Lipids in the progression of chronic renal failure

Longitudinal change in estimated GFR among CKD patients: A 10-year follow-up study of an integrated kidney disease care program in Taiwan

BACKGROUND

This study examined the progression of chronic kidney disease (CKD) by using average annual decline in estimated GFR (eGFR) and its risk factors in a 10-year follow-up CKD cohort.

METHODS

A prospective, observational cohort study, 4600 individuals fulfilled the definition of CKD, with or without proteinuria, were followed for 10 years. The eGFR was estimated by the MDRD equation. Linear regression was used to estimate participants' annual decline rate in eGFR. We defined subjects with annual eGFR decline rate <1 ml/min/1.73 m2 as non-progression and the decline rate over 3 ml/min/1.73 m2 as rapid progression.

RESULTS

During the follow-up period, 2870 (62.4%) individuals had annual eGFR decline rate greater than 1 ml/min/1.73 m2. The eGFR decline rate was slower in individuals with CKD diagnosed over the age of 60 years than those with onset at a younger age. Comparing to subjects with decline rate <1 ml/min/1.73 m2/year, the odds ratio (OR) of developing rapid CKD progression for diabetes, proteinuria and late onset of CKD was 1.72 (95% CI: 1.48-2.00), 1.89(1.63-2.20) and 0.68 (0.56-0.81), respectively. When the model was adjusted for the latest CKD stage, comparing to those with CKD stage 1, patients with stage 4 and stage 5 have significantly higher risks for rapid progression (OR, 5.17 (2.60-10.25), 19.83 (10.05-39.10), respectively). However, such risk was not observed among patients with the latest CKD stage 2 and 3. The risk for incident ESRD was 17% higher for each 1 ml/min/1.73 m2 increasing in annual decline rate.

CONCLUSIONS

Not everyone with CKD develops ESRD after a 10-year follow-up. Absolute annual eGFR decline rate can help clinicians to better predict the progression of CKD. Individuals with renal function decline rate over 3 ml/min/1.73 m2/year require intensive CKD care.

Statins in nephrotic syndrome: a new weapon against tissue injury

The nephrotic syndrome is characterized by metabolic disorders leading to an increase in circulating lipoproteins levels. Hypertriglyceridemia and hypercholesterolemia in this case may depend on a reduction in triglyceride-rich lipoproteins catabolism and on an increase in hepatic synthesis of Apo B-containing lipoproteins. These alterations are the starting point of a self-maintaining mechanism, which can accelerate the progression of chronic renal failure. Indeed, hyperlipidemia can affect renal function, increase proteinuria and speed glomerulosclerosis, thus determining a higher risk of progression to dialysis. 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase is the rate-limiting enzyme in cholesterol synthesis from mevalonate and its inhibitors, or statins, can therefore interfere with the above-mentioned consequences of hyperlipidemia. Statins are already well known for their effectiveness on primary cardiovascular prevention, which cannot be explained only through their hypolipemic effect. As far as kidney diseases are concerned, statin therapy has been shown to prevent creatinine clearance decline and to slow renal function loss, particularly in case of proteinuria, and its favorable effect may depend only partially on the attenuation of hyperlipidemia. Statins may therefore confer tissue protection through lipid-independent mechanisms, which can be triggered by other mediators, such as angiotensin receptor blockers. Possible pathways for the protective action of statins, other than any hypocholesterolemic effect, are: cellular apoptosis/proliferation balance, inflammatory cytokines production, and signal transduction regulation. Statins also play a role in the regulation of the inflammatory and immune response, coagulation process, bone turnover, neovascularization, vascular tone, and arterial pressure. In this study, we would like to provide scientific evidences for the pleiotropic effects of statins, which could be the starting point for the development of new therapeutical strategies in different clinical areas.

