Intestinal 'Condom' For Weight Loss?

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.

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Vagal Nerve Blockade for Weight Loss?

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.

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Bariatric Surgery - More Long Term, High Quality Data Needed

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.

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Do iWant the iWatch?

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 drsue.ca 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.

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