Leptin: How Diabetes and Obesity Are Linked

[Guest guest]

http://www.mercola.com/2005/apr/2/leptin_diabetes.htm

 

Leptin: How Diabetes and Obesity Are Linked

 

 

Like two peas in a pod, the obesity and type 2 diabetes epidemics have

joined forces in an attempt to ravage America's health ... and it's

working, as hundreds of millions of people have been significantly

affected by this deadly pair.

 

But how are these two epidemics intertwined? Popular belief is that if

one eats too much sugar, they'll get fat and develop diabetes; and, if

they don't get diabetes it's merely because their body is producing

enough insulin to keep up with the sugar. However, researchers have

discovered evidence that there's more to the obesity-diabetes

connection than this classic way of thinking: The missing link? Leptin.

 

Mice Studies Shed Light on the Subject

 

Research on mice has suggested that leptin is the key, as it regulates

blood sugar through two different brain-body passageways:

 

* One: Responsible for controlling appetite and fat storage

* Two: Responsible for telling the liver what to do with its

stored glucose

 

While it was previously found that disrupting the appetite-controlling

passageway leads to obesity (which significantly increases the risk of

diabetes), results of the study indicated that it likely takes

disruptions in both of leptin's passageways to trigger full-blown

diabetes.

 

Mice used in the study were genetically modified to disable what is

known as the leptin-STAT3 cell-signaling passageway that leads from

the brain to the body. This s/s strain of mice was still able to

produce leptin and the receptor it attaches to when sending STAT3

signals in the body. Further, after eating too much and becoming

obese, s/s mice did not develop diabetes; however, other strains of

mice that did not produce leptin or have receptors became obese,

developed diabetes and died.

 

Therefore, even when disrupting the leptin-STAT3 signal, the s/s mice

were still able to keep their glucose under control, suggesting the

likelihood of a brain-liver signaling passageway responsible for

regulating blood sugar.

 

Cell Metabolism March 2005; Vol 1, 169-178 (Free Full-Text Article)

 

Newswise Mar 16, 2005

 

Dr. Mercola's Comment:

 

One of the more popular articles on my Web site is a transcript of a

lecture about the importance of insulin by Dr. Ron Rosedale, who is an

expert on leptin physiology, a very powerful and influential hormone

that has totally changed the way science looks at fat, nutrition and

metabolism. I interviewed him last year for the book he wrote, The

Rosedale Diet, and I invited him to give a guest editorial comment on

this article.

 

Guest Comment by Dr. Ron Rosedale:

 

This study illustrates several very important points about health. We

are not a single life, but instead are a republic of cells and our

health depends on how accurately the instructions are conveyed to

those cells so that they can act in harmony. It further supports the

notion that leptin may be " on top of the food chain " in metabolic

importance and relevance to disease.

 

Leptin is the way that your fat stores speak to your brain to let your

brain know how much energy is available and, very importantly, what to

do with it. Studies have shown that leptin plays significant if not

primary roles in heart disease, obesity, diabetes, osteoporosis,

autoimmune diseases, reproductive disorders, and perhaps the rate of

aging itself. Many chronic diseases are now linked to excess

inflammation such as heart disease and diabetes. High leptin levels

are very pro-inflammatory, and leptin also helps to mediate the

manufacture of other very potent inflammatory chemicals from fat cells

that also play a significant role in the progression of heart disease

and diabetes.

 

Leptin: A Key Player in Your Health

 

Leptin plays a far more important role in your health than, for

instance, cholesterol, however few doctors are taught to pay attention

to it, or even know much about it. Leptin's critical importance is

largely unknown to the medical community because there are no known

drugs that regulate its activities and therefore there is no incentive

to spend money to educate doctors about leptin's crucial role in

health and disease. The only known way to reestablish proper leptin

(and insulin) signaling is via diet and, as such, these can have a

more profound effect on your health than any other known modality of

medical treatment.

 

The study also supports prior studies that have shown the brain and

liver to be of paramount importance in regulating your blood sugar

levels especially in type 2 or insulin resistant diabetes. It had been

previously believed that the insulin sensitivity of muscle and fat

tissues were the most important factor in determining whether one

would become diabetic or not. It should be noted that leptin plays a

vital role in regulating your brain's hypothalamic activity which in

turn regulates much of your " autonomic " functions; those functions

that you don't necessarily think about but which determines much of

your life (and health) such as:

 

* Body temperature

* Heart rate

* Hunger

* Stress response

* Fat burning or storage

* Reproductive behavior and

* Newly discovered roles in bone growth and blood sugar levels

 

The study also illustrates the complexity of hormonal orchestration.

Especially with very important hormones like insulin and leptin with

far ranging effects, a particular cell can be resistant to one effect

while the other stays intact. For instance, it had been shown

previously that cells may become resistant to the effects of insulin

on glucose influx (which may be protective in limiting the amount of

glucose entering cells and thus intracellular glycation), while that

same cell may not become resistant to the effects of insulin on

cellular proliferation that tell cells to multiply, as these are

mediated by two separate pathways.

 

Thus a person with high insulin levels, being insulin resistant in

regards to glucose, would still be at a much higher risk of cancer,

and this indeed is what happens; high insulin levels are associated

with many common forms of cancer. Also, different organ systems become

resistant at different rates. Therefore, just taking or artificially

raising (by drugs) insulin, and/or leptin, will not correct the

problems in the orchestration of the signals, any more than playing

the tuba louder will fix mistakes in the written music.

 

However a strategic diet that emphasizes good fats and avoids blood

sugar spikes coupled with targeted supplements to enhance insulin and

leptin sensitivity (such as my Rosedale Diet and Dr. Mercola's Total

Health Program), by resensitizing your cell's ability to hear hormonal

messages correctly, will allow your life to be the symphony it was

meant to be.

 

Related Articles:

 

Obese Brains

 

Mysterious Hormone's Role in Successful Weight Loss

 

How Does Obesity Cause Diabetes?