Blog | Thursday, August 16, 2012

QD: News Every Day--Statins cleared on cognition and cancer, but cataracts a concern


Statins should be given despite cautions about cognition, cancer and diabetes, a review concluded. But the ophthalmologist should at least be kept in the loop, as cataracts may be associated with the drug class, another study reported.

First, the review and its conclusions appeared at the Journal of the American College of Cardiology.

Reports about memory loss, forgetfulness and confusion are rare and reversible. Of the nine observational studies that considered this side effect, four showed beneficial effects of statins on cognitive performance, three found no effect and two found an increased risk.

Finally, observed associations between low cholesterol and increased risk of cancer might originate from reverse causality or confounding. Cancer might be causing the low cholesterol, and confounding factors such as age, smoking, and alcohol use might also explain some of the observed associations. And, those with low cholesterol may simply live long enough to develop cancer, the authors commented.

Finally, the Women’s Health Initiative investigated the relationship between statins and diabetes, and while it had some limitations, it reported an association between statins and diabetes. However, because of the overwhelming benefit of statins, reducing cardiovascular events by 25% to 45%, the small increase in relative risk for the development of diabetes is outweighed by the cardiovascular benefit.

Now, a second study in the August issue of Optometry and Vision Science showed that statin use was substantially higher in patients with type 2 diabetes and was associated with age-related cataracts.

Researchers reviewed 6,397 patient files and calculated statin use among patients with type 2 diabetes (n=452) and without it (n=5,884). Prevalence of statin use was 56% for those with type 2 diabetes and 16% for those without it.

With adjustment for other factors, diabetes was associated with an 82 percent increase in cataract risk and statin use with a 57 percent increase. Statistically, the increase in cataract risk associated with statins was similar to that associated with diabetes, researchers reported in a press release.

Type 2 diabetes was significantly associated with nuclear sclerosis (odds ratio [OR]=1.62, 1.14 to 2.29) and cortical cataract (OR=1.37, 1.02 to 1.83). Statin use was associated with nuclear sclerosis (OR=1.48, 1.09 to 2.00) and posterior subcapsular cataract (OR=1.48, 1.07 to 2.04).

The 50% probability of cataract in statin users occurred at age 51.7 and 54.9 years in patients with type 2 diabetes and without diabetes, respectively. In non-statin users, it was significantly later at age 55.1 and 57.3 years for patients with type 2 diabetes and without diabetes, respectively (P less than 0.001).