Long-term efficacy and tolerability of simvastatin in a large cohort of elderly hypercholesterolemic patients

A common missense variant of LILRB5 is associated with statin intolerance and myalgia

Aims

A genetic variant in LILRB5 (leukocyte immunoglobulin-like receptor subfamily-B) (rs12975366: T > C: Asp247Gly) has been reported to be associated with lower creatine phosphokinase (CK) and lactate dehydrogenase (LDH) levels. Both biomarkers are released from injured muscle tissue, making this variant a potential candidate for susceptibility to muscle-related symptoms. We examined the association of this variant with statin intolerance ascertained from electronic medical records in the GoDARTS study.

Methods and results

In the GoDARTS cohort, the LILRB5 Asp247 variant was associated with statin intolerance (SI) phenotypes; one defined as having raised CK and being non-adherent to therapy [odds ratio (OR) 1.81; 95% confidence interval (CI): 1.34-2.45] and the other as being intolerant to the lowest approved dose of a statin before being switched to two or more other statins (OR 1.36; 95% CI: 1.07-1.73). Those homozygous for Asp247 had increased odds of developing both definitions of intolerance. Importantly the second definition did not rely on CK elevations. These results were replicated in adjudicated cases of statin-induced myopathy in the PREDICTION-ADR consortium (OR1.48; 95% CI: 1.05-2.10) and for the development of myalgia in the JUPITER randomized clinical trial of rosuvastatin (OR1.35, 95% CI: 1.10-1.68). A meta-analysis across the studies showed a consistent association between Asp247Gly and outcomes associated with SI (OR1.34; 95% CI: 1.16-1.54).

Conclusion

This study presents a novel immunogenetic factor associated with statin intolerance, an important risk factor for cardiovascular outcomes. The results suggest that true statin-induced myalgia and non-specific myalgia are distinct, with a potential role for the immune system in their development. We identify a genetic group that is more likely to be intolerant to their statins.

Common nonsynonymous substitutions in SLCO1B1 predispose to statin intolerance in routinely treated individuals with type 2 diabetes: a go-DARTS study

SLCO1B1 gene variants are associated with severe statin-induced myopathy. We examined whether these variants are also associated with general statin intolerance in a large population of patients with type 2 diabetes receiving statins as part of routine clinical care. A total of 4,196 individuals were genotyped for rs4149056 (Val174Ala) and rs2306283 (Asp130Asn). Intolerance was defined by serum biochemistry and also by discontinuation, switching, or reduction in dose of the prescribed statin drug. Ala174 was associated with higher intolerance (odds ratio = 2.05, P = 0.043), whereas Asp130 was associated with lower intolerance (odds ratio = 0.71, P = 0.026). Ala174 was associated with a lower low-density lipoprotein cholesterol (LDLc) response to statins (P = 0.01) whereas 130D was associated with a greater LDLc response to statins (P = 0.048), as previously reported; however, this association was no longer present when data for statin-intolerant individuals were removed from the analysis. This study suggests that common genetic variants selected for an extreme phenotype of statin-induced myopathy also predispose to more common milder statin intolerance and may, for this reason, impact lipid-lowering efficacy.

Should the Insulin Resistance Syndrome be Treated in the Elderly?

The insulin resistance syndrome represents the co-occurrence of hyperglycaemia, hypertension, central and overall obesity, and dyslipidaemia characterised by low high density lipoprotein-cholesterol (HDL-C) and high triglyceride levels. Epidemiologic studies have revealed an increasing prevalence of the insulin resistance syndrome in elderly populations. Indeed, recent data indicate that over 40% of US adults aged > or =60 years meet current criteria for the insulin resistance syndrome. Patients with this syndrome are at increased risk for the development of both cardiovascular disease (CVD) and type 2 diabetes mellitus, two of the most significant health problems among people >65 years of age. Identification and treatment of the insulin resistance syndrome may thus represent an important approach to reducing the overall burden of morbidity and mortality in the elderly. While development of the insulin resistance syndrome is partly determined by modifiable environmental factors, there may be a genetic basis for the syndrome, with high levels of concordance among monozygotic twins. Ongoing research focusing on the pathophysiology of this syndrome has implicated insulin resistance as the central disorder underlying both the development of diabetes as well as the pro-thrombotic endothelial dysfunction characteristic of CVD. Studies aimed at reversing insulin resistance have identified weight loss, exercise and pharmacological treatment with metformin, thiazolidinediones, HMG-CoA reductase inhibitors (statins) and ACE inhibitors as potential therapies to prevent the development of type 2 diabetes. However, although insulin sensitisation may be beneficial for preventing type 2 diabetes, there are no data yet available to show whether this strategy will reduce the incidence of CVD. Increased exercise and other healthy lifestyle changes form the cornerstone of therapy for elderly patients with the insulin resistance syndrome. In addition, active identification and aggressive management of traditional cardiovascular risk factors are the current standard of care. For elderly patients, recent studies have conclusively demonstrated the safety and efficacy of pharmacological management of elevated blood pressure and cholesterol levels.