Dyslipidemia and the progression of renal disease in chronic renal failure patients

Dyslipidemia is a common complication of progressive kidney disease and contributes to the high cardiovascular morbidity and mortality of chronic kidney disease (CKD) patients. Recent evidence also suggests a role for dyslipidemia in the development and progression of renal disease. Experimental studies have demonstrated that lipids may induce glomerular and tubulointerstitial injury, and that lipid-lowering treatments ameliorate renal injury. Various lipid abnormalities have been associated with the development and progression of renal disease in diabetic and nondiabetic patients. Population-based studies and studies of diabetic patients have reported associations of various lipid abnormalities with the development of renal disease. In patients with CKD, lipid abnormalities have also been associated with renal disease progression. Post hoc analyses of some large clinical trials on patients with vascular disease, diabetes, or dyslipidemia, and a meta-analysis of small, prospective, controlled studies on patients with CKD (diabetics and nondiabetics) suggest that statins may slow the progression of kidney disease. It is unclear whether the beneficial renal effects of statins are due to the reduction of serum cholesterol levels and/or their pleiotropic effects. There is also evidence for synergistic renoprotective effects between statins and renin-angiotensin system inhibitors. According to the results of post hoc analysis of several studies, treatment with fibrates does not seem to confer renoprotection, but evidence is scarce. In summary, there is growing evidence that lipid abnormalities may be a risk factor for renal disease, and that statins appear to confer a renoprotective effect.

Kidney disease and cardiovascular disease: implications of dyslipidemia

Cardiovascular complications are common inpatients with kidney disease. Regulating the lipid levels in these patients is important so that the risks of kidney and cardiovascular complications can be minimized. Lipid regulation decreases the incidence of coronary vascular events and other vascular complications in patients with kidney disease; however, whether lipid regulation slows progression of kidney disease is not yet known. Additional studies of the implications of dyslipidemia in patients with kidney disease are needed.

Apolipoprotein A-IV predicts progression of chronic kidney disease: the mild to moderate kidney disease study

It has not been established firmly whether dyslipidemia contributes independently to the progression of kidney disease. Lipid and lipoprotein parameters, including levels of total, HDL, and LDL cholesterol; triglycerides; lipoprotein(a); apolipoprotein A-IV; and the apolipoprotein E and A-IV polymorphisms, were assessed in 177 patients who had mostly mild to moderate renal insufficiency and were followed prospectively for up to 7 yr. Progression of kidney disease was defined as doubling of baseline serum creatinine and/or terminal renal failure necessitating renal replacement therapy. In univariate analysis, patients who reached a progression end point (n = 65) were significantly older and had higher serum creatinine and proteinuria as well as lower GFR and hemoglobin levels. In addition, baseline apolipoprotein A-IV and triglyceride concentrations were higher and HDL cholesterol levels were lower. Multivariate Cox regression analysis revealed that baseline GFR (hazard ratio 0.714; 95% confidence interval [CI] 0.627 to 0.814 for an increment of 10 ml/min per 1.73 m(2); P < 0.0001) and serum apolipoprotein A-IV concentrations (hazard ratio 1.062; 95% CI 1.018 to 1.108 for an increment of 1 mg/dl; P = 0.006) were significant predictors of disease progression. Patients with apolipoprotein A-IV levels above the median had a significantly faster progression (P < 0.0001), and their mean follow-up time to a progression end point was 53.7 mo (95% CI 47.6 to 59.8) as compared with 70.0 mo (95% CI 64.6 to 75.4) in patients with apolipoprotein A-IV levels below the median. For the apolipoprotein E polymorphism, only the genotype epsilon2/epsilon4 was associated with an increased risk for progression. In summary, this prospective study in patients with nondiabetic primary kidney disease demonstrated that apolipoprotein A-IV concentration is a novel independent predictor of progression.

The role of statins in chronic kidney disease

Chronic kidney disease is associated with cardiovascular event rates that are at least as high as in patients with established atherosclerotic cardiovascular disease or in those with diabetes mellitus. Chronic kidney disease is therefore considered a cardiovascular disease risk equivalent. Treatment of dyslipidemia, which is very common in this population and reflects the pattern seen in the metabolic syndrome, reduces cardiovascular events in patients with chronic kidney disease. Thus, patients with chronic kidney disease should be evaluated and treated for dyslipidemia. Dyslipidemia is a risk factor for the development of impaired kidney function. Dyslipidemia is also associated with progressive renal disease in subjects with no overt renal disease, as well as those with diabetic and nondiabetic kidney disease. Although definitive randomized controlled trials are lacking, the collective evidence suggests that treatment of dyslipidemia is associated with less decline in renal function. The use of potent statins in high doses can lead to transient proteinuria via impairment of proximal tubular receptor--mediated endocytosis, in a dose-dependent manner. Over the long term, however, the use of statins results in a reduction in proteinuria and in the rate of decline of renal function. Several large definitive trials that are currently underway to examine the safety and efficacy of statins in cardiovascular and renal protection should provide more definitive answers on the role of these drugs in this very high risk population.

