Lovastatin in the treatment of multifactorial hyperlipidemia associated with proteinuria

HMG CoA reductase inhibitors (statins) for people with chronic kidney disease not requiring dialysis

BACKGROUND

Cardiovascular disease is the most frequent cause of death in people with early stages of chronic kidney disease (CKD), and the absolute risk of cardiovascular events is similar to people with coronary artery disease. This is an update of a review first published in 2009 and updated in 2014, which included 50 studies (45,285 participants).

OBJECTIVES

To evaluate the benefits and harms of statins compared with placebo, no treatment, standard care or another statin in adults with CKD not requiring dialysis.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 4 October 2023. Studies in the Register are identified through searches of CENTRAL, MEDLINE, EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov. An updated search will be undertaken every three months.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs that compared the effects of statins with placebo, no treatment, standard care, or other statins, on death, cardiovascular events, kidney function, toxicity, and lipid levels in adults with CKD (estimated glomerular filtration rate (eGFR) 90 to 15 mL/min/1.73 m2) were included.

DATA COLLECTION AND ANALYSIS

Two or more authors independently extracted data and assessed the study risk of bias. Treatment effects were expressed as mean difference (MD) for continuous outcomes and risk ratios (RR) for dichotomous benefits and harms with 95% confidence intervals (CI). The risk of bias was assessed using the Cochrane risk of bias tool, and the certainty of the evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 63 studies (50,725 randomised participants); of these, 53 studies (42,752 participants) compared statins with placebo or no treatment. The median duration of follow-up was 12 months (range 2 to 64.8 months), the median dosage of statin was equivalent to 20 mg/day of simvastatin, and participants had a median eGFR of 55 mL/min/1.73 m2. Ten studies (7973 participants) compared two different statin regimens. We were able to meta-analyse 43 studies (41,273 participants). Most studies had limited reporting and hence exhibited unclear risk of bias in most domains. Compared with placebo or standard of care, statins prevent major cardiovascular events (14 studies, 36,156 participants: RR 0.72, 95% CI 0.66 to 0.79; I2 = 39%; high certainty evidence), death (13 studies, 34,978 participants: RR 0.83, 95% CI 0.73 to 0.96; I² = 53%; high certainty evidence), cardiovascular death (8 studies, 19,112 participants: RR 0.77, 95% CI 0.69 to 0.87; I² = 0%; high certainty evidence) and myocardial infarction (10 studies, 9475 participants: RR 0.55, 95% CI 0.42 to 0.73; I² = 0%; moderate certainty evidence). There were too few events to determine if statins made a difference in hospitalisation due to heart failure. Statins probably make little or no difference to stroke (7 studies, 9115 participants: RR 0.64, 95% CI 0.37 to 1.08; I² = 39%; moderate certainty evidence) and kidney failure (3 studies, 6704 participants: RR 0.98, 95% CI 0.91 to 1.05; I² = 0%; moderate certainty evidence) in people with CKD not requiring dialysis. Potential harms from statins were limited by a lack of systematic reporting. Statins compared to placebo may have little or no effect on elevated liver enzymes (7 studies, 7991 participants: RR 0.76, 95% CI 0.39 to 1.50; I² = 0%; low certainty evidence), withdrawal due to adverse events (13 studies, 4219 participants: RR 1.16, 95% CI 0.84 to 1.60; I² = 37%; low certainty evidence), and cancer (2 studies, 5581 participants: RR 1.03, 95% CI 0.82 to 1.30; I² = 0%; low certainty evidence). However, few studies reported rhabdomyolysis or elevated creatinine kinase; hence, we are unable to determine the effect due to very low certainty evidence. Statins reduce the risk of death, major cardiovascular events, and myocardial infarction in people with CKD who did not have cardiovascular disease at baseline (primary prevention). There was insufficient data to determine the benefits and harms of the type of statin therapy.

AUTHORS' CONCLUSIONS

Statins reduce death and major cardiovascular events by about 20% and probably make no difference to stroke or kidney failure in people with CKD not requiring dialysis. However, due to limited reporting, the effect of statins on elevated creatinine kinase or rhabdomyolysis is unclear. Statins have an important role in the primary prevention of cardiovascular events and death in people who have CKD and do not require dialysis. Editorial note: This is a living systematic review. We will search for new evidence every three months and update the review when we identify relevant new evidence. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.

Dyslipidemia and cardiovascular health in childhood nephrotic syndrome

Children with steroid-resistant nephrotic syndrome (SRNS) are exposed to multiple cardiovascular risk factors predisposing them to accelerated atherosclerosis. This risk is negligible in steroid-sensitive nephrotic syndrome, but a substantial proportion of children with SRNS progress to chronic kidney disease, exacerbating the already existing cardiovascular risk. While dyslipidemia is an established modifiable risk factor for cardiovascular disease in adults with NS, it is uncertain to what extent analogous risks exist for children. There is increasing evidence of accelerated atherosclerosis in children with persistently high lipid levels, especially in refractory NS. Abnormalities of lipid metabolism in NS include hypertriglyceridemia and hypercholesterolemia due to elevated apolipoprotein B-containing lipoproteins, decreased lipoprotein lipase and hepatic lipase activity, increased hepatic PCSK9 levels, and reduced hepatic uptake of high-density lipoprotein. Existing guidelines for the management of dyslipidemia in children may be adapted to target lower lipid levels in children with NS, but they will most likely require both lifestyle modifications and pharmacological therapy. While there is a lack of data from randomized controlled trials in children with NS demonstrating the benefit of lipid-lowering drugs, therapies including statins, bile acid sequestrants, fibrates, ezetimibe, and LDL apheresis have all been suggested and/or utilized. However, concerns with the use of lipid-lowering drugs in children include unclear side effect profiles and unknown long-term impacts on neurological development and puberty. The recent introduction of anti-PCSK9 monoclonal antibodies and other therapies targeted to the molecular mechanisms of lipid transport disrupted in NS holds promise for the future treatment of dyslipidemia in NS.

