Readers will recall previous posts on the STAMPEDE trial, an ongoing trial of 150 patients who had type 2 diabetes and a BMI of 27 to 43 who were randomly assigned to receive intensive medical therapy alone or intensive medical therapy plus Roux-en-Y gastric bypass or sleeve gastrectomy.
Now the 5 year results of this trial have been published in the New England Journal of Medicine.
Of the 150 patients who underwent randomization, 1 patient in the medical-therapy group died during the 5-year follow-up period (from myocardial infarction during year 4) and 1 patient in the sleeve-gastrectomy group had a stroke; 134 of the remaining 149 patients (90%) completed 5 years of follow-up. One patient in the medical-therapy group, underwent gastric bypass during year 3, owing to failure of the medical treatment. One patient in the sleeve-gastrectomy group underwent gastric bypass during year 4 for the treatment of a gastric fistula.
At 5 years, the criterion for the primary end point (Hba1c <6% without the use of anti-diabetic mediations) was met by 2 of 38 patients (5%) who received medical therapy alone, as compared with 14 of 49 patients (29%) who underwent gastric bypass and 11 of 47 patients (23%) who underwent sleeve gastrectomy.
At 5 years, changes from baseline observed in the gastric-bypass and sleeve-gastrectomy groups were superior to the changes seen in the medical-therapy group with respect to body weight (−23%, −19%, and −5% in the gastric-bypass, sleeve-gastrectomy, and medical-therapy groups, respectively), triglyceride level (−40%, −29%, and −8%), high-density lipoprotein cholesterol level (32%, 30%, and 7%), use of insulin (−35%, −34%, and −13%), and quality-of-life measures.
Excessive weight gain was observed in 19% of the patients in the medical-therapy group and in no patients in either surgical group.
No major late surgical complications were reported except for the one reoperation mentioned above.
From these findings the author conclude that,
“…bariatric surgery was superior to intensive medical therapy in terms of glycemic control, weight reduction, medication reduction, improvement in lipid levels, and quality of life. Patients who underwent gastric bypass or sleeve gastrectomy were significantly more likely to achieve and maintain a glycated hemoglobin level of 6.0% or less, with or without medications, than were those who received intensive medical therapy alone…The surgically treated patients had superior glycemic control throughout the 5-year period while also using fewer diabetes medications, including insulin. More than 88% of the surgical patients had glycemic control that was considered to be very good to acceptable (average glycated hemoglobin level of 7.0%), without the use of insulin. A majority of the surgical patients who achieved a glycated hemoglobin level of 6.0% or less reached that target without the use of diabetes medications, whereas none of the patients in the medical-therapy group reached that target without the use of diabetes medications.”
No doubt this study supports the notion of long-term benefits of bariatric surgery (even in people with BMI in the 27-34 range) compared to intensive medical treatment alone. Clearly, this should be a treatment that may be considered for patients with type 2 diabetes, who struggle with glycemic control.
Yesterday, I discussed the desperate need for scalable obesity treatments.
I pointed out that neither behavioural nor surgical interventions are readily scalable to provide long-term obesity treatments to the over 7,000,000 Canadians currently considered to have obesity.
I also noted that, like for other chronic diseases, only medical treatments with anti-obesity medications have the potential for scalability in the millions – we do this regularly for the millions of people living with diabetes, hypertension, heart disease, or any of the other common chronic diseases affecting Canadians.
Nevertheless, before we discuss what it would take to scale up medical treatments, let us take a look at whether all 7,000,000 affected Canadians really need obesity treatment.
Let us first note that the number 7,000,000 refers to Canadians with a BMI over 30. This may well overestimate the problem – as not everyone will actually need or likely benefit from anti-obesity treatments (BMI measures size – not health!).
In fact, if we apply the actual WHO definition of obesity, namely the presence of abnormal or excess body fat that impairs health, we can perhaps readily reduce this number by about 5-10% (anyone with Edmonton Obesity Stage 0) obesity, as these individuals are pretty healthy despite their excess weight. As there is no evidence that these rather healthy individuals would experience any long-term benefits from anti-obesity treatments, it would be entirely reasonable to take a “watch and wait” approach.
The 7,000,000 also includes an additional 15-20% of people, who would have rather mild impairments in health (Edmonton Obesity Stage 1), associated with a very low long-term risk – for these there is also no proven long-term benefit of obesity treatment.