Apolipoprotein E gene polymorphism in renal transplant recipients: effects on lipid metabolism, atherosclerosis and allograft function

INTRODUCTION

Atherosclerosis is a serious complication and leading cause of mortality in renal transplant recipients (RTRs). Hyperlipidemia may be associated with progression of renal disease and chronic allograft dysfunction. Similarities in the pathogenesis of glomerulosclerosis and atherosclerosis have been proposed. Apolipoprotein (apo) E gene code forms three major isoforms (E2, E3, and E4) with variable effects on lipid metabolism.

PATIENTS AND METHODS

A total of 118 patients, at a mean age of 40 +/- 8 yr, were included in the study. Apo E genotyping was carried out on genomic DNA using polymerase chain reaction and restriction enzyme. Carotid artery intima media thickness and atherosclerotic plaques were evaluated by B-mode ultrasonography. The plasma levels of lipids and lipoproteins and acute phase reactants were also studied. Allograft function was evaluated by measuring serum creatinine and creatinine clearance values.

RESULTS

The frequencies of E2, E3, and E4 alleles were 0.10, 0.78, and 0.12 respectively. Carotid artery atherosclerosis was found in 25% of E2 carriers, 30% of E3 carriers, and 57% of E4 carriers. Total cholesterol, total triglyceride, low-density lipoprotein, very low-density lipoprotein, apo B 100 levels were found to be higher in apo E4 carriers. Median apo A1 level was higher and allograft functions were better in apo E2 carriers (p < 0.05). Multiple regression analysis showed that allograft functions were negatively correlated with elevated acute phase reactants (p < 0.01) and only the age, but not the apo E genotypes, was an independent risk factor for atherosclerotic vascular disease (p < 0.01).

DISCUSSION

The pathogenetic events linking lipid metabolism and allograft functions and development of atherosclerosis are complex and multifactorial in RTRs. Our results showed that apo E genotypes have influences on lipids, lipoproteins and allograft functions. The ultimate role of apo E4 gene polymorphism as a risk factor for development and progression of atherosclerosis in RTRs should be sought in further studies.

Association of dyslipidemia and effects of statins on nonmacrovascular diseases

BACKGROUND

Statins have mechanisms of action that expand their effects beyond cholesterol lowering and atherosclerotic medical conditions.

OBJECTIVE

This review summarizes clinical evidence for the association of dyslipidemia and the effects of statin use on aortic stenosis, Alzheimer's dementia (AD), osteoporosis, prevention of diabetes mellitus (DM), diabetic retinopathy, age-related macular degeneration, and diabetic/nondiabetic nephropathy.

METHODS

An English-language literature search was conducted using MEDLINE (1966-June 2003). Bibliographies of retrieved articles were reviewed. Search terms included statin, HMG-CoA reductase inhibitors, aortic stenosis, Alzheimer's dementia, osteoporosis, prevention of diabetis, diabetic retinopathy, age-related macular degeneration, diabetic nephropathy, and nondiabetic nephropathy.

