Arya M. Sharma, MD

Obesity is complex. Few health professionals are specifically trained in obesity management - few health systems have invested in managing it.

As regular readers will recall, Alberta Health Services recently launched a province-wide obesity initiative ranging from population health and community projects, across primary care, to establishing speciality centres for complex medical and surgical management of kids and adults with severe obesity.

Currently, around 100 health professionals and administrators from across the province, working on getting this initiative off the ground are meeting in Edmonton to discuss details of the plan. Many have already worked in obesity and chronic disease management and bring their own views and experience to the table. This is immensely important as sharing of best practices is one of the key mechanisms to ensure that we do more of what works and less of what doesn’t.

It is also essential that we establish common ground on the basic principles and practice of addressing this health problem - the sooner we are all on the same page, the sooner we can begin working towards consistency in obesity prevention and care across the province.

This will not happen overnight - there will be learnings, there will be things that work well and things that don’t.

But I am fully confident that in the end we will be moving in the right direction towards reducing the emotional, physical, and economic burden of obesity on all Albertans.

We may not be able to cure obesity, but we can certainly do a much better job at preventing and treating it.

AMS
Edmonton, Alberta

Yesterday, I applauded the Canadian Obesity Network for being internationally recognised as Canada’s official professional obesity association.

This is important because, although obesity now affects one in four adult Canadians, we are by no means alone with this problem.

Indeed, as noted by the Lancet in 2006,

“No health system is yet meeting the challenges of managing obesity, and no society has developed an effective strategy to prevent it.”

This is both a challenge and an opportunity for Canada. Challenge because our problem cannot be solved by simply importing successful models from elsewhere - there are none!

Opportunity, because we may well be the first to develop promising approaches that could serve as a ‘made in Canada’ solution to others.

Indeed, today I will be speaking at a Caribbean obesity conference in Bridgetown, Barbados, where obesity is rampant and diabetes is endemic. While the health care models that we are adopting in Canada to deal with our own obesity problems may not be easily transferable to Barbados, the same principles will likely hold true.

Public health measures based on the principles of shame, blame, tax, and ban, will prove as unhelpful here as they have proven unsuccessful everywhere else - not surprising as these measures fail to address the psychosocial and biological root causes of the problem.

There is also no doubt that health services approaches that do not embrace the complexity, heterogeneity, and chronicity of obesity, will be doomed to fail - obesity management has to be fully integrated into a chronic disease management framework that includes professional assessment, patient education, and lifelong self-management.

While not everyone with excess body fat needs to lose weight - many do. This will not be achieved by promoting endless cycles of yo-yo dieting with little or no professional help - there may well be far more harm in this than any potential benefit.

The causes of obesity are complex - the solutions cannot be simple.

Doing nothing is clearly not an option but let us at least stop doing things that have already been shown to fail (like simply telling people to eat less and move more).

AMS
Bridgetown, Barbados

Yesterday, the Canadian Obesity Network announced that it is now Canada’s official representative in the International Association for the Study of Obesity (IASO), the umbrella organization for 52 national obesity associations, representing 56 countries.

Click here for a brief history of IASO.

Canada was previously represented at IASO by The Obesity Society (TOS), formerly known as the North American Association for the Study of Obesity (NAASO), which continues to be the leading scientific society dedicated to the study of obesity in the USA and Mexico and will remain as the regional representative for North America within IASO.

According to IASO President Prof. Philip James,

“With a diverse and active professional community in place and a successful track record in obesity, the time was right for the Canadian Obesity Network to become a member of IASO and represent Canada.”

TOS President Dr. Patrick O’Neil adds that

“This decision has the full support of both the TOS and IASO governing councils as well as the CON-RCO board of directors. The three organizations believe this will benefit all our members, and we look forward to close collaboration as we work towards improving obesity prevention and treatment globally.”

