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Intestinal 'Condom' for Weight Loss?

>> Monday, September 29, 2014

Another interesting approach to less invasive obesity/metabolic surgery that is currently being studied is the duodenal-jejunal bypass liner.  This is a temporary 60-cm liner that is delivered into the upper part of the small intestine endoscopically (ie, by putting a camera and insertion equipment down through the mouth).  It is left in place for a number of months, and then removed.  It's sometimes referred to as the 'duodenal condom' in that... well, you can see the resemblance... but both ends are open to allow food to pass through.

The idea behind this is to mimic (in a shorter version) the intestinal component of the Roux-en-Y gastric bypass surgery, where the intestines are surgically rerouted to bypass about the first 150cm of small intestine.  We think (based on studies) that one of the major reasons why type 2 diabetes often improves dramatically after gastric bypass surgery is the hormone changes that happen when the intestine is rerouted in this fashion; therefore, there is a lot of interest in seeing whether the liner would have an effect not only on weight loss, but also on type 2 diabetes.

                               Gastric Bypass Surgery

A clinical trial was recently done on the liner, where 77 patients with type 2 diabetes and obesity were randomized to receive either the liner, or dietary counselling (control group).  After 6 months, patients who had the liner had greater weight loss, better diabetes control, and required less diabetes medication than the control group.

Patients then had the liners removed, and both groups were followed up for an additional 6 months after liner removal, with 66 patients completing the full study. There was some weight regain in the group who had previously had the liner, though at 1 year they still had greater weight loss than the control group.  At 1 year, there was no longer a difference in diabetes control between the groups.

In the short term, it appears that the liner is quite effective to help people lose weight and improve their type 2 diabetes control.  However, removal of the liner has to happen at some point, because the longer the liner is left in, the higher the risk that it can lose its hold and migrate further down the intestine, or cause bleeding or perforation (a hole in the intestinal wall), which are all serious complications.  So far, the liner has been shown to have a low risk of these complications after 6 months, and a few studies have now been published suggesting the risk is also low after 1 year.

The liner's current temporary nature is reminiscent of many of the 'diets' out there - they do nothing to help make permanent lifestyle changes, so after the diet (or the liner) is gone, the likelihood is that weight will be regained, along with its metabolic complications.  It would be interesting if the liner could be left in safely for a longer period of time - I'll be watching this area with interest, as the duration of study is growing.  In the meantime, while the liner's results look good in the short term, I'm not overly enthusiastic about an intervention if it is only temporary.

Follow me on twitter! @drsuepedersen © 2014


Vagal Nerve Blockade for Weight Loss?

>> Monday, September 22, 2014

As severe obesity has proven so difficult to treat, much study is underway to try to find innovative treatment options.

The vagus nerve is thought to play an important role in the feeling of fullness (called 'satiety') and metabolism, so the question has arisen as to whether blocking this nerve could help to treat obesity.
An interesting study recently reported in the Journal of the American Medical Association (JAMA) was published, evaluating whether intermittent blockade of the vagus nerve would be effective to induce weight loss.

This study was a randomized, controlled trial of 239 patients with a Body Mass Index (BMI) between 35-45, where an electrical device was implanted to intermittently block the vagal nerve in half of the patients, and the other half had a 'sham' surgery (meaning they went through the implantation procedure, but the device was not hooked up to the vagus nerve).  All patients received lifestyle counseling.

They found that at 1 year, the vagal blockade patients lost a little more weight (3.2%) than the control group, but the vagal blockade group also had a higher risk of serious adverse events (8.6% vs none in the control group). Interestingly, the control group, with lifestyle counseling only, lost 6% of their body weight (compared to 9.2% in the vagal blockade group), showing that lifestyle counseling alone (plus a possible placebo effect of the sham surgery) can result in substantial weight loss.

So, based on this study, intermittent vagal nerve blockade doesn't seem like a promising option - weight loss benefits are minimal, and the rate of serious adverse events is concerning.

Follow me on twitter! @drsuepedersen © 2014


Do iWant the iWatch?