RESULTS

Three retrospective cohort trials have shown an association between statin use and the progression of aortic stenosis; one of these trials observed a 45% decrease in aortic valve area in 1 year. In AD, one cross-sectional analysis found 60% to 73% lower AD rates in lovastatin or pravastatin recipients ( P<0.001 ). Of the multiple observational studies on the effect of statins on fracture risk, some have shown a decreased risk, with an odds ratio as low as 0.50 (95% CI, 0.33-0.76); others have demonstrated no association. A post hoc analysis of the West of Scotland Coronary Prevention Study found a 30% reduction in the development of DM ( P=0.042 ), but this was not duplicated in the Anglo-Scandinavian Cardiac Outcomes Trial-Lipid Lowering Arm. A small clinical trial of 6 patients (11 eyes) demonstrated improved retinal hard exudates with pravastatin treatment in patients with diabetic retinopathy. In a cross-sectional analysis, age-related macular degeneration was found to be less common among statin users than nonusers (4% [ 1/27 ] vs 22% [ 76/352 ]; P=0.02. Multiple small clinical trials of 19 to 56 patients with diabetic and nondiabetic nephropathy at various stages generated inconsistent results for an association between statin use and decreased albumin excretion rate and decreased rate of decline in glomerular filtration.

CONCLUSION

Data of variable quantity and quality support the use of statins as adjuncts in the treatment of nonmacrovascular diseases.

Hyperlipidemic profiles during remission in childhood idiopathic nephrotic syndrome

Hyperlipidemia, an important characteristic of idiopathic nephrotic syndrome in children (NS), is usually observed during the active phase of the disease and disappears with the resolution of the proteinuria. However, persisting lipid anomalies during remission have been reported in a few studies and raise the question of the later development of atherosclerosis. Plasma lipid profiles in 25 children with NS at remission, with or without active prednisone treatment, were compared with those of an age-matched population. The results indicate that plasma total and LDL-cholesterol levels were above the 95(th) percentile for age and sex in 12 of the 25 patients (48%) with 7 of them having apolipoprotein B and triglyceride concentrations above the 95(th) percentile. Moreover, frequently relapsing children were more likely to have abnormal lipid profile during the remission. We conclude that close monitoring of lipid levels during the remission of the NS especially in those with frequent relapses, is necessary to select the high-risk patients.

Cholesterol and the risk of renal dysfunction in apparently healthy men

Despite extensive knowledge about abnormal lipid patterns in patients with end-stage renal disease, the association between cholesterol and the development of renal dysfunction is unclear. We evaluated this association in a prospective cohort study among 4,483 initially healthy men participating in the Physicians' Health Study who provided blood samples in 1982 and 1996. Main outcome measures were elevated creatinine, defined as >/= 1.5 mg/dl (133 micromol/L), and reduced estimated creatinine clearance, defined as </=55 ml/min. Cholesterol parameters included total cholesterol (<200, 200 to 239, and >/= 240 mg/dl), HDL (<40 or >/= 40 mg/dl), total non-HDL cholesterol, and the ratio of total cholesterol to HDL. We used logistic regression to calculate age- and multivariable adjusted odds ratios as a measure for the relative risk. After 14 yr, 134 men (3.0%) had elevated creatinine and 244 (5.4%) had reduced creatinine clearance. The multivariable relative risk for elevated creatinine was 1.77 (95% confidence interval [CI], 1.10 to 2.86) for total cholesterol >/= 240 mg/dl, 2.16 (95% CI, 1.42 to 3.27) for HDL <40 mg/dl, 2.34 (95% CI, 1.34 to 4.07) for the highest quartile of total cholesterol/HDL ratio (>/= >6.8), and 2.16 (95% CI, 1.22 to 3.80) for the highest quartile of non-HDL cholesterol (>/= 196.1). Similar although smaller associations were observed between cholesterol parameters and reduced creatinine clearance. Elevated total cholesterol, high non-HDL cholesterol, a high ratio of total cholesterol/HDL, and low HDL in particular were significantly associated with an increased risk of developing renal dysfunction in men with an initial creatinine <1.5 mg/dl.

Dyslipidaemia and the progression of renal disease in chronic renal failure patients

BACKGROUND

Dyslipidaemia is common in patients with chronic renal failure (CRF), and there is increasing evidence to support the role of dyslipidaemia as a contributing factor in the progression of chronic renal disease. However, few prospective studies have been carried out which address the possible relationship between dyslipidaemia and the rate of progression of renal disease in patients with renal failure.

