Association of HMG-CoA reductase inhibitors with neuropathy

Lipids, Lipid-Lowering Therapy, and Neuropathy: A Narrative Review

Statins, or 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, are the mainstay of treatment for hypercholesterolemia as they effectively reduce LDL-C levels and risk of atherosclerotic cardiovascular disease. Apart from hyperglycemia, dyslipidemia and HDL dysfunction are known risk factors for neuropathy in people with obesity and diabetes. Although there are case reports of statin-induced neuropathy, ad hoc analyses of clinical trials and observational studies have shown that statins may improve peripheral neuropathy. However, large randomized controlled trials and meta-analyses of cardiovascular outcome trials with statins and other lipid-lowering drugs have not reported on neuropathy outcomes. Because neuropathy was not a prespecified outcome in major cardiovascular trials, one cannot conclude whether statins or other lipid-lowering therapies increase or decrease the risk of neuropathy. The aim of this review was to assess if statins have beneficial or detrimental effects on neuropathy and whether there is a need for large well-powered interventional studies using objective neuropathy end points.

Synergistic effects of pomegranate juice and atorvastatin for improving cerebellar structure and function of breast-feeding rats maternally fed on a high cholesterol diet

A highly cholesterol-diet is associated with atherosclerosis and little about the development of cerebellar cortex disorder. The study illustrated the changes of cerebellar cortex of rat neonate maternally fed on high cholesterol diet and the capacity of pomegranate alone or in combination with atorvastatin to improve it. Eighty-eight pregnant Wister rats were divided into eight groups (n = 11); control, pomegranate supplemented group (daily orally 0.4 mL (20 %), atorvastatin (10 mg/kg BT), hypercholesterolemia (dietary consumption 3% cholesterol for 6 weeks prior to conception and throughout gestation and lactation period), hypercholesterolemia and pomegranate or atorvastatin, hypercholesterolemia and atorvastatin and pomegranate. Dams and their offspring were sacrificed at 21 days post-partum. Sera of mother and cerebellum of offspring were investigated biochemically as well as histo-cytological changes of cerebellar cortex of offspring. Offspring maternally fed on high cholesterol diet showed damage of the cerebellar Purkinje and granular cells associated with demyelination, increased caspase 3 immunohistochemistry and increased DNA damage. These were associated with decreased brain neurotransmitters and increase apoptic markers. Dams supplemented pomegranate and/or atorvastatin improved the assayed parameters more than that of atorvastatin alone. The authors concluded that pomegranate juice contains potent antioxidant nutrients capable of reducing the cytotoxicity of hypercholesterolemia and atorvastatin, and enhancing the structure and function of the cerebellar cortex.

Chronic exposure to environmentally relevant levels of simvastatin disrupts zebrafish brain gene signaling involved in energy metabolism

Simvastatin (SIM), a hypocholesterolaemic drug belonging to the statins group, is a widely prescribed pharmaceutical for prevention of cardiovascular diseases. Several studies showed that lipophilic statins, as SIM, cross the blood-brain barrier and interfere with the energy metabolism of the central nervous system in humans and mammalian models. In fish and other aquatic organisms, the effects of SIM on the brain energy metabolism are unknown, particularly following exposure to low environmentally relevant concentrations. Therefore, the present study aimed at investigating the influence of SIM on gene signaling pathways involved in brain energy metabolism of adult zebrafish (Danio rerio) following chronic exposure (90 days) to environmentally relevant SIM concentrations ranging from 8 ng/L to 1000 ng/L. Real-time PCR was used to determine the transcript levels of several genes involved in different pathways of the brain energy metabolism (glut1b, gapdh, acadm, accα, fasn, idh3a, cox4i1, and cox5aa). The findings here reported integrated well with ecological and biochemical responses obtained in a parallel study. Data demonstrated that SIM modulates transcription of key genes involved in the mitochondrial electron transport chain, in glucose transport and metabolism, in fatty acid synthesis and β-oxidation. Further, SIM exposure led to a sex-dependent transcription profile for some of the studied genes. Overall, the present study demonstrated, for the first time, that SIM modulates gene regulation of key pathways involved in the energy metabolism in fish brain at environmentally relevant concentrations.