>> Sunday, September 14, 2014

Big news in the technology world - the Apple Watch was unveiled for the first time, and it's expected to arrive on shelves in 2015.  Of the multitude of fascinating features, one aspect that is getting a lot of attention is the iWatch's ability to track physical activity and provide integrated fitness/activity apps to help guide your progress.   You may find yourself asking - is this something that iWant? that iNeed? Will iBenefit?? Can iTrust it??

While there are many fitness apps out there, here's what catches my attention: the iWatch can measure your heart rate, and your total body movements (via an accelerometer).  It also uses the GPS and wifi in your iPhone to track how far you've moved.  There's a little circular icon that fills up each day as you move - even letting you know how many minutes you have stood during the day.

Pretty nifty that you can now track your activity, heart rate, and personal info all together in one internet-linked system.  I also really like the encouraging nature of the movement icons filling up, with Apple's stated goal to be 'Sit less, move more, and get some exercise by completing each ring each day.'

There are rumblings as well that the iWatch will someday be able to check blood sugar without poking the skin.   (Currently, the closest a diabetic can get to this is with a continuous glucose monitor, which still requires that a sensor is worn under the skin, and it has to be calibrated against the standard finger-poke twice a day.  There is also a brand new technology just approved in Europe early this month, whereby a small round sensor is placed on the skin with a small filament that is inserted just under the skin; a reader is scanned over the sensor to get a glucose result. More on this on soon - stay tuned.)      As testing blood sugars can be painful and frustrating for my diabetic patients, this news not only got me sitting up, but also spiked my own heart rate to well over 100.

With real time, painless monitoring of these parameters, I get carried away into a dream land where patients could be monitored in second-to-second real time with internet data transmission to their family members, caregivers, or health care professionals anywhere in the world... do I dare to dream?? (editorial note: there are a number of established glucose monitor companies working on this for blood glucose monitoring, in various stages of development)

Before we get carried away, though, we need a lot of questions answered.  How have they validated their technology?  How accurate is their accelerometer? How accurate is the heart rate monitor?  Can the heart rate monitor pick up irregularities and notify the patient or caregiver?  If they are going to incorporate a blood glucose monitor, how will this be tested and validated for precision and accuracy?  I suspect these details and information will become available as the iWatch unfolds into the marketplace, but if we as people, patients, and health care professionals are going to trust the data, we need to know that the studies have been done to prove that it is worthy of our trust.

Definitely exciting, though - my eyes will be focussed on these interesting developments in health technology.

Thanks to Glenn for the heads' up, and to Anita Dobson for her input!

Follow me on twitter! @drsuepedersen © 2014


Bariatric Surgery - More Long Term, High Quality Data Needed

>> Monday, September 8, 2014

Based on the available evidence, bariatric (obesity) surgery is effective to improve upon complications medical conditions related to obesity (such as type 2 diabetes and sleep apnea) and helpful for weight loss.  However, most of this data is based on shorter term results, and there is a concern regarding gaps in high-quality knowledge as to the benefits and risks of bariatric surgery over the long term.

In a recent literature review by Puzziferri and colleagues in Journal of the American Medical Association,  the current status of long term high quality data in bariatric surgery research was assessed.  They examined the literature to see just how much high quality longer term data is out there (defined as studies of 2 years or more, with follow up data on at least 80% of patients by the 2 year mark).

They found that only 29 studies total (less than 3% of studies identified) had 80% or more of patients followed up past the 2 year mark (7,971 patients total).  On analysis of available data in these studies, they found that the average excess weight loss was 66% for gastric bypass surgery, vs 45% for gastric band.  Type 2 diabetes remission rates (based on 6 studies) were 67% for gastric bypass, vs 29% for gastric band.  Remission of hypertension (high blood pressure, based on 3 studies) was 38% for gastric bypass and 17% for gastric banding. There wasn't enough data to analyze these parameters for sleeve gastrectomy.  No study had data past 5 years.  Concerningly, only half of the studies reported on complications at least 2 years after surgery.

