-triglycerides. Apolipoprotein (apo) A-I did not change, whereas apo A-II, B, C-II, C-III, E, and B/A-I ratio were significantly lowered. Pravastatin did not affect measured activity of lecithin: cholesterol acyltransferase, post-heparin plasma lipoprotein lipase or hepatic triglyceride lipase. HD and CAPD patients responded almost equally to the treatment. IDL elevation was present independent of serum total cholesterol, and it was lowered by pravastatin even in non-hypercholesterolemic subjects. There was no critical adverse effect besides transient and asymptomatic increase of serum creatine kinase level. We conclude that pravastatin can be a safe and effective approach to the management of dyslipidemia in uremic patients who have an elevated level of IDL.
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PMID:Reduction of intermediate density lipoprotein by pravastatin in hemo- and peritoneal dialysis patients. 760 82

Recombinant human interleukin-2 (rIL-2) is used to treat refractory cancers. During such treatment, patients develop severe hypocholesterolemia along with striking alterations in the concentration and composition of the circulating lipoproteins. The present study was undertaken to gather information about the pathogenesis of these abnormalities. Patients were studied before-, during- and after a 5-day course of high dose i.v. rIL-2. Whole plasma cholesterol was markedly reduced by rIL-2 administration (52%; P < 0.001), whereas the triglyceride concentration did not change. Thus, the lipoproteins became triglyceride enriched (P = 0.004). Low density lipoprotein cholesterol, apolipoprotein B (apoB), high density lipoprotein cholesterol, and apoA-I concentrations all decreased. Esterified cholesterol levels were markedly reduced. Total plasma apoE increased markedly, and two kinds of abnormal particles appeared: 1) beta-migrating, very low density lipoproteins; and 2) discoidal, apoE- and phospholipid-containing particles with abnormal density and electrophoretic mobility. The activities of two lipoprotein triglyceride hydrolases, lipoprotein lipase and hepatic lipase, fell significantly during treatment and returned promptly to pretreatment levels after rIL-2 was discontinued. Lecithin:cholesteryl acyltransferase (LCAT) activity also decreased significantly (64%) during treatment, but in contrast to the lipases, remained low for at least 5 days after the last dose of rIL-2 (P < 0.001). High dose i.v. rIL-2 induces severe dyslipidemia with deficiencies of both postheparin lipases and acute LCAT deficiency. Most, if not all, of the lipoprotein changes observed are explained by the LCAT deficiency that follows IL-2-induced hepatocellular injury and cholestasis.
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PMID:Acute dyslipoproteinemia induced by interleukin-2: lecithin:cholesteryl acyltransferase, lipoprotein lipase, and hepatic lipase deficiencies. 914 52

Familial combined hyperlipidemia (FCHL) is characterized by different lipid phenotypes (IIa, IIb, IV) and elevated apolipoprotein B (apo B) levels in affected family members. Despite intensive research, the genes involved in the expression of this complex disorder have not been identified, probably because of problems associated with phenotype definition, unknown mode of inheritance, and most probably genetic heterogeneity. To explore the genetics of FCHL in the genetically homogeneous Finnish population, we collected 14 well-documented Finnish pedigrees with premature coronary heart disease and FCHL-like dyslipidemia. The lipolytic enzymes lipoprotein lipase (LPL), hepatic lipase (HL), and hormone-sensitive lipase (HSL) were selected as initial candidate genes because of their central roles in apo B and triglyceride metabolism. On the basis of the pedigree structures, a dominant mode of inheritance was adopted for linkage analyses, and serum total cholesterol and/or triglyceride levels exceeding the 90th percentile level were set as diagnostic criteria (criterion 1). In pairwise linkage analyses with intragenic markers, no evidence for linkage was found. Instead, the significantly negative LOD scores suggested exclusion of all three loci for single major gene effect. LOD scores were -14.63, -5.03, and -5.70 for the three LPL polymorphisms (theta=0.00); -9.40, -6.30, and -4.74 for the three HL polymorphisms (theta=0.00); and -15.29 for the HSL polymorphism (theta=0.00). The results were very similar when apo B levels over the 90th percentile were used as criteria for affected status (criterion 2). Also, when linkage calculations were carried out using an intermediate or recessive mode of inheritance, the results of pairwise linkage analysis remained negative. Furthermore, when haplotypes were constructed from multiple polymorphisms of the LPL and HL genes, no segregation with the FCHL phenotype could be observed in the 14 Finnish families. Data obtained by the affected sib-pair method supported these findings, suggesting that the LPL, HL, or HSL genes do not represent major loci influencing the expression of the FCHL phenotype.
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PMID:No evidence of linkage between familial combined hyperlipidemia and genes encoding lipolytic enzymes in Finnish families. 915 46

