Printer Friendly Page
VA RESEARCH: FAT ON CHEST AND UPPER BACK
INCREASES RISK OF INSULIN RESISTANCE --
This is the first time such an association has
been demonstrated, say the researchers.
For more on VA research, use the VA Watchdog
search engine...click here...
http://www.yourvabenefits.org/ses
search.php?q=va+research&op=ph
Story here...
http://www.eurekalert.
org/pub_releases/2007-08/uo
c--foc081707.php
Story below:
-------------------------
Fat on chest and upper back increases risk of
insulin resistance
Upper trunk fat –– deposits of fat on the chest and back –– is
associated with an increased risk of insulin resistance, a condition
that is a precursor of type 2 diabetes, according to a study led by
researchers at the San Francisco VA Medical Center (SFVAMC).
It is the first time such an association has been demonstrated, say the
researchers.
The association was equally strong in both HIV infected subjects and HIV
negative control subjects in the Study of Fat Redistribution and
Metabolic Change in HIV Infection (FRAM), a national long-term
longitudinal study of HIV infected people taking modern antiretroviral
therapy and HIV negative controls.
The presence of visceral fat, which is located between and around the
internal organs, was also associated with an increased risk of insulin
resistance in both populations. The researchers found that each type of
fat contributes independently to insulin resistance whether or not the
other type is present.
The study appears in online Publish Ahead of Print section (
http://www.jaids.com/pt/re/jaids/paptoc.htm ) of the Journal of
Acquired Immune Deficiency Syndromes.
“We knew about the insulin resistance risk associated with visceral fat,
which has been shown in previous studies, but no one had ever looked at
the contribution of upper trunk fat,” says lead author and FRAM
principal investigator Carl Grunfeld, MD, PhD, chief of the metabolism
and endocrine sections at SFVAMC. “Strikingly, there was very little
difference between HIV infected people and controls. If you have fat up
top, it’s bad for you.”
In insulin resistance, cells in the body become increasingly resistant
to the action of insulin, a hormone that regulates blood glucose levels.
The result is chronically high blood glucose, which has many adverse
health effects.
The researchers measured visceral and subcutaneous fat deposits in the
legs, arms, upper trunk, and lower trunk of 926 HIV infected subjects
and 258 HIV negative controls. They divided each population into
tertiles, or thirds, based on the amount of fat in each location. Among
the HIV infected subjects in the highest tertile of upper trunk fat, 57
percent showed insulin resistance; of those, half lacked high visceral
fat. Among the highest tertile of controls with upper trunk fat, 61
percent were insulin resistant. A third of that group did not have high
visceral fat.
“So, basically, there are people who have a lot of fat in their upper
trunk and not so much inside their belly, yet they are at risk for
insulin resistance,” observes Grunfeld, who is also a professor of
medicine at the University of California, San Francisco (UCSF). “And
there are people with a lot of visceral fat but not upper trunk fat who
are in the same boat. But if you’ve got both, it’s a double whammy. Your
risk of insulin resistance is quite high.”
Grunfeld says that the researchers looked at all regions of the body
where fat is usually deposited in order to investigate abnormalities in
fat distribution that have been reported in HIV infection, particularly
the presence of so-called “buffalo hump,” a prominent fat deposit in the
middle of the upper back. “But we found that fat in that area was
present, and associated with the same risk for insulin resistance, in
both HIV infected and control subjects,” he says.
Grunfeld explains the lack of difference in risk between HIV infected
and HIV negative subjects by noting that two thirds of all Americans are
overweight and one third are obese. “With the new, highly effective
antiretroviral medications, Americans with HIV now have the same weight
problems as everybody else,” he says. “No matter who you are, if you eat
too much and you don’t exercise, you’re going to be at risk for insulin
resistance, cardiovascular disease, and every other problem associated
with being overweight.”
###
Coauthors of the paper were David Rimland, MD, of the Atlanta Veterans
Affairs Medical Center; Cynthia L. Gilbert, MD, of the Washington, DC,
Veterans Affairs Medical Center; William G. Powderly, MD, formerly of
Washington University, St. Louis, Mo., and now of University College,
Dublin, Ireland; Stephen Sidney, MD, of Kaiser Permanente, Oakland,
Calif.; Michael G. Shlipak, MD, MPH, of SFVAMC and UCSF; Peter Bacchetti,
PhD, of UCSF; Rebecca Scherzer, MS, of the Northern California Institute
for Research and Education (NCIRE) and SFVAMC; Steven M. Haffner, MD, of
the University of Texas Health Sciences Center, San Antonio, Tex., and
Steven B. Heymsfield, MD, formerly of Columbia University School of
Medicine and now at Merck, Inc.
The research was funded by grants from the National Institutes of Health
that were administered in part by NCIRE.
NCIRE - the Veterans Health Research Institute - is the largest research
institute associated with a VA medical center. Its mission is to improve
the health and well-being of veterans and the general public by
supporting a world-class biomedical research program conducted by the
UCSF faculty at SFVAMC.
SFVAMC has the largest medical research program in the national VA
system, with more than 200 research scientists, all of whom are faculty
members at UCSF.
UCSF is a leading university that advances health worldwide by
conducting advanced biomedical research, educating graduate students in
the life sciences and health professions, and providing complex patient
care.
-------------------------
Larry Scott --
