Metformin benefits for non-diabetics include its potential role in managing heart failure (HF), a condition where the heart struggles to pump blood efficiently, leading to symptoms like shortness of breath, fatigue, and fluid retention. These symptoms can severely limit daily activities and negatively impact quality of life. This article will focus on metformin’s role in non-diabetic individuals with Heart Failure with Moderately Reduced Ejection Fraction (HFmrEF). HFmrEF occurs when the left ventricle has an ejection fraction of 41-49%. Ejection fraction refers to the percentage of blood in the left ventricle that is pumped out. Normal values range from 55-70%, and a reduced ejection fraction is considered 40% or less in heart failure. Some individuals may have normal ejection fractions and still experience heart failure, but this is beyond the scope of this discussion.
Metformin’s Role in Heart Failure Treatment
A recent study from the Journal of Medicine and Life has highlighted metformin, commonly known for managing type 2 diabetes, as a promising treatment for heart failure, particularly in patients with HFmrEF. This research suggests that metformin could offer significant benefits beyond its traditional use in blood sugar control.
1. Improvement in Ejection Fraction (EF)
Patients treated with metformin demonstrated a significant improvement in ejection fraction (EF), a key indicator of heart function. The study reported a 6.1% increase in EF for the metformin group, compared to a 3.2% increase in the control group. This improvement indicates that metformin may enhance cardiac efficiency in patients with heart failure.
2. Reduction in Left Ventricular End-Diastolic Diameter (LVEDD)
Metformin was also associated with reduced left ventricular end-diastolic diameter (LVEDD), a measure of the heart’s size and function. Lower LVEDD indicates reduced stress on the heart, which is beneficial for long-term heart health and can help slow the progression of heart failure. The idea is that if the heart doesn’t have to work as hard to pump blood, the left ventricle’s muscle will shrink back to normal levels, which is a good thing! This is because more blood volume per heartbeat is possible as the muscle is not using up the precious volume of the lumen of the heart.
3. Decrease in NT-proBNP Levels
One of the most significant findings was the substantial decrease in NT-proBNP levels, a biomarker for heart failure severity (higher is worse). Patients taking metformin saw a 719.9 pg/ml reduction, compared to 271.9 pg/ml in the control group. Lower NT-proBNP levels are associated with better heart failure management and improved outcomes.
4. Cardiac Protective Effects
The study concluded that metformin offers cardiac protective effects by improving ejection fraction and reducing NT-proBNP levels. These benefits, combined with metformin’s affordability and availability, make it a compelling option for inclusion in heart failure treatment protocols.
Caveats
The study was open-label rather than a clinical trial in which it was blinded. Furthermore, There was a lack of morbidity and mortality data, likely because the duration of the study was too short, which is also the reason why another indicator, ST2 (a cardiac health marker where a higher value is worse) levels, did not come down also likely owing to the duration. Despite the lack of prolonged clinical trials, metformin is an extremely safe medicine with decades of use, and physicians should be open-minded to adding this medicine to a patient’s heart medication regimen. Supplementing vitamin B12 when on metformin is essential as the medicine uses up the body’s B12 storage. A complete blood count is also recommended to be ordered once a year to ensure that vitamin B12 is adequate. A high mean corpuscular volume may infer a low vitamin B12 level on the routine blood test.
Is Metformin Right for Heart Failure Patients?
Metformin shows promise as a valuable addition to heart failure treatment, particularly for those with mid-range ejection fraction heart failure. While the findings are promising, consulting with a healthcare provider is important to determine if metformin is appropriate for individual treatment plans. Ongoing research and longer-term studies will further clarify the role of metformin in heart failure management.
