Rationale and design of a trial improving outcome of type 2 diabetics on hemodialysis. Die Deutsche Diabetes Dialyse Studie Investigators

Non-high-density lipoprotein cholesterol: a target of lipid-lowering in dialysis patients

BACKGROUND

The finding of an increased prevalence and levels of atherogenic lipoproteins in the context of normal plasma total and low-density lipoprotein (LDL) cholesterol (LDL-C) levels in hemodialysis (HD) patients highlights the need to look beyond the basic assessment of plasma concentrations of total cholesterol and LDL-C. Measurement of atherogenic lipoproteins (remnant lipoprotein particles [RLPs], particularly intermediate-density lipoprotein [IDL]), is not routinely performed at the present time.

METHODS

The National Cholesterol Education Program guidelines indicate that the secondary goal in persons with triglyceride levels greater than 200 mg/dL is non-high-density lipoprotein cholesterol (HDL-C). Non-HDL-C comprises all RLPs, including IDL, as well as atherogenic small dense LDL.

RESULTS

We propose, for practical reasons, that non-HDL-C be used as a primary target in HD patients when lipid-lowering therapy is indicated. However, it remains unclear whether and how effective statins are in lowering remnant particle levels in dialysis patients. Recent data show that both simvastatin and atorvastatin reduce non-HDL-C levels effectively. Atorvastatin preferentially reduces RLP levels in patients with combined hyperlipidemia.

CONCLUSION

The safety profile of statins predisposes prescription of this class of drugs to correct dyslipidemia or modulate lipoprotein particle composition in uremic patients. Whether atorvastatin influences myocardial infarction or all-cause mortality by adequately correcting dyslipidemia should be seen fairly quickly in the 1,252 dialysis patients with diabetes randomly assigned in the ongoing Die Deutsche Diabetes Dialyse study.

Intima-media thickness of carotid artery predicts cardiovascular mortality in hemodialysis patients

BACKGROUND

Cardiovascular disease is the leading cause of death in patients with end-stage renal disease (ESRD). Previous studies showed that patients with ESRD had increased intima-media thickness of the carotid artery (CA-IMT). In the present study, we examined whether CA-IMT would predict cardiovascular mortality in patients with ESRD.

METHODS

The cohort consisted of 438 patients with ESRD treated with hemodialysis. CA-IMT was measured by high-resolution B-mode ultrasonography.

RESULTS

During the follow-up period of 30 months, 82 deaths, including 44 cardiovascular fatal events, occurred. Compared with those with CA-IMT less than 1.0 mm, those with moderately increased CA-IMT (1.0 to 2.0 mm) and those with severely increased CA-IMT (>or=2.0 mm) showed a significantly greater risk for death from cardiovascular causes; odds ratios were 3.17 (95% confidence interval [CI], 1.41 to 7.17; P = 0.005) and 10.20 (95% CI, 3.67 to 28.3; P < 0.0001), respectively, in a multivariate Cox analysis including age, sex, duration of hemodialysis therapy, presence of diabetes mellitus, blood pressure, body mass index, and high-density lipoprotein and non-high-density lipoprotein cholesterol levels as covariates. Conversely, CA-IMT was not significantly associated with noncardiovascular mortality.

CONCLUSION

These results indicate that increased CA-IMT is an independent predictor of cardiovascular mortality in the hemodialysis population.

Traditional cardiac risk factors in individuals with chronic kidney disease

Individuals with chronic kidney disease (CKD) are at increased risk for the development and progression of cardiovascular disease (CVD). The increased risk is due to a higher prevalence of both traditional risk factors as well as nontraditional risk factors. In this review we focus on individuals at all stages of CKD and discuss modifiable traditional risk factors, namely hypertension, dyslipidemia, diabetes mellitus and poor glycemic control, smoking, and physical inactivity. The prevalence of each risk factor and its relationship with CVD is described. Treatment recommendations are provided using evidence available from populations with CKD or evidence extrapolated from the general population when there are insufficient data on individuals with CKD.

