Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033687 (proteinuria)
 24,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The abnormalities of lipid metabolism in nephrotic syndrome consist in an increase in total and low-density lipoprotein (LDL) cholesterol, apolipoproteins B (ApoB), C-II and C-III, associated in patients with heavier or marked hypoalbuminemia with an increase in triglycerides and very low-density lipoprotein (VLDL) cholesterol, while the high-density lipoproteins (HDL) are distributed abnormally (increased HDL3 fraction and decreased HDL2 fraction) and the Apo A-I to Apo B ratio is reduced. Both increased hepatic lipoprotein synthesis and reduced removal capacity contribute to this hyperlipidemia. Proteinuria may lead to the lipoprotein abnormalities through stimulation of VLDL synthesis by the liver induced by hypoalbuminemia, although it has been more recently suggested that urinary protein loss is associated with the urinary loss of some important cofactor for the regulation of lipid synthesis or catabolism. Treatment of lipid abnormalities in patients with long-lasting heavy proteinuria is mandatory, because they may cause or contribute to accelerated atherosclerosis, but also because they appear to accelerate progression of renal disease by favouring mesangial sclerosis. Four groups of lipid-lowering drugs have been tested: 1) bile acid-binding resins; 2) fibric acid; 3) probucol; 4) inhibitors of HMG CoA reductase. The drugs of the last group appear to be effective and safe in short-term experiments, but long-term studies are necessary to confirm their validity. A dietary approach, consisting in a strictly vegetarian soy diet, very rich in poly- and monounsaturates fatty acids, has been recently tested by the author, with very promising results.
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PMID:Lipid changes in the nephrotic syndrome: new insights into pathomechanisms and treatment. 175 84

Hyperlipidemia is common in patients with glomerular proteinuria. It may contribute to atherosclerotic complications and accelerate glomerular damage. Early trials of the fibric acid derivative clofibrate led to a myositis syndrome causing many nephrologists to abandon attempts at treatment of nephrotic hyperlipidemia. Recent trials with lipid-lowering medications have been successful without major side effects. The bile acid sequestrants colestipol and cholestyramine bind bile acids in the gut and deplete the hepatic cholesterol pool, thus inducing LDL hepatocyte receptors. Recent studies showed a reduction of total cholesterol of 8-20% and LDL cholesterol of 19-31% without significant changes in HDL cholesterol. Probucol has reduced total cholesterol 23-30% and LDL cholesterol 23-25% in nephrotic patients. Although HDL cholesterol was reduced, the LDL/HDL ratio remains favorably changed. The fibric acid derivative gemfibrozil inhibits adipose lipolysis and enhances lipoprotein lipase activity thus decreasing LDL synthesis and increasing its removal. It caused a large decrease in triglycerides with a 13-15% decrease in total and LDL cholesterol in a recent trial. HDL cholesterol increased 18%. The HMG-CoA reductase inhibitors inhibit the rate-limiting step in cholesterol biosynthesis hence inducing an increase in LDL receptors on hepatocytes. Trials have shown decreases of 18-36% in total cholesterol and 18-47% in LDL cholesterol, while HDL cholesterol was either increased or unchanged. The use of lipid-lowering agents of several classes has been effective in ameliorating the progression of glomerular damage in a number of different models of glomerulosclerosis. Nevertheless, so far in humans lipid lowering drugs have not been established to have an effect on either the degree of proteinuria or the progression of glomerulosclerosis.
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PMID:Lipid-lowering agents in proteinuric diseases. 225 70

