Featured Research

from universities, journals, and other organizations

Fat Buildup Found In Hearts Of Obese Or Diabetic Heart Failure Patients

Date:
November 11, 2004
Source:
University Of Texas Medical School At Houston
Summary:
Diabetic or obese patients suffering advanced heart failure have higher levels of fat embedded in their hearts and greater molecular evidence of haywire cardiac metabolism, a research team led by cardiologists at The University of Texas Medical School at Houston reports in the November issue of the FASEB Journal.

HOUSTON (Nov. 1, 2004) -- Diabetic or obese patients suffering advanced heart failure have higher levels of fat embedded in their hearts and greater molecular evidence of haywire cardiac metabolism, a research team led by cardiologists at The University of Texas Medical School at Houston reports in the November issue of the FASEB Journal.

Heart failure, progressive and potentially fatal weakening of the heart muscle, is associated with both obesity and diabetes, but the mechanisms by which damage occurs are not well-understood, said senior author Heinrich Taegtmeyer, M.D., Ph.D., professor of cardiology.

"In cardiology, we've long been concerned about fat accumulating in the artery walls and blocking the flow of blood to the heart. What we are finding now is that the buildup of fat doesn't stop in the blood vessels, it's actually worse in heart muscle cells," Taegtmeyer said. "We also report in this paper that diabetes and obesity appear to cause metabolic irregularities in the heart tissue."

Gene expression and protein findings in the paper provide potential long-term targets for treating heart failure, which afflicts 5 million U.S. patients annually.

Researchers examined 27 failing hearts that were removed during transplants and compared them to eight donor hearts that were not failing but were otherwise unsuitable for transplant.

Eight of the failing hearts (30 percent) showed high levels of triglycerides – a fat storage and transport molecule. Levels of triglycerides in failing hearts were four times the level in obese or diabetic patients as they were in non-failing hearts.

The research team associated this buildup of triglycerides in the heart muscle, called lipotoxicity, with dysfunctional expression of genes related to the heart's metabolism of fatty acids, its contractile function, and an inflammatory protein known to contribute to insulin resistance.

The human results track with a rat model of the lipotoxic heart, which has been shown to cause improper cardiac contraction in the rodents, said first author Saumya Sharma, M.D., a cardiology fellow and researcher in Taegtmeyer's lab.

A normal heart derives two-thirds of its energy requirement by metabolizing fatty acids, which are carried in triglycerides, Sharma said. Lipotoxic hearts store some triglycerides in the muscle tissue rather than metabolizing them.

In obese people, Taegtmeyer and his team theorize that this occurs because the person's fat cells, which capture and store excess triglycerides, fill up. Because people have a set number of fat cells, once they are full, excess fat lodges in muscle tissue, where it wreaks molecular havoc.

"The heart is a muscle, too, and it's not spared from this onslaught of fat," Taegtmeyer explained. "The heart is designed to contract, but if lipids (fat) displace its contractile proteins, that results in impaired heart function."

Taegtmeyer and colleagues are testing this hypothesis among obese patients who have elected to have bariatric surgery (surgical reduction of stomach size). Patients in the study volunteer to have their cardiac function analyzed and to provide a small sample of thigh muscle tissue before and after their surgery. Taegtmeyer's team will then assess whether weight loss after surgery results in improved heart function and decreased levels of lipids in muscle tissue.

Earlier research by Taegtmeyer showed that diabetes causes toxic levels of lipids and glucose to build up in the heart.

###

Failing hearts in the study were provided by the Texas Heart Institute at St. Luke's Episcopal Hospital and the DeBakey Heart Center at Methodist Hospital in Houston.

The Federation of American Societies for Experimental Biology publishes the FASEB Journal.


Story Source:

The above story is based on materials provided by University Of Texas Medical School At Houston. Note: Materials may be edited for content and length.


Cite This Page:

University Of Texas Medical School At Houston. "Fat Buildup Found In Hearts Of Obese Or Diabetic Heart Failure Patients." ScienceDaily. ScienceDaily, 11 November 2004. <www.sciencedaily.com/releases/2004/11/041104003751.htm>.
University Of Texas Medical School At Houston. (2004, November 11). Fat Buildup Found In Hearts Of Obese Or Diabetic Heart Failure Patients. ScienceDaily. Retrieved September 16, 2014 from www.sciencedaily.com/releases/2004/11/041104003751.htm
University Of Texas Medical School At Houston. "Fat Buildup Found In Hearts Of Obese Or Diabetic Heart Failure Patients." ScienceDaily. www.sciencedaily.com/releases/2004/11/041104003751.htm (accessed September 16, 2014).

Share This



More Health & Medicine News

Tuesday, September 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

President To Send 3,000 Military Personnel To Fight Ebola

President To Send 3,000 Military Personnel To Fight Ebola

Newsy (Sep. 16, 2014) President Obama is expected to send 3,000 troops to West Africa as part of the effort to contain Ebola's spread. Video provided by Newsy
Powered by NewsLook.com
Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

AFP (Sep. 16, 2014) Since the arrival of Ebola in Ivory Coast, Ivorians have been abandoning their pets, particularly monkeys, in the fear that they may transmit the virus. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Study Links Male-Pattern Baldness To Prostate Cancer

Study Links Male-Pattern Baldness To Prostate Cancer

Newsy (Sep. 16, 2014) New findings suggest men with a certain type of baldness at age 45 are 39 percent more likely to develop aggressive prostate cancer. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

      Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins