JAMA: Taking the medication metformin hydrochloride was associated with
reduced risk of developing the sight-threatening disease open-angle
glaucoma in people with diabetes, according to a study published online
by JAMA Ophthalmology. Medications that mimic caloric restriction such as metformin can
reduce the risk of some late age-onset disease. It is unknown whether
these caloric mimetic drugs affect the risk of age-associated eye
diseases such as macular degeneration, diabetic retinopathy, cataract or
glaucoma.
Researcher Julia E. Richards, Ph.D., of the University of Michigan,
Ann Arbor, and coauthors examined metformin use and the risk of
open-angle glaucoma (OAG) using data from a large U.S. managed care
network from 2001 through 2010.
Of 150,016 patients with diabetes, 5,893 (3.9 percent) developed OAG.
Throughout the study period, 60,214 patients (40.1 percent) filled at
least one metformin prescription; 46,505 (31 percent) filled at least
one sulfonylurea prescription; 35,707 (23.8 percent) filled at least one
thiazolidinedione prescription; 3,663 (2.4 percent) filled at least one
meglitinide prescription; and 33,948 (22.6 percent) filled at least one
insulin prescription. Some patients filled prescriptions for multiple
medications.
Study results indicate that patients prescribed the highest amount of
metformin (greater than 1,110 grams in two years) had a 25 percent
reduced risk of OAG risk compared with those who took no metformin.
Every one-gram increase in metformin was associated with a 0.16 percent
reduction in OAG risk, which means that taking a standard dose of 2
grams of metformin per day for two years would result in a 20.8 percent
reduction in risk of OAG.
“Although the impact of metformin on risk is known for some traits
such as cardiovascular disease, diabetes and some specific cancers, this
study points out the importance of understanding the potential impact
of CR (caloric restriction) mimetic drugs on the risk of developing
other medical conditions that affect older persons. It will also be
important to elucidate the mechanisms of metformin action, at both the
molecular and clinical level, in the ocular tissues involved in OAG
pathology,” the study concludes.
(JAMA Ophthalmol. Published online May 28, 2015. doi:10.1001/jamaopthalmol.2015.1440. Available pre-embargo to the media at http://media.jamanetwork.com.)