Insulin is a
hormone that is needed to allow the body to use up sugar from the blood
and change it into to energy. Muscles, fat, and liver cells become
unable to react to insulin when insulin resistance occurs. The excess
unconverted sugar, in the form of glucose, resides and stays in the
bloodstream. That is why blood glucose levels rise up considerably in
diabetes.
"Insulin
resistance not only predisposes individuals to type 2 diabetes, it is
also a major risk factor for cardiovascular disease," said the co-lead
author, Timothy Graham, MD., from the Kahn laboratory. "Unfortunately,
in the clinical setting, it is often difficult to distinguish
individuals with and without insulin resistance."
Researchers at
Kahn’s laboratory last year, discovered that RBP4 causes insulin
resistance. RBP4 is a protein which is released from fat. Before this
discovery, RBP4 was only understood to participate in the delivery of
vitamin A.
From this previous
research, Graham along with co-lead author Qin Yang, MD., PhD., wanted
to measure blood serum levels of RBP4 and at the same time determine if
there was any changes in insulin resistance.
Participants in
this study were either obese, had impaired glucose tolerance with
pre-diabetes, or had type 2 diabetes. They also had participants that
were non-obese and healthy to compare against the glucose impaired
individuals. The results showed that those that had the highest level
of insulin resistance also had the highest levels of RBP4 in all cases.
The researchers also noticed that high levels of RBP4 also correlated to
the metabolic syndrome that includes high triglyceride levels, obesity
with excess abdominal weight, high blood pressure, and decreased levels
of the “good” HDL cholesterol.
Further testing
was completed with participants that were of normal body weight and
normal blood glucose levels, but had a genetic risk because type 2
diabetes was prevalent in their families. The researchers discovered
that there were elevated RBP4 levels in this group too.
The researchers
wanted to see if exercise would help lower the RBP4 levels and at the
same time improve insulin responsiveness. Approximately two-thirds of
the participants that exercised not only improved their insulin
sensitivity but the also decreased the level of RBP4 at the same time.
The other one-third participants did not improve the insulin sensitivity
and the RBP4 levels remained the same.
"Collectively,
these findings tell us that RBP4 is a useful marker for therapeutic
improvement and that this protein could play a causal role in insulin
resistance in humans, just as our lab previously showed in mice," said
Kahn.
"Being able to
determine diabetes risk well before the onset of symptoms could provide
an important opportunity for patients to take preventive measures," she
adds. "For those who are overweight or sedentary, this could mean making
changes to their diet and fitness routines. For those who are lean and
fit, but have a family history of type 2 diabetes, this could mean
taking anti-diabetic medication. Either way, these findings could help
clinicians to better manage this growing epidemic."
Nicole Wilson
Best Syndication
Books
on Diabetes
Keywords an misspellings: impaired insuelin
inselin insolin impairement glucouse gluecose gucose blood serum levels
reserch study proteins tests diagnose diagnosis prevent treat treatment
diabetic diebetes diabets suger
blud diabetec biabetes
