Carolyn M. Machan, OD, and colleagues of University of Waterloo, Ontario, Canada, found that people with type 2 diabetes also have an additional risk of cataracts similar to statin users. However, more research is necessary in order to have better knowledge on the true nature of the association.
Cataracts Risk Is Increased by Both Diabetes And StatinsThe researchers analyzed 6,400 patients from the University of Waterloo's optometry clinic in 2007 to 2008. Of those participants, 452 were struggling with type 2 diabetes. While controlling for factors such as sex, high blood pressure, and smoking, the experts evaluated diabetes and statin treatment as possible risk factors.
While 56% of patients with type 2 diabetes were taking statins, and 16% of people without diabetes were taking statins, diabetes and statin use were both significantly associated with an elevated rate of age-related cataracts.
Statin use was associated with a 57% increase in cataracts risk while diabetes was associated with an 82% increase, after adjusting for other factors. The statistical analysis showed that the increase in cataract risk associated with statins was similar to that associated with diabetes.
However, the associations were different for certain types of cataracts. For example, one specific type long linked to diabetes, called posterior sub capsular cataracts, was not significantly linked anymore after adjusting for statin treatment.
Even though there was a high rate of statin use among diabetes patients, the two risk factors were independent of each other. Older diabetic patients who took statins had the fastest increase risk of cataracts, and the slowest was seen in non-diabetic patients who did not take statins. Compared to the non-diabetics who did not take statins, diabetic patients taking the drug developed cataracts 5.6 years earlier on average.
Type 2 diabetes is a known risk factor for developing age-related cataracts. Cataracts refers to a common vision problem that occurs when there is clouding of the crystalline lens of the eye. Previous studies have shown that animals have a link between long-term treatment with statins (at high doses) and cataracts.
The results suggest that statins might be linked to cataracts in humans as well. The researchers say that the study cannot prove that these drugs are responsible for causing cataracts, but believe that such a link is possible.
Pointing out that further research is necessary, Dr. Machan and team explained that the known benefits of statin treatment for type 2 diabetes is probably worth any increased risk of cataracts. They hope that their study will help people become more aware of the risks of treatments for type 2 diabetes, and will also help the development of alternative drugs that can lower cholesterol that are not going to increase any risk of cataracts.
Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science, said:
"Considering the increase in the prevalence of diabetes and the corresponding increase in the use of statins, the authors feel these findings serve to encourage further research on the long-term effect of statins on the human crystalline lens."