METHODS

Between January 1985 and December 1997, we prospectively assessed the risk of CRF progression to dialysis in a cohort of 138 patients. Forty CRF patients reached end-stage renal disease (ESRD) and had to start supportive therapy during the follow-up period [group ESRD(+)]. The remaining 98 CRF patients served as controls [group ESRD(-)]. Potential clinical and laboratory risk factors for more rapid CRF decline to dialysis, including lipid abnormalities and baseline creatinine clearance were determined at the start of the follow-up period.

RESULTS

Several significant differences were found in univariate analysis between the two groups of CRF, ESRD(+) and ESRD(-), namely a shorter follow-up period, a lower level of baseline creatinine clearance, a faster rate of creatinine clearance decline, a higher level of serum triglycerides, fibrinogen, total homocyst(e)ine and proteinuria, and a lower level of serum high-density lipoprotein in the ESRD(+) group than in the ESRD(-) group. However, by multivariate Cox analysis proteinuria [relative risk (95% confidence interval) 1.32 (1.16-1.50) for each g/day P = 0.001], baseline creatinine clearance [0.53 (0.40-0.70) for each 10 ml/min, P = 0.001] and chronic interstitial nephritis and hypertensive nephrosclerosis [0.38 (0.17-0.84) for presence, P = 0.005] were the only significant risk factors for CRF progression to dialysis. Hypertriglyceridaemia and male gender were selected in the final model, but were of borderline significance.

CONCLUSIONS

These results suggest a limited role for dyslipidaemia in the progression of chronic renal disease to dialysis in CRF patients, in contrast with the powerful influence of proteinuria, baseline creatinine clearance and nephropathy type in predicting this progression.

Lipoprotein abnormalities as a risk factor for progressive nondiabetic renal disease

Renal disease is accompanied by characteristic alterations of lipoprotein metabolism, which appear as a consequence of nephrotic syndrome or renal insufficiency and are primarily reflected in an altered apolipoprotein profile rather than elevated plasma lipid levels. Their full characterization requires identification of discrete lipoprotein particles. While nephrotic syndrome results in increased concentrations of both cholesterol- and triglyceride-rich apoB-containing lipoproteins, renal insufficiency is characterized by an accumulation of intact or partially metabolised triglyceride-rich apoB-containing lipoproteins. The dyslipidemia has been discussed as a contributory factor for the progression of renal insufficiency through development of glomerulosclerosis and tubulointerstitial lesions together with accelerated atherosclerosis. Several experimental studies have shown that hyperlipidemia accelerates renal damage. Lipid-lowering treatment can reduce renal lesions and preserve renal function. The documentation in human nondiabetic progressive renal insufficiency is more limited. We have found that increased concentrations of triglyceride-rich, but not cholesterol-rich, apoB-containing lipoproteins are, associated with a more rapid loss of renal function. The underlying pathophysiological mechanisms for the relation between triglyceride-rich apoB-containing lipoproteins and progression of renal insufficiency are not fully understood. Treatment with hypolipemic drugs may attenuate the renal dyslipidemia, but thus far there have been no reports about controlled clinical trials testing the possible effect of such treatment on the progression of renal insufficiency. In summary, there is evidence to suggest that some specific lipoprotein abnormalities are a risk factor for the progression of renal dysfunction, but the final test of such assumptions still rests on the results of urgently needed controlled intervention studies.

