A new study by RDM's Dr William Watson and DPAG's Dr Peregrine (Perry) Green has found that the heart can increase its use of fat as well as glucose as fuel on demand, even in patients where the heart is failing. Moreover, using fat leads to increased energy production, and a stronger heartbeat. These findings, published in the journal Circulation, run counter to the traditional view that the reason hearts fail is because of an inability to switch between glucose and fat when needed.
Heart failure is a condition that affects nearly a million people in the United Kingdom alone. “Treatments for heart failure usually includes blood pressure medications and water tablets, to reduce the strain on the heart,” said Dr Watson. “But effective medications to actually improve the pumping strength of the heart have so far remained elusive.” Researchers have tried for decades to increase the heart's glucose usage to achieve this but with little success. So doctoral students William Watson and Perry Green took a different track.
They focussed on fat in a complex piece of research that involved 35 volunteers and experiments both in a state-of-the-art MRI scanner and during pacemaker implantation when measurements of flow and pressure could be taken alongside blood sampling from within the heart. This allowed the researchers to track the heart’s function and how it used and produced energy when patients with heart failure were given either a mixture of insulin and glucose, or a mixture of fats, directly into the bloodstream. Much to their surprise, the team found that the heart’s energy use and pumping action was better after the fat infusion, rather than the insulin and glucose mixture.
Dr Green said: “The results challenge the glucose-centric direction of this field of research over the last half century.” The research team now think that strategies promoting fat metabolism could potentially form the basis for future therapies for heart failure.
The research was led by a collaboration between Consultant Cardiologists Associate Professor Oliver Rider in the Oxford Centre for Clinical Magnetic Resonance Research (OCMR) and DPAG's Associate Professor Neil Herring, and was supported by the British Heart Foundation.
Prof Herring said “Although this is early days, we think that these results set an exciting new direction for this field”. Prof Rider added “This research has answered a major question in heart failure research and has the potential to translate into beneficial new medications for patients in the future.”
The full paper "Retained Metabolic Flexibility of the Failing Human Heart" is available to read in Circulation.