Myth Buster #3: Vertical Sleeve Gastrectomy Is Not a Metabolic Procedure

MythBusters Discovery Channel

Metabolic Surgery as a term is used throughout this Blog.  Aside from the dramatic weight loss associated with Bariatric Surgery, this is as exciting an effect, often times resulting in remission or resolution of previously difficult to control Diabetes.

Relatively new to the scene of Bariatric surgery as a stand alone procedure, VSG can also impart metabolic effects for those obese patients with concomitant DM2, even without the "intestinal rerouting" associated with the the Gastric Bypass.

More and more studies are coming out showing a favorable  impact of VSG  on Diabetes type 2, which leads to the question of how, and requires taking a look into the physiology beyond the weight loss that imparts this effect.

VSG is typically viewed as a restrictive procedure, whereby 80% of the stomach is removed, creating a column of a stomach along the lesser curve, without the bypassing the normal route of food from the stomach to the small intestine, as is a part of a Gastric Bypass.

Aditionally, studies have borne out the following after VSG:

   *Improved post prandial glucose levels, associated with a potent increase in the early insulin secretory response to nutrients in the GI tract.
   *Circulating GI hormone levels are also affected, with a dramatic increase in GLP-1 post prandially
   *Additional to glucose regulation, Triglycerides in plasma are also reduced, which points to an dual effect on the liver post operatively.

Controversy remains, however, regarding which procedure reigns supreme for its metabolic effect, but in either case, surgery wins out again over medical management.  The data is still unclear, although studies are ongoing longitudinally, regarding which procedure should be performed for which type of patient. However, what is clear is that there is more to a VSG than just a restrictive and associated weight loss component at the heart of this metabolic surgical procedure.

Adapted from L Kaplan, R Seeley, J Harris. "Myth #3:  VSG is not a metabolic procedure".  MARS initiative publication, Bariatric Times Vol 9 No 9. C12-C13.

Myth Buster #2: Bariatric Surgery Induces Weight Loss via Restriction and Malabsorption

This one got me at first, too. 

This was an interesting idea of a myth that has it's root in the perception of the actual problem with obesity, and how we traditionally have thought of the corresponding benefit of Bariatric Surgery.  Restricting the amount the patient eats, and inducing malabsorption have their part in the success of these procedures, but there is more at work than just that, owing to the uniquely high efficacy of these procedures for weight loss and metabolic benefit.

Restriction 
  
   So what about a patient that has had a jaw wiring?  Why do they remain hungry, and seek the means to override their mechanical restriction?

Malabsorption

   Other operations that create an isolated protein-calorie malabsorption cause an increase in hunger - is there a CNS modulation effect at work with Gastric Bypass and BilioPancreatic Diversion?

Physiological Changes

   Several additional clinical observations support a primarily physiological model for weight loss after Bariatric Surgery.  Few patients become underweight after surgery unless a complication ensues. It would be expected to "overshoot" on occasions if the effect of surgery was purely mechanical. Also, patients that become pregnant after surgery gain weight at an appropriate rate, suggesting that the physiological changes of pregnancy can overcome those as changed by the surgery. And lastly, reports of Bariatric surgery performed on relatively "thin" patients (BMI<30), or animal models, consistently show relatively minimal weight loss.

   Changes in several GI peptide hormones (GLP-1, PYY, CCK, Amylin) likely contribute to a changed physiology post-surgery.  In contrast, the opposite changes are observed after dietary restriction alone (medical models of weight loss), which suggests the body attempts to counter-regulate the induced weight loss physiologically, through increased hunger and decreased energy expenditure.

   Beyond altering gut hormones through surgery, there seems to be other factors that regulate energy balance and metabolic function.  There also seems to be a change in the set point (see last "Myth Buster's" Blog entry), whereby a lower set point for weight is defended as the higher one once was.

In summary, to the degree whereby Obesity is viewed primarily as a behavioral, rather than a physiologic disorder, so goes the thinking of how to respond to the disease state- medically (calorie reduction and increased energy expenditure) or surgically.  Thinking of surgery as a powerful medical therapy, a "pharmacology on steroids" may make the surgical option more acceptable.

From MythBusters

Adapted from L Kaplan, R Seeley, J Harris. "Myth #2:  Bariatric Surgery induces weight loss primarily by mechanical restriction and nutrient malabsorption"  MARS initiative publication, Bariatric Times Vol 9 No 9. C8-C11.


  

  

IN-FLAM-MA-TION...

From whotalking.com

This might take you back.

Or date me...

Remember that Electric Company song about "-tion"?  That's when TV was exciting, even though we in our family were limited to just an hour a day. We usually chose wisely.

That's what my mind went to when I heard a recent CME Audio Digest talk on the Metabolic Syndrome.

The reason why is that the speaker, Bariatric Surgeon Dr. Sayeed Ikramuddin from the Cleveland Clinic Florida, stated that the basis of the Metabolic Syndrome and all of its associated end-organ havoc is secondary to inflammation.  Interesting concept.

Here's the breakdown, and the punchline comes in when we discuss what happens to inflammatory markers, and disease processes, after Bariatric Surgery and the associated rapid weight loss that is expected.

Metabolic Syndrome has as its hallmark insulin resistance, usually thought of as an extension of Type 2 DM.  It is heralded by increased glucose production, with elevated fasting BGs, and relatively insufficient Beta-cell secretion of insulin.  Adipose tissue, liver and muscle tissue are all effected, and as they are effected, they further impair insulin signaling and insulin sensitivity, furthering the metabolic derangement.  Inflammation increases overall via cytokines, M-1 pro-inflammatory cells, and can be measured clinically by C Reactive Protein, and Tumor Necrosing Factor (TNF).

Completing the inflammatory syndrome is central obesity, elevated serum triglycerides, and HTN.

Studies have shown that with the relatively quick reduction in adipose (inflammatory) tissue after Bariatric Surgery, TNF decreased as  measured at 3, 6, and 12 mos post op.  This reduction in inflammation, was also evident in the other paramaters in the metabolic syndrome, that is reduced LDL, Glucose, and Free Fatty Acids.

So, now the quality measures in Diabetes...the ever-elusive goals / composite measures as put out by the ADA:  

           *LDL <100
           *Glycohemoglobin <7
           *Sysytolic BP <130

Again, Dr. Ikramuddin gave a study that demonstrated a 5% to 39% success rate in getting patients to goal in a study at his institution after successful Bariatric Surgery.  And, he contrasted that with the national averages of getting Diabetic patients to those goals: 7%.

He closed by saying that the disease process of Metabolic Syndrome and insulin resistance will take care of itself if we do not. The diminished fertility rate alone, let alone the increased mortality of the syndrome, will become self-selecting.

Sobering thought... Season's Greetings...

Exhibit F

Photo by Wonderlane

And now, another case report.

This is a patient I saw in the office today, a young female S/P Gastric Bypass with a history of Type 1 DM. Definitely not the majority of our Diabetes patients in general, as most are Type 2's, but an interesting look at the early changes that occur in a type 1 patient after a metabolic surgery such as the Bypass.

I saw this patient recently as a 1 mos post Bypass check up.

Demographic:  21 y/o F

Start Weight:  252   BMI:  46

Date of Surgery:  11/12  Laparoscopic Gastric Bypass

DM Hx:  DM 1 since 13 years old.  Note from Endocrinology stated she had gained 100# over the previous 6 years while under their care.  Glycohemoglobins in the past never below 10%, control consistently poor.  Poor compliance with self monitoring of BGs.  Regimen prior to surgery was 56 units of Lantus once daily, and Novolog 1 unit for every 4 CHO.

Current DM Hx:  Lost the prerequisite 20# prior to surgery with a mild improvement in insulin sensitivity.  Now, 1 mos after her Bypass, her Lantus dose is decreased to 38 units once daily, and Novolog 1 unit for every 10 CHO.  She describes an easier time with her Diabetic control now, and has gained some momentum with weight loss, with her weight at 219 today, down 40# since start of the pre-surgical process.  

Take Home Point:  An overweight type 1 patient, while not being the rule for that disease state as they are classically lean, can also benefit from weight loss and the metabolic effects of Bariatric Surgery.  Again, her improvement in insulin sensitivity was noted perioperatively, as she was able to be sent home on almost half of her previous basal Lantus dose.  Her insulin sensitivity was also significantly improved as measured by her meal time dosing ratio that went from 1 unit of Novolog for every 4 CHO to 1 unit for every 10 CHO.  

Her new found consistent blood glucose control on an advancing "regular" diet (from post op liquids and pureed foods) in conjunction with steady weight loss has her on a 'health high'.  She is now taking much better care of herself, eating right, exercising, and enjoying her new appearance- a slimming version of her previous self.  Good stuff.

On another note, this patient was being seen by Endocrinology, who had mentioned the need for weight loss on numerous previous visits, mentioned surgical possibilities, and was ready to refer her for weight loss surgery when she was ready.  As mentioned in other places in this blog, given the necessary component that behavior enables to determine a successful outcome, a patient "talked into" surgery, even when indications are strong, often fares sub-optimally   Timing really is everything.  

Again, nice to see that in this case, a somewhat uncommon case of an obese type 1 patient in need of much better glucose control, not to mention comorbidities of asthma and intermittent low back pain, was introduced to the concept of surgery for weight loss, the referring MD had the additional metabolic benefits in mind, and she is now well on her way to healthier living.  Awesome!

Myth Buster #1:Weight Control Can Be Easily Achieved Through Lifestyle Modificatioln

From EHow Myth Busters

I was reading a recent published set of articles in the Bariatric Times (yes that is a legit title for a magazine...) and from a new initiative called the Metabolic Applied Research Strategy that published 5 myths that have direct applicability to this Blog, and I will post a few of them here and there over the coming weeks.

The first one is the most basic, and debunks the myth that lifestyle modification is alone sufficient for substantial weight loss in the obese (BMI > 30) population. It was interesting to me to find that there are many factors at work in undermining success, rather than the typical return to the previous indiscretions of poor dietary practices and lack of regular exercise.

Studies have shown that 80% of those who intend to lose weight through exercise and dietary change may initially lose at least 10% of their body weight, but more than 95% of those will regain all of their lost weight (or more) within the subsequent 2 - 5 years.

Surely there are volitional forces at work, but the regain in weight is not purely a matter of "choice". There are physiological factors at work that are intent on countering that weight loss for the long term.

It is true that body weight is a regulated by delicate balance between caloric intake and energy expenditure. Due to elaborate mechanisms, however, losing and maintaining that weight is quite difficult.

Fat mass is the primary source for both expected and unexpected (e.g. infection, illness, injury, increased physical activity) energy expenditures, and 'adequate' reserves are necessary.  The amount of stored fat is highly regulated based on genetic, developmental, and environmental influences.  Additionally, the physiology of body weight regulation is complex, with robust and redundant systems to ensure sufficient, but not excessive energy stores. Metabolic adaptation can occur, however, in the setting of overeating with resultant weight gain, as well as food restriction and weight loss.

The overall effect of these physiological mechanisms are to defend a stable body fat mass, or "set point" for energy storage.  Hence, the key to obesity is why certain individuals have such elevated set points.  Like so many other metabolic and physiologic 'set points' of the body (blood glucose, LDL, BP, Hct, etc.) they are not firmly "fixed" and reflect the integration of genetic predisposition.

Genetics, developmental history  and environmental exposure seem to contribute to an individual's set point for body fat mass, but the recent epidemic in obesity likely results from a change in the modern environment, leading to an inappropriately elevated set point.  Once that new set point is established, however, normal physiological mechanisms work to defend it.

Some environmental factors at work in our modern society:

*Alterations in the chemical and nutrient of food, that effect both intake and fat mass set point

*Lack of exercise and their resultant change in physiology of the body

*Chronic stress, personal distress, and disruption of regular circadian rhythms promoting obesity and metabolic dysfunction

And, unfortunately, the physiological mechanisms leading to the set point are so strong that even in the setting of willful contradictory actions (lifestyle modification), physiology almost always wins.

Fortunately for those that are morbidly obese, and perhaps beyond the ability to lose substantial amounts of weight due to chronic lack of success, and/or significant life-compromising co morbidites, there is Bariatric / Metabolic surgery which has been shown to induce the needed profound metabolic and physiologic effects that can lead to long-term durable weight loss.



Adapted from L Kaplan, R Seeley, J Harris. "Myth #1 Weight can be reliably controlled by voluntarily adjusting energy balance through diet and exercise."MARS initiative publication, Bariatric Times Vol 9 No 9. C5-C6.

"What About Exercise?"

"What about it?" patients often ask in return.

From Pati.Clark.blogspot.com

I must say I ask the exercise question at least 15 times a day seeing patients in follow up after their Bariatric procedures. The answers honestly often disappoint, but it is a teaching and coaching start point nonetheless.  It is an essential part of the path toward wellness after surgery.

So, What is considered exercise?  What role does exercise play in the post-procedure lifestyle of a surgical patient?  What do we expect from them? Furthermore, what is to be expected from a regular exercise program to lose or maintain weight?

Exercise certainly has its numerous literal definitions, but in the obese and unfit population, the definition becomes a bit more relative and has to be taken in context to their current health situation.  We are certainly not going to expect a patient with a BMI of 50 who hasn't been very active, and has little prior formal exercise experience to 'work out' 5 x per week for 30 minutes each time right off the bat. That may be a long term goal, but initially needs to be scaled back.

Essentially, any increase in their current energy expenditure through informal or formal exercise is a plus, on the way to a healthy lifestyle that includes regular exercise. This may include parking farther away from your car when you shop, walking at lunch time while on a break at work, consistently doing stairs instead of the elevator, walking instead of a cart for 9 holes, etc.

Now, our expectations do certainly increase for those who have had surgery and are losing weight, and those patients are required to get into regular exercise as a part of their usage of their "tool" that surgery has created for them.

