Between 2011 and 2012, 78 million adults in the United States had low-density lipoprotein (LDL) cholesterol levels that met the criteria for cholesterol medicine or had other health conditions that put them at high risk for heart disease and stroke. Heart disease, the No. 1 killer in the U.S., accounts for a half-million deaths per year.
The World Health Organization reports that high cholesterol contributes to about 56 percent of cases of coronary heart disease worldwide and causes more than 4 million deaths each year. In most parts of the world, the number of female deaths attributed to high cholesterol is slightly higher than the number of male deaths. The highest prevalence of high cholesterol occurs in women between the ages of 65 and 74.
About 95 million American adults age 20 or older have total cholesterol levels greater than 200 mg/dL, and nearly 29 million adults have total cholesterol levels higher than 240 mg/dL. Only 1 out of every 3 adults with high LDL cholesterol has the condition under control, and slightly more than half (55 percent, or 43 million) who need cholesterol medicine are currently taking it.
During 2011-12, more than one-quarter (27.9 percent) of adults 40 years of age and older reported using a prescription cholesterol-lowering medication in the past 30 days, an increase from 2003-04, when 1 in 5 adults used a cholesterol-lowering medication (19.9 percent).
Simvastatin was the most commonly used cholesterol-lowering medication, with 42 percent reporting its use followed by atorvastatin (20.2 percent), pravastatin (11.2 percent), rosuvastatin (8.2 percent), and lovastatin (7.4 percent).
Statins are relatively inexpensive and do not have many downsides; the most common complaint is myalgia, which is experienced by about 10 percent of patients. In addition to reducing the risk of cardiovascular disease, statins have been linked to benefits for other diseases and conditions, such as chronic pulmonary disease, chronic kidney disease, some cancers, dementia, Alzheimer’s disease, Parkinson’s disease, and infections. So, why shouldn’t everyone be on a statin?
The answer is because after a review of statins and multiple non-cardiovascular outcomes, the jury is still out. Researchers reviewed hundreds of meta-analyses of observational and randomized controlled trials of statin use in non-cardiovascular conditions.
Credibility assessments based on summary effect sizes from a random-effects model, between-study heterogeneity, 95 percent prediction interval, small-study effect, excess significance, and credibility ceilings were devised to classify evidence.
For observational studies, no convincing (class I) evidence, two highly suggestive (class II) associations (decreased cancer mortality in patients with cancer and decreased exacerbation in patients with chronic obstructive pulmonary disease), 21 suggestive (class III) associations, and 42 weak (class IV) associations were identified. One outcome from the randomized-controlled trials (decreased all-cause mortality in patients with chronic kidney disease) showed enough evidence with no hints of bias.
For adverse events, observational studies showed suggestive evidence that statins increase the risk for diabetes and myopathy. Among the randomized-controlled trials, no statistically significant effects were found on myopathy, myalgia, or rhabdomyolysis.
Although the researchers found suggestive evidence of statin use and lower risk of cancer, Alzheimer’s disease, dementia, kidney injury, and infection, no current evidence supports prescribing statins for use in these conditions.
Overall, the investigators concluded that the review does not warrant making any changes to the current clinical recommendations. Researchers suggest that at the present time, statins may not be good for everyone, and clinicians should reserve statin prescriptions for patients with other conditions pending further investigation.
