Tuesday, November 24, 2009

New Link Discovered Between Insulin And Core Body Temperature

New Link Discovered Between Insulin And Core Body Temperature

A team led by scientists at The Scripps Research Institute have discovered a direct link between insulin - a hormone long associated with metabolism and metabolic disorders such as diabetes - and core body temperature. While much research has been conducted on insulin since its discovery in the 1920s, this is the first time the hormone has been connected to the fundamental process of temperature regulation.

The paper was published recently in an advance, online issue of the journal Diabetes, a journal of the American Diabetes Association, and will appear in the January print edition of the publication.

The scientists found that when insulin was injected directly into a specific area of the brain in rodents, core body temperature rose, metabolism increased, and brown adipose (fat) tissue was activated to release heat. The research team also found that these effects were dose-dependent - up to a point, the more insulin, the more these metabolic measures rose.

"Scientists have known for many years that insulin is involved in glucose regulation in tissues outside the brain," said Scripps Research neurobiologist Manuel Sanchez-Alavez, who was first author of the new paper with Bartfai lab colleagues Iustin V. Tabarean and Olivia Osborn (now at the University of California, San Diego). "The connection to temperature regulation in the brain is new."


The authors note that while their new paper illuminates a key piece of the puzzle of the body's metabolic processes, it also raises many intriguing questions: How does insulin get to the brain's preoptic area - does it cross the blood-brain barrier or is it produced locally? Are diabetics, who are insensitive to insulin in peripheral tissues, still sensitive to insulin in the brain; if so, could this dichotomy be used in the development of a new therapy? Could scientists find a way to use these new insights to increase energy expenditure for the purpose of weight loss?

Very interesting. I have a low body temperature, so I wonder if there's a relationship between low body temps and pre-diabetes? I wonder if anyone has found that overweight people have lower body temps- kind of a sign of slow metabolism? Insulin resistance in the brain is also an interesting prospect because dopamine needs insulin to be utilized, and low dopamine causes ADD, and ADD and obesity are related conditions.

Sunday, November 08, 2009

'Spoonful Of Sugar' Makes The Worms' Life Span Go Down

Spoonful Of Sugar Makes The Worms Life Span Go Down

If worms are any indication, all the sugar in your diet could spell much more than obesity and type 2 diabetes. Researchers reporting in the November issue of Cell Metabolism, a Cell Press publication, say it might also be taking years off your life.

By adding just a small amount of glucose to C. elegans usual fare of straight bacteria, they found the worms lose about 20 percent of their usual life span. They trace the effect to insulin signals, which can block other life-extending molecular players.

Friday, November 06, 2009

Insulin’s Role in the Aging Body :: Scienceline

Insulin’s Role in the Aging Body - Scienceline

Insulin, a hormone well known for its role in diabetes, may also lie at the root of another common but serious medical condition: age-related muscle loss, known as sarcopenia.

In fact, sarcopenia is in part due to muscle tissue not responding properly to insulin, according to a new study in the journal Diabetologia.

The researchers found that an increased dose of insulin restored the muscle-building processes that tend to deteriorate with old age. Unfortunately, insulin cannot be used as a treatment for sarcopenia due to its toxic effects in high concentrations. Still, the new results help clarify its role in muscle growth and could serve as a basis for future treatments. Sarcopenia affects 24 percent of adults between 45 and 70 years old, and half of people over 80.

“The new finding serves as a proof of concept,” said Elena Volpi, a researcher at the University of Texas Medical Branch at Galveston. “It confirms our belief that the age-related decline in muscle growth is a true case of insulin resistance, which is an important piece to the larger puzzle of treating sarcopenia.”


In type 2 diabetes, insulin resistance — a condition in which normal amounts of insulin fail to produce a typical insulin response in the body — prevents the body from storing sugar molecules in cells, eventually leading to high blood sugar. Test subjects in the Texas study, however, had normal blood sugar levels. This suggests the insulin resistance seen in elderly people is not a matter of sugar control.

Instead, the researchers believe insulin resistance seen in old age results from changes in blood flow. In addition to helping store sugar, insulin acts as a signal for the dilation of blood vessels to increase blood flow and deliver nutrients to muscle tissue. When capillaries fail to respond to these signals, blood flow slows down and muscle growth decreases.