Effect of atorvastatin on dyslipidemia and carotid intima-media thickness in children with refractory nephrotic syndrome: a randomized controlled trial

BACKGROUND

Dyslipidemia is an important cardiovascular risk factor in steroid-resistant nephrotic syndrome (SRNS). Efficacy of statins for treatment of hyperlipidemia in children with SRNS is unclear.

METHODS

This prospective, randomized, double-blind, placebo-controlled, parallel-group clinical trial enrolled 30 patients with SRNS, aged 5-18 years, with serum low-density lipoprotein cholesterol (LDL-C) levels between 130 and 300 mg/dl, to receive a fixed dose of atorvastatin (n = 15, 10 mg/d) or placebo (n = 15) by block randomization in a 1:1 ratio. Primary outcome was change in serum LDL-C at 12 months. Change in levels of other lipid fractions, carotid intima-media thickness (cIMT), flow-mediated dilation (FMD) of the brachial artery, and adverse events were also evaluated.

RESULTS

At the end of 12 months, atorvastatin was not superior to placebo in reducing plasma LDL-C levels, median percentage reduction 15.8% and 9.5% respectively, in atorvastatin and placebo arms (n = 14 in each; P = 0.40). Apolipoprotein B levels significantly declined with atorvastatin in modified intention-to-treat analysis (P = 0.01) but not in the per-protocol analysis. There was no significant effect on other lipid fractions, cIMT and FMD. Adverse events were similar between groups. Change in serum albumin was negatively associated with change in serum LDL-C, very low-density lipoprotein cholesterol, total cholesterol, triglyceride, and apolipoprotein B (P < 0.001), irrespective of receiving atorvastatin, age, gender, body mass index, and serum creatinine.

CONCLUSIONS

Atorvastatin, administered at a fixed daily dose of 10 mg, was not beneficial in lowering lipid levels in children with SRNS; rise in serum albumin was associated with improvement in dyslipidemia.

Prevention of phenytoin-induced gingival overgrowth by lovastatin in mice

Drug-induced gingival overgrowth is caused by the antiseizure medication phenytoin, calcium channel blockers, and ciclosporin. Characteristics of these drug-induced gingival overgrowth lesions differ. We evaluate the ability of a mouse model to mimic human phenytoin-induced gingival overgrowth and assess the ability of a drug to prevent its development. Lovastatin was chosen based on previous analyses of tissue-specific regulation of CCN2 production in human gingival fibroblasts and the known roles of CCN2 in promoting fibrosis and epithelial to mesenchymal transition. Data indicate that anterior gingival tissue overgrowth occurred in phenytoin-treated mice based on gross tissue observations and histomorphometry of tissue sections. Molecular markers of epithelial plasticity and fibrosis were regulated by phenytoin in gingival epithelial tissues and in connective tissues similar to that seen in humans. Lovastatin attenuated epithelial gingival tissue growth in phenytoin-treated mice and altered the expressions of markers for epithelial to mesenchymal transition. Data indicate that phenytoin-induced gingival overgrowth in mice mimics molecular aspects of human gingival overgrowth and that lovastatin normalizes the tissue morphology and the expression of the molecular markers studied. Data are consistent with characterization of phenytoin-induced human gingival overgrowth in vivo and in vitro characteristics of cultured human gingival epithelial and connective tissue cells. Findings suggest that statins may serve to prevent or attenuate phenytoin-induced human gingival overgrowth, although specific human studies are required.

HMG CoA reductase inhibitors (statins) for people with chronic kidney disease not requiring dialysis

BACKGROUND

Cardiovascular disease (CVD) is the most frequent cause of death in people with early stages of chronic kidney disease (CKD), for whom the absolute risk of cardiovascular events is similar to people who have existing coronary artery disease. This is an update of a review published in 2009, and includes evidence from 27 new studies (25,068 participants) in addition to the 26 studies (20,324 participants) assessed previously; and excludes three previously included studies (107 participants). This updated review includes 50 studies (45,285 participants); of these 38 (37,274 participants) were meta-analysed.

OBJECTIVES

To evaluate the benefits (such as reductions in all-cause and cardiovascular mortality, major cardiovascular events, MI and stroke; and slow progression of CKD to end-stage kidney disease (ESKD)) and harms (muscle and liver dysfunction, withdrawal, and cancer) of statins compared with placebo, no treatment, standard care or another statin in adults with CKD who were not on dialysis.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register to 5 June 2012 through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs that compared the effects of statins with placebo, no treatment, standard care, or other statins, on mortality, cardiovascular events, kidney function, toxicity, and lipid levels in adults with CKD not on dialysis were the focus of our literature searches.

DATA COLLECTION AND ANALYSIS

Two or more authors independently extracted data and assessed study risk of bias. Treatment effects were expressed as mean difference (MD) for continuous outcomes (lipids, creatinine clearance and proteinuria) and risk ratio (RR) for dichotomous outcomes (major cardiovascular events, all-cause mortality, cardiovascular mortality, fatal or non-fatal myocardial infarction (MI), fatal or non-fatal stroke, ESKD, elevated liver enzymes, rhabdomyolysis, cancer and withdrawal rates) with 95% confidence intervals (CI).

