April 22, 2021 Are you living with type 2 diabetes and kidney disease?

For many years, doctors did not give metformin to people who have both type 2 diabetes and kidney disease, because they believed it caused an increased risk of lactic acidosis—a rare but serious condition that can cause severe muscle pain, cramps, nausea, and weakness.

Researchers from Johns Hopkins Medicine in Baltimore, who studied the medical records of more than 75,000 people with type 2 diabetes, did find a link between metformin and acidosis—but only in patients with severely decreased kidney function, not in those with only a mild or moderate decrease in function.

Published in the July 2018 issue of the Journal of the American Medical Association, the study is important for two reasons: Diabetes is the leading cause of kidney disease in Canada, and up to one-half of all people with diabetes will have signs of kidney damage in their lifetime. Also, metformin is often the first oral drug recommended for people newly diagnosed with type 2 diabetes.

According to the Diabetes Canada 2018 Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada, metformin has many benefits over other drugs that people with type 2 diabetes can take to control blood sugar, including less weight gain, a lower risk of heart attack, and higher long-term survival.

This article appeared in Diabetes Dialogue, Winter 2019.