High-dose statins associated with more admissions for acute kidney injury

Higher-dose statin therapy was associated with more hospital admissions for acute kidney injury than lower-intensity treatment, a study found.

Although the effect seemed to be strongest in the first 120 days after initiation of statin treatment, increased risk of admission remained elevated for at least two years, researchers noted.

To quantify an association between acute kidney injury and use of higher-dose statins (defined as ≥10 mg of rosuvastatin, ≥20 mg of atorvastatin and ≥40 mg of simvastatin) versus lower-dose statins, researchers conducted a retrospective observational analysis including more than 2 million patients age 40 years or older who were newly treated with statins from January 1997 through April 2008 in the U.S., United Kingdom and Canada. Each person hospitalized for acute kidney injury was matched with 10 controls.

Results appeared online March 19 at BMJ.

Among 2,008,003 patients without chronic kidney disease, there were 4,691 hospitalizations for acute kidney injury within 120 days of treatment. Among 59,636 patients with chronic kidney disease, there were 1,896 hospitalizations.

In patients without chronic kidney disease, current users of higher-dose statins were 34% more likely to be hospitalized with acute kidney injury within 120 days after starting treatment (fixed-effect rate ratio, 1.34; 95% CI, 1.25 to 1.43) than lower-dose statin users. Users of higher-dose statins with chronic kidney disease had a 10% increase in admission rate (fixed-effect rate ratio, 1.10; 95% CI, 0.99 to 1.23), a nonsignificant difference compared to lower-dose statin users.

Researchers noted that clinicians should consider this potential risk before prescribing high-dose statins when treatment with a lower dose is an option. In previous studies of statins, more intensive statin treatment in secondary prevention was associated with a 0.3% reduction in absolute risk in major coronary events per year of treatment. But these previous studies could have overstated statins' efficacies in typical clinical practice, and mostly involved comparisons of a low dose of a statin to its highest possible dose, the authors said.

“In reality, clinicians would not choose between, for example, 10 mg of atorvastatin and 80 mg of atorvastatin,” researchers wrote. “Given what is likely to be a small magnitude of incremental cardiovascular benefit of high potency statins over low potency statins in reality, a pressing question is how to identify patients for whom the risk-benefit balance for high potency statin treatment is unfavorable.”

An editorial noted, “Despite extensive experience with the use of statins over many years, optimization of doses to derive benefit but minimize risk is still evolving. The results of the current study indicate that a randomized controlled trial is needed to compare the adverse effects of high and low potency statins.”