MAIN RESULTS

We included 50 studies (45,285 participants): 47 studies (39,820 participants) compared statins with placebo or no treatment and three studies (5547 participants) compared two different statin regimens in adults with CKD who were not yet on dialysis. We were able to meta-analyse 38 studies (37,274 participants).The risk of bias in the included studies was high. Seven studies comparing statins with placebo or no treatment had lower risk of bias overall; and were conducted according to published protocols, outcomes were adjudicated by a committee, specified outcomes were reported, and analyses were conducted using intention-to-treat methods. In placebo or no treatment controlled studies, adverse events were reported in 32 studies (68%) and systematically evaluated in 16 studies (34%).Compared with placebo, statin therapy consistently prevented major cardiovascular events (13 studies, 36,033 participants; RR 0.72, 95% CI 0.66 to 0.79), all-cause mortality (10 studies, 28,276 participants; RR 0.79, 95% CI 0.69 to 0.91), cardiovascular death (7 studies, 19,059 participants; RR 0.77, 95% CI 0.69 to 0.87) and MI (8 studies, 9018 participants; RR 0.55, 95% CI 0.42 to 0.72). Statins had uncertain effects on stroke (5 studies, 8658 participants; RR 0.62, 95% CI 0.35 to 1.12).Potential harms from statin therapy were limited by lack of systematic reporting and were uncertain in analyses that had few events: elevated creatine kinase (7 studies, 4514 participants; RR 0.84, 95% CI 0.20 to 3.48), liver function abnormalities (7 studies, RR 0.76, 95% CI 0.39 to 1.50), withdrawal due to adverse events (13 studies, 4219 participants; RR 1.16, 95% CI 0.84 to 1.60), and cancer (2 studies, 5581 participants; RR 1.03, 95% CI 0.82 to 130).Statins had uncertain effects on progression of CKD. Data for relative effects of intensive cholesterol lowering in people with early stages of kidney disease were sparse. Statins clearly reduced risks of death, major cardiovascular events, and MI in people with CKD who did not have CVD at baseline (primary prevention).

AUTHORS' CONCLUSIONS

Statins consistently lower death and major cardiovascular events by 20% in people with CKD not requiring dialysis. Statin-related effects on stroke and kidney function were found to be uncertain and adverse effects of treatment are incompletely understood. Statins have an important role in primary prevention of cardiovascular events and mortality in people who have CKD.

Lipid-lowering agents for nephrotic syndrome

BACKGROUND

Nephrotic syndrome is the collective name given to a group of symptoms that include proteinuria, lipiduria, hypoalbuminaemia, oedema, hypercholesterolaemia, elevated triglycerides, and hyperlipidaemia. Hyperlipidaemia is thought to aggravate glomerulosclerosis (hardening of blood vessels in the kidneys) and enhance progression of glomerular disease. Studies have established that reduction in total cholesterol and low density lipoprotein (LDL) cholesterol is associated with reduction in risk of cardiovascular diseases. In 2011, the European Society of Cardiology and European Atherosclerosis Society guidelines for the management of dyslipidaemia recommended use of statins as first-line agents in the management of nephrotic dyslipidaemia. However, the effectiveness and safety of statins for people with nephrotic syndrome remains uncertain. Furthermore, the efficacy of second-line lipid-lowering drugs, such as ezetimibe and nicotinic acid, has not been proven in patients with nephrotic syndrome who are unable to tolerate statin therapy.

OBJECTIVES

This review aimed to evaluate the benefits and harms of lipid-lowering agents in adults and children with nephrotic syndrome.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register (to 18 March 2013) through contact with the Trials Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

All randomised controlled trials (RCTs) and quasi-RCTs (RCTs in which allocation to treatment was obtained by alternation, use of alternate medical records, date of birth or other predictable methods) looking at participants with nephrotic syndrome that compared any lipid-lowering agent to placebo, no treatment or other lipid-lowering agents, given for not less than four weeks, were included.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility and risk of bias, and extracted data. Statistical analyses were performed using a random effects model. Dichotomous results were expressed as risk ratios (RR) with 95% confidence intervals (CI). For continuous measures mean difference (MD) was used, or the standardised mean difference (SMD) where different scales had been used.

MAIN RESULTS

We included five RCTs enrolling a total of 203 participants. Of these, four studies compared statins with no treatment or placebo, and one compared fibrates with placebo. We found no published studies comparing second-line agents such as ezetimibe, bile acid sequestrants, and nicotinic acid with placebo or no treatment. Our assessment of the risk of bias found that one study was judged overall to be at low risk of bias and the remaining four were judged to be at high risk of bias.Most outcomes were supported by single study data. One study reported significantly increased high density lipoprotein (HDL) cholesterol among participants in the statin arm compared with the no treatment group (MD 5.40 mg/dL, 95% CI 2.31 to 8.49). Another study reported higher serum albumin in the statin group compared to those who received no treatment (MD 0.60 g/dL, 95% CI 0.14 to 1.06). No serious adverse events, such as rhabdomyolysis, were reported, however some minor events occurred. One study reported no significant difference in the number of participants with elevated liver enzymes (RR 3.00, 95% CI 0.13 to 69.52); three studies reported liver enzymes remained within the normal range (no data provided). Four studies reported creatinine phosphokinase (CPK). One study indicated that CPK values fluctuated in both the simvastatin and placebo groups (no data provided); the remaining three studies reported CPK either stayed within the normal range (one study) or there was no significant difference between the lipid lowering agents and placebo.

AUTHORS' CONCLUSIONS

None of the included studies reported patient-centred outcomes including all-cause mortality, cardiovascular mortality, or non-fatal myocardial infarction; only single studies reported cholesterol (HDL, LDL and total cholesterol), triglycerides, serum creatinine, blood urea nitrogen, liver enzymes, and protein (serum, urine). High quality RCTs need to be conducted to assess the safety and efficacy of lipid-lowering drugs for people with nephrotic syndrome.

