Taking the metformin is associated with reduced risk of developing the sight-threatening disease open-angle glaucoma in diabetes patients, according to a US study.
Researchers from the University of Michigan examined metformin use and the risk of open-angle glaucoma (OAG) using data from 2001-10. Of 150,016 patients with diabetes, 3.9% developed OAG.
Throughout the study period, 40.1% filled at least one metformin prescription.
“It will be important to elucidate the mechanisms of metformin action”
Meanwhile, 31% filled at least one sulfonylurea prescription, 23.8% filled at least one thiazolidinedione prescription, 2.4% filled at least one meglitinide prescription, and 22.6% filled at least one insulin prescription. Some patients filled prescriptions for multiple medications.
The study results indicated that patients prescribed the highest amount of metformin – greater than 1,110 grams in two years – had a 25% reduced risk of OAG risk, compared with those who took no metformin.
Every one-gram increase in metformin was associated with a 0.16% 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% reduction in risk of OAG.
The authors said: “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,’ they said online in the journal JAMA Ophthalmology.