Hypercholesterolemia frequently accompanies the nephrotic syndrome, but the mechanism responsible for elevation of plasma cholesterol is poorly understood. Specifically, the contribution of abnormal hepatic cholesterol metabolism to elevated concentrations of serum cholesterol has never been studied in depth. The objective of the present study was to define the alteration of hepatic cholesterol metabolism in puromycin induced nephrotic syndrome in rats. Studies involved measurements of specific activities of four enzymes participating in the maintenance of hepatic cholesterol metabolism: HMG-CoA-reductase, the rate limiting enzyme of cholesterol synthesis; cholesterol 7 alpha-hydroxylase, the rate limiting enzyme in bile acid synthesis; acyl CoA: cholesterol acyltransferase, the enzyme responsible for esterification of cholesterol; and cholesterol ester hydrolase (CEH), an enzyme which hydrolyzes cholesterol. Multiple injections of puromycin resulted in a production of nephrotic syndrome with massive proteinuria, hypoalbuminemia, hypercholesterolemia, ascites and edema. HMG-CoA-reductase (nmol/hr/mg protein) and cholesterol 7 alpha-hydroxylase activities (nmol/hr/mg protein) in rats with nephrotic syndrome were not statistically significant as compared to control rats (4.0 +/- 0.7 and 2.0 +/- 0.6 vs. 3.3 +/- 0.4 and 1.6 +/- 0.2), respectively. Our results also demonstrate, for the first time, that the normal diurnal rhythm in HMG-CoA reductase activity is no longer present in the nephrotic animals. The activities in the nephrotics in the day was 4.0 nmol/hr/mg and at night, 3.9 nmol/hr/day, compared to the control values of 3.3 nmol/hr/mg in the day and 6.9 nmol/hr/mg at night. ACAT activities were 428 +/- 78 versus 302 +/- 64 pmol/min/mg/protein (P = NS).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Studies of alteration of hepatic cholesterol metabolism in puromycin-induced nephrotic syndrome in rats. 825 56

Experimental evidence suggests that lipid lowering therapy could slow the progression of renal disease in humans. We have conducted a double-blind, placebo controlled trial of the HMG CoA reductase inhibitor simvastatin in patients with the nephrotic syndrome or significant proteinuria (> 1 g/day) and hypercholesterolemia (> or = 6.5 mmol/liter). Patients were placed on a lipid lowering diet for at least 10 weeks before randomization. After a four-week placebo run-in, 30 adults were randomized to simvastatin or placebo therapy (10 mg/day, increasing to 20 to 40 mg/day as required) for 24 weeks. There were seven dropouts, none of whom were "definitely" related to drug therapy. Total and LDL cholesterol levels fell by a mean of 33 and 31%, respectively, in simvastatin treated patients, compared with only 5 and 1% in patients on placebo (P < 0.001, P = 0.002, respectively). Apolipoprotein B100 levels fell by a mean of 31% in the simvastatin group but rose 0.3% in the placebo group (P = 0.014). There were no significant changes in HDL levels. There were no significant differences between the groups in their urine protein levels, their rise in plasma creatinine, or decline in plasma inulin clearance. Simvastatin is a safe, effective therapy for hypercholesterolemia in proteinuric states. A much larger trial is needed to show if potent lipid-lowering therapy slows progression of hypercholesterolemic proteinuric diseases.
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PMID:Simvastatin therapy for hypercholesterolemic patients with nephrotic syndrome or significant proteinuria. 826 45

Hepatic lipid and apolipoprotein synthesis is increased in the nephrotic syndrome. Catabolism of triglyceride-rich lipoproteins is impaired in nephrotic syndrome but not in rats with hereditary analbuminemia (NA), suggesting that lipid synthesis should be increased by analbuminemia in the absence of proteinuria. In this study the rate of cholesterol and fatty acid synthesis in liver and extrahepatic tissue was measured in female NA and control Sprague-Dawley (SD) rats to determine whether lipid synthesis was indeed increased in isolated analbuminemia and to identify the site(s) of increased lipogenesis. We also measured the concentrations of apolipoproteins (apo) AI, B, and E in plasma, as well as the levels of the respective mRNAs in liver. Plasma cholesterol, triglycerides, and apo AI, B, and E were all increased severalfold in the NA rat (P < 0.001). Although liver apolipoprotein mRNA content was significantly increased (P < 0.001) for apo AI (643%), B (273%), and E (299%), 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity in liver microsomes and hepatic cholesterol synthesis were not significantly increased in the NA rats. Hepatic fatty acid synthesis and intestinal cholesterol synthesis were not increased in the NA rats. Surprisingly, intestinal fatty acid synthesis was elevated by 60% (P < 0.01). The NA rats demonstrated approximately fourfold increases in the incorporation of 3H2O into circulating cholesterol and fatty acids (P < 0.001). A 56% increase in the synthesis of total nonsaponifiable lipid was found in the extravisceral carcass (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Extrahepatic lipogenesis contributes to hyperlipidemia in the analbuminemic rat. 834 16