So, while the existing high quality long term data is encouraging, we are still lacking in quantity of good quality data (clinical trials with low long term dropout rates) to have a thorough understanding of long term effects of bariatric surgery.  While we do have encouraging observational studies to guide us on longer term benefits vs risks of bariatric surgery (encouraging particularly for gastric bypass surgery and sleeve gastrectomy), randomized controlled clinical trials ideally need to be done and patients followed long term (with less dropouts) to have a more comprehensive understanding of long term effects.

The above being said - as discussed in a recent study by Courcoulas and colleagues, and as I can certainly attest to from my own research experiences - this is a tall order to fill.

Follow me on twitter! @drsuepedersen © 2014


Low Salt Intake - Good Or Bad For Your Heart Risk?

>> Tuesday, September 2, 2014

High blood pressure, called hypertension, is a major risk factor for cardiovascular disease.  Because we know that high salt intake is associated with a higher risk of having high blood pressure (especially in those who are genetically prone to hypertension, and those who carry other medical conditions that increase risk for hypertension such as obesity), huge efforts have been made around the world to try to get the general population to eat less salt.  Interestingly, recent studies have raised the question as to whether too little salt may be associated with higher heart risk as well.

This issue was addressed in a recent issue of the New England Journal of Medicine, with two studies (3 articles) and an accompanying editorial.

The first study, called the PURE study, looked at urine samples from over 100,000 adults in 18 countries, and found that 96% of people studied exceed the current US guidelines for sodium intake. They found that the relationship between blood pressure and salt intake was strongest in those with high salt intake.  They also found that people with both high and low sodium excretion had a higher risk of cardiovascular disease.

Interestingly, high salt intake was more strongly associated with high blood pressure in people with lower potassium intake, and there was a lower risk of cardiovascular events and death in people who had higher potassium intake.  These findings suggest that higher potassium diets might achieve better blood pressure reduction and cardiovascular protection than sodium reduction alone.

The second study, called the NUTRICODE study, looked at global salt intake based on surveys from 66 countries, analyzed data from 107 published clinical trials, and found a strong relationship between sodium intake and cardiovascular events.  They estimated that a whopping 1.65 million cardiovascular deaths in 2010 were attributable to excess sodium consumption.

So where does this leave us?   One major take home message is that 96% of people studied are eating more salt than what is recommended.  We know that excess salt intake is linked to increased risk of high blood pressure and heart disease, so for the vast majority of us, cutting back on our excess salt intake is needed.  There is much added salt in our food supply, especially in processed foods, so cutting back on manufactured food is one of many steps in the right direction!

Second, it appears that eating more potassium may be beneficial - BUT - there are many people in whom it could be dangerous to up potassium intake, such as patients with kidney problems.  There are also many medications (especially some blood pressure meds) that can increase potassium levels.  Too much potassium in the blood can be dangerous, so it is VERY important to discuss with your doctor before making any changes to your potassium intake.

As to whether low salt intake could increase the risk of heart disease - the question has definitely been raised by the above data.  The American Institute of Medicine has evaluated the data, and concluded that current data is not sufficient to make conclusions on this.  Now, we need a high quality clinical trial to give us a definitive answer to this provocative question.

Follow me on twitter! @drsuepedersen © 2014



I am excited that you have arrived at my site, and I hope you are too - consider this the first step towards a Healthier New You!! As a medical doctor, Endocrinologist, and obesity specialist, I am absolutely passionate about helping people with weight management. Though there is certainly no magic cure for obesity, there IS a successful treatment plan out there for you - it is all about understanding the elements that contribute to your personal weight struggle, and then finding the treatment plan that suits your needs and your lifestyle. The way to finding your personal solution is to learn as much as you can about obesity: how our toxic environment has shaped us into an overweight society; the diversity of contributors to obesity; and what the treatment options out there are really all about. Knowledge Is Power!!

Are you ready to change your life? Let's begin our journey together, towards a healthier, happier you!!

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