The Potential Role of HMG-CoA Reductase Inhibitors in Pediatric Nephrotic Syndrome

OBJECTIVE

To evaluate the safety and efficacy of the hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) as a potential treatment option for the dyslipidemia associated with childhood nephrotic syndrome.

DATA SOURCES

Searches of MEDLINE (1966–April 2004), Cochrane Library, International Pharmaceutical Abstracts (1977–April 2004), and an extensive manual review of journals were performed using the key search terms nephrotic syndrome, familial hypercholesterolemia, dyslipidemia, and HMG-CoA reductase inhibitor.

STUDY SELECTION AND DATA EXTRACTION

Two prospective uncontrolled studies evaluating the safety and efficacy of statin therapy in pediatric nephrotic syndrome were included.

DATA SYNTHESIS

While an extensive amount of data is available in adult nephrotic syndrome in which statin therapy decreases total plasma cholesterol 22–39%, low-density lipoprotein cholesterol (LDL-C) 27–47%, and total plasma triglycerides 13–38%, only 2 small uncontrolled studies have been conducted evaluating the utility of these agents in pediatric nephrotic syndrome. These studies indicate that statins are capable of safely reducing total cholesterol up to 42%, LDL-C up to 46%, and triglyceride levels up to 44%.

CONCLUSIONS

Lowering cholesterol levels during childhood may reduce the risk for atherosclerotic changes and may thus be of benefit in certain patients with nephrotic syndrome. Statins have demonstrated short-term safety and efficacy in the pediatric nephrotic syndrome population. Implementing pharmacologic therapy with statins in children with nephrotic syndrome must be done with care until controlled studies are conducted in this population.

Genetic polymorphism in paraoxonase is a risk factor for childhood focal segmental glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) is an important cause of end-stage renal failure (ESRF) in children. Our previous studies have shown that Arab children in Israel have a worse prognosis compared with Jewish patients despite similar clinical presentation and management. Progression of proteinuric glomerular diseases has been associated with alterations in lipid metabolism, and similarities have been drawn between the mechanisms underlying atherosclerosis and glomerulosclerosis. Paraoxonase (PON) is a high-density lipoprotein (HDL)-associated enzyme involved in preventing the oxidation of low-density lipoprotein (LDL), and an association has been shown between two genetic polymorphisms in PON1 and the risk of coronary artery disease. The aim of this study was to determine the frequency of these genetic polymorphisms in PON1 in Arab and Jewish children with FSGS and to determine any association with severity of outcome. Forty-seven children (21 Arab and 26 Jewish) with biopsy-proven FSGS and 274 healthy controls of matching ethnic origin were studied. The glutamine (A)-192-arginine (B) and the methionine (M)-55-leucine (L) polymorphisms were analyzed. The frequency of the A allele was similar in patients and controls (0.68 versus 0.71), as was that of the L allele (0.63 versus 0.6). When subgroups were analyzed, the prevalence of the LL genotype in Arab patients was significantly greater than in Jewish patients (57.1% versus 26.9%, P: < 0.05) and Arab controls (57.1% versus 28.9%, P: < 0.03). A trend in association was found between homozygosity for the L allele and progression of renal disease in Arab children. Homozygosity for the L allele is a risk factor for developing FSGS in Arab children and may be associated with a worse prognosis.

The effect of pravastatin on renal function and lipid metabolism in patients with renal dysfunction with hypertension and hyperlipidemia. Pravastatin and Renal Function Research Group

The effect of pravastatin on renal function in hypertensive patients with mild renal dysfunction and hyperlipidemia was examined. A total of 57 subjects given dihydropyridine calcium blockers were randomly assigned to placebo (n = 25) and pravastatin groups (n = 32). The period of study was 6 months. In the placebo group, lipid metabolism did not change throughout the study period, but the serum creatinine concentration (Scr) increased from a baseline of 1.6+/-0.07 mg/dl to 2.1+/-0.2 mg/dl in the 6th month of study and blood urea nitrogen (BUN) increased from 26.2+/-1.1 mg/dl to 32.4+/-30.1 mg/dl. In the pravastatin group, the serum total cholesterol decreased from a baseline of 251.4+/-7.3 mg/dl to 218.2+/-6.5 mg/dl in the 6th month of study, while Scr (1.3+/-0.07 mg/dl vs. 1.3 +/-0.09 mg/dl) and BNU (20.5+/-1.2 mg/dl vs. 21.0+/-1.4 mg/dl) did not change. The change in Scr in the placebo group was significantly different from that in the pravastatin group (F = 3.75, p = 0.05). The slope of the change in 1/Scr was 0.02+/-0.07 dl x mg(-1) x month(-1) in placebo group and -0.01+/-0.03 dl x mg(-1) month(-1) in pravastatin group (P<0.05). The results indicate that pravastatin attenuates the deterioration of renal function in patients with mild renal dysfunction, together with an improvement of lipid metabolism.

Conservative treatment to slow deterioration of renal function: evidence-based recommendations

Despite current specific therapy, progressive deterioration of renal function in patients with primary glomerulonephritis occurs. Nonspecific renoprotective interventions that have been studied include blood pressure control, antihypertensive medications, and protein-restricted diets. To prepare this article, a MEDLINE search was conducted, followed by secondary and tertiary searches. Research papers were assessed for level of evidence, and graded recommendations were formulated. Protein-restricted diets (to 0.4 to 0.6 g/kg/day) are not recommended for all patients with reduced renal function (grade A). Very low-protein diets of 0.4 g/kg/day should be considered for patients with severe renal dysfunction (serum creatinine of more than 350 micromol/liter; grade A). However, there are concerns about recommending these diets for all patients because of the potential for long-term negative outcomes such as nutritional deficiencies. Target blood pressure for persons with proteinuria of more than 1 g/day should be less than 125/75 mm Hg [mean arterial pressure (MAP) < 92 mm Hg; grade C]. For persons with proteinuria of less than 1 g/day, the target blood pressure should be approximately MAP 98 mm Hg (less than 130/80; grade C). Angiotensin-converting enzyme inhibitor (ACEI) therapy is recommended in preference to placebo, conventional, or beta-blocker therapy for renoprotection (grade A). ACEI therapy cannot be recommended above calcium channel blockers in patients with nondiabetic renal disease (grade A).

