Atorvastatin treatment for hyperlipidemia in pediatric renal transplant recipients

SLCO1B1 Genetic Variation Influence on Atorvastatin Systemic Exposure in Pediatric Hypercholesterolemia

This clinical study examined the influence of SLCO1B1 c.521T>C (rs4149056) on plasma atorvastatin concentrations in pediatric hypercholesterolemia. The participants (8-21 years), including heterozygous (c.521T/C, n = 13), homozygous (c.521C/C, n = 2) and controls (c.521T/T, n = 13), completed a single-oral-dose pharmacokinetic study. Similar to in adults, the atorvastatin (AVA) area-under-concentration-time curve from 0 to 24 h (AUC0-24) was 1.7-fold and 2.8-fold higher in participants with c.521T/C and c.521C/C compared to the c.521T/T participants, respectively. The inter-individual variability in AVA exposure within these genotype groups ranged from 2.3 to 4.8-fold, indicating that additional factors contribute to the inter-individual variability in the AVA dose-exposure relationship. A multivariate model reinforced the SLCO1B1 c.521T>C variant as the central factor contributing to AVA systemic exposure in this pediatric cohort, accounting for ~65% of the variability in AVA AUC0-24. Furthermore, lower AVA lactone concentrations in participants with increased body mass index contributed to higher exposure within the c.521T/T and c.521T/C genotype groups. Collectively, these factors contributing to higher systemic exposure could increase the risk of toxicity and should be accounted for when individualizing the dosing of atorvastatin in eligible pediatric patients.

Promoting cardiovascular health post-transplant through early diagnosis and adequate management of hypertension and dyslipidemia

Despite correction of underlying solid organ failure by transplantation, pediatric transplant recipients still have increased mortality rates compared to the general pediatric population, in part due to increased cardiovascular risk. In particular, pediatric kidney and non-kidney transplant recipients with chronic kidney disease have significant cardiovascular risk that worsens with declining kidney function. Biomarkers associated with future cardiovascular risk such as casual and ambulatory hypertension, dyslipidemia, vascular stiffness and calcification, and left ventricular hypertrophy can be detected throughout the post-transplant period and in patients with stable kidney function. Among these, hypertension and dyslipidemia are two potentially modifiable cardiovascular risk factors that are highly prevalent in kidney and non-kidney pediatric transplant recipients. Standardized approaches to appropriate BP measurement and lipid monitoring are needed to detect and address these risk factors in a timely fashion. To achieve sustained improvement in cardiovascular health, clinicians should partner with patients and their caregivers to address these and other risk factors with a combined approach that integrates pharmacologic with non-pharmacologic approaches. This review outlines the scope and impact of hypertension and dyslipidemia in pediatric transplant recipients, with a particular focus on pediatric kidney transplantation given the high burden of chronic kidney disease-associated cardiovascular risk. We also review the current published guidelines for monitoring and managing abnormalities in blood pressure and lipids, highlighting the important role of therapeutic lifestyle changes in concert with antihypertensive and lipid-lowering medications.

Dyslipidemia after pediatric renal transplantation-The impact of immunosuppressive regimens

Dyslipidemia contributes to cardiovascular morbidity and mortality in pediatric transplant recipients. Data on prevalence and risk factors in pediatric cohorts are, however, scarce. We therefore determined the prevalence of dyslipidemia in 386 pediatric renal transplant recipients enrolled in the CERTAIN registry. Data were obtained before and during the first year after RTx to analyze possible non-modifiable and modifiable risk factors. The prevalence of dyslipidemia was 95% before engraftment and 88% at 1 year post-transplant. Low estimated glomerular filtration rate at 1 year post-transplant was associated with elevated serum triglyceride levels. The use of TAC and of MPA was associated with significantly lower concentrations of all lipid parameters compared to regimens containing CsA and mTORi. Immunosuppressive regimens consisting of CsA, MPA, and steroids as well as of CsA, mTORi, and steroids were associated with a three- and 25-fold (P<.001) increased risk of having more than one pathologic lipid parameter as compared to the use of TAC, MPA, and steroids. Thus, amelioration of the cardiovascular risk profile after pediatric RTx may be attained by adaption of the immunosuppressive regimen according to the individual risk profile.