Statins for children with familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia is one of the most common inherited metabolic diseases and is an autosomal dominant disorder meaning heterozygotes, or carriers, are affected. Those who are homozygous have severe disease. The average worldwide prevalence of heterozygous familial hypercholesterolemia is at least 1 in 500, although recent genetic epidemiological data from Denmark and next generation sequencing data suggest the frequency may be closer to 1 in 250. Diagnosis of familial hypercholesterolemia in children is based on elevated total cholesterol and low-density lipoprotein cholesterol levels or DNA-based analysis, or both. Coronary atherosclerosis has been detected in men with heterozygous familial hypercholesterolemia as young as 17 years old and in women with heterozygous familial hypercholesterolemia at 25 years old. Since the clinical complications of atherosclerosis occur prematurely, especially in men, lifelong treatment, started in childhood, is needed to reduce the risk of cardiovascular disease. In children with the disease, diet was the cornerstone of treatment but the addition of lipid-lowering medications has resulted in a significant improvement in treatment. Anion exchange resins, such as cholestyramine and colestipol, were found to be effective, but they are poorly tolerated. Since the 1990s studies carried out on children aged 6 to 17 years with heterozygous familial hypercholesterolemia have demonstrated significant reductions in their serum total and low-density lipoprotein cholesterol levels. While statins seem to be safe and well-tolerated in children, their long-term safety in this age group is not firmly established. This is an update of a previously published version of this Cochane Review.

OBJECTIVES

To assess the effectiveness and safety of statins in children with heterozygous familial hypercholesterolemia.

SEARCH METHODS

Relevant studies were identified from the Group's Inborn Errors and Metabolism Trials Register and Medline. Date of most recent search: 04 November 2019.

SELECTION CRITERIA

Randomized and controlled clinical studies including participants up to 18 years old, comparing a statin to placebo or to diet alone.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for inclusion and extracted data.

MAIN RESULTS

We found 26 potentially eligible studies, of which we included nine randomized placebo-controlled studies (1177 participants). In general, the intervention and follow-up time was short (median 24 weeks; range from six weeks to two years). Statins reduced the mean low-density lipoprotein cholesterol concentration at all time points (high-quality evidence). There may be little or no difference in liver function (serum aspartate and alanine aminotransferase, as well as creatinine kinase concentrations) between treated and placebo groups at any time point (low-quality evidence). There may be little or no difference in myopathy (as measured in change in creatinine levels) (low-quality evidence) or clinical adverse events (moderate-quality evidence) with statins compared to placebo. One study on simvastatin showed that this may slightly improve flow-mediated dilatation of the brachial artery (low-quality evidence), and on pravastatin for two years may have induced a regression in carotid intima media thickness (low-quality evidence). No studies reported rhabdomyolysis (degeneration of skeletal muscle tissue) or death due to rhabdomyolysis, quality of life or compliance to study medication.

AUTHORS' CONCLUSIONS

Statin treatment is an effective lipid-lowering therapy in children with familial hypercholesterolemia. Few or no safety issues were identified. Statin treatment seems to be safe in the short term, but long-term safety remains unknown. Children treated with statins should be carefully monitored and followed up by their pediatricians and their care transferred to an adult lipidologist once they reach 18 years of age. Large long-term randomized controlled trials are needed to establish the long-term safety issues of statins.

Lipid-lowering drugs (statins) and peripheral neuropathy

Background and aim

Peripheral neuropathy is a disorder with often unknown causes. Some drugs, including statins, are proposed to be among the causes of peripheral neuropathy. This study aimed at evaluating this condition by electrodiagnostic study among patients who had received statins.

Methods

This case-control study was conducted in Shiraz, Iran in 2015, and included 39 patients aged 35–55 who had received statins for at least 6 months, and 39 healthy matched controls. Using electrodiagnosis, the sensory and motor wave features (amplitude, latency and nerve conduction velocity) of the peripheral nerves (Median, Ulnar, Tibial, Sural, and Peroneal) were evaluated among the subjects. Data were analyzed using SPSS software and p<0.05 was considered statistically significant.

Results

Regarding the occurrence of neuropathy, there were no significant differences in any of the definitions presented for peripheral neuropathy. However, the difference was close to significance for one definition [2 abnormalities in 2 nerves (p=0.055)]. Regarding mean values of the features, significant differences were observed in two features: amplitude of the peroneal motor nerve (p=0.048) and amplitude of the sural sensory nerve (p=0.036).

Conclusion

Since statins are widely used, awareness regarding their side-effects would lead to better treatment. Even though no significant differences were found between the groups regarding the occurrence of peripheral neuropathy, there were significant differences in amplitudes of the sural sensory response and the peroneal motor response. This indicates the involvement of peripheral nerves. Therefore, we recommend that patients and physicians should be informed about the possible symptoms of this condition.