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors are established drugs for the treatment of hypercholesterolemia, but several studies have shown that benefits obtained with these drugs are not causally related only to regression of cholesterol lowering. Moreover, in experimental models of progressive renal disease, statins have reduced the extent of glomerulosclerosis. This study evaluated the antiproteinuric effect of a daily dose of 40 mg fluvastatin for 6 months in moderately proteinuric patients with immunoglobulin A nephropathy, stable renal function, and no indicators of poor long-term prognosis. The effects of therapy were evaluated on the basis of 24-hour proteinuria (total proteinuria and albuminuria), albuminemia, creatinine clearance, cholesterol, and triglyceride values. Renal function remained stable in all patients. A significant decrease in proteinuria was observed after 6 months of therapy and persisted for all the observations. An increase in serum albumin was observed after 6 months of therapy. This study suggests that there is an antiproteinuric effect of HMG-CoA reductase inhibitors in moderately proteinuric patients with immunoglobulin A nephropathy.
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PMID:Effect of fluvastatin on proteinuria in patients with immunoglobulin A nephropathy. 1080 Dec 53

We retrospectively evaluated the response to steroids (S) +/- angioten-sin-converting enzyme inhibitors (ACEI) vs. ACEI in nephrotic patients with FSGS seen in our clinic from 1992 - 1999. Of 48 patients with biopsy-proven FSGS, 30 had pre-therapy and follow-up evaluations of proteinuria. Of these, 22 were nephrotic (> or = 3 g protein/24 h). Twelve/22 were treated with S and 10/22 with ACEI +/- HMG-CoA reductase inhibitor (statin) alone. 92% of S patients received ACEI during follow-up, 83% concurrently with steroid treatment. The two cohorts (S vs. ACEI) were not different in age (34 +/- 12 vs. 33 +/- 12), sex (75% vs. 78% male), or ethnicity (83% vs. 83% African American). Mean follow-up time was 16 (range 4 - 61 months) vs. 23 months (range 6 - 56 months). Mean S dose was 70 mg qd (range 60 - 100 mg), with mean treatment duration of 4 months. Nephrotic patients were compared with regard to degree of proteinuria at follow-up. There were no complete remissions (proteinuria < or = 200 mg/24 h) in either group. There was no difference in partial remissions (> 200 mg to < 3 g proteinuria/24 h) between the two groups - 5/12 vs. 6/10 (p = 0.434). There was no difference in the proportion of patients progressing to ESRD. Although proteinuria decreased significantly with time in both groups, there was no significant treatment effect. There was no significant time or treatment effect on serum creatinine. Mean arterial pressure and serum cholesterol were not significantly different between the groups. Thus, treatment with S +/- ACEI is no more effective in reducing proteinuria in FSGS than treatment with ACEI alone.
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PMID:Effects of angiotensin-converting enzyme inhibitor and steroid therapy on proteinuria in FSGS: a retrospective study in a single clinic. 1152

Previous studies indicate that acute tubular injury causes free cholesterol (FC) and cholesteryl ester (CE) accumulation within renal cortex/proximal tubules. This study assessed whether similar changes occur with glomerulopathy/nephrotic syndrome, in which high-circulating/filtered lipoprotein levels increase renal cholesterol supply. Potential adaptive changes in cholesterol synthetic/transport proteins were also assessed. Nephrotoxic serum (NTS) or passive Heymann nephritis (PHN) was induced in Sprague-Dawley rats. Renal injury (blood urea nitrogen, proteinuria) was assessed 2 and 7 days (NTS), or 10 and 30 days (PHN) later. FC and CE levels in renal cortex, isolated glomeruli, and proximal tubule segments were determined. SR-B1 (a CE influx protein), ABCA1 (a FC exporter), and HMG CoA reductase protein/mRNA levels were also assessed. FC was minimally elevated in renal cortex (0 to 15%), the majority apparently localizing to proximal tubules. More dramatic CE elevations were found ( approximately 5 to 15x), correlating with the severity of proteinuria at any single time point (r >/= 0.85). Cholesterol increments were associated with decreased SR-B1, increased ABCA1, and increased HMG CoA reductase (HMGCR) protein and its mRNA. Tubule (HK-2) cell culture data indicated that SR-B1 and ABCA1 levels are responsive to cholesterol supply. Experimental nephropathy can increase renal FC, and particularly CE, levels, most notably in proximal tubules. These changes are associated with adaptations in SR-B1 and ABCA1 expression, which are physiologically appropriate changes for a cholesterol overload state. However, HMGCR protein/mRNA increments can also result. These seem to reflect a maladaptive response, potentially contributing to a cell cholesterol overload state.
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PMID:Experimental glomerulopathy alters renal cortical cholesterol, SR-B1, ABCA1, and HMG CoA reductase expression. 1250 11