Management of hyperlipidemia in children with refractory nephrotic syndrome: the effect of statin therapy

The efficacy and safety of hydroxymethylglutaric coenzyme A reductase inhibitor (statins) in the treatment of hyperlipidemia were evaluated in 12 infants and children with steroid-resistant nephrotic syndrome followed prospectively for 1 to 5 years. All patients experienced a hypolipidemic response with a marked reduction in their total cholesterol (40%), low-density lipoprotein cholesterol (44%), and triglyceride levels (33%), but no appreciable change in high-density lipoprotein cholesterol. Statin therapy was well tolerated without clinical or laboratory adverse effects. In spite of a significant hypolipidemic response to statin therapy there were no changes observed in the degree of proteinuria, hypoalbuminemia, or in the rate of progression to chronic renal failure. Long-term controlled studies with statin therapy are needed to further document or negate their renoprotective role in refractory nephrotic syndrome.

Focal segmental glomerulosclerosis

Over the last 2 decades, we have learnt that focal segmental glomerulosclerosis (FSGS) is a ubiquitous phenomenon underlying the progressive deterioration of many different types of renal diseases in both pediatric and adult populations. FSGS may also be the primary renal lesion, whether in new disease entities such as glycogen storage disease and human immunodeficiency virus infection, or in idiopathic FSGS. Although the mechanism which triggers the development of primary FSGS still remains unknown, laboratory and clinical studies have identified several key pathophysiological events leading to end-stage renal disease. While therapeutic modalities have not changed remarkably, a recent study, although uncontrolled, demonstrated an impressive efficacy of intravenous steroid pulse therapy in inducing remission. Nevertheless, it remains largely unknown whether such a forced remission decreases the overall risk of developing chronic renal failure. Studies have revealed an important pathophysiological role of angiotensin and the therapeutic efficacy of angiotensin converting enzyme inhibitors in progressive loss of renal function in diseases where glomerulosclerosis is secondary; however, it remains to be verified whether these results hold true in primary FSGS. As a result of the improvement in allograft survival rate, the benefit of renal transplant outweighs the risk of recurrence of FSGS, hence transplantation continues to be a vital therapy for FSGS patients who have reached renal failure. Thus, FSGS is not one disease, but rather a range of lesions seen in many settings. The type of lesions and the patient's unique genetic factors contribute to prognosis, and also may dictate choice of optimum therapy.

Lipid-lowering therapy in patients with renal disease

A growing number of clinical trials have examined the effects of different lipid lowering strategies in patients with renal disease. We carried out a meta-analysis to compare and contrast the relative efficacy of various antilipemic therapies in different renal disease settings. Studies that investigated one or more therapies designed to lower serum lipids were combined using weighted multiple linear regression. The analysis adjusted treatment effects for differences in baseline lipid levels and possible placebo effects. The results showed that antilipemic therapies generally had similar effects on lipids in different renal disease settings. In nephrotic syndrome the greatest and most consistent reductions in low density lipoprotein cholesterol (LDL) were seen with 3-hydroxy-3-methylglutaryl co-enzyme A (HMG-CoA) reductase inhibitors (regression coefficient with 95% confidence interval in mg/dl = -63, -79 to -46). Similar results were seen for LDL in renal transplant (-51, -57 to -45), renal insufficiency (-62, -82 to -42), hemodialysis (-65, -80 to -50) and continuous ambulatory peritoneal dialysis (CAPD) patients (-84, -104 to -64). Fibric acid analogues had less effect on LDL, but caused greater reductions in triglycerides: -132, -178 to -87, in nephrotic syndrome; -69, -93 to -45 in transplant: -107, -169 to -45 in renal insufficiency; -72, -120 to -24 in hemodialysis; and -96, -162 to -30 in CAPD. In general, the effects of diet and other therapies were less consistent. Despite possible limitations of this meta-analysis, the results provide a useful framework for choosing antilipemic therapy, and point to areas for future long-term studies examining the safety and efficacy of lipid lowering strategies in patients with renal disease.

The role of lipids in nephrosclerosis and glomerulosclerosis

Hyperlipidemia and lipoprotein abnormalities are often encountered in patients with nephrotic syndrome or chronic renal disease and also in those undergoing haemodialysis and with renal transplant. Even though the significance of lipid deposition in renal tissue and the role of lipoproteins in the pathogenesis of renal disease in man is unclear, experimental and clinical data indicate a possible damaging effect of a disturbed lipid metabolism on the kidney. In humans, glomerular lipid deposition is observed in genetic diseases such as Fabry's disease, lecithin:cholesterol acyltransferase activity (LCAT) deficiency and arteriohepatic dysplasia, and in diseases with acquired disturbance of lipid metabolism such as nephrotic syndrome and cholestatic liver disease. Studies on animals with lupus nephritis, aminonucleoside nephrosis, reduced renal mass, diabetes mellitus or systemic hypertension have shown that cholesterol can increase the incidence of glomerulosclerosis. As most of these studies have been performed in the rat, which has a different lipoprotein profile to that of man, these results should be carefully interpreted with regard to their relevance for humans. In vitro cell culture studies on human glomerular cells have given some preliminary insights into the cellular mechanisms of lipid induced glomerular damage. Apo E-containing lipoproteins, which are pathologically elevated in many renal diseases, are avidly taken up by human mesangial cells. These cells seem to play a central role in the initiation of glomerulosclerosis by inducing proliferation and production of excess extracellular matrix. Lipoproteins are able to stimulate DNA synthesis in these cells, and increase the synthesis of mitogens and extracellular matrix protein. The pathogenic role of oxidized lipoproteins has not yet been defined. Human mesangial cells do not seem to take up these modified lipoproteins. However, macrophages infiltrate glomeruli and may constitute the stimulus for the generation of minimally modified lipoproteins and their cellular uptake. The data from animal experiments suggest that treatment that corrects hyperlipidemia may have an ameliorative effect on renal function. Thus, there are strong indications that lipoproteins may play a critical role in mediating the development of glomerulosclerosis.