A multidisciplinary program for achieving lipid goals in chronic hemodialysis patients

BACKGROUND

There is little information on how target lipid levels can be achieved in end stage renal disease (ESRD) patients in a systematic, multidisciplinary fashion.

METHODS

We retrospectively reviewed a pharmacist-directed hyperlipidemia management program for chronic hemodialysis (HD) patients. All 26 adult patients on chronic HD at a tertiary care medical facility were entered into the program. A clinical pharmacist was responsible for laboratory monitoring, patient counseling, and the initiation and dosage adjustment of an appropriate 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor (statin) using a dosing algorithm and monitoring guidelines. The low-density lipoprotein (LDL) cholesterol goal was leq; 100 mg/dl. A renal dietitian provided nutrition counseling and the nephrologist was notified of potential or existing drug interactions or adverse drug reactions (ADRs). Patients received a flyer containing lipid panel results to encourage compliance. Data was collected at program initiation and for 6 months thereafter.

RESULTS

At the start of the program, 58% of patients were at target LDL cholesterol. At 6 months, 88% had achieved target LDL (p = 0.015). Mean LDL cholesterol decreased from 96 +/- 5 to 80 +/- 3 mg/dl (p < 0.01), and mean total cholesterol decreased from 170 +/- 7 to 151 +/- 4 mg/dl (p < 0.01). Fifteen adjustments in drug therapy were made. Eight adverse drug reactions were identified; 2 required drug discontinuation or an alternative agent. Physicians were alerted to 8 potential drug-drug interactions, and appropriate monitoring was performed.

CONCLUSIONS

Our findings demonstrate both feasibility and efficacy of a multidisciplinary approach in management of hyperlipidemia in HD patients.

FOSIDIAL: a randomised placebo controlled trial of the effects of fosinopril on cardiovascular morbidity and mortality in haemodialysis patients. Study design and patients' baseline characteristics

The prevalence of end stage renal disease (ESRD) is growing in western countries. Patients with ESRD are more frequently elderly and diabetic and are exposed to very high cardiovascular morbidity and mortality. The main aim of the FOSIDIAL study is to assess the efficacy and safety of fosinopril, an angiotensin converting enzyme (ACE) inhibitor, in reducing the mortality and cardiovascular events in haemodialysis patients presenting with left ventricular hypertrophy. A total number of 397 patients are included in the study. They are aged 50-80 years (average 66.7 years) and have been undergoing haemodialysis for 4.8 years. All have left ventricular hypertrophy with cardiac mass index > 100 g/m2 in women and > 130 g/m2 in men, measured within 3 months prior to inclusion. Baseline cardiac mass index is 174 g/m2. After a 2 week placebo period, the patients are randomised into two groups receiving either fosinopril 5-20 mg/day, or a placebo for a duration of 24 months. The target dose is reached at the sixth, seventh or eighth week of treatment. Depending on tolerance, 300 patients reached the maximum recommended dose. Patients are subsequently assessed clinically every 3 months until the end of the study. The primary outcome is a composite endpoint of fatal and nonfatal major cardiovascular events. Secondary endpoints are individual cardiovascular events, event-free survival, overall mortality and all-cause hospitalisations. The trial began in October 1998. All patients were included by December 2000 and follow-up is ongoing. The last visit for the last patient is scheduled for 30 December 2002. We report here on the study design and the baseline characteristics of the study population.

Hyperlipidemia in kidney disease: causes and consequences

Dyslipidemias are common in patients with chronic kidney disease. The causes vary with the stage of kidney disease, the degree of proteinuria, and the modality of end-stage renal disease treatment. Dyslipidemias have been associated with kidney disease progression, and a number of small, randomized, controlled trials of lipid-lowering agents have been conducted. Unfortunately, the results of these trials, although encouraging, have been inconclusive because of the small numbers of patients enrolled. Dyslipidemias may also contribute to the high incidence of cardiovascular disease in patients with chronic kidney disease. This is most likely for patients with chronic renal insufficiency and for kidney transplant recipients. Less certain is the role of dyslipidemias in the pathogenesis of cardiovascular disease among dialysis patients.

