Full without food: Can surgery cure obesity? - health - 02 September 2009 - New Scientist

Full without food: Can surgery cure obesity? - health - 02 September 2009 - New Scientist


Over the past decade, genetic and endocrinological research has pointed to a complex set of hormones and neural signals that control food intake (New Scientist, 9 August 2003, p 38). There seem to be two systems at work: one that aims to keep body-fat stores constant over long periods of time, and another that controls food intake over the course of a day.

It is this short-term control mechanism that has been thrust into the limelight thanks to gastric bypass surgery. "Suddenly, the signalling from the gut has turned out to be much more potent than people believed - and possibly a better drug target," says Nick Finer, an endocrinologist at University College London.

Our digestive system produces both hormones that make you hungry and those that make you feel full, or sated. Ghrelin, produced by the lower part of the stomach, is a powerful promoter of hunger, while the small intestine releases a number of hormones when it senses the presence of food. These aid digestion as well as producing feelings of satiety, and include cholecystokinin, glucagon-like peptide-1 (GLP-1), oxyntomodulin and PYY.

Current thinking is that changes to the levels of any or all of these hormones could be responsible for the effects of the bypass. Shrinking the stomach seems to reduce ghrelin production, which would curtail hunger signals. A bypass also delivers nutrients to the more distant parts of the small intestine faster and in greater quantities than normal, which would stimulate the release of more satiety hormones.

The other surprising outcome from bypass surgery is its effects on type 2 diabetes, a condition in which people can no longer regulate their blood sugar. After eating, the pancreas normally releases insulin, a hormone that reduces excess glucose in the blood. In type 2 diabetes, though, the body cannot respond to insulin properly or the pancreas fails to make enough of the hormone, or sometimes both.

Type 2 diabetes is much more common in people who are overweight, and it was expected that the weight loss following a bypass would improve symptoms. But doctors have been amazed by just how quickly this happens - sometimes in a matter of hours and certainly long before any significant weight loss occurs. Many bypass patients have been able to throw away their diabetes drugs. "If you change the anatomy of the bowel, you improve diabetes like nothing else has ever done," says Francesco Rubino at Cornell University-New York Presbyterian Hospital in New York. The upshot is that bypass surgery is now being considered for diabetics of lower and lower weight - perhaps even approaching normal weight if their diabetes is severe enough.

(see "A surgical cure for diabetes?").

new glucagon and GLP-1 co-agonist eliminates obesity

Qnexa Obesity

Qnexa Obesity

VIVUS announces that obese patients on Qnexa had a weight lost averaging 14.7%.

Read full details.

What Vivus says about the trial:

• The EQUATE trial demonstrated superior weight loss with both the full-dose and mid-dose of Qnexa, as compared to the individual components and placebo.
  
• Subjects treated with full-dose and mid-dose Qnexa had an average weight loss of 9.2% and 8.5% respectively, as compared to weight loss of 1.7% reported in the placebo group (ITT LOCF p<0.0001).
  
• Average weight loss was 19.8 pounds and 18.2 pounds in the treatment arms as compared to 3.3 pounds in the placebo group.
  
• Qnexa was well tolerated with no drug-related serious adverse events in the study.

Read more.

Time to get excited about real help for serious weight loss ?

• Remember this is not really new technology because Qnexa is a combination of phentermine and topamax.
• There are side affects - lots of them.
• Qnexa is not yet available. In fact it has yet been submitted for approval by FDA.

Sleep Apnea

Sleep Apnea is becoming an epidemic - maybe at a rate of 24% in men and 9% in women.It looks as if the rise in Sleep Anea is tracking the spread of obesity. According to an article in the Lancet, severe Sleep Apnea is correlated with a three-fold increase in the risk of a heart attack (or similar cardiac incident).

The rise of Sleep Apnea as an important health issue motivated the ACSM (American College of Sports Medicine) to devote the whole of its October-December 2007 Certified News to the topic of Sleep Apnea. The issue was headlined as "Obstructive Sleep Apnea: An Elephant in the Closet of Importance to the Exercise Professional."

So what can be done ? The answer :

• lose weight - maybe as little as 12 pounds and 10% of body weight should make a big difference
• use a sleep aid such as a CPAP.

Is there a problem ? Well yes, because Sleep Apnea makes exercise more difficult:

• heart rate does not increase the way it should in a healthy body
• blood pressure goes up more than it should during exercise.
• wearing a CPAP every night is no bed of roses and hence long-term, every night use of a CPAP is unlikely. The peaceful image of a CPAP in use at the head of this blog is just a tad idealized. Read this forum to get an idea of what it's really like.
  

Can a Personal Trainer help ?
Is there an exercise prescription for Sleep Apnea ?
At the moment the ACSM does not have any specific exercise recommendations for Sleep Apnea but the issue of Certified News referred to above is the start of defining such a prescription.

One major problem standing in the way of a simple exercise prescription is the possibility, even likelihood, that anyone with severe obstructive sleep apnea is going to have other health issues such as obesity, Type 2 Diabetes, hypertension and a variety of heart issues such as congestive heart failure, cardiac arhythmias and perhaps a stroke risk.

The bottom line is to try for 45 to 60 minutes of low intensity exercise every day (or at least 5 days) a week. Low intensity is defined by the ACSM for this purpose as being 40%to 60% of maximum heart rate. This is longer than ACSM recommendations for hypertension, Type 2 diabetes and CV diseases but at a lower intensity.

The ACSM emphasizes that exercise for anyone with severe sleep apnea should be concluded gradually with an extended cool down period of at least 15 minutes. One additional ACSM recommendation is to closely monitor blood pressure and in particular to measure blood pressure 5 to 15 minutes after the end of exercise cool down. This is to check that blood pressure has returned to baseline value. If it has not then either the exercise intensity was too high or the cool down was too short.

Exercise is Medicine

This is a worthy effort to persuade doctors to discuss exercise with their patients on a frequent basis.

The Exercise is Medicine has the potential to contain a wealth of information. Right now it is good and over time might become excellent. If Exercise is Medicine has a fault, it is that it contains a long list of files (pretty much all relevant) but you have to dive into each to get just a small snack of information. It looks as if the American College of Sports Medicine and American Medical Association emptied out their library files to start this web site.

Once in a while you might wonder how much your doctor knows about weight problems, obesity and how to lose weight, become fitter and healthier. The answer is contained within the weighty tome - nearly 300 pages - entitled
Clinical Guidelines on the Identification, Evaluation and Treatment of Overweight and Obesity in Adults.

This is not essential reading but it is worth a glance because it shows why
there has been slow progress in dealing with the obesity issue and why
Exercise is Medicine could be a fresh start.