How well tolerated are lipid-lowering drugs?

It has been clearly established that lipid-lowering treatments [such as 3-hydroxyl-3-methylglutamyl coenzyme A reductase inhibitors ('statins') or fibrates] can reduce cardiovascular events, and with one of the statins even total mortality, in high-risk populations. Intervention studies have not included the very old, but it is generally assumed that this patient group would benefit from these treatments to an extent similar to younger patients. Worries about the associations seen in observational studies between low cholesterol levels and cancer, cerebral haemorrhage or mood and behaviour change have been largely overcome by findings from the latest large drug intervention trials, which do not show any increase in these conditions with statin or fibrate treatments. The common adverse effects associated with these drugs are relatively mild and often transient in nature. Potentially more serious adverse effects, which are more clearly related to drug treatment and are probably dose-dependent, include elevations in hepatic transaminase levels and myopathy; however, these effects are uncommon and generally resolve rapidly when treatment is stopped. The risk of myopathy with fibrate treatment is increased in patients with renal impairment, and the risk of myopathy with statin treatment increases with co-administration of drugs that inhibit statin metabolism or transport. Other adverse effects are related to specific drugs, for example, clofibrate is associated with an increased risk of gallstones. Studies in elderly patients have not shown an increased risk of adverse effects with lipid-lowering drugs compared with younger patients, but in clinical practice there may be some increased risk, particularly with regards to drug interactions. Therefore, lipid-lowering drugs should be administered with extra caution to elderly patients.

Randomized clinical trials and recent patterns in the use of statins

BACKGROUND

Three landmark trials involving 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) were published between 1994 and 1996 (the Scandinavian Simvastatin Survival Study [4S], the West of Scotland Coronary Prevention Study, and the Cholesterol and Recurrent Events trial). These trials provided evidence that lipid-lowering therapy decreases cardiovascular events, including mortality. Whether these recent data caused a shift toward statin use has not been evaluated.

METHODS

Data from the National Ambulatory Medical Care Survey in 1980, 1981, 1985, and 1989 through 1998 were used. We analyzed 5053 visits by patients taking lipid-lowering medications to office-based physicians selected by stratified random sampling. The main outcome measure was use of specific lipid-lowering medications, including statins.

RESULTS

In 1980 resins and niacin were the most commonly used lipid-lowering medications. By 1985 rising use of fibrates caused reductions in niacin use and resin use. By 1989 statins replaced fibrates as the most heavily used medications. Statin use climbed continuously thereafter, accounting for 90% of visits by patients treated for hypercholesterolemia in 1998. In time series analyses, increases in overall statin use were temporally unrelated to the publication of clinical trials, although the 4S trial may have contributed to a shift from older statins to simvastatin. For patients receiving lipid-lowering therapy in 1993 to 1998, statin use was significantly more likely for female patients, white patients, and patients visiting cardiologists.

CONCLUSIONS

Although the market for lipid-lowering medications is dominated by statins, the rise in statins predated the recent clinical trials supporting their use.

Use of lipid lowering drugs for primary prevention of coronary heart disease: meta-analysis of randomised trials

OBJECTIVE

To summarise the effect of primary prevention with lipid lowering drugs on coronary heart disease events, coronary heart disease mortality, and all cause mortality.

DESIGN

Meta-analysis.

IDENTIFICATION

Systematic search of the Medline database from January 1994 to June 1999 for English language studies examining drug treatment for lipid disorders (use of the MeSH terms "hyperlipidemia" and "anticholesteremic agents," keyword searches for individual drug names, and a search strategy for identifying randomised trials to capture relevant articles); identification of older studies through systematic reviews and hand search of bibliographies.

INCLUSION CRITERIA

All randomised trials of at least one year's duration that examined drug treatment for patients with no known coronary heart disease, cerebrovascular disease, or peripheral vascular disease and that measured clinical end points, including all cause mortality, coronary heart disease mortality, and non-fatal myocardial infarctions.

DATA EXTRACTION

Review of the articles and extracted relevant data by two authors separately, with disagreements resolved by consensus.

RESULTS

Four studies met eligibility criteria. Drug treatment reduced the odds of a coronary heart disease event by 30% (summary odds ratio 0.70, 95% confidence interval 0.62 to 0.79) but not the odds of all cause mortality (0.94, 0.81 to 1.09). When statin drugs were considered alone, no substantial differences in results were found.

CONCLUSIONS

Treatment with lipid lowering drugs lasting five to seven years reduces coronary heart disease events but not all cause mortality in people with no known cardiovascular disease.