Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Joslin study finds excess insulin levels an unlikely cause of atherosclerosis

A number of studies have shown that excess insulin circulating in the bloodstream is a major independent risk factor for cardiovascular disease. However, a new study from Joslin Diabetes Center finds that this condition, called hyperinsulinemia, is itself not a cause of atherosclerosis.

In humans, insulin resistance, a condition in which insulin becomes less effective at lowering blood sugar levels, coexists with hyperinsulinemia. Both are associated with atherosclerosis, the buildup of cholesterol in blood vessels that causes coronary artery disease, heart attack, and stroke.

In this condition, vascular cells could become dysfunctional because of hyperinsulinemia or because vascular cells themselves are insulin resistant, which is caused by increased insulin production from pancreatic beta cells as a compensatory mechanism to overcome insulin resistance.

Scientists have known for some time that insulin resistance and hyperinsulinemia cause increased lipids in the circulation, which indirectly leads to atherosclerosis. However, the Joslin study, published in the May issue of the journal Arteriosclerosis, Thrombosis, and Vascular Biology, shows that, without other factors such as high blood pressure and high cholesterol, hyperinsulinemia alone does not cause atherosclerosis.

"For years, scientists have suspected that high levels of insulin could affect vascular cells negatively," says lead author Christian Rask-Madsen, MD, PhD, a research associate at Joslin's Dianne Nunnally Hoppes Laboratory for Diabetes Complications. "We know that people with type 2 diabetes and insulin resistance are susceptible to atherosclerosis, but our study shows that excess insulin alone does not promote this complication."

To study the effects of hyperinsulinemia on atherosclerosis, Rask-Madsen and his colleagues created mice with fewer insulin receptors in every tissue of the body and compared them to mice with intact insulin receptors. Insulin receptors make cells responsive to insulin, a hormone that circulates in the bloodstream. Both sets of mice were genetically modified to have high cholesterol, but were similar in terms of body weight, glucose metabolism, and lipid and blood pressure levels.

Reducing the insulin receptors from one set of mice did not significantly impair their glucose metabolism, says Rask-Madsen—certainly not enough to make the animals overtly insulin resistant—but it did increase the amount of circulating insulin by reducing its removal from the blood. This model allowed the researchers to study the effects of hyperinsulinemia without the confounding effects of insulin resistance.

The new findings build on a 2010 study conducted by Rask-Madsen, which found that insulin resistance only in endothelial cells is sufficient to increase susceptibility to atherosclerosis. George King, MD, Joslin's chief scientific officer, is the senior author of both studies.

Taken together, Rask-Madsen says, the findings of the two studies suggest that "when we look at new ways to prevent atherosclerosis, we should focus on improving insulin signaling in vascular cells rather than blocking the action of insulin in these cells."

Contributors to the paper include Joslin's Erica Buonomo, Qian Li, Kyoungmin Park, Allen Clermont and Oluwatobi Yerokun, and Mark Rekhter of Lilly Research Laboratories. Funding came from the National Institutes of Health.

About Joslin Diabetes Center

Joslin Diabetes Center, located in Boston, Massachusetts, is the world's largest diabetes research and clinical care organization. Joslin is dedicated to ensuring that people with diabetes live long, healthy lives and offers real hope and progress toward diabetes prevention and a cure. Joslin is an independent, nonprofit institution affiliated with Harvard Medical School.

Our mission is to prevent, treat and cure diabetes. Our vision is a world free of diabetes and its complications.

Keep up with Joslin research and clinical news at Inside Joslin at,

Become a fan of Joslin on Facebook at

Follow Joslin on Twitter @JoslinDiabetes

Jeffrey Bright | EurekAlert!
Further information:

More articles from Health and Medicine:

nachricht Resolving the mystery of preeclampsia
21.10.2016 | Universitätsklinikum Magdeburg

nachricht New potential cancer treatment using microwaves to target deep tumors
12.10.2016 | University of Texas at Arlington

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>