Extrarenal complications of the nephrotic syndrome

The systemic complications of nephrotic syndrome are responsible for much of the morbidity and mortality seen with this condition. This review discusses the causes for the hypoalbuminemia and the associated metabolic abnormalities of the nephrotic syndrome. No unifying hypothesis exists for the induction, maintenance, and resolution of nephrotic edema. In view of the wide spectrum of renal diseases leading to the nephrotic syndrome, more than a single mechanism may be responsible for the renal salt retention in these diverse conditions. Although hypoalbuminemia may be important, especially when plasma oncotic pressure is very low (serum albumin < 1.5 to 2.0 g/dL), primary impairment of salt and water excretion by the nephrotic kidney appears to be a major factor in pathogenesis of the edema. However, the decreased serum albumin and/or oncotic pressure seen with nephrotic syndrome is a major contributing factor to the development of the hyperlipidemia of nephrotic syndrome. Patients with unremitting nephrotic syndrome should be considered for combined dietary and lipid-lowering drug therapy. Urinary losses of binding proteins lead to the observed abnormalities in the endocrine system and in trace metals, and urinary losses of coagulation factors contribute to the hypercoagulable state. At present, selective renal venography is recommended when the suspicion of renal vein thrombosis is justified by clinical presentation. The impact on renal function caused by treating asymptomatic chronic renal vein thrombosis is undetermined, but anticoagulation for chronic renal vein thrombosis is associated with relatively few complications.

Lipid abnormalities in the nephrotic syndrome: causes, consequences, and treatment

Hyperlipidemia so commonly complicates heavy proteinuria that it has come to be regarded as an integral feature of the nephrotic syndrome (NS). Characteristically, total plasma cholesterol and triglyceride levels are elevated, as are very-low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) cholesterol. Although high-density lipoprotein (HDL) concentrations may be normal, HDL subtypes are abnormally distributed, with a reduction of HDL2 and an increase in HDL3. In addition, lipoprotein (a) [Lp (a)] levels may be elevated. The mechanisms underlying these abnormalities are multifactorial, involving both increased rates of lipoprotein synthesis and defective clearance and catabolism of circulating particles. Although recent dietary and therapeutic studies have demonstrated that nephrotic hyperlipidemia can be effectively treated, the need for such intervention has not been clearly established. This pattern of lipoprotein abnormality is associated with an increased risk of cardiovascular disease in the general population, and several studies have suggested that nephrotic individuals are more likely to develop atherosclerosis. However, no prospective trials have evaluated the relationship between deranged lipid metabolism and coronary or cerebral artery disease in patients with NS. In addition, although recent experimental studies suggest that lipid abnormalities may accelerate renal injury and that lipid-lowering agents may protect renal function, there is little current evidence to suggest that such intervention is of value in preserving residual renal function in humans. Further studies are clearly required to assess the potential long-term benefits of lipid-lowering intervention in individuals with NS. In the meantime, based on data generated from other population groups, a rational approach to the clinical management of hyperlipidemia in these patients is presented.

Metabolic effects of converting enzyme inhibitors: focus on the reduction of cholesterol and lipoprotein(a) by fosinopril

It is generally believed that the use of angiotensin-converting enzyme (ACE) inhibitors has no effect on the lipid profile. Our recent data show that in patients with proteinuric renal disease, serum levels of total cholesterol and lipoprotein(a) [Lp(a)] may be lowered during treatment with an ACE inhibitor, fosinopril sodium. During a 12-week randomized, placebo-controlled, double-blind study involving 26 patients with mild-to-moderate renal impairment, fosinopril administration was associated with significant decreases in both urinary protein excretion and serum total cholesterol levels, whereas placebo was not. During a 6-week washout phase, both parameters returned to baseline in fosinopril-treated patients and remained unchanged in placebo recipients. In addition, fosinopril-treated patients had a decrease in plasma levels of Lp(a), whereas this was not seen in placebo-treated patients. When data from a subset of 13 patients with proteinuric renal disease and hypertension were examined, a significant decrease in serum total cholesterol levels was observed; this decrease reversed after discontinuation of fosinopril. Analysis of the effect of fosinopril on plasma Lp(a) levels in a subset of patients who had type II diabetes mellitus and overt proteinuria revealed a significant decrease in plasma Lp(a) after administration of fosinopril. Moreover, fosinopril lowered plasma Lp(a) levels in blacks, whose pretreatment levels were higher than those of whites with comparable degrees of proteinuria and levels of serum total cholesterol. Thus, the reduction in serum Lp(a) levels may be related not only to amelioration of proteinuria, but also to another direct action of fosinopril on the metabolism of Lp(a).

Simvastatin therapy for hypercholesterolemic patients with nephrotic syndrome or significant proteinuria

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.