Pediatric Statin Administration: Navigating a Frontier with Limited Data

Increasingly, children and adolescents with dyslipidemia qualify for pharmacologic intervention. As they are for adults, 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase inhibitors (statins) are the mainstay of pediatric dyslipidemia treatment when lifestyle modifications have failed. Despite the overall success of these drugs, the magnitude of variability in dose-exposure-response profiles contributes to adverse events and treatment failure. In children, the cause of treatment failures remains unclear. This review describes the updated guidelines for screening and management of pediatric dyslipidemia and statin disposition pathway to assist the provider in recognizing scenarios where alterations in dosage may be warranted to meet patients' specific needs.

Long-term effects of paediatric kidney transplantation

Renal transplantation in paediatric patients usually provides excellent short-term and medium-term results. Early diagnosis of chronic kidney disease and active therapy of end-stage renal disease before and after transplantation enables the majority of children to grow and develop normally. The adverse effects of immunosuppressive medication and reduced graft function might, however, hamper long-term outcomes in these patients and can lead to metabolic complications, cardiovascular disease, reduced bone health, and malignancies. The neurocognitive development and quality of life of paediatric transplant recipients largely depend on the primary diagnosis and on graft function. Poor adherence to immunosuppression is an important risk factor for graft loss in adolescents, and controlled transition to adult care is of utmost importance to ensure a continued normal life. In this Review, we discuss the outcomes and long-term effects of renal transplantation in paediatric recipients, including consequences on growth, development, bone, metabolic, and cardiovascular disorders. We discuss the key problems in the care of paediatric renal transplant recipients and the remaining challenges that should be the focus of future research.

Lipid-lowering efficacy of atorvastatin

BACKGROUND

This represents the first update of this review, which was published in 2012. Atorvastatin is one of the most widely prescribed drugs and the most widely prescribed statin in the world. It is therefore important to know the dose-related magnitude of effect of atorvastatin on blood lipids.

OBJECTIVES

Primary objective To quantify the effects of various doses of atorvastatin on serum total cholesterol, low-density lipoprotein (LDL)-cholesterol, high-density lipoprotein (HDL)-cholesterol and triglycerides in individuals with and without evidence of cardiovascular disease. The primary focus of this review was determination of the mean per cent change from baseline of LDL-cholesterol. Secondary objectives • To quantify the variability of effects of various doses of atorvastatin.• To quantify withdrawals due to adverse effects (WDAEs) in placebo-controlled randomised controlled trials (RCTs).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 11, 2013), MEDLINE (1966 to December Week 2 2013), EMBASE (1980 to December Week 2 2013), Web of Science (1899 to December Week 2 2013) and BIOSIS Previews (1969 to December Week 2 2013). We applied no language restrictions.

SELECTION CRITERIA

Randomised controlled and uncontrolled before-and-after trials evaluating the dose response of different fixed doses of atorvastatin on blood lipids over a duration of three to 12 weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility criteria for studies to be included and extracted data. We collected information on withdrawals due to adverse effects from placebo-controlled trials.

MAIN RESULTS

In this update, we found an additional 42 trials and added them to the original 254 studies. The update consists of 296 trials that evaluated dose-related efficacy of atorvastatin in 38,817 participants. Included are 242 before-and-after trials and 54 placebo-controlled RCTs. Log dose-response data from both trial designs revealed linear dose-related effects on blood total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides. The Summary of findings table 1 documents the effect of atorvastatin on LDL-cholesterol over the dose range of 10 to 80 mg/d, which is the range for which this systematic review acquired the greatest quantity of data. Over this range, blood LDL-cholesterol is decreased by 37.1% to 51.7% (Summary of findings table 1). The slope of dose-related effects on cholesterol and LDL-cholesterol was similar for atorvastatin and rosuvastatin, but rosuvastatin is about three-fold more potent. Subgroup analyses suggested that the atorvastatin effect was greater in females than in males and was greater in non-familial than in familial hypercholesterolaemia. Risk of bias for the outcome of withdrawals due to adverse effects (WDAEs) was high, but the mostly unclear risk of bias was judged unlikely to affect lipid measurements. Withdrawals due to adverse effects were not statistically significantly different between atorvastatin and placebo groups in these short-term trials (risk ratio 0.98, 95% confidence interval 0.68 to 1.40).

