Published: Sep 19, 2013 | Updated: Sep 20, 2013
By Chris Kaiser, Cardiology Editor, MedPage Today
Full Story: http://www.medpagetoday.com/cardiology/dyslipidemia/41753
Action Points
- Statins clear cholesterol from the blood but they may do so at the risk of obstructing vision.
- Note that in both analyses, researchers found an inverse relationship with levels of LDL cholesterol and cataract risk, but not for levels of HDL cholesterol.
Statins clear cholesterol from the blood but they may do so at the risk of obstructing vision, a new propensity score-matched study suggested.
In the primary analysis of 6,972 matched pairs of statin users and nonusers, those taking the cholesterol-lowering medication had a 9% increased risk of developing cataracts (95% CI 1.02-1.17), reportedIshak Mansi, MD, of the VA North Texas Health System at the University of Texas Southwestern in Dallas, and colleagues.
In a secondary subgroup analysis of 33,513 patients (6,113 on statins) who had no comorbidity, based on the Charlson comorbidity index, the use of statins remained significantly associated with cataracts (OR 1.27, 95% CI 1.15-1.40), according to the study published online in JAMA Ophthalmology.
“The association between statin use and cataract formation has been the topic of controversy since the class of medications was introduced in the 1980s,” Anurag Shrivastava, MD, attending cataract and glaucoma surgeon at Montefiore Medical Center in the Bronx, N.Y., told MedPage Today.
“Some studies have demonstrated causation, while others have actually shown a protective effect. Indeed, the unique mechanism of these medications may hypothetically have either effect,” he added.
Regarding prior inconsistent findings, Shrivastava, who was not involved in the study, said that the “propensity score-matched analysis elegantly allows for the best comparison possible from the database, limiting the vast majority of expected confounders in the analysis.”
There are certainly limitations with this analysis, but the design has allowed for a “much clearer view of the association than prior studies have to date,” he added.
Not only do cataracts diminish quality of life, but they carry a high financial burden — costing about $4.7 billion a year to treat in the U.S. — and understanding the “modifiable risk factors for the condition needs to be a public health priority,” the authors wrote.
It becomes even more important, they said, as statins are increasingly being used in primary prevention.
For the study, Mansi and colleagues retrospectively selected patients enrolled in the San Antonio Military Multi-Market Area as Tricare Prime or Plus.
For baseline inclusion, they identified patients enrolled in the system between Oct. 1, 2003 and Sept. 30, 2005. The follow-up period for identifying occurrence of cataracts was between Oct. 1, 2005 and March 1, 2010.
The mean age of those in the primary analysis was 56, with 54% being men.
In the secondary analysis, the mean age of statin users and nonusers was 56 and 46, respectively, with men comprising 60% of users versus 48% of nonusers.
In both analyses, researchers found an inverse relationship with levels of LDL cholesterol and cataract risk, but not for levels of HDL cholesterol.
The results remained consistent in all subgroups of statin users at various durations of statin use — greater than 2 years, greater than 4 years, and greater than 6 years.
Shrivastava said it’s “unlikely that there are explicit preventative measures that should be advised specifically for patients on statin medications based upon this, or other studies.”
He noted that general recommendations for cataract prevention include a balanced diet, healthy lifestyle, no smoking, and protection from ultraviolet light, along with strict glycemic control for diabetics.
But physicians should pay special attention to statin users taking steroidal medications for any reason because those drugs are associated with both cataracts and glaucoma, Shrivastava said.
Nevertheless, the benefits of statins outweigh the risk of cataracts, he said.
Strengths of the study include the propensity score-matching, a large cohort of patients followed-up longitudinally within the same healthcare system, and the consistency of military healthcare provision, the authors said.
The limitations include its retrospective design, the potential for residual confounding, no data on the visual significance of the cataract, and the use of pharmacy data to ascertain statin use. Also, the increase in the prevalence of cataracts could be due to more sensitive methods of detection, Mansi and colleagues said.
One author received funding support from the National Institutes of Health.
Only one author, Frei, had conflicts of interest to report, which included relationships with AstraZeneca, Bristol-Myers Squibb, Elan, Forest, Ortho-McNeil Janssen, and Pfizer.
From the American Heart Association:
Primary source: JAMA Ophthalmology