VANCOUVER, BC — Statin therapy significantly elevates the risk of developing cataracts severe enough to warrant surgery, suggests analyses of two distinct cohorts, one from Canada and another from the US, that add to a hazy landscape of prior studies variously concluding for or against such a risk for the widely used drugs.
For now, the possibility of such a risk from statins and its potential mechanisms should be explored in prospective trials, "especially in light of increased statin use for primary prevention of cardiovascular disease and the importance of acceptable vision in old age, when cardiovascular disease is common," according to the report, published in the December 2014 issue of the Canadian Journal of Cardiology with lead author Dr Stephanie J Wise (University of British Columbia, Vancouver).
"However, because the relative risk is low and because cataract surgery is effective and well tolerated, this association should be disclosed but not be considered a deterrent to use of statins when warranted for cardiovascular risk reduction," they write.
"For those of us who have prescribed high doses of statins for almost 3 decades, there is certainly no epidemic of cataracts among our longtime lipid-clinic patients," write Drs Steven E Gryn and Robert A Hegele (Western University, London, ON) in an accompanying editorial.
"Nevertheless, if the findings of Wise et al are confirmed, physicians might need to factor in this potential risk when discussing statin use with patients," they continue. "As with the statin-diabetes correlation, the risk of cataracts is greatest among individuals who are already predisposed to develop them."
And, in patients at high CV risk, "the prevention of CVD, stroke, and their associated morbidity and mortality vastly outweighs the risk of cataracts. Even among lower-risk patients, for whom the benefit/risk ratio is less dramatic, most patients would still probably prefer having to undergo earlier non–life-threatening cataract surgery over suffering a major vascular event."
Cohort From British Columbia
One of the cohorts consisted of men and women who went to ophthalmologists from 2000 to 2007, as recorded in British Columbia Ministry of Health databases. Cases consisted of 162 501 patients who during follow-up became candidates for surgery to correct cataracts; they were matched on the basis of age and follow-up time with 650 004 control subjects with no such history of cataracts. Together, their mean age was 73 years and they were followed for about 1.7 years.
For this group, the relative risk (RR) of cataracts severe enough for surgery associated with statin use for at least a year was 1.27 (95% CI 1.24–1.30) adjusted for age, follow-up time, sex, and cataract risk factors prior to cohort entry, including diabetes, hypertension, glaucoma, MI or stroke, and treatment with steroids or selective serotonin reuptake inhibitors (SSRIs).
The adjusted RR for lovastatin was 1.14 (95% CI 1.04–1.26) and for rosuvastatin (Crestor, AstraZeneca) was 1.42 (95% CI 1.27–1.59), with risks for other statins falling in between.
The All-Male US Cohort
The other cohort derived from IMS LifeLink, a US health claims database, and included men aged 40 to 85 years (mean about 72 years) seen from 2001 to 2011; the 45 065 patients who developed cataracts made up the cases and 450 650 subjects with no history of cataracts were the controls. Follow-up averaged 1.9 years.
The similarly adjusted RR for surgery-indicated cataracts associated with at least a year of statin therapy was 1.07 (95% CI 1.04–1.10). The RRs ranged from 1.03 for fluvastatin to 1.14 for lovastatin and reached significance for the latter agent and simvastatin, atorvastatin, and use of more than one statin; the risk was nonsignificant for pravastatin and rosuvastatin as well as fluvastatin.
The editorialists point out that despite matching, the case-control analyses could still have been confounded by unknown factors and that, indeed, some of the risk factors for cataracts are also risk factors for cardiovascular disease, which often leads to statin therapy.
"Furthermore, as the authors mention, smoking is an important risk factor that could not be adjusted for because the databases could not provide such information. So although this report adds to our accumulated knowledge on this topic, it by no means puts the issue to rest."
Wise reported no she had no relevant financial relationships; disclosures for the other authors are listed in the article. Gryn discloses consulting for Novartis and Hegele discloses serving "on the CME honoraria and advisory board consultation for Valeant, Amgen, Sanofi, and Aegerion."
Heartwire from Medscape © 2014 Medscape, LLC
Cite this: Cataracts From Statins? More Signals Emerge in Analyses - Medscape - Dec 10, 2014.