AUTHORS' CONCLUSIONS

This update resulted in no change to the main conclusions of the review but significantly increases the strength of the evidence. Studies show that atorvastatin decreases blood total cholesterol and LDL-cholesterol in a linear dose-related manner over the commonly prescribed dose range. New findings include that atorvastatin is more than three-fold less potent than rosuvastatin, and that the cholesterol-lowering effects of atorvastatin are greater in females than in males and greater in non-familial than in familial hypercholesterolaemia. This review update does not provide a good estimate of the incidence of harms associated with atorvastatin because included trials were of short duration and adverse effects were not reported in 37% of placebo-controlled trials.

Statin use in Australian children: a retrospective audit of four pediatric hospitals

AIM

The aim of this study was to perform an audit of the use of statins in Australian pediatric hospitals.

METHODS

A retrospective audit of patients prescribed statins during a visit to a pediatric hospital, as in- or outpatients, was performed in four major children's hospitals in three Australian states. Patients were identified through hospital pharmacy dispensing records. Statin use (dose, type) as well as medical history was recorded.

RESULTS

A total of 157 patients under the age of 18 were included in the audit. The most common reasons for being prescribed a statin included history of organ transplantation, renal disease and familial hypercholesterolemia (FH). Four statins were prescribed: atorvastatin (n = 77), pravastatin (n = 45), simvastatin (n = 25) and rosuvastatin (n = 10). All statins, apart from rosuvastatin, were used in very young children (1-7 years old). Polypharmacy was common in these patients, including combinations with calcineurin inhibitors and diltiazem, which can increase systemic statin exposure. A small number of very young children were prescribed high doses of statin, based on mg/kg dosing.

CONCLUSIONS

Statins were prescribed to children younger than suggested by current Australian guidelines, with atorvastatin being the preferred statin of choice. Long-term safety studies on the use of statins in children have only included FH patients so far, who are generally healthy besides their raised lipid levels. Further long-term safety studies are needed to include the more vulnerable transplant and renal patients, identified in this audit as being prescribed statins. This can help formulate guidelines for the safest possible use of this class of drugs in the pediatric setting, including the possibility of weight-based recommendations for younger children.

Lipid lowering efficacy of atorvastatin

BACKGROUND

Atorvastatin is one of the most widely prescribed drugs and the most widely prescribed statin in the world. It is therefore important to know the dose-related magnitude of effect of atorvastatin on blood lipids.

OBJECTIVES

To quantify the dose-related effects of atorvastatin on blood lipids and withdrawals due to adverse effects (WDAE).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library Issue 4, 2011, MEDLINE (1966 to November 2011), EMBASE (1980 to November 2011), ISI Web of Science (1899 to November 2011) and BIOSIS Previews (1969 to November 2011). No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled and uncontrolled before-and-after trials evaluating the dose response of different fixed doses of atorvastatin on blood lipids over a duration of 3 to 12 weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. WDAE information was collected from the placebo-controlled trials.

MAIN RESULTS

Two hundred fifty-four trials evaluated the dose-related efficacy of atorvastatin in 33,505 participants. Log dose-response data revealed linear dose-related effects on blood total cholesterol, low-density lipoprotein (LDL)-cholesterol and triglycerides. Combining all the trials using the generic inverse variance fixed-effect model for doses of 10 to 80 mg/day resulted in decreases of 36% to 53% for LDL-cholesterol. There was no significant dose-related effects of atorvastatin on blood high-density lipoprotein (HDL)-cholesterol. WDAE were not statistically different between atorvastatin and placebo for these short-term trials (risk ratio 0.99; 95% confidence interval 0.68 to 1.45).

AUTHORS' CONCLUSIONS

Blood total cholesterol, LDL-cholesterol and triglyceride lowering effect of atorvastatin was dependent on dose. Log dose-response data was linear over the commonly prescribed dose range. Manufacturer-recommended atorvastatin doses of 10 to 80 mg/day resulted in 36% to 53% decreases of LDL-cholesterol. The review did not provide a good estimate of the incidence of harms associated with atorvastatin because of the short duration of the trials and the lack of reporting of adverse effects in 37% of the placebo-controlled trials.