Statins for children with familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia is one of the most common inherited metabolic diseases and is an autosomal dominant disorder meaning heterozygotes, or carriers, are affected. Those who are homozygous have severe disease. The average worldwide prevalence of heterozygous familial hypercholesterolemia is at least 1 in 500, although recent genetic epidemiological data from Denmark and next generation sequencing data suggest the frequency may be closer to 1 in 250. Diagnosis of familial hypercholesterolemia in children is based on elevated total cholesterol and low-density lipoprotein cholesterol levels or DNA-based analysis, or both. Coronary atherosclerosis has been detected in men with heterozygous familial hypercholesterolemia as young as 17 years old and in women with heterozygous familial hypercholesterolemia at 25 years old. Since the clinical complications of atherosclerosis occur prematurely, especially in men, lifelong treatment, started in childhood, is needed to reduce the risk of cardiovascular disease. In children with the disease, diet was the cornerstone of treatment but the addition of lipid-lowering medications has resulted in a significant improvement in treatment. Anion exchange resins, such as cholestyramine and colestipol, were found to be effective, but they are poorly tolerated. Since the 1990s studies carried out on children aged 6 to 17 years with heterozygous familial hypercholesterolemia have demonstrated significant reductions in their serum total and low-density lipoprotein cholesterol levels. While statins seem to be safe and well-tolerated in children, their long-term safety in this age group is not firmly established. This is an update of a previously published version of this Cochane Review.

OBJECTIVES

To assess the effectiveness and safety of statins in children with heterozygous familial hypercholesterolemia.

SEARCH METHODS

Relevant studies were identified from the Group's Inborn Errors and Metabolism Trials Register and Medline.Date of most recent search: 20 February 2017.

SELECTION CRITERIA

Randomized and controlled clinical studies including participants up to 18 years old, comparing a statin to placebo or to diet alone.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for inclusion and extracted data.

MAIN RESULTS

We found 26 potentially eligible studies, of which we included nine randomized placebo-controlled studies (1177 participants). In general, the intervention and follow-up time was short (median 24 weeks; range from six weeks to two years). Statins reduced the mean low-density lipoprotein cholesterol concentration at all time points (moderate quality evidence). Serum aspartate and alanine aminotransferase, as well as creatinine kinase concentrations, did not differ between treated and placebo groups at any time point (low quality evidence). The risks of myopathy (low quality evidence) and clinical adverse events (moderate quality evidence) were very low and also similar in both groups. In one study simvastatin was shown to improve flow-mediated dilatation of the brachial artery (low quality evidence), and in another study treatment with pravastatin for two years induced a significant regression in carotid intima media thickness (low quality evidence).

AUTHORS' CONCLUSIONS

Statin treatment is an effective lipid-lowering therapy in children with familial hypercholesterolemia. No significant safety issues were identified. Statin treatment seems to be safe in the short term, but long-term safety remains unknown. Children treated with statins should be carefully monitored and followed up by their pediatricians and their care transferred to an adult lipidologist once they reach 18 years of age. Large long-term randomized controlled trials are needed to establish the long-term safety issues of statins.

Intermittent Nondaily Dosing Strategies in Patients with Previous Statin-Induced Myopathy

OBJECTIVE

To review the safety and efficacy of alternative intermittent statin dosing regimens in patients with previous intolerance due to myopathy.

DATA SOURCES

Literature was accessed through MEDLINE (1946 -December 2012) and EMBASE (1966-December 2012) using relevant MeSH and Emtree search terms, including statins, HMG Co-A reductase inhibitors, simvastatin, atorvastatin, lovastatin, fluvastatin, pravastatin, pitavastatin, rosuvastatin, myopathy, and myalgias. Web of Science (1955-December 2012) and the aforementioned databases were additionally searched using combinations of the following text words: statin intolerance, alternate dosing, nondaily dosing, weekly dosing, statin-induced myopathy, and intermittent statin dosing. References of identified articles were reviewed for additional citations.

STUDY SELECTION AND DATA EXTRACTION

All identified English-language peer-reviewed publications were evaluated. Articles (excluding meeting abstracts) specifically addressing nondaily statin use in patients with previous statin-induced myopathy were reviewed.

DATA SYNTHESIS

Although statins have achieved significant reductions in cardiovascular morbidity and mortality, as many as 10% of patients prescribed these therapies experience myopathies. Intermittent statin regimens ranging from every-other-day to once- weekly dosing have emerged in an attempt to maintain efficacy while moderating the incidence of adverse effects. The results reported in 10 publications investigating varying regimens with atorvastatin and/or rosuvastatin revealed that at least 70% of patients were able to tolerate an intermittent dosing strategy without a recurrence of previous treatment-limiting adverse effects. Although the degree of low-density lipoprotein cholesterol–lowering varied appreciably among studies (12–38%), the addition of a nondaily statin regimen facilitated attainment of National Cholesterol Education Program goals for some.