A placebo-controlled trial examining atorvastatin in dyslipidemic patients undergoing CAPD

BACKGROUND

Individuals with chronic renal disease are at high risk of cardiovascular morbidity and mortality, and therefore the management of dyslipidemia is particularly important in this patient population. This double-blind randomized study investigated the efficacy and safety of the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, atorvastatin, in continuous ambulatory peritoneal dialysis (CAPD) patients with dyslipidemia.

METHODS

Following a two- to four-week baseline period, patients with low-density lipoprotein (LDL)-cholesterol > or =3.5 mmol/L (135 mg/dL) were randomized to receive either atorvastatin 10 mg (N = 82) or placebo (N = 95) for 16 weeks. If LDL-cholesterol remained > or =3.5 mmol/L, the dose of atorvastatin was titrated to 20 mg and 40 mg after four and eight weeks, respectively.

RESULTS

After four weeks a significantly greater proportion of patients receiving atorvastatin 10 mg had achieved the LDL-cholesterol goal < or =3.5 mmol/L compared with patients receiving placebo (85.4% vs. 16.0%; P < or = 0.001). The statistically significant difference between the two groups was maintained at week 8 and week 16 (P < or = 0.001 at both time points). At week 16, patients receiving atorvastatin had significantly greater reductions from baseline in LDL-cholesterol, total cholesterol, triglycerides and total cholesterol:HDL-cholesterol ratio (all P = 0.0001), and a significantly greater increase from baseline in HDL-cholesterol (P = 0.001) than patients receiving placebo. The overall adverse event profile for atorvastatin was similar to that observed with placebo.

CONCLUSIONS

Atorvastatin was effective in achieving target LDL-cholesterol levels in a high proportion of the dyslipidemic CAPD patients studied at doses that are well tolerated.

Atorvastatin: an updated review of its pharmacological properties and use in dyslipidaemia

Atorvastatin is a synthetic hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitor. In dosages of 10 to 80 mg/day, atorvastatin reduces levels of total cholesterol, low-density lipoprotein (LDL)-cholesterol, triglyceride and very low-density lipoprotein (VLDL)-cholesterol and increases high-density lipoprotein (HDL)-cholesterol in patients with a wide variety of dyslipidaemias. In large long-term trials in patients with primary hypercholesterolaemia. atorvastatin produced greater reductions in total cholesterol. LDL-cholesterol and triglyceride levels than other HMG-CoA reductase inhibitors. In patients with coronary heart disease (CHD), atorvastatin was more efficacious than lovastatin, pravastatin. fluvastatin and simvastatin in achieving target LDL-cholesterol levels and, in high doses, produced very low LDL-cholesterol levels. Aggressive reduction of serum LDL-cholesterol to 1.9 mmol/L with atorvastatin 80 mg/day for 16 weeks in patients with acute coronary syndromes significantly reduced the incidence of the combined primary end-point events and the secondary end-point of recurrent ischaemic events requiring rehospitalisation in the large. well-designed MIRACL trial. In the AVERT trial, aggressive lipid-lowering therapy with atorvastatin 80 mg/ day for 18 months was at least as effective as coronary angioplasty and usual care in reducing the incidence of ischaemic events in low-risk patients with stable CHD. Long-term studies are currently investigating the effects of atorvastatin on serious cardiac events and mortality in patients with CHD. Pharmacoeconomic studies have shown lipid-lowering with atorvastatin to be cost effective in patients with CHD, men with at least one risk factor for CHD and women with multiple risk factors for CHD. In available studies atorvastatin was more cost effective than most other HMG-CoA reductase inhibitors in achieving target LDL-cholesterol levels. Atorvastatin is well tolerated and adverse events are usually mild and transient. The tolerability profile of atorvastatin is similar to that of other available HMG-CoA reductase inhibitors and to placebo. Elevations of liver transaminases and creatine phosphokinase are infrequent. There have been rare case reports of rhabdomyolysis occurring with concomitant use of atorvastatin and other drugs.