Hepatic lipase (HL) plays an important role in catabolism of chylomicron remnants, conversion of intermediate density lipoprotein (IDL) to low-density lipoprotein (LDL) and reverse transport of cholesterol to the liver. Several features of the nephrotic dyslipidemia point to the possible presence of HL deficiency. In an attempt to address this possibility, gene expression of HL was studied in rats with puromycin-induced nephrotic syndrome (NS). The results were compared with those obtained in a group of placebo-treated control animals. The NS group showed marked proteinuria, hypoalbuminemia, hypercholesterolemia, hypertriglyceridemia, normal creatinine clearance and normal hepatic tissue cholesterol concentration. HL activity of the liver tissue was reduced by approximately 60% in the NS group as compared to that found in the normal control group. The reduction of HL activity in the NS group was accompanied by a reduction of HL mRNA of virtually similar magnitude. HL activity of the liver tissue was inversely related to urinary protein excretion, serum cholesterol and serum triglyceride concentrations. In contrast, HL activity was directly related to serum albumin concentration and HL mRNA. No significant difference was observed in HL activity between the control group and the pre-nephrotic animals studied at days 1 and 5 following puromycin administration. This observation excludes an acute effect of puromycin as a possible cause of HL deficiency in the NS animals. Thus, NS in this model results in a marked down-regulation of HL expression which may, in part, contribute to the nephrotic dyslipidemia.
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PMID:Down-regulation of hepatic lipase expression in experimental nephrotic syndrome. 918 85

Women with polycystic ovary syndrome (PCOS) appear at increased cardiovascular risk due in part to a dyslipidemia characterized by increased plasma triglyceride and reduced high density lipoprotein (HDL) cholesterol levels. This is a detailed exploratory study of HDL composition in 35 obese [body mass index (BMI), > 27] and 22 nonobese subjects with PCOS and in 14 healthy obese and 18 nonobese women. Although we found reduced levels of total and HDL2 cholesterol in obese women with PCOS, HDL composition was modified by depletion of lipid relative to protein, with reduced ratios of HDL total cholesterol and HDL phospholipids to apolipoprotein A-I (apoA-I) compared to those in obese controls (P = 0.008 and P = 0.012, respectively). This was explained by reduced cholesterol (P = 0.004) and phospholipid (although not significant, P = 0.07) in HDL with no change in the content of apoA-I, its major protein. Obesity, insulin resistance, and hyperandrogenemia are features of PCOS and potentially affect lipid metabolism. Insulin sensitivity was assessed by the reduction in endogenous glucose concentration after exogenous insulin; the insulin, glucose, and fatty acid responses to oral glucose; and the fasting insulin concentration. When age, BMI, free androgen index, insulin sensitivity determined by all methods, and the presence of PCOS were subjected to stepwise multivariate regression analysis, the presence of PCOS was the most consistent predictor of lipid-depleted HDL (HDL total cholesterol/apoA-I and HDL phospholipids/apoA-I). We speculate that altered activity of hepatic lipase or lipid transfer protein could explain this aspect of the dyslipidemia. Obesity has an important influence on the lipid profile. Obese PCOS and control subjects had higher levels of cholesterol, triglyceride, apoB, and fatty acids than their lean counterparts, and BMI proved the best predictor of blood levels on multiple regression analysis. In contrast, lean PCOS patients had normal sensitivity to insulin and lipid profiles similar to those of the lean controls and did not manifest the HDL abnormalities. Although in PCOS, correlations were obtained between the free androgen index and cholesterol, triglyceride, and apoB levels and between the integrated glucose and insulin responses after oral glucose and fasting fatty acid and triglyceride levels, when age and adiposity were included as covariates only fatty acids and the integrated glucose response remained significantly correlated. Among the controls, total, low density lipoprotein cholesterol, triglycerides, and apoB were related to aspects of insulin sensitivity independent of age and BMI. Lipid metabolism in PCOS is dependent on several related factors, but subjects with PCOS who are obese show a specific reduction in HDL lipid, suggesting a reduced capacity for cholesterol removal from tissues with diminished antiatherogenic potential. Efforts should be directed toward reducing obesity in PCOS to improve the metabolic disturbance in addition to ameliorating the presenting symptoms.
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PMID:Altered composition of high density lipoproteins in women with the polycystic ovary syndrome. 932 74