Membership in IASO offers members of the Network a number of benefits including:

- Discounted fees for the Specialist Certification in Obesity Professional Education (SCOPE) education program
- Discounted fees to IASO events, including ICO and Hot Topic Conferences
- Substantially discounted fees for IASO journals (Pediatric Obesity, Clinical Obesity and Obesity Reviews)
- Access to an exclusive repository of obesity prevalence data

More importantly, perhaps, the many excellent obesity research programs and other initiatives happening across Canada will now gain even more international visibility and attention through this membership in IASO.

I, for one, certainly look forward to this new and expanded role for the Canadian Obesity Network on the global stage.

AMS
Dallas, TX

As regular readers will be well aware, our recent publications on the Edmonton Obesity Staging System clearly show that BMI alone is a rather poor measure of mortality risk associated with excess weight.

Thus, according to our analyses of the NHANES population, 20-30% of obese individuals (Stage 0/1) had virtually no increased mortality risk even over the almost 20 year observation period, compared to Stage 2/3 individuals, who had substantially increased risk. Conversely, even in the ‘overweight’ category (BMI 25-30), almost 50% of individuals had a mortality risk as high of that of obese Stage 2/3 individuals.

This means that indications for obesity treatment based on BMI alone will overtreat a substantial number of obese individuals, who may have little benefit in terms of mortality, and miss an even greater number of individuals, who may well benefit from such treatments.

These observations are directly relevant to yesterday’s post on the findings of the SOS study.

As readers will recall, not only was there no relationship between BMI levels and cardiovascular outcomes in the SOS population but the overall cardiovascular risk of these participants - despite the majority being ’severely’ obese - was surprisingly low. In fact, the annual risk for experiencing an adverse cardiovascular outcome for SOS participants was well under 1% per year!

This risk level is highly reminiscent of the overall risk of Stage 0 obese individuals in our NHANES analyses.

Thus, it is readily apparent why it took almost 15 years to demonstrate any cardiovascular benefit of bariatric surgery in the SOS study - clearly this was a very ‘low-risk’ obese population.

Contrast this to the almost 3% annual cardiovascular event rate for the participants in the SCOUT trial, which, by definition, consisted exclusively of Stage 2/3 individuals. In this population, it took less than 3.5 years of even very modest weight-loss (3 to 10 kg) to significantly reduce cardiovascular outcomes.

But did surgery prove more beneficial in higher-risk participants in the SOS trial? It certainly did!

In fact, the only predictor of greater benefit of having bariatric surgery in the SOS paper proved to be having an elevated plasma insulin level - a rather crude marker of insulin resistance. It is fair to assume that these participants were in fact those with higher obesity Stages (elevated fasting insulin levels alone, would already suggest at least Stage 1 obesity).

The importance of this difference is reflected in the numbers-needed-to-treat (NNT): as low as 21 in participants with baseline plasma insulin concentrations above the median (>17.0 mU/L) and as high as 173 in individuals below or at the median (≤17.0 mU/L) insulin concentration.

This essentially means that you would need to operate only 21 patients with Stage 1+ obesity to ’save’ one life (over 15 years) but 173 Stage 0 patients for the same benefit. It does not take a financial genius to figure out that from a ‘cost-per-life-saved’ perspective, operating on Stage 1+ patients is a ‘no-brainer’ whereas operating on Stage 0 patients would (and should) probably raise some eyebrows (especially in a publicly funded healthcare system).

Thus, as we have argued before (and argued by Livingstone in an editorial accompanying the SOS paper in JAMA), it is high time we fully appreciate the “inadequacy of BMI as an indication for bariatric surgery” and begin adopting more sophisticated criteria (such as those of the Edmonton Obesity Staging System) to ensure that this treatment is available to those who are likely to benefit the most.