CONCLUSIONS

Although areas of uncertainty remain, intermittent dosing (particularly with rosuvastatin and atorvastatin) in previously intolerant patients is a useful strategy to capitalize on the benefits of this therapy. Larger scale randomized trials are necessary to more clearly define the role of this strategy and the optimal choice of regimen.

The Toxicology of HMG—CoA Reductase Inhibitors: Prediction of Human Risk

The discovery that 3-hydroxy-3-methyglutaryl coenzyme A reductase was a rate-determining step in the biosynthesis of cholesterol led to the discovery of inhibitors of this enzyme. To support the development of these agents (statins) as potential hypocholesterolemic drugs, a variety of preclinical studies were conducted in several animal species. Not unexpectedly due to the central role played by mevalonic acid and its products including cholesterol in development and maintenance of cellular homeostasis, administration of high dosage levels of these agents led to the expression of a broad variety of adverse effects in many different tissues. Using the tools of toxicologic pathology and classical risk assessment, these varied toxicities were evaluated by many groups relative to the conditions of use in human therapy and a perspective was developed on potential human risk. These approaches of mechanism-based risk assessment predicted that most of the adverse effects observed in animals would not be seen under conditions of human use and supported the successful introduction of one of the most important classes of human medicines.

Low serum vitamin D occurs commonly among multiple myeloma patients treated with bortezomib and/or thalidomide and is associated with severe neuropathy

PURPOSE

Previous studies have shown that low serum vitamin D levels have been associated with many skeletal and non-skeletal disorders. We studied the relationship between 25-hydroxyvitamin D (25D) levels and motor and sensory peripheral neuropathy (PN) among multiple myeloma (MM) patients who have been treated with bortezomib and/or thalidomide.

METHODS

We performed a study of 111 MM patients who had received at least one of these two agents for at least 12 weeks by correlating physical exam/neurologic assessment findings with patient self-assessment responses.

RESULTS

The median age of study patients was 66 years (range 42-89 years) and 54 % were males. 25D levels were determined, and complete history and physical and neurologic examinations were performed at the same study visit. In addition, study subjects completed questionnaires regarding symptoms related to motor and sensory PN. Overall, patients had a median serum 25D level of only 32 ng/ml; 42 % of patients were considered either 25D-deficient (<20.0 ng/mL; 16 % of patients) or 25D-insufficient (20.0-29.9 ng/mL; 26 %). Notably, we found that 25D-deficient MM patients were more likely to have severe PN (>grade 2) of both motor (p = 0.0415) and sensory (p = 0.0086) types although the overall incidence of PN was not higher in this patient population.

CONCLUSION

These results show that the severity of peripheral neuropathy is associated with lower vitamin D levels and provides the rationale for monitoring vitamin D for myeloma patients especially those receiving drugs associated with the development of peripheral neuropathy.

Statins for children with familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia is one of the most common inherited metabolic diseases; the average worldwide prevalence of heterozygous familial hypercholesterolemia is at least 1 in 500. Diagnosis of familial hypercholesterolemia in children is based on highly elevated low-density lipoprotein (LDL) cholesterol level or DNA-based analysis, or both. Coronary atherosclerosis has been detected in men with heterozygous familial hypercholesterolemia as young as 17 years old and in women with heterozygous familial hypercholesterolemia at 25 years old. Since the clinical complications of atherosclerosis occur prematurely, especially in men, lifelong hypolipidemic measures, started in childhood, are needed to reduce the risk of cardiovascular disease. In children with familial hypercholesterolemia, diet is as yet the cornerstone of treatment. Anion exchange resins, such as cholestyramine and colestipol, have also been found to be effective, but are poorly tolerated. Since the 1990s statin studies have been carried out among children with familial hypercholesterolemia (aged 7 to 17 years). Statins greatly reduced their serum LDL cholesterol levels. Even though statins seem to be safe and well-tolerated in children, their long-term safety in this age group is not firmly established.

OBJECTIVES

To assess the effectiveness and safety of statins in children with familial hypercholesterolemia.

SEARCH METHODS

Relevant studies were identified from the Group's Inborn Errors and Metabolism Trials Register and Medline.Date of most recent search: 14 October 2013.

SELECTION CRITERIA

Randomized and controlled clinical studies including participants up to 18 years old, comparing a statin to placebo or to diet alone.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for inclusion and extracted data.

