TUESDAY, June 20, 2006 (HealthDay News) -- A five-year study of people who took cholesterol-lowering statin drugs found they had a 40 percent lower incidence of the most common kind of cataract.
And the incidence of nuclear cataracts, in which the lens of the eye grows cloudy as a person ages, was 60 percent lower in statin users who never smoked and didn't have diabetes, the researchers said.
The best explanation is that the benefit is linked to statins' antioxidant activity, said Kristine Lee, a statistician at the University of Wisconsin School of Medicine and Public Health, who was involved with the study.
"Part of the reason we looked at statins is that oxidative stress is related to cataract development," Lee said.
No relationship was found between statin use and two less common forms of the eye condition, cortical and posterior subcapsular cataracts.
The findings appear in the June 21 issue of the Journal of the American Medical Association.
The Wisconsin researchers examined data from the Beaver Dam Eye Study, which followed 1,299 persons who were first examined between 1998 and 2000. In the five-year follow-up period 12.2 percent of the statin users developed nuclear cataracts, compared to 17.2 percent of people who weren't taking the drugs.
Because smoking and diabetes are known to increase the risk of nuclear cataracts, the researchers did a further analysis. That's where they discovered the 60 percent lower risk in nonsmokers without diabetes who took statins.
The results support a similar study reported in 2001 in the Annals of Internal Medicine, said Dr. Hershel Jick, associate professor of medicine at Boston University School of Medicine, and the author of the earlier report.
That study was done because animal trials indicated that members of the chemical class that includes statins might increase the risk of cataracts. But data from a large-scale British health survey found no such association, Jick said.
The Wisconsin study adds a new dimension "because they were able to separate out one type of cataract from another," Jick said. But, he added, "It's an observational study and not definitive" because it lacked the controls that are hallmarks of gold-standard medical research.
"But it is something I personally take seriously," Jick said.
Lee said it's too soon to recommend that people take statins to reduce their risk of cataracts. "Further research is definitely needed," she said. "Other statin studies should add this dimension to their findings."
More information
For more on cataracts, visit the U.S. National Library of Medicine.
