Study Unveils Connection Between Obesity and Heart Failure

A new study by Johns Hopkins Medicine researchers has recently revealed that obesity affects muscle structure in patients with heart failure with preserved ejection fraction (HFpEF). It is a form of heart failure. 

HFpEF is more common in patients with severe obesity and diabetes. But there are few effective therapies and the lack of studies on human heart tissue makes it challenging to develop them. Hospitalization and death rates in these patients are very high (30-40% over 5 years). Hence, understanding the underlying causes of HFpEF is crucial.  

One of the researchers, David Kass said that HFpEF is a complex syndrome that involves abnormalities in various organs, similar to those in weak hearts. Despite heart contraction appearing fine in HFpEF, heart failure symptoms persist. Despite previous attempts to treat HFpEF using standard HF drugs failing, success has come from drugs used to treat diabetes and obesity. 

An SGLT2 inhibitor is the only evidence-based drug for HFpEF that has improved symptoms and reduced long-term rehospitalization rates and mortality endpoints. It is a diabetes treatment. The weight loss drug GLP1-receptor agonist has also been found to improve symptoms in patients with HFpEF. These drugs have shown effectiveness not only in diabetes but also in HFpEF.  

In this study, researchers involved 25 patients with obesity-related HFpEF and diabetes. They collected the muscle tissues of the heart and compared them to heart tissues from 14 normal people. They used an electron microscope to examine the structure of muscle tissues at high magnification. It provides a clear view of the ultrastructure of muscle cells, mitochondria and force-generating sarcomeres. 

When researchers observed the muscle tissues under an electron microscope, they found significant ultrastructural abnormalities in obese patients with HFpEF. They have some abnormalities such as pale, swollen mitochondria, tattered sarcomeres and numerous fat droplets. These abnormalities were not linked to diabetes status. They were less prominent in less obese patients. 

This study, published in the journal Nature Cardiovascular Research, shows that obesity increases the risk of HFpEF. This study is very important as it provides a clearer understanding of the impact of obesity on heart disease. Hence, healthcare professionals should consider this study and prescribe effective medication to obese people.  

Reference Link:  

Mariam Meddeb et al, Myocardial ultrastructure of human heart failure with preserved ejection fraction, Nature Cardiovascular Research (2024).  

DOI: 10.1038/s44161-024-00516-x