Plasma lipid profile in rats with gentamicin-induced nephrotoxicity

1. Administration of gentamicin to rats at doses of 20, 40 or 80 mg kg-1 d-1 for 6 days induced nephrotoxicity exhibited by elevated plasma creatinine concentration and a decrease in alkaline phosphatase activity in rat kidney cortex. 2. Gentamicin treatment produced significant elevation in plasma total cholesterol amounting to 70% at the 80 mg kg-1 dose. At this dose, the combined cholesterol fractions of low density and very low density lipoproteins increased by more than two-fold. 3. Gentamicin treatment also caused significant increase in plasma triglyceride concentration, while plasma phospholipid levels showed dose-dependent reductions. 4. In another experiment recovery of the aforementioned parameters was assessed 7 and 14 days after the withdrawal of gentamicin, administered at a dose of 40 mg kg-1 d-1 for 6 days. After 7 days from drug discontinuation, both plasma creatinine and total cholesterol concentrations returned to the control levels, while triglyceride concentration was still significantly higher than control 14 days after stoppage of treatment. 5. Plasma phospholipid concentration and the activity of cortical alkaline phosphatase were still significantly lower than control 14 days after cessation of the treatment.

Treatment of hyperlipidemia in the nephrotic syndrome: the effects of pravastatin therapy

The hyperlipidemia of the nephrotic syndrome is characterized by an elevation of total cholesterol (TC) and low-density lipoprotein cholesterol (LDLC), with a normal or low high-density lipoprotein cholesterol (HDLC), and an increase in triglycerides (TGs) later in the course of the disease. If sustained, this lipid profile probably places these patients at increased risk for cardiovascular disease. Despite extensive trials of diet and drug therapy in patients with primary hyperlipidemias, few such trials exist in patients with the nephrotic syndrome. We conducted a randomized, prospective, double-blind, placebo-controlled trial to investigate the efficacy and safety of pravastatin, the newest cholesterol synthesis inhibitor, in the treatment of the hyperlipidemia of the nephrotic syndrome. After dietary modification was implemented, 13 patients received pravastatin and eight received placebo. All patients were maintained on a low-fat, low-cholesterol diet for the duration of the trial (24 weeks). The dose of pravastatin was increased from the initial 20 mg/d to 40 mg/d at week 10 or 18 if TC remained elevated (> 50th percentile). A bile acid sequestrant was added at week 18 if TC remained elevated and if the patient was already receiving the maximal pravastatin dosage. Dietary modification did not significantly change the lipid profile. Pravastatin (20 mg/d) reduced TC by 22% from a baseline of 301 +/- 28 mg/dL (P < 0.05) and LDLC by 28% from a baseline of 222 +/- 28 mg/dL (P < 0.05). When used at 40 mg/d (in six patients) no further change in the lipid profile was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

A clinical overview of dyslipidemias: treatment strategies

The strong epidemiologic relationship between specific lipoprotein levels (such as elevated low-density lipoprotein cholesterol or decreased high-density lipoprotein cholesterol) and the future development of coronary heart disease has been well documented. Within the past several years, landmark clinical trials have clearly demonstrated that the incidence of coronary heart disease events is reduced when lipoprotein abnormalities are corrected via pharmacologic therapy. These findings have prompted clinicians to become more vigilant with regard to recognition of dyslipidemias and institution of treatment. This review focuses on the more common primary and secondary dyslipidemias and the currently available lipid-lowering therapies for each disorder. Results of recent coronary angiographic trials are discussed, and implications for the medical management of established coronary heart disease are assessed.

Lipid changes in the nephrotic syndrome: new insights into pathomechanisms and treatment

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.

[Pathophysiology and therapy of lipid metabolism disorders in kidney diseases]

Nephrotic syndrome, uremia, hemodialysis, peritoneal dialysis, and renal transplantation are accompanied by alterations in lipoprotein metabolism In nephrotic patients, total cholesterol, LDL, VLDL and triglycerides are elevated, while HDL may be increased, normal, or decreased. The pathophysiology includes increased hepatic synthesis of VLDL and cholesterol, decreased activity of lipoprotein lipase, and increased urinary excretion of HDL. The risk of coronary heart disease (CHD) is increased in nephrotic patients and elevated LDL-cholesterol may contribute to this risk. Cholesterol lowering diet and drugs are indicated. Presently, Lovastatin and Simvastatin are the most potent cholesterol lowering drugs in nephrotic patients with good evidence of long-term safety. Most patients with impaired renal function or on hemodialysis have moderate hypertriglyceridemia due to decreased lipoprotein lipase activity. HDL may be slightly decreased. Although the risk of CHD is increased in these patients, triglyceride lowering drugs are not indicated, since no benefit can be expected. Peritoneal dialysis is accompanied by elevated VLDL in addition to hypertriglyceridemia. Reabsorption of large amounts of glucose from peritoneal dialysis fluid increases the carbohydrate load and stimulates hepatic VLDL synthesis. Cholesterol lowering therapy may be advantageous, but the experience is very limited. Side effects of lipid lowering drugs may be aggravated in renal failure. Total cholesterol, LDL, VLDL, and triglycerides are elevated in 50% of patients following renal transplantation. Corticosteroids and cyclosporin are major causes of hyperlipidemia. Cholesterol lowering therapy is indicated since the incidence of CHD is increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of HMG-CoA reductase inhibitors in hypercholesterolemic patients on hemodialysis

