THURSDAY, Jan. 13 (HealthDayNews) -- The link between
weight loss caused by muscle wasting and congestive heart failure is
outlined in a Tulane University Medical Center study in the current issue of
the Journal of Clinical
Investigation.
It's known that congestive heart failure -- the leading cause of
cardiovascular disease and related death -- is associated with elevated blood
levels of angiotensin II, which causes blood vessel contraction, high blood
pressure and muscle wasting.
While it was recognized that weight loss caused by muscle wasting is an
important predictor of poor outcomes in patients with heart failure, researchers
had a poor understanding of the mechanisms underlying this association.
In previous research with rats, the Tulane scientists found that
administration of angiotensin II resulted in a reduction in body weight and a
decrease in levels of insulin-like growth factor-1 (IGF-1) in both blood and
skeletal muscle.
In this new study, the Tulane team found that angiotensin II inhibited IGF-1
signaling in skeletal muscle. They concluded that this is causally related to
the loss of skeletal muscle.
The scientists also found a complete reversal of angiotensin-induced muscle
loss in mice genetically engineered to overproduce IGF-1.They found strong
evidence that a specific signaling kinase pathway is involved in the ability of
IGF-1 to prevent muscle loss.