A medication commonly used in diabetes care might be effective in preventing a common type of heart failure, according to new research from the University of Arizona.
The drug is metformin. The most commonly prescribed medication for diabetes, it helps reduce blood sugar by restoring the body’s response to insulin and decreasing the amount of glucose released into the bloodstream by the liver. The cardiac condition is known as heart failure with preserved ejection fraction, or HFpEF. In HFpEF, the heart pumps normally but the wall of the left ventricle is too stiff. The heart is unable to fill properly and the blood supply to the rest of the body is lowered. Common symptoms are shortness of breath with exertion, fatigue and chest discomfort. Almost half of all heart failure patients are considered to have HFpEF, it’s more common in women, and as of now there are no drugs for the condition.
Because the researchers already knew that metformin increases the dilation of the left ventricle and lowers the rate of heart failure in people with diabetes, they decided to test whether it could help with HFpEF. They gave metformin to mice with HFpEF-like symptoms and discovered that the medication reduced stiffness in the left ventricle.
The researchers then set out to learn how the metformin was able to reduce stiffness, and they ascertained that it had to do with an important muscle protein called titin. Titin helps heart muscle recoil after it’s stretched, but in HFpEF patients an element was making the titin too stiff. The metformin, however, caused titin to become less stiff, or, to use the researchers’ term, to become “more compliant.” More compliant titin led to a reduction of stiffness in the heart muscle.
One of the most encouraging facets of the new research is that metformin has been around for a long time and its safety is established. According to Henk Granzier, PhD, one of the study authors, “…metformin is a potential therapy for patients with HFpEF. Because the drug is already approved and well-tolerated in humans, using it to target titin stiffness presents a unique opportunity for immediate translation to the clinic.”