Childhood nephrotic syndrome is a rare condition with an incidence of 1-2 per 100000 children aged below 16 years. Untreated idiopathic nephrotic syndrome (INS) is associated with increased risks of life-threatening infection, thromboembolism, lipid abnormalities, and malnutrition. The aim of the management of INS in children is to induce and maintain complete remission with resolution of proteinuria and edema without serious adverse effects of therapy. The majority of children have corticosteroid sensitive idiopathic nephrotic syndrome (CSINS), and in these children, corticosteroid therapy is the mainstay of therapy to induce remission. Data from a meta-analysis of randomized controlled trials (RCTs) indicate that prolonged courses of corticosteroids (up to 7 months) given in the first episode of CSINS reduce the risk of relapse. Nevertheless, many children relapse, and are at risk of corticosteroid toxicity if frequent courses of corticosteroids are required. Data from RCTs supports the use of alkylating agents (cyclophosphamide, chlorambucil), cyclosporine, and levamisole in these children to achieve prolonged periods of remission. The specific management of corticosteroid-resistant idiopathic nephrotic syndrome (CRINS) is more difficult since few therapies are consistently effective, and data from RCTs are limited. In such children, cyclosporine, alkylating agents, and high dose intravenous methylprednisone may be used. In addition to specific therapies for INS, supportive therapies are commonly used to control edema (loop diuretics, aldosterone antagonists, albumin infusions, angiotensin-converting enzyme inhibitors), reduce the risk of infection (antibacterials, pneumococcal vaccination) and thromboembolism (aspirin [acetylsalicylic acid]), and to control hyperlipidemia (HMG-CoA reductase inhibitors), especially in children with CRINS.
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PMID:The management of idiopathic nephrotic syndrome in children. 1271 20

Limited data suggest that HMG-CoA reductase inhibitors (statins) may slow loss of renal function in individuals with chronic renal insufficiency. This study was conducted to determine whether pravastatin reduced rates of loss of renal function in people with moderate chronic renal insufficiency. This was a post hoc subgroup analysis of a randomized double-blind placebo controlled trial. Data were analyzed from the CARE study (a randomized trial of pravastatin versus placebo in 4159 participants with previous myocardial infarction and total plasma cholesterol < 240 mg/dl). Participants with estimated GFR (MDRD-GFR) < 60 ml/min per 1.73 m(2) body surface area at baseline were considered to have moderate chronic renal insufficiency. Multivariate regression was used to calculate rates of decline in MDRD-GFR for individuals receiving pravastatin and placebo, controlling for prospectively determined covariates that might influence rates of renal function loss. Change in renal function could be calculated in 3384 individuals, of whom 690 (20.4%) had MDRD-GFR < 60 ml/min per 1.73 m(2) and were eligible for inclusion. Among all individuals with MDRD-GFR < 60 ml/min per 1.73 m(2)), the MDRD-GFR decline in the pravastatin group was not significantly different from that in the placebo group (0.1 ml/min per 1.73 m(2)/yr slower; 95% CI, -0.2 to 0.4; P = 0.49). However, there was a significant stepwise inverse relation between MDRD-GFR before treatment and slowing of renal function loss with pravastatin use, with more benefit in those with lower MDRD-GFR at baseline (P = 0.04). Rate of change in MDRD-GFR in the pravastatin group was 0.6 ml/min per 1.73 m(2)/yr slower than placebo (95% CI, -0.1 to 1.2; P = 0.07) in those with MDRD-GFR < 50 ml/min, and 2.5 ml/min per 1.73 m(2)/yr slower (95% CI, 1.4 to 3.6 slower; P = 0.0001) in those with MDRD-GFR < 40 ml/min per 1.73 m(2)/yr. Pravastatin also reduced rates of renal loss to a greater extent in participants with than without proteinuria at baseline (P = 0.006). It is concluded that pravastatin may slow renal function loss in individuals with moderate to severe kidney disease, especially those with proteinuria. These findings require confirmation by a large randomized trial conducted specifically in people with chronic renal insufficiency.
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PMID:Effect of pravastatin on loss of renal function in people with moderate chronic renal insufficiency and cardiovascular disease. 1276 Dec 62


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