Role of dyslipidemia in the progression of chronic renal disease

The connection between lipids and the rate of progression of chronic renal disease was retrospectively examined in 70 patients who were divided into 2 groups according to their baseline creatinine clearance (CCr): Group 1 (Gp1) contained 30 patients with CCr 60-40 mL/min followed for 40.0 +/- 13.3 months; Group 2 (G2) contained 40 patients with CCr 39-15 mL/min followed for 39.0 +/- 18.2 months. The following parameters were considered: basal and final CCr proteinuria per unit of CCr (UProt/CCr); the difference between final and basal UProt/CCr (delta UProt/CCr); the change in CCr/month (delta CCr); baseline triglycerides (TG), total (TC), HDL (HDLC) and LDL (LDLC) cholesterol, Apo AI, Apo B, Lp(a). Besides in basal CCr the 2 groups significantly differed in the final CCr, final UProt/CCr, delta UProt/CCr, delta CCr. No differences were observed concerning lipid parameters except for Lp(a) (G1 14.8 +/- 13.6, G2 28.7 +/- 27.4 mg/dL; p < 0.05). Baseline TG (G1 184.1 +/- 61.3, G2 187.5 +/- 72.1 mg/dL) and Apo B (only G2 1.05 +/- 0.32 g/L) were significantly higher than normal subjects and the Apo AI/Apo B ratio (G1 1.42 +/- 0.43, G2 1.33 +/- 0.45) were significantly lower than in normal subjects. delta CCr, while inversely correlated in both groups with delta UProt/CCr (p < 0.01), only in G2 did it correlate directly with the Apo AI/Apo B ratio (p < 0.05) and inversely with Apo B and LDLC (p < 0.05). Although a correlation between Lp(a) and delta CCr was not found, 20/22 patients (3/5 G1, 17/17 G2) with a level > 30 mg% ran a progressive course. A natural progression of CRI, heralded by an increasing UProt, is highly frequent when baseline CCr is < 40 mL/min; only then lipids seem to add a burden to the renal damage.

The effect of metabolic acidosis on serum apolipoprotein A I and apolipoprotein B levels in children with chronic renal failure

In this report serum apolipoprotein A I (Apo A I) and apolipoprotein B (Apo B) levels were determined in children with chronic renal disease (CRD) during metabolic acidosis, after the correction of metabolic acidosis and in healthy children to look for the effect of metabolic acidosis on Apo A I and B levels. It was found that Apo A I levels were significantly decreased during metabolic acidosis (p < 0.05) but Apo A I/Apo B ratios were not affected before and after the correction of acidosis in the CRD group (p > 0.05) although it was significantly different from those in the controls (p < 0.01).

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.

Lipoprotein metabolism and renal failure

Lipoprotein metabolism is altered in the majority of patients with renal insufficiency and renal-failure, but may not necessarily lead to hyperlipidemia. The dyslipoproteinemia of renal disease has characteristic abnormalities of the apolipoprotein (apo) profile and lipoprotein composition. It develops during the asymptomatic stages of renal insufficiency and becomes more pronounced as renal failure advances. The qualitative characteristics of renal dyslipoproteinemia are not modified substantially by dialysis treatment. Patients with chronic renal disease may therefore be exposed to dyslipoproteinemia for long periods of time. The characteristic plasma lipid abnormality is a moderate hypertriglyceridemia. The alterations of lipoprotein metabolism affect both the apoB-containing very low-density and intermediate-density, and low-density lipoproteins and the apoA-containing high-density lipoproteins. The main underlying abnormality of lipoprotein transport is a decreased catabolism of the apoB-containing lipoproteins caused by decreased activity of lipolytic enzymes and altered lipoprotein composition. There is an increase of intact or partially metabolized, triglyceride-rich, apoB-containing lipoproteins with a disproportionate elevation of apoC-III and, to a lesser extent, apoE, resulting in a marked increase of the intermediate-density lipoproteins and an enrichment of triglycerides, apoC-III, and apoE in the low-density lipoproteins. In high-density lipoproteins there are decreases in the concentrations of cholesterol, apolipoproteins A-I and A-II, and the high-density lipoprotein-2 to high-density lipoprotein-3 ratio. These abnormalities result in a characteristic decrease of the apoA-I to apoC-III ratio and anti-atherogenic index apoA-I/apoB. The pathophysiologic links between the renal insufficiency and the abnormalities of lipoprotein transport are still poorly defined. Changes in the action of insulin on lipolytic enzymes, possibly mediated via increased levels of parathyroid hormone, have been suggested to play a contributory role. The clinical consequences of a defective lipoprotein transport may be related to the atherogenic character of lipoprotein abnormalities. Renal dyslipoproteinemia may contribute to the development of atherosclerotic vascular disease and progression of glomerular and tubular lesions with subsequent deterioration of renal function. Dietary and/or pharmacologic intervention may ameliorate the uremic dyslipoproteinemia, but the long-term clinical effects of such treatment have yet to be established.