Review finds suggestive evidence insufficient to move practice
No benefits of statins beyond cardiovascular protection have strong enough evidence to support a guideline recommendation, a review of meta-analyses found.
None of the 278 non-cardiovascular disease (CVD) outcomes assessed based on the results of 112 meta-analyses of observational studies and 144 meta-analyses of randomized controlled trials (RCTs) yielded "convincing," class I evidence that statins help.
But there were two "highly suggestive" health benefits with class II observational evidence: reduced cancer mortality pooling all patients with cancer and fewer exacerbations in patients with chronic obstructive pulmonary disease (COPD), reported Evropi Theodoratou, MSc, PhD, of University of Edinburgh, and colleagues in the Annals of Internal Medicine.
High-quality evidence from RCTs well-powered statistically to look at mortality did support an all-cause mortality benefit in chronic kidney disease patients. There was also further suggestive or weak observational evidence for a mortality benefit in various patient subgroups both overall and for specific causes of death, Theodoratou's group found.
"The absence of convincing evidence of an association between statins and non-CVD outcomes supports leaving the current recommendations unchanged," the researchers concluded.
The benefits of statins for CVD care and lowering cholesterol are backed by sound evidence, the investigators noted. However, recent reports "have claimed that statins also are associated with outcomes of several other diseases, such as cancer and diabetes," they continued.
The credible effect on all-cause mortality risk in chronic kidney disease "may also be related to its favorable impact on cardiovascular outcomes," commented Ambarish Pandey, MD, of the University of Texas Southwestern Medical Center in Dallas.
But what the review didn't find may be important as well, noted Pandey, who was not involved in the review.
"This large-scale review allays the concerns regarding harmful effects of statins with respect to diabetes and myopathy. It is reassuring for the clinical practitioners that the authors did not find any credible evidence to suggest that statins may have these potential harmful effects," Pandey told MedPage Today.
Evidence for a variety of other benefits was suggestive: reductions in risk of Alzheimer's disease, dementia, and infection, for instance, as well as sustained virologic response in hepatitis C infection. Weak evidence was found for benefits in risk of Parkinson disease, renal dysfunction, and mild cognitive impairment.
There was weak or suggestive observational evidence for health risks related to diabetes, myopathy, cataract, and pancreatitis. But the RCT data actually suggested a benefit with regard to pancreatitis and only supported a risk of diabetes and myositis.
"Reports that statins are 'harmful' have gotten a lot of press, and as a result, patients often are reluctant to start a statin despite their proven cardiovascular benefits. I hope this huge study helps correct some of this misinformation and patient reluctance to use statins," Eric Peterson, MD, of Duke University School of Medicine in Durham, North Carolina, who was not involved in the study, told Medpage Today.
The investigators acknowledged the limitations of their work, including that in aggregating studies, relevant data and outcomes not listed in the meta-analyses may have been missed. Study credibility was based on several assumptions and arbitrary thresholds, the researchers noted.
Annals of Internal Medicine
Source Reference: He Y, et al “Statins and multiple noncardiovascular outcomes umbrella review of meta-analyses of observational studies and randomized controlled trials” Annals Inter Med 2018; DOI: 10.7326/M18-0808.
Read the original article on Medpage Today: Jury Still Out on Statins' Benefit Beyond the Heart