The technique detects fat accumulation in cells of the beating heart in a way no other clinical method can, the researchers said, and may provide a way to screen patients for early signs of heart disease in diabetes.
“Hearts beat; people breathe; and magnetic resonance imaging is very sensitive to motion, so we had to find a way to electronically ‘freeze’ the image of the heart,” said Dr. Lidia Szczepaniak, assistant professor of internal medicine at UT Southwestern and senior author of a study appearing in the Sept. 4 issue of Circulation.
“We wanted a noninvasive method to study the beating human heart,” Dr. Szczepaniak said.
Dr. Szczepaniak and her colleagues developed a technique that captures the signal from a beating heart as a person lies in an ordinary magnet used for MRI scanning.
The researchers knew that fat builds up in the hearts of people with heart failure or non-insulin-dependent diabetes (type 2) from earlier studies involving patients undergoing heart transplants, but they didn’t know if this fatty buildup occurred before or after the diabetic conditions developed.
“There is currently no way to clinically evaluate the fatty heart,” Dr. Szczepaniak said. “Using this technique, which analyzes magnetic signals, we might be able to determine if people are prone to heart disease very early before the disease progresses. This method might also allow us to measure the effectiveness of medical treatments targeted toward lowering fat in the heart.”
In the new study, the UT Southwestern researchers used an ordinary MRI system, but added the newly developed computer software to convert the signals from a moving heart into a single image.
They looked at lean and obese people with normal blood sugar, obese people beginning to show abnormal sugar metabolism, and obese people with full-blown type 2 diabetes.
Their most important finding, Dr. Szczepaniak said, was that fat buildup in the heart develops before the onset of diabetes. They also found that the amount of fat in the heart of people with abnormal sugar metabolism was significantly higher than in those with normal blood sugar, whether obese or lean.
The amount of fat in the heart was unrelated to the amount of fat in the bloodstream or liver, indicating that measuring any of those factors could not predict accumulation of fat in the heart. Fat in the heart did correspond to the amount of fat in the stomach region, however.
The researchers recruited some participants from the Dallas Heart Study — a multi-ethnic, population-based study of more than 6,000 patients in Dallas County designed to examine cardiovascular disease.
Detecting fat in heart cells is especially important because once a heart cell dies, it is not replaced by a new one, as happens in many other tissues, said Dr. Roger Unger, professor of internal medicine at UT Southwestern and a co-author of the paper. “When you lose a heart cell, that’s it — you can’t get it back.”
Some researchers, including those at UT Southwestern, believe that as a person becomes over-weight, fat accumulates in normal fat cells, but eventually fat cells can’t store fat any more. Eventually the excess of fat kills other cells — a hypothesis supported by a recent study by Dr. Unger in mice.
“Dr. Szczepaniak is translating our rodent studies into humans, and that is a huge technological breakthrough,” Dr. Unger said.
But Dr. Unger also cautioned that no sophisticated test can replace common sense in fighting obesity: “You don’t need a fancy test to tell a patient not to eat too much.”
Other UT Southwestern researchers involved in the study were Dr. Jonathan McGavock, former postdoctoral fellow in internal medicine; Dr. Ildiko Lingvay, assistant professor of internal medicine; Dr. Ivana Zib, former medical fellow; Tommy Tillery, magnetic resonance imaging technician; Naomi Salas, former research assistant; Dr. Benjamin Levine, professor of internal medicine; Dr. Philip Raskin, professor of internal medicine; and Dr. Ronald Victor, professor of internal medicine.
The work was supported by the Heart and Stroke Foundation of Canada, the Canadian Institutes for Health Research, the Canadian Diabetes Association, the National Institutes of Health, the American Diabetes Association, the Donald W. Reynolds Foundation and Takeda Pharmaceuticals North America Inc.
Aline McKenzie | EurekAlert!
Penn first in world to treat patient with new radiation technology
22.09.2017 | University of Pennsylvania School of Medicine
Skin patch dissolves 'love handles' in mice
18.09.2017 | Columbia University Medical Center
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy