New Bariatric Surgery Guidelines are Out!

It's been an exciting few weeks - not only are the Canadian Diabetes Association 2013 guidelines out, but so too have the Clinical Practice Guidelines for Bariatric Surgery been updated!

These guidelines, published as a joint effort by the American Association of Clinical Endocrinologists, The Obesity Society, and the American Society for Metabolic & Bariatric Surgery, have some exciting new updates and features.

The guidelines address 7 key questions:

1.  Which patients should be offered bariatric surgery? 

2.  Whic bariatric surgical procedure should be offered? 

3.  How should potential candidates for bariatric surgery be managaed preoperatively? 

4.  What are the elements of medical clearance for bariatric surgery? 

5.  How can early postoperative care be optimized? 

6.  How can optimal follow-up of bariatric surgery be achieved? 

7.  What are the criteria for hospital admission after bariatric surgery?


A few headliners that caught my eye:

1.  Sleeve gastrectomy is no longer considered to be investigational; it is now considered to be a mainstream bariatric procedure. (though it has been 'unofficially' considered to be mainstream for some time already)

2.  Emerging data to suggest that bariatric surgery could be offered to patients with a BMI between 30-34.9 with diabetes or the metabolic syndrome, though the current evidence is limited by the small number of patients studied, and the lack of long term outcomes (so far).   See my previous comments on this issue here.

3.  There are excellent preoperative and postoperative checklists to help guide health care providers in terms of what needs to be asked about, checked for, and monitored.

The guidelines are a must-read for anyone involved in the care of bariatric patients.

Dr Sue Pedersen www.drsue.ca © 2013 

Follow me on Twitter for daily tips! @drsuepedersen

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Sex Drive, Fertility, and Bariatric Surgery

It is a well known fact that obesity is a risk factor for female infertility, and that fertility is often seen to improve after obesity surgery.  While it has been generally thought that improvements in various hormones after surgery are the reason for the improvement in fertility, a recent study suggests that it is not just about the physiology, but also the psychology.

The study, by Dr Legro and colleagues, included 29 women having gastric bypass surgery.  They looked at ovulation rates before and up to 2 years after gastric bypass surgery, and they also looked at responses to a questionnaire designed to assess sexual function.

Interestingly, they found that despite half of these women reporting irregular periods before surgery, 90% were actually ovulating before surgery.  While they did see some improvements in the hormonal parameters of the menstrual cycle after surgery, what was most impressive was the marked improvement in the sexual function questionnaire scores, with the biggest improvements seen in sexual desire and arousal.

It's important to note is that the group in this study was comprised of women who were relatively healthy obese women, so the ovulation rate may have been unusually high in this group.  However, the Bottom Line of the study is that improvements in sex drive and enjoyment may be a major factor in the improvement in fertility seen after gastric bypass surgery.

The most important thing to point out is that pregnancy MUST be avoided for 1-2 years after bariatric surgery (exact recommendation varies by clinic and country), due to concerns for fetal undernutrition and poor fetal growth as well as potential nutritional deficiencies.  Furthermore, there are concerns that the birth control pill may not be absorbed properly after bariatric surgery, and therefore, the pill MUST NOT be relied on for contraception.    Therefore, be sure to speak to your doctor about these issues before surgery, such that appropriate plans can be made to avoid pregnancy until it's safe to proceed.

Dr Sue Pedersen www.drsue.ca © 2013 

Follow me on Twitter for daily tips! @drsuepedersen

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Baseline Body Weight Does Not Predict Success of Bariatric Surgery

Currently, the critieria for who qualifies for bariatric surgery typically includes a body mass index (BMI) criterion - ie, a patient has to be at a certain body weight relative to their height to qualify for surgery.

A review of data to date on the landmark SOS trial was just published by L. Sjöstrom, which I encourage anyone interested in this field to read.  They have now followed SOS study patients for 20 years - though it's noted that many patients have dropped out of the study follow up along the way, so we do have to take the results with a large grain of salt.

While there are many results in this study that are very worthy of discussing, what I wanted to point out today is that the SOS study showed a benefit of obesity surgery to decrease the risk of death, diabetes, and cardiovascular disease, as well as a decreased risk of cancer in women. What is even more interesting is that the baseline BMI did NOT predict the effect of surgery on any of these endpoints.  (For those who download the article - see figure 7).  Interestingly, higher baseline insulin levels did predict favorable outcomes with regards to bariatric surgery decreasing the risk of death, cardiovascular disease, and diabetes (but not cancer).

This data therefore lends further evidence to the fact that BMI criteria should not be a fixed and fast rule for who qualifies for obesity surgery and who doesn't; looking at the whole patient and their metabolic profile (as always) is important!

Dr Sue Pedersen www.drsue.ca © 2013 

Follow me on Twitter for daily tips! @drsuepedersen

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Bariatric Surgery and Bone Health

The decision to undergo obesity (bariatric) surgery is a complex one, as the potential benefits and potential risks are many.  A longterm potential complication that is often overlooked is the effect that bariatric surgery can have on bones.


As outlined in an excellent review by Brzozowska and colleagues, the effect of bariatric surgery on bone health is not well understood.  As the potential effects, as well as what we know (and don't) is quite variable depending on what type of bariatric surgery is performed, here are a few notes organized by procedure:  (you can also read more about the procedures in general here)

Gastric Bypass Surgery:  We know that gastric bypass alters bone metabolism in favor of bone breakdown.  In many cases, this is at least partially due to vitamin D and/or calcium deficiency - both require supplementation lifelong after gastric bypass, and inadequate replacement will cause bone depletion over time.  There are many other factors involved as well - several hormones made in the fat tissue and the gut that change after gastric bypass surgery have been implicated in changes in bone metabolism as well. 

Sleeve Gastrectomy:  As a newer procedure, very little is known about the effect of sleeve gastrectomy on bone.  The available data suggests that sleeves do affect bone metabolism and can cause bone loss over time.

Gastric Banding:  It is not known whether gastric banding has an adverse effect on bones or not - studies done so far have shown conflicting results.  Gastric banding is a less invasive procedure that doesn't cause calcium or vitamin D deficiency, and doesn't cause as many hormonal changes as the other two surgeries.  (That being said, gastric banding is falling out of favor due to its poor longterm efficacy and high reoperation rates over the long term.)

A few important caveats to the above discussion:

1.  It is not known whether changes in bone metabolism seen with bariatric surgery result in an increase in fracture risk - more study is needed.

2.  The long term effect on bone metabolism is not known, as most studies done to date are only a year or two in duration.  Longer term studies will help us to understand the effect on long term fracture risk as well, which is the most important outcome measure.

3.  The effect on bones may be different not only by the type of surgical procedure, but also by age and gender - again, more study is needed.

The Bottom Line: Anyone having bariatric surgery should have a baseline bone density done before surgery, and bone density should be monitored after surgery as well (guidelines are available here).   While adequate calcium and vitamin D is an important component of bone health, there is much more about the effects of bariatric surgery on bone that we still don't understand.


Dr Sue Pedersen www.drsue.ca © 2012 

Follow me on Twitter for daily tips! @drsuepedersen

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New Data on Type 2 Diabetes and Obesity Surgery

At the European Association for the Study of Diabetes (EASD) meeting in Berlin today, I had the pleasure of sitting in on a session discussing the effects of obesity surgery on type 2 diabetes.  Whereas previous years of diabetes meetings have seen very sparse attendance at bariatric surgery talks, this session was absolutely packed. 

At this session, a number of fascinating studies were
presented.  Highlights included: (be warned - it's a very science-heavy blog this week!)

A study by S. Steven and colleagues (UK) looked at a group of 92
patients who had type 2 diabetes prior to having gastric bypass
surgery, with the aim of determining which factors were associated
with a greater chance of diabetes remission after surgery. One of
their findings was that the degree of weight loss achieved post op was
the main determinant of diabetes remission - controversial, as the
bulk of currently available evidence suggests that remission of
diabetes is independent of weight lost.

A study by Pournaras and colleagues found that a nifty removable liner placed
inside of the first 60cm of small intestine (called a duodenal-jejunal
bypass liner) improved type 2 diabetes control over a 1 year trial period.
This introduces the question as to whether, in the future, we can
consider less invasive alternatives to bariatric surgery (such as
these) to help control type 2 diabetes.


A couple of elegant studies out of Denmark (including colleagues Jens Juul Holst and Sten Madsbad who I collaborate with on research studies personally) and Sweden were presented, designed to give us a better understanding of just how obesity surgery improves type 2 diabetes (with a lot of arrows pointing to the increase in the hormone GLP-1 that is seen after surgery).

Finally, there was a neat study from Finland showing that the insulin resistance of fat in femoral bone marrow improves with bariatric surgery (I personally had not previously thought about bone marrow being insulin resistant!).  

Overall, a very exciting day, and a very exciting meeting!

Dr Sue Pedersen www.drsue.ca © 2012 drsuetalks@gmail.com

Follow me on Twitter for daily tips! @drsuepedersen

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Obesity Surgery to Treat Type 2 Diabetes?

At the recent inaugural meeting of the Canadian Association of Bariatric Physicians and Surgeons, I was asked to review the recent consensus statement released by the International Diabetes Federation on the use of bariatric (obesity) surgery to treat patients with obesity and type 2 diabetes. 

(Skip to MY BOTTOM LINES below for a summary, or read through for the nitty gritty!)

The International Diabetes Federation consensus states:

1.  Bariatric surgery is an appropriate treatment for people with type 2 diabetes 
and obesity not achieving recommended treatment targets with medical 
therapies, especially when there are other major co-morbidities.

2.  Surgery should be an accepted option in people who have type 2 diabetes 
and a body mass index (BMI) of 35 or more.  (note - you can calculate your BMI in the right column here)

3.  Surgery should be considered as an alternative treatment option in patients 
with a BMI between 30 and 35 when diabetes cannot be adequately controlled 
by optimal medical regimen, especially in the presence of other major 
cardiovascular disease risk factors.


As I reviewed at the meeting, the literature shows that most patients with obesity and poorly controlled type 2 diabetes experience an improvement in their diabetes with obesity surgery (especially gastric bypass and sleeve gastrectomy).  We have more data for patients with a BMI ≥35 than we do for patients with a BMI of 30-35 at this point in time, but the literature for the latter group is growing. 

A large proportion of patients with type 2 diabetes will go into remission from their diabetes (meaning their diabetes goes away) after bariatric surgery, which of course sounds like a very attractive possibility to the person who has to deal with diabetes on a daily basis.


HOWEVER: 

• Based on the data we have currently available, about half of these cases of diabetes that went into remission after gastric bypass surgery come back by 5 years after surgery (called 'recurrence').
• Almost all of the long term data for diabetes remission rates is in patients with a BMI ≥ 35; there is almost no data to help us understand what the long term recurrence rate of type 2 diabetes is in the BMI 30-35 group.  People who have diabetes with this lower BMI may have a stronger genetic predisposition towards having diabetes, so it is plausible that these people would be less likely to have their diabetes stay away over the long term.
• There is little data to help us understand long term recurrence rates of diabetes after sleeve gastrectomy (which is becoming increasingly popular - read more about the types of surgeries here).
• The definition of diabetes 'remission' was previously quite loose and has now become much stricter; therefore, the remission rates reported in the literature are overinflated.

MY BOTTOM LINES on this controversial topic are:

1.  For people with a BMI of ≥ 35, with POORLY CONTROLLED diabetes:   Bariatric surgery is an option that provides a good opportunity to improve diabetes control.

2.  For people with BMI 30-35, with POORLY CONTROLLED diabetes:  There is very little information to guide us in this group of patients, but so far, it appears that bariatric surgery could provide a good opportunity to improve diabetes control.

3.  For people with BMI of ≥ 35 with GOOD CONTROL of their diabetes: Bariatric surgery can offer an opportunity to make diabetes go away - but for at least half of these patients (and possibly more over the longer term), the diabetes will come back. 

4.  For people with BMI of 30-35 with GOOD CONTROL of their diabetes: Bariatric surgery can make diabetes go away, but we don't yet know what percentage return to diabetes.  Due to genetics, their risk of return to diabetes may be higher than those with BMI ≥35.

5.  Any patient whose diabetes goes into remission after bariatric surgery MUST be followed for the rest of their life for screening for the possible return of diabetes.

And of course, for ALL people who are thinking about having bariatric surgery, the risks and benefits of the procedure as a whole must be carefully weighed by both patient and their health care providers, to decide if this intervention is the right thing for them.



Dr Sue Pedersen www.drsue.ca © 2012 drsuetalks@gmail.com

Follow me on Twitter for daily tips! @drsuepedersen

PS - Bariatric surgery has been shown to PREVENT development of Type 2 diabetes as well (scientists - recent follow up to the SOS study published in the New England Journal of Medicine) - a story for another day's blog!

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Obesity Surgery - Which Type is Best?

This weekend, I've had the pleasure of attending and being invited to speak at the inaugural meeting of the Canadian Association of Bariatric Physicians and Surgeons in Toronto.  While I will share with you the information from my talk in an upcoming post (which was about the treatment of diabetes with obesity surgery), what I would like to share with you today is a fantastic debate held this morning, about which type of obesity surgery is the 'best' overall surgery.


The three main types of bariatric (obesity) surgery were compared:

1.  Gastric Banding:  This is an inflatable band that is placed around the upper part of the stomach.  It works by making the reservoir of the stomach smaller, so that only small amounts of solid food can be consumed, resulting in a sense of fullness after only a small amount of food.  The band can be adjusted to make it looser or tighter by filling or deflating it with salt water via a port that lies just under the skin.

2.  Sleeve Gastrectomy:  In this surgery, most of the stomach is removed, and the shape of the remaining stomach looks like a 'sleeve' - hence the name. 

3.  Gastric Bypass:   This surgery is the most complex of the three.  First, the stomach is made smaller (though the rest of the stomach is not physically removed).  Next, the small intestine is rerouted so that food bypasses the first part of the intestine, and absorption of nutrients first begins about 1.5 meters further down the intestinal canal.

Dr David Urbach of the University of Toronto began the debate with a discussion of the laparascopic adjustable gastric band.    On the positive side, the early complication rate of gastric bands is lower than for sleeve gastrectomy or gastric bypass.  However, the gastric band is not as effective to produce weight loss, and it's not as good to improve complications of obesity (eg diabetes, high blood pressure, sleep apnea).  Over the long term, gastric banding is not looking very good - as blogged previously, at 12 years after gastric banding, one study showed that 60% of people who had gastric banding needed a reoperation of some kind.  At 10 years, about half of patients have had their band removed (either because of complications, or because it was not effective).  While some people do have sustained weight loss over the long term with a band, a substantial proportion regain weight as well.

Dr Urbach concluded that gastric banding is probably not a good long term treatment for obesity, nor for the medical problems that go along with obesity.  He went so far as to say that the band is perhaps best considered only as a cosmetic procedure for patients wishing for weight loss.



Dr James Ellesmere of Dalhousie University reviewed sleeve gastrectomy.    He started off by noting that the sleeve is also quite a safe procedure to perform, with a low complication rate and a low risk of needing reoperation in the future.  In terms of short term risk of surgery, the risk is a bit higher than the short term risk of gastric banding, but lower than the risk of gastric bypass surgery.  The success in weight loss falls between banding and gastric bypass, and the improvement in complications of obesity (diabetes, sleep apnea, high blood pressure etc) also falls between banding and bypass.  An important down side of sleeves is that it is a newer procedure, and therefore, not much is known about long term efficacy (very few studies over 5 years exist).   The few studies that do exist show that there is variability in long term results - as with all of these surgeries, weight regain can occur.

Bottom line of sleeve gastrectomy:  It falls between gastric bands and gastric bypass in terms of benefits and risks, and we don't yet have a lot of long term data (though this data is coming). 


In regards to gastric bypass surgery, Dr John Hagen of the University of Toronto reviewed data that show that gastric bypass is the most effective of these surgeries to cause weight loss, and to improve diseases associated with obesity (diabetes, sleep apnea, etc).  As such, it is considered the gold standard surgery in many centres.  However, there is a significant downside as well: as it's the most invasive surgery, there is higher short term operative risk.  In addition, because food is not digested in the first part of the intestine, many crucial nutrients are not sufficiently absorbed from a regular diet - therefore, the patient undergoing this surgery must be prepared to take a mandatory array of vitamins and nutrients for the rest of their lives. 

Bottom line:  Gastric bypass has the highest success rate, but also the highest risk. 


My take on this discussion?  As always, the decision to undergo obesity surgery is a very serious one, and every person is different.  Risks and benefits not only of the types of surgery, but of surgery in general, must be carefully weighed by the patient and their health care providers.  In terms of which type of surgery to choose, gastric banding does not appear to be a good long term treatment strategy; gastric bypass surgery and sleeve gastrectomy appear to be the best options to consider.


Dr Sue Pedersen www.drsue.ca © 2012 drsuetalks@gmail.com

Follow me on Twitter for daily tips! @drsuepedersen

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