Unusual pattern of dyslipidemia in children receiving steroid minimization immunosuppression after renal transplantation

BACKGROUND AND OBJECTIVES

Corticosteroids are an important contributor to posttransplant hyperlipidemia. Since 2004, we have used a steroid minimization immunosuppression protocol. This study investigated the effect of steroid minimization on dyslipidemia in pediatric renal allograft recipients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Children (<18 years) who underwent renal transplants at our center from January 2001 to January 2008 were studied. Data analyzed included age, gender, race, body mass index, cholesterol, triglyceride, LDL cholesterol, HDL cholesterol, and steroid dose. Data between the cohorts receiving maintenance steroids and steroid-minimization were compared using multivariable analyses. The primary outcome measures were the prevalence of, and the effect of steroid use, on dyslipidemia.

RESULTS

Twenty-nine patients were studied. Sixteen were receiving maintenance steroids, and 13 were on a steroid minimization regimen. Mixed effects analysis of covariance models demonstrated that at 1 month, children receiving maintenance steroids had higher cholesterol compared with the steroid minimization group. Statistically significant differences in total cholesterol were not seen at other time points. Similar findings were noted for the LDL cholesterol, LDL/HDL, and cholesterol/HDL ratios. At 1 month, the serum HDL cholesterol was substantially lower in the steroid minimization group. Differences in the HDL cholesterol levels remained significant throughout the first year.

CONCLUSIONS

Steroid use is a significant independent risk factor for hypercholesterolemia during the first post-transplant month. The significance of lower HDL cholesterol among patients receiving steroid minimization needs further study and may be cause for concern.

Adverse effects of immunosuppression in pediatric solid organ transplantation

Solid organ transplantation is a life-saving treatment for end-stage organ failure in children. Immunosuppressant medications are used to prevent rejection of the organ transplant. However, these medications are associated with significant adverse effects that impact growth and development, quality of life (QOL), and sometimes long-term survival after transplantation. Adverse effects can differ between the immunosuppressants, but many result from the overall state of immunosuppression. Strategies to manage immunosuppressant adverse effects often involve minimizing exposure to the drugs while balancing the risk for rejection. Early recognition of immunosuppressant adverse effects may help to reduce morbidities associated with solid organ transplantation, improve QOL, and possibly increase overall patient survival.

Rational approach to the treatment for heterozygous familial hypercholesterolemia in childhood and adolescence: a review

Atherosclerosis represents a disease that begins in childhood and in which LDL cholesterol plays a pivotal role for the development of the pathology. Children and adolescents with high cholesterol levels are more likely than their peers to present cholesterol elevation as adults. The identification of genetic dyslipidemias associated with premature cardiovascular disease is crucial during childhood to delay or prevent the atherosclerotic process. Guidelines for the diagnosis and treatment of hypercholesterolemia during pediatric age are available from the National Cholesterol Education Program. A heart-healthy diet should begin at the age of 2 yr and a large number of studies have demonstrated no adverse effects on nutritional status, growth, pubertal development, and psychological aspects in children and adolescents limiting total and saturated fat intake. Pharmacotherapy should be considered in children over 10 yr of age when LDL cholesterol concentrations remain very high despite severe dietary therapy, especially when multiple risk factors are present. The only lipid-lowering drugs recommended up to now for childhood and adolescence are resins reported to be effective and well tolerated, although compliance is very poor because of unpalatability. The use of statins is increasing and seems to be effective and safe in children, even if studies enrolled a small number of patients and evaluated efficacy and safety for short-term periods. Recently, an interesting drug represented by ezetimibe has been found that may provide cholesterol-lowering additive to that reached with statin treatment. This review provides an update on recent advances in the diagnosis, therapy, and follow-up of familial hypercholesterolemia during pediatric age and adolescence.

Atorvastatin affects interleukin-2 signaling by altering the lipid raft enrichment of the interleukin-2 receptor beta chain

Although the immunomodulatory properties of statins are in part independent of their lipid-lowering effects, cholesterol is a major component of lipid rafts. We therefore studied the effects of atorvastatin (AS) on the raft enrichment of the interleukin-2 receptor (IL-2R) beta chain previously described by us and on early IL-2R signaling events in activated human T cells. We found that concomitant AS exposure during a 3-day stimulation with phytohemagglutinin (PHA) attenuates activation-associated events, such as the enhanced surface expression of the raft marker GM-1 and the induced expression of the activation marker CD25 (the IL-2R alpha chain). In contrast, brief AS treatment after PHA stimulation increased GM-1 surface expression and virtually abolished the selective raft enrichment of the IL-2R beta chain. Although this AS-associated increase in GM-1 expression resembled that seen in the presence of the raft-disrupting cholesterol chelator methyl-beta-cyclodextrin (MBCD), the two agents had contrasting effects on the tyrosine phosphorylation of the IL-2R beta chain by exogenous IL-2: MBCD essentially abolished this event, whereas AS tended to enhance it and shifted its occurrence out of rafts. We conclude that AS affects IL-2R signaling by altering the raft enrichment of the IL-2R beta chain and propose that this effect is one mechanism underlying the immunomodulatory properties of statins.