The efficacy of lovastatin and simvastatin, competitive inhibitors of 3-hydroxy-3-methyl glutaryl coenzyme A reductase, was investigated in 40 hemodialysis (HD) patients displaying hypercholesterolemia and moderate hypertriglyceridemia (selection of 40 patients required screening of 700 hemodialysis patients). After a four-week placebo period, lovastatin or simvastatin was administered to two groups of 20 patients in increasing doses over a period of three months. Thirty-six patients completed the study. Lovastatin (1st month 20 mg; 2nd and 3rd months 40 mg day-1) and simvastatin (1st month 10 mg, 2nd month 20 mg and 3rd month 40 mg day-1) reduced total serum cholesterol from 280.3 +/- 9.4 to 213.0 +/- 6.7 (-24%) and 295.0 +/- 12.2 to 202.3 +/- 8.9 mg/dl (-31.4%), LDL cholesterol from 161.9 +/- 10.7 to 112.1 +/- 7.9 (-30.8%) and 181.8 +/- 14.7 to 107.4 +/- 8.1 mg/dl (-40.9%), as well as apolipoprotein B (apo B) from 116.0 +/- 6.6 to 83.3 +/- 3.7 (-28.2%) and 134.4 +/- 8.2 to 84.1 +/- 5.3 mg/dl (-37.4%), respectively. Furthermore, the ratio of LDL apo B/LDL cholesterol increased significantly (0.63 +/- 0.02 vs. 0.71 +/- 0.05 and 0.63 +/- 0.02 vs. 0.66 +/- 0.02, respectively). Another remarkable effect was the reduction of cholesterol concentration in VLDL (72.4 +/- 8.9 vs. 47.3 +/- 6.8 [lovastatin] and 78.3 +/- 11.1 vs. 50.7 +/- 8.8 mg/dl [simvastatin], respectively). Therefore, the ratio of triglycerides/cholesterol in VLDL increased (3.2 +/- 0.2 vs. 3.8 +/- 0.3 and 3.2 +/- 0.2 vs. 4.0 +/- 0.2, respectively), indicating VLDL formation poor in cholesterol and rich in triglycerides.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of simvastatin treatment on the dyslipoproteinemia in CAPD patients

HMG-CoA reductase inhibitors have been proven effective in decreasing the plasma cholesterol levels in patients affected with various forms of hypercholesterolemia, familial dysbetalipoproteinemia, familial combined hyperlipidemia and in nephrotic and diabetic dyslipidemia. The purpose of this study was to monitor and evaluate the efficiency and safety of the therapy with simvastatin, an HMG-CoA reductase inhibitor, in a group of patients treated by continuous ambulatory peritoneal dialysis (CAPD) with severe hypercholesterolemia. Monitoring of the changes occurring in the various lipids and apolipoproteins in these patients included the measurements of the plasma lipids and apolipoproteins A-I, A-II, B, C-II, A-IV and Lp(a). Lipoproteins were separated by gel filtration, on a Superose 6HR column, before and after 24 weeks of treatment. The patterns were compared to those observed in a group of primary hyperlipidemic patients treated with Lovastatin, a compound of the same class. The drug was well tolerated by the CAPD patients and no adverse reaction was observed. In addition to the decrease of the total and LDL cholesterol, similar to that reported in other groups of patients, we further observed a decrease of the apo E concentration in both the CAPD and the hyperlipidemic patients. This decrease was especially pronounced in the HDLE fraction and could involve an upregulation of the apo B-E and/or apo E receptor. These results should provide information about the mechanism of action of this drug in patients with end-stage renal disease.

Use of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors in various forms of dyslipidemia

The inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase are highly effective in treating severe elevations of serum cholesterol, and are being widely used for this purpose. In our laboratory, these drugs have been used for the treatment of other forms of dyslipidemia including primary moderate hypercholesterolemia, primary mixed hyperlipidemia, diabetic dyslipidemia, hyperlipidemia of the nephrotic syndrome, and primary hypoalphalipoproteinemia. In these conditions, the HMG CoA reductase inhibitors proved effective in substantially decreasing levels of both low-density lipoproteins and very low density lipoproteins, as well as apolipoprotein B. In some patients, they may even increase levels of high-density lipoproteins. The primary mode of action of HMG CoA reductase inhibitors appears to be to increase the synthesis of hepatic receptors for lipoproteins containing apolipoprotein B, although a reduction in synthesis of these lipoproteins has not been ruled out with certainty. Regardless of mechanisms, drugs of this type appear to have the potential for effective therapy of various forms of dyslipidemia beyond primary severe hypercholesterolemia.

The effects of lovastatin in hyperlipidemic patients with the nephrotic syndrome

Hypercholesterolemia may pose a substantial risk for cardiovascular disease. The present investigation was designed to evaluate the safety and efficacy of the cholesterol synthesis inhibitor, lovastatin, in 13 nephrotic patients with 5.6 +/- 0.7 g/24 h of albuminuria. All patients were maintained on a low cholesterol diet throughout the study. After a 4-week placebo period, lovastatin was administered, 20 mg twice daily for 6 weeks. Lovastatin reduced total cholesterol by 27% from 8.6 +/- 0.6 mmol/L (331 +/- 24 mg/dL) to 6.3 +/- 0.4 mmol/L (242 +/- 17 mg/dL) (P less than 0.01), low-density lipoprotein cholesterol by 27%, from 5.8 +/- 0.5 mmol/L (223 +/- 20 mg/dL) to 4.2 +/- 0.6 mmol/L (163 +/- 22 mg/dL) (P less than 0.01), and apolipoprotein B by 29%, from 153 +/- 12 mg/dL to 109 +/- 8 mg/dL to 109 +/- 8 mg/dL P less than 0.01). Triglycerides and very-low-density lipoprotein (VLDL) cholesterol levels were also reduced by 30% and 37%, respectively (P less than 0.01). High-density lipoprotein (HDL) cholesterol, and apolipoproteins A-1 and A-2 were not significantly altered. Renal function and urine protein excretion were not affected by lovastatin. Although one patient developed diarrhea and discontinued treatment before completing 6 weeks of lovastatin, the other 12 patients had no adverse effects. In this short-term study, lovastatin therapy had few side effects and had favorable effects on the lipoprotein profile of nephrotic syndrome patients.