MAIN RESULTS

We found 21 potentially eligible studies, of which we included eight randomized placebo-controlled studies (1074 participants). In general, the intervention and follow-up time was short (median 24 weeks; range from six weeks to two years). Statins reduced the mean LDL cholesterol concentration at all time points. Serum aspartate and alanine aminotransferase, as well as creatinine kinase concentrations, did not differ between treated and placebo groups at any time point. The risks of myopathy and clinical adverse events were very low and also similar in both groups. In one study simvastatin was shown to improve flow-mediated dilatation of the brachial artery, and in another study treatment with pravastatin for two years induced a significant regression in carotid intima media thickness.

AUTHORS' CONCLUSIONS

Statin treatment is an efficient lipid-lowering therapy in children with familial hypercholesterolemia. No significant safety issues were identified. Statin treatment seems to be safe in the short term, but long-term safety is unknown. Children treated with statins should be carefully monitored and followed up by their pediatricians or physicians into adulthood. Large long-term randomized controlled trials are needed to establish the long-term safety issues of statins.

Peripheral neuropathy induced by red yeast rice in a patient with a known small bowel gastrointestinal tumour

Peripheral neuropathy is a well-recognised side effect of the cholesterol-lowering statins. Red yeast rice (RYR) is a traditional Chinese herb, widely available over-the-counter that has also been found to reduce cholesterol. Little data is available regarding its side effect profile. We report a case of a 60-year-old male receiving therapeutic imatinib for metastatic gastrointestinal tumour (GIST), who developed peripheral neuropathy while also taking RYR. The symptoms completely settled following withdrawal of the RYR and he has subsequently continued to take imatinib for over 2 years with no adverse effects. Further research into the safety profile of RYR is needed. The importance of questioning patients about over the counter medications and herbal remedies cannot be overemphasised.

Low-density lipoprotein reduction: is the risk worth the benefit?

Outcomes from recent lipid-lowering trials have led to an update of the third Report of the National Cholesterol Education Program (NCEP) Adult Treatment Panel's guidelines for treatment of hypercholesterolemia in adults. The updated NCEP guidelines now offer an optional goal of low-density lipoprotein (LDL) cholesterol of less than 70 mg/dL for high-risk individuals. Epidemiologic and clinical trial data suggest that for every 30-mg/dL change in LDL, the relative risk for coronary heart disease changes by about 30%. Statin therapy effectively lowers LDL and has an overall excellent safety profile in clinical trials. However, the use of high-dose statin therapy also entails greater risk of adverse events, such as myopathy and liver function test abnormalities, and this must be carefully weighed against the potential benefit for each patient. Alternative approaches targeting high-density lipoproteins and triglycerides may offer yet another option for coronary heart disease prevention in high-risk patients.

Advances in Understanding Drug-Induced Neuropathies

Many commonly used medications have neurotoxic adverse effects; the most common of these is peripheral neuropathy. Neuropathy can be a dose-limiting adverse effect for many medications used in life-threatening conditions, such as malignancy and HIV-related disease. Epidemiological evidence supports previous case reports of HMG-CoA reductase inhibitors (or 'statins') causing an axonal sensorimotor neuropathy or a purely small-fibre neuropathy in some patients. The neuropathy improves when the medication is withdrawn. Despite the association between HMG-CoA reductase inhibitors and neuropathy, the risk is low compared with the significant vascular protective benefits. Oxaliplatin, a new platinum chemotherapy agent designed to have fewer adverse effects than other such agents, has been shown to cause a transient initial dysaesthesia in addition to an axonal polyneuropathy. Thalidomide, an old therapy currently being utilised for new therapeutic indications (e.g. treatment of haematological malignancies), is associated with a painful, axonal sensorimotor neuropathy that does not improve on withdrawal of the drug. Nucleoside reverse transcriptase inhibitors are important components of highly active antiretroviral therapy, but are associated with a sensory neuropathy that is likely to be due to a direct effect of these drugs on mitochondrial DNA replication. New research demonstrates that lactate levels may help discriminate between neuropathy caused by nucleoside analogues and HIV-induced neuropathy. Understanding the mechanism of drug-induced neuropathy has led to advances in preventing this disabling condition.

The "Statinth" wonder of the world: a panacea for all illnesses or a bubble about to burst

After the introduction of statins in the market as effective lipid lowering agents, they were shown to have effects other than lipid lowering. These actions were collectively referred to as 'pleiotropic actions of statins.' Pleiotropism of statins formed the basis for evaluating statins for several indications other than lipid lowering. Evidence both in favour and against is available for several of these indications. The current review attempts to critically summarise the available data for each of these indications.