In Band patients, who customarily lose weight at a slower rate, exercise may be the missing component that is needed to lose more weight / more consistently, when the Band is tuned up reasonably well and their diet is relatively sound (portion size and quality of foods).  Additionally, whatever they tell me as far as frequency and duration of exercise when I ask, if their weight loss is lacking, I usually say that they can do more than they currently are doing (exercise)...either more frequently or more intensely.  Those that do take it to heart are usually very surprised at the results!

Additionally, with the Sleeve and Bypass patients, regular varied exercise helps to maintain lean body mass when weight loss is occurring  rapidly. This often requires at least the 60-80+ grams of protein per day we recommend to inhibit muscle breakdown, depending on the intensity of the exercises performed.

Once patients start to lose weight, get some momentum going, and feel better about their body image, it gets easier to get them out there - to the gym or the great outdoors.  Many come to experience that they actually love exercise, and/or return to love it like they did when they were younger and more fit.

During the weight maintenance phase, generally starting 12 - 15 mos after their surgery when they are near or at their goal weight, exercise also plays another key role, stabilizing the their weight in addition to making up for some other behavioral / dietary indiscretions that will occur now and then.

And when all else fails, bring sex into the equation... It is one of the studied benefits of regular exercise!  That often gets some attention.  Other benefits, especially in our obese, post operative population include:

     *Improving Cardiovascular Fitness and Lipid Profile
     *Improving Bone Density
     *Preventing or Delaying development of Type 2 DM
     *Increasing Lean Body Mass and Strength
     *Controlling Anxiety and Depression
     *Promoting a Sense of Well-Being
     *Increasing Resistance to Infection
     *Improving Energy Level and Quality of Sleep
     *Reducing Symptoms of DJD
     *And, Yes, Improving Sexual Desire, Arousal, and Performance.  There, I said it.

Whatever it takes!  Just Do It.
 

Exhibit E

Photo by M Clock

It's time for another patient profile.  And it's time for a Band Diabetes success story.

If you haven't already done so, make sure you take a look at the previous section of posts exclusively on the Gastric Band (Backstage Pass to the Band), and take note of it...

The Band is a valuable tool in the battle against Diabesity as well. 

 Maybe not as sexy as the near immediate metabolic benefit of the Sleeve and the Bypass, with the gastric transection required to do the procedure, but it still has it's place and a potential long term benefit.  

Again, as the studies show, surgery beats non-surgical weight loss, in terms of durability, hands down.

Here is this patient's story, I saw her this week in follow up.

Demographic:  45 y/o F

Start Weight:  230 lb  BMI:  35.6

Date of Surgery:  5/2010  Laparoscopic Adjustable Gastric Banding

DM Hx:  Onset of Diabetes type 2 9/2009.  Started oral agent at that time, Glucophage, but quickly discontinued due to GI side effects.  Glipizide ER 7.5 QD was then started with less side effects, with good results.  Meds were initiated after  failed attempt at weight loss to improve her insulin sensitivity and improve her glycemic control.  BG 180 random, glyco was 8.0 at time of referral for Band. Patient wanted a way to curb her appetite and achieve a durable weight loss to help her DM2 and Hyperlipidemia.  No DM complications at time of surgery.

Current DM Hx:  Current weight is 189, BMI of 30.  Off oral DM meds, last Glycohemoglobin  was 6.1.  Much more active now with exercise, and enjoying her sense of decreased hunger in between meals and the reinforced nature of appropriate portion control.  She is also happy about the improvement in her lipid panel- had labs drawn per her PCP recently and she reported an improved total cholesterol, but I didn't get her actual breakdown yet in the mail.  

Take Home Point:  Nice to have a young patient with mild early Diabetic disease undergo a surgical procedure and see such a drastic improvement in her control of glucose, currently off all meds.  That's the way to get the biggest bang for your Bariatric buck.  Add to that her improved sense of well-being, more palatable / tolerable exercise, and improvement in other co morbidities, and we have a winner!

Who also wins though?  The PCP for an easier time managing this patient as far as her co morbidities go.  The health care system for less burdened care with additional Rx and specialist consults potentially in the future, etc. And of course the patient, for the reasons listed above.

In some ways, this is a simple patient presentation, but it also highlights catching the patient early at a lower BMI, earlier in their Diabetic disease, and being responsive to her desire to have the surgery for her well-researched reasons for health benefits beyond medicines. I believe that's a Trifecta!

It also illustrates the fact that even modest weight loss, in the right  setting, can make a huge difference in a patient's health.  Some of you doubters out there may say that the same results can be achieved with lifestyle modification or other non-surgical means, and you may be right... but surgical weight loss has repeatedly stood the test of time vs. non-surgical means.  I agree though, neither is perfect.

Ask someone who has a substantial weight / BMI how many diets and weight loss programs they have tried...and how much weight they have lost...and kept off...   If it were only that "easy"...