Study Title:

Effects of Statins on Energy and Fatigue With Exertion

Study Abstract

To our knowledge, this is the first randomized evidence affirming unfavorable statin effects on energy and exertional fatigue. Effects were seen in a generally healthy sample given modest statin doses, and both simvastatin and pravastatin contributed to the significant adverse effect of statins on energy and fatigue with exertion. Particularly for women, these unfavorable effects were not uncommon. Findings support case reports citing adverse effects to these outcomes and are buttressed by literature rationale.1 ,6 These findings are important, given the central relevance of energy and functional status to well-being.

These effects, germane to quality of life, merit consideration when prescribing or contemplating use of statins, particularly in groups without expected net morbidity/mortality benefit, extending to “high-risk” primary prevention and women and elderly persons (including those with coronary artery disease).7 - 9 There was a significant relation between EnergyFatigEx and actual activity: reduced activity and exertional tolerance (irrespective of activity) in turn predict hard adverse outcomes. Effects may take time to manifest, as may benefits of statin use. Thus, long-term trials are important, if statin use is to be recommended in younger individuals. Meanwhile, physicians should be alert to patients' reports of exertional fatigue or diminished energy during statin use.

From Reuters Health press release: (

The popular cholesterol-lowering drugs known as statins might take a toll on people's energy levels, a new study suggests.

Researchers say the potential side effect, which has yet to be confirmed by other experiments, is a particular concern for women. They estimate that out of 10 women taking Merck's Zocor, also called simvastatin, four would have less energy or feel more tired during exercise due to the drug.

Dr. Beatrice Golomb, who led the new research, told Reuters Health that many patients experience fatigue after starting on a statin, but that the evidence until now has been limited to observations.

Statins are generally thought to be safe drugs, but may cause muscle and joint pain in some patients.

Dr. Franz Messerli, who runs the hypertension program at St. Luke's-Roosevelt Hospital in New York and was not involved in the research, said the new findings were concerning and not unexpected given statins' effect on muscle tissue.

But another expert cautioned that the study had some limitations and said patients shouldn't stop taking their medication before talking to a doctor.

"Fatigue is reversible and not fatal," Dr. Kausik Ray told Reuters Health by email. "Risks and benefits in absolute terms should be discussed on a case by case basis."

Ray, who studies heart disease prevention at St. George's University of London, added that in his experience fatigue is not a common problem with statins.

But Golomb, of the University of California, San Diego, countered that doctors often fail to make the link between fatigue and statin use in their patients.

"Often it doesn't show up right away so physicians may not recognize the effect," she told Reuters Health.

Golomb and her colleagues used data from an earlier study of more than 1,000 men and women who had been randomly assigned to take either Zocor, another statin sold as Pravachol by Bristol-Myers Squibb (also called pravastatin) or an inactive placebo pill for six months.

The participants rated their energy levels at the beginning of the study and again after six months on a scale from -2 ("much less") to +2 ("much more"). The researchers then constructed a combined measure of how tired the participants felt overall and during exercise.

The findings suggested about 15 percent of statin users would feel more tired generally or during exercise due to the drugs, Golomb said. Both statins contributed to the effect, which was particularly strong in women.

Neither Merck nor Bristol-Myers Squibb could provide comments on the findings, which are published in Archives of Internal Medicine.

Studies have found that in people without heart disease the benefits of statins are very small at best. As a result, Golomb said, it's worth considering potential side effects such as fatigue before taking the drugs.

And for people on the drugs who feel more tired than usual, it might be worth dropping them altogether if there is little chance of benefit in the first place, she added.

St. George's Ray noted, however, that the link between the energy measure and actual exercise was weak, questioning the real-life importance of the results.

Study Information

Beatrice A. Golomb, MD, PhD; Marcella A. Evans, BS; Joel E. Dimsdale, MD; Halbert L. White, PhD
Effects of Statins on Energy and Fatigue With Exertion: Results From a Randomized Controlled Trial
Arch Intern Med
2012 August
University of California, San Diego.

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