End-stage renal failure (ESRF) is associated with dyslipidemia and accelerated atherosclerosis. Triglyceride-rich lipoproteins accumulate and qualitative changes take place in low-density lipoprotein (LDL), with a predominance of the small dense LDL phenotype. Increased small dense LDL (LDLIII) is a known risk factor for cardiovascular disease. To assess the extent of LDLIII formation in ESRF and identify factors contributing to LDLIII production, we analyzed LDL subfractions by density-gradient ultracentrifugation, very low-density lipoprotein subfractions, and lipase activity in 75 patients with ESRF (25 hemodialysis [HD], 25 peritoneal dialysis [PD], and 25 predialysis patients) and 40 age- and sex-matched controls. The percentage of LDLIII was increased in all three patient groups compared with controls (PD, 33% +/- 29% [mean +/- SD]; P < 0.005; HD, 30% +/- 22%; P < 0.01; predialysis, 26% +/- 26%; P < 0.01; all versus controls, 14% +/- 10%). Plasma LDLIII concentration was increased only in PD patients (median, 84 mg/dL; interquartile range [IQR], 29 to 160 mg/dL versus controls; median, 31 mg/dL; IQR, 26 to 54 mg/dL). In other patient groups, total LDL level was less, with heterogeneity in LDLIII concentrations. Forty percent of PD patients and 28% of HD and predialysis patients had LDLIII concentrations greater than 100 mg/dL compared with 2.5% of controls (P = 0.002). Plasma triglyceride levels (r(2) = 38.4%; P < 0.001) and hepatic lipase activity (r(2) = 6.7%; P < 0.03) were independent predictors of LDLIII concentration. The strong association between LDLIII concentration and triglyceride level was present in all three patient groups (HD, r(2) = 47.9%; PD, r(2) = 45. 2%; predialysis, r(2) = 25.8%); plasma triglyceride levels greater than 177 mg/dL (2.0 mmol/L) had an 86% specificity and 79% sensitivity for predicting an LDLIII concentration greater than 100 mg/dL. We conclude that the atherogenic lipoprotein phenotype predominates in ESRF, with excess LDLIII particularly prominent in PD patients. Atherogenic levels of LDLIII are found in patients with triglyceride levels greater than 177 mg/dL. This is likely to represent a further cardiovascular risk factor in this population.
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PMID:Atherogenic lipoprotein phenotype in end-stage renal failure: origin and extent of small dense low-density lipoprotein formation. 1079 19

Low activity of hepatic lipase (HL) has been associated with high levels of triglycerides and high density lipoproteins, but the association of the HL promoter variants with insulin sensitivity has not been investigated. Therefore, in this study, the relationship of the G-250A promoter variant of the HL gene to the rates of insulin-stimulated glucose uptake measured by the hyperinsulinemic euglycemic clamp was investigated in 110 control subjects (82 men and 28 women, aged 50.7+/-7.6 [mean+/-SD] years, body mass index 26. 1+/-3.6 kg/m(2)) and in 105 first-degree relatives (65 men and 40 women, aged 47.8+/-16.0 years, body mass index 26.9+/-5.3 kg/m(2)) of 34 families with familial combined hyperlipidemia (FCHL). The A-250 allele of the HL promoter was associated with low rates of insulin-stimulated whole-body nonoxidative glucose disposal in control subjects (41.1+/-12.7 micromol. kg(-1). min(-1) in subjects with the G-250G genotype, 36.9+/-13.1 micromol. kg(-1). min(-1) in subjects with the G-250A genotype, and 29.9+/-13.5 micromol. kg(-1). min(-1) in subjects with the A-250A genotype; P=0.012 adjusted for age and sex) and with low rates of insulin-stimulated whole-body glucose oxidation in FCHL family members (16.7+/-4.2 versus 15.0+/-4. 4 versus 14.1+/-4.4 micromol. kg(-1). min(-1), P=0.024). In addition, the A-250 allele was associated with high levels of fasting insulin (P=0.047), very low density lipoprotein cholesterol (P=0.007), and total (P=0.009) and very low density lipoprotein (P=0.005) triglycerides in control subjects and with high levels of low density lipoprotein triglycerides (P=0.001) in FCHL family members (n=340). We conclude that the G-250A promoter variant of the HL gene is associated with dyslipidemia and insulin resistance. Mechanisms via which this polymorphism could affect insulin sensitivity remain to be elucidated.
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PMID:G-250A substitution in promoter of hepatic lipase gene is associated with dyslipidemia and insulin resistance in healthy control subjects and in members of families with familial combined hyperlipidemia. 1089 18


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