No convincing evidence exists to support an association between statin use and non-cardiovascular disease (CVD) outcomes, and the current recommendations should not be changed, concluded the authors of an umbrella review published in the Annals of Internal Medicine.
Although the role of statins in reducing CVD is well supported, its use and efficacy in other outcomes—including cancer and diabetes—is not.
“An estimated 38.6 million persons in the United States (around 12% of the population) were using statins in 2011 to 2012, and recent guidelines have pushed for wider use. Because of the worldwide increase in statin use in the past several years, interest has grown regarding the potential effect of these drugs on non-CVD outcomes,” wrote these researchers, led by author Yazhou He, MD, Sichuan University West China School of Medicine, Chengdu, People’s Republic of China.
Dr. He and colleagues undertook this review of meta-analyses to assess the quantity, validity, and credibility of existing evidence about any associations between statins and non-CVD outcomes, as well as the effects of statins on these outcomes.
They searched MEDLINE, EMBASE, and other sources to identify meta-analyses of 112 observational studies and 144 randomized controlled trials (RCTs), which focused on 278 unique non-CVD outcomes. Upon their analysis, they discovered the following:
- For decreased cancer mortality in cancer patients and decreased exacerbations of chronic obstructive pulmonary disease (COPD), no class I (convincing) evidence and only two class II (highly suggestive) associations were found in observational studies. Researchers also found 21 class III (suggestive) associations, and 42 class IV (weak) associations.
- In RCTs, the outcome of decreased all-cause mortality in patients with chronic kidney disease (CKD) had sufficient evidence to support statin intake. However, researchers found no evidence that statins improve kidney function.
- Suggestive evidence was found showing that statins increase the risk for diabetes and myopathy in observational studies.
- In RCTs, statins had no statistically significant effects on myopathy, myalgia, or rhabdomyolysis.
“We report a dearth of convincing evidence that statins had a major role in the 278 unique non-CVD outcomes assessed. We identified only two highly suggestive associations (decreased cancer mortality in patients with cancer who had pre-diagnosis statin intake and reduced exacerbations in patients with COPD) from observational studies, and one outcome (lower all-cause mortality in patients with CKD) from RCTs, which were classified as having high credibility,” wrote the authors.
“Other potential non-CVD associations identified in this umbrella review include a lower risk for cancer, Alzheimer disease, dementia, kidney injury, and infection. We also identified evidence of potential harms from statins, such as induced diabetes and myopathy; however, the evidence had a relatively low level of credibility,” they concluded.
Therefore, the results of this umbrella review of existing meta-analyses do not support any change in the existing clinical recommendations regarding statin use for non-CVD conditions.