There is still much to be learned about the long-term effects of commonly prescribed drugs such as statins.
This week an observational study pointed to an association between statin use and the diagnosis of cataracts needing surgery in two different populations, one in the U.S. and the other in Canada. None of the patients had a history of cataracts at baseline.
The degree of risk differed between the two groups, as did the patient populations in this case-controlled analysis. The U.S. group, for instance, included only men and the Canadian group had men and women.
Earlier this year we took an in-depth look at the 2013 American Heart Association/American College of Cardiology guidelines on reducing atherosclerotic risk, which have been met with resistance. The guidelines do away with setting cholesterol targets and advocate a risk calculator that, if followed, would greatly increase the number of patients in certain populations to qualify for statins.
The guidelines may expose people who some cardiologists see as low risk to long-term use of statins. This may be especially concerning in younger patients who may take statins for decades with little data on potential long-term risks and unintended adverse effects.
In an interview, Rodney A. Hayward, MD, co-director of the Center for Practice Management and Outcomes Research at the Ann Arbor Veterans Affairs Healthcare System in Michigan, commended the guideline writers for abandoning targets. Analyses by his research team support the argument that there is no evidence that achieving low-density lipoprotein cholesterol targets improves outcomes.
Hayward, who also is a professor in the internal medicine department at the University of Michigan, added that most statin studies followed patients for five to six years. The studies established statins’ safety in the short term but not over extended time periods.
“Whenever you talk about a little more benefit but it is 25 to 30 years down the line, you have to really know how safe this medicine is long term,” he said. “We don’t even know it will be more effective. We need to look at long-term consequences of being on a statin. We tend to think of medications as innocent until proven guilty, and extending them constitutional rights is not in the best interest of our patients.”
Observational studies carry many caveats, and the cataract study is no exception. The authors emphasized that the risk of statin users developing cataracts appears to be low and the cardiovascular benefits of statin use is well established. But these kinds of studies also can send an early signal worth watching.
Editor, Cardiovascular Business