Prospective monitoring of lipid profiles in children receiving pravastatin preemptively after renal transplantation

Hyperlipidemia is common after renal transplantation (Tx) and contributes to the increased cardiovascular morbidity seen in the post-transplant period. Limited data are available on the utility of the statins in children after renal Tx. This 12-month prospective study was undertaken to determine the efficacy of pravastatin in reducing dyslipidemia after renal Tx in children and to determine predictors of dyslipidemia after Tx. From August 2001 to April 2004, all 17 newly transplanted pediatric renal transplant recipients at our center were preemptively treated with pravastatin from the immediate post-transplant period. Fasting lipid profiles were obtained at 1, 3, 6 and 12 months after Tx. Trends in the lipid profile were analyzed using the repeated measures general linear model (GLM). A historical cohort of pediatric renal-transplant recipients not treated with pravastatin was used as the control population. The mixed effects GLM was used for multivariable logistic regression analyses to determine the independent effect of age, pretransplant cholesterol (Chol), body mass index (BMI), creatinine clearance (CrCl), and corticosteroid and tacrolimus doses on the development of dyslipidemia. The mean age of the children at Tx was 8.7 yr. The GLM analysis showed that with time, there was a significant decline in the total Chol, serum triglyceride (TG), LDL and also HDL-Chol (p-value <0.05 for each). Compared with the controls, the mean serum Chol was lower at all time points post-transplant in the treated patients. However, despite treatment, the prevalence of hypercholesterolemia increased from 31% pretransplant to 53% at 1-month, but declined thereafter to 6% at 3 and 6 months and 0% at 1 yr. Multivariable regression analyses showed the prednisone dose, pretransplant Chol and age to be the most important risk factors for the development of dyslipidemia. No child developed complications related to therapy. In summary, pravastatin is safe in the post-transplant period in children and reduces serum Chol, LDL-Chol and TG. An unexpected finding in our study was the decline in HDL-Chol after Tx. Whether the preemptive use of the statins will result in lower cardiovascular morbidity, especially considering the concomitant reduction in HDL-Chol remains to be determined.

Assessing cardiovascular risk in children with chronic kidney disease. B-type natriuretic peptide: a potential new marker

Elevated plasma B-type natriuretic peptide (BNP) level is a hallmark of altered left ventricular (LV) structure and function. Measurement of circulating BNP has proved to be a sensitive and specific diagnostic test for congestive heart failure (CHF) and coronary syndrome in adults. Further, BNP levels constitute a strong predictive marker for future cardiovascular (CV) events. In high CV risk populations, such as adults with hypertension or chronic kidney disease (CKD), increased BNP predicts CV morbidity and mortality in symptomatic or asymptomatic patients. However, caution is needed in interpreting plasma BNP levels, as they increase with both age and decreased renal function. Despite increasing evidence of the value of BNP in the medical literature in adults, data in children are limited to those with congenital heart disease. It is appropriate to analyze the potential application of this tool in children with CKD, a well-known factor for CV disease.

Risk factors for cardiovascular disease in pediatric renal transplant recipients

About 1,000 children develop end-stage renal disease (ESRD) each year in the United States and about 5,000 children are currently receiving dialysis. Children who develop ESRD are eligible to receive renal replacement therapy, including renal transplantation. There are inherent risks associated with transplantation, including renal insufficiency, infections, post-transplant lymphoproliferative disorder, and cardiovascular disease (CVD). Potential risk factors for CVD in pediatric renal transplant recipients include renal insufficiency, hyperlipidemia, hyperhomocysteinemia, inflammation, malnutrition, anemia, and hyperglycemia/insulin resistance. Despite evidence that many children may possess various risk factors for CVD post-renal transplantation, there are very few studies that have attempted to assess the link between these risk factors and CVD in pediatric renal transplant recipients.