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Association of Metformin Use With Age-Related Macular Degeneration: A Case-Control Study

Andrea L. Blitzer, S. Ham, K. Colby, D. Skondra

JAMA ophthalmology, 2021

312 participants · 102 citations

Abstract

Importance

Age-related macular degeneration (AMD), the leading cause of irreversible blindness in older adults, appears to have no effective preventive measures. The common antidiabetic drug metformin has been shown to have protective outcomes in multiple age-associated diseases and may have the potential to protect against the development of AMD.

Objective

To determine whether metformin use is associated with reduced odds of developing AMD.

Design, Setting, and Participants

This case-control study of patients from a nationwide health insurance claims database included a population-based sample of patients. Those aged 55 years and older with newly diagnosed AMD from January 2008 to December 2017 were defined as cases and matched with control participants. Data analyses were completed from June 2019 to February 2020.

Exposures

Dosage of metformin and exposure to other prescribed medications, as identified from outpatient drug claims.

Main Outcomes and Measures

Risk of developing AMD.

Results

A total of 312 404 affected individuals were included (181 817 women [58.2%]). After matching, 312 376 control participants were included (172 459 women [55.2%]; age range, 55 to 107 years). The case group had a slightly higher percentage of participants with diabetes (81 262 participants [26.0%]) compared with the control group (79 497 participants [25.5%]). Metformin use was associated with reduced odds of developing AMD (odds ratio [OR], 0.94 [95% CI, 0.92-0.96]). This association was…

How strong is the evidence?

Evidence Hub reads this as a case-control, done in people. Its evidence level is 4 of 5 (Low · observational). Observational designs can show an association but not prove cause. Reported size: 312 participants or records.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

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