AMS
London, UK

Padwal RS, Pajewski NM, Allison DB, & Sharma AM (2011). Using the Edmonton obesity staging system to predict mortality in a population-representative cohort of people with overweight and obesity. CMAJ : Canadian Medical Association journal = journal de l’Association medicale canadienne, 183 (14) PMID: 21844111

Livingston EH (2012). Inadequacy of BMI as an indicator for bariatric surgery. JAMA : the journal of the American Medical Association, 307 (1), 88-9 PMID: 22215170

One of the major concerns around the childhood obesity epidemic is that early onset obesity may be associated with greater health risks when these kids grow into obese adults compared to individuals who only become obese as adults.

This hypothesis was recently tested in a study Markus Juonala (Finland) and colleagues in a study published last month in the New England Journal of Medicine.

The researchers examined data from four prospective cohort studies that measured childhood and adult BMI with a mean length of follow-up was 23 years.

Data were compared between four groups:

Group 1: nonobese kids who grew into nonobese adults(n=4742)
Group 2: obese kids who grew into nonobese adults (n=274)
Group 3: obese kids who grew into obese adults (n=500)
Group 4: nonobese kids who grew into obese adults (n=812)

All analyses were adjusted for age, sex, height, length of follow-up, and their respective cohorts.

The not so good new is that when childhood obesity persists into adulthood (Group 3), the risk is markedly higher than in Group 1 (never obese) - unfortunately, this is what happens to most of obese kids as 82% of them grew into obese adults.

The good news, however, is that there was absolutely no difference in the cardiovascular risk factors (diabetes, hypertension, dyslipidemia, or intima-media thickess) between Group 1 (never obese) and Group 2 (only obese as kids but not as adults) - this suggests that any increased risk associated with being an obese kid can be virtually completely reversed if they manage to grow into nonobese adults.

Unfortunately, the health risks associated with adult-onset obesity (Group 4) were exactly as bad as with childhood-onset obesity. In other words, even if you managed to get through childhood with normal weight - gaining weight as an adult put you at the same risk as if you’d been obese all your life.

These findings certainly provide important nuances to the discussions about where obesity prevention and treatment resources should be focussed.

Obviously, if you can prevent or treat childhood obesity, thereby reducing the number of obese adults, you would substantially lower risk. But this may be easier said than done, as so far, we are not exactly sure that ’successful’ obesity treatment in childhood actually prevents adult obesity (we certainly hope it does but no one has yet shown this to be the case). In fact, in this study, two out of three obese adults were nonobese as kids!

On the other hand, even if you get through childhood with normal weight only to go on and become an obese adult, you may as well have been obese all your life. This finding suggests that potential benefits of treating adult obesity may not depend on whether or not you were an obese kid or not. Incidentally, we are also not sure that treatment success in adulthood is any different between childhood-onset and adult-onset obesity.

I am also very much intrigued by the finding that growing into a nonobese adult essentially reverses all of the risk (and damage?) that may have incurred from childhood obesity. This is in someway reminiscent of how the risks of tobacco smoking are now known to be largely reversed within a few years of smoking cessation.

So, on the one hand, it looks like it may never be too late (even as an adult) to lose the excess weight (at least if you do have weight-related risk factors - EOSS 1+).

On the other hand, any cardiometabolic benefits of preventing or treating childhood obesity will only be relevant to population health if this actually prevents or reduces the burden of obesity in adulthood - simply ‘delaying’ the onset of obesity into adulthood by focussing most of our efforts on kids (as suggested recently by Canada’s Health Ministers), may have less benefit than some of us may suspect.

I look forward to hopefully lively discussion on this issue.

AMS
Edmonton, Alberta

p.s. Registration for the International School on Obesity Research and Management (ISORAM 2012, Lake Louise March 25-30 is now open - click here to register).

Juonala M, Magnussen CG, Berenson GS, Venn A, Burns TL, Sabin MA, Srinivasan SR, Daniels SR, Davis PH, Chen W, Sun C, Cheung M, Viikari JS, Dwyer T, & Raitakari OT (2011). Childhood adiposity, adult adiposity, and cardiovascular risk factors. The New England journal of medicine, 365 (20), 1876-85 PMID: 22087679