CONCLUSION

Atorvastatin is an appropriate first-line lipid-lowering therapy in numerous groups of patients at low to high risk of CHD. Additionally it has a definite role in treating patients requiring greater decreases in LDL-cholesterol levels. Long-term studies are under way to determine whether achieving very low LDL-cholesterol levels with atorvastatin is likely to show additional benefits on morbidity and mortality in patients with CHD.

3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors and rhabdomyolysis: considerations in the renal failure patient

An intense debate has developed as to the risk-benefit ratio of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) following the withdrawal of cerivastatin. The development of rhabdomyolysis in cerivastatin-treated patients should have surprised few since myotoxicity is an accepted class effect of statins. What has sprung from the cerivastatin experience though is a concern for other members of this class. Such misgivings, although understandable, are ill advised. Without question, differences exist in the risk of rhabdomyolysis occurrence amongst the various statins. In this regard, pravastatin and fluvastatin are least likely to produce rhabdomyolysis, which, in part, relates to the fact they are not metabolized by the cytochrome P450 3A4 pathway. When muscle damage occurs with statins it is most often the result of a drug-drug interaction rather than a specific adverse response to statin monotherapy. Such drug-drug interactions increase plasma concentrations of a statin and thereby increase the risk of myotoxicity. A growing consensus exists which supports an expanded use of statins in a range of patient groups including the renal failure patient. Polypharmacy and altered drug metabolism increase the risk of myotoxicity, albeit to an ill-defined degree, in this population. Many factors should enter into the choice of a statin in the multiply medicated renal failure patient.

Cardiovascular abnormalities and hypertension in the elderly dialysis patient

Elderly individuals comprise an ever-increasing proportion of patients on renal replacement therapy (RRT). As in younger patients, cardiovascular events are the major cause of death in the elderly on RRT, although the relative proportion succumbing to cardiovascular events is similar to that in young patients. An important observation is that the elderly are particularly likely to experience higher mortality if dialysis technique is suboptimal; they also experience particular benefit from successful renal transplantation. The latter observation has led to an "old for old" program in Europe.

Abnormalities in uremic lipoprotein metabolism and its impact on cardiovascular disease

Patients with end-stage renal disease (ESRD) suffer from a secondary form of complex dyslipidemia consisting of both quantitative and qualitative abnormalities in serum lipoproteins resulting from alterations in lipoprotein metabolism and composition. The prominant features of uremic dyslipidemia are an increase in serum triglyceride levels (due to elevated very low density lipoprotein [VLDL]-remnants and intermediate-density lipoprotein [IDL]) and low high-density lipoprotein (HDL) cholesterol. Low-density lipoprotein (LDL) cholesterol often is normal, but the cholesterol may originate from the atherogenic small and dense LDL subclass (sdLDL). The apolipoprotein B (apoB)-containing part of the lipoprotein may undergo modifications (enzymatic- and advanced glycation end-product [AGE]-peptide modification, oxidation, or glycosilation). Modifications contribute to impaired LDL receptor-mediated clearance from plasma and promote prolonged circulation. While LDL particles undergo a vicious cycle of accumulation and modification, reverse cholesterol transport is also impaired due to low lecithin:cholesterol acyltransferase (LCAT) and paraoxonase activity. Therefore, discoid HDL particles are structurally altered and hepatic cholesterol clearance is limited. The composition of HDL may also be altered during states of inflammation. The contribution of this complex and atherogenic form of dyslipidemia to cardiovascular disease in patients with renal disease is unclear at present. Most studies are negative in demonstrating the predictive power of serum lipids for the development of cardiovascular disease. This is most likely due to interference with deteriorating aspects of the activated acute-phase response. Nevertheless, patients with renal disease belong to a very high cardiovascular risk group and dyslipidemia should most likely be subjected to sufficient lipid-lowering therapy in most patients. Because it is also still unclear whether we have available therapies with sufficient impact on LDL size, remnant lipoprotein-lowering, and restoration of HDL function, we urgently need the results from large scale intervention trials such as the 4D-trial and the CHORUS study.