Thus, we can readily exclude about 20 to 30% of individuals for whom the risk-benefit ratio (and thus, the cost-benefit relationship) would hardly justify the use of prescription medications.
This would reduce the number needed to treat by as many as 2 million – leaving us with about 5,000,000 left to treat.
Of these (by definition), all would have Edmonton Obesity Stage 2 or higher, meaning that they will all have some obesity related health impairments.
However, many of these individuals will have obesity related health risks (e.g. hypertension, diabetes, sleep apnea) that are currently well managed with other available treatments (e.g. anti-hypertensive or anti-diabetic medications, CPAP, etc.). For these well-managed patients, it is not clear what additional value anti-obesity medications would offer.
Let us assume that this number of well managed patients is about 50% of the remaining 5,000,000 – this leaves us with only 2,500,000 individuals with obesity related health problems that are not well managed with the available treatments for their comorbidities. It is probably only in these individuals that medical obesity treatment would make sense – both in terms of cost and benefit.
Let us further assume that for another 50% of the remaining for various reasons (e.g. too sick, too old, no ready access to medically supervised care, not interested in obesity treatment, etc.) medical treatment for obesity is not feasible.
This would leave us with only about 1,250,000 patients where medical treatment with prescription drugs would be both practical and likely cost-effective.
This is now a much more manageable problem. In fact, this is only about half the number of Canadians currently living with diabetes, a problem that is routinely managed with medical treatments.
So where are the anti-obesity treatments for these patients?
That will be the topic of tomorrow’s post.
Although “weight-loss” is a booming global multi-billion dollar business, we desperately lack effective long-term treatments for this chronic disease – the vast majority of people who fall prey to the natural supplement, diet, and fitness industry will on occasion manage to lose weight – but few will keep it off.
Thus, there is little evidence that the majority (or even just a significant proportion) of people trying to lose weight with help of the “commercial weight loss industry” will experience long-term health benefits.
When it comes to evidence-based treatments, there is ample evidence that behavioural interventions can help patients achieve and sustain important health benefits, but the magnitude of sustainable weight loss is modest (3-5% of initial weight at best).
Furthermore, although one may think that “behavioural” or “lifestyle” interventions are cost-effective, this is by no means the case. Successful behaviour change requires significant intervention by trained health professionals, a limited and expensive resource to which most patients will never have access. Moreover, there is ample evidence showing maintenance of long-term behaviour change requires significant on-going resources in terms of follow-up visits – thus adding to the cost.
This severely limits the scalability of behavioural treatments for obesity.
If for example, every Canadian with obesity (around 7,000,000) met with a registered dietitian just twice a year on an ongoing basis (which is probably far less than required to sustain ongoing behaviour change), the Canadian Health Care system would need to provide 14,000,000 dietitian consultations for obesity alone.
Given that there are currently fewer than 10,000 registered dietitians in Canada, each dietitian would need to do 14,000 consultations for obesity annually (~ 70 consultations per day) or look after approximately 7,000 clients living with obesity each year. Even if some of these consultations were not done by dietitians but by less-qualified health professionals, it is easy to see how this approach is simply not scalable to the size of the problem.
A similar calculation can be easily made for clinical psychologists or exercise physiologists.
Thus, behavioural interventions for obesity, delivered by trained and licensed healthcare professionals are simply not a scalable (or cost-effective) option.
At the other extreme, we now have considerable long-term data supporting the morbidity, mortality, and quality of life benefits of bariatric surgery. However, bariatric surgery is also not scalable to the magnitude of the problem
There are currently well over 1,500,000 Canadians living with obesity that is severe enough to warrant the costs and risks of surgery. However, at the current pace of 10,000 surgeries a year (a number that is unlikely to dramatically increase in the near future), it would take over 150 years to operate every Canadian with severe obesity alive today.
This is where we have to look at how Canada has made significant strides in managing the millions of Canadians living with other chronic diseases?
How are we managing the over 5,000,000 Canadians living with hypertension?
How are we managing the over 2.5 million Canadians living with diabetes?
How are we managing the over 1.5 million Canadians living with heart disease?
The answer to all is – with the help of prescription medications.
There are now millions of Canadians who benefit from their daily dose of blood pressure-, glucose-, and cholesterol-lowering medications. The lives saved by the use of these medications in Canada alone is in the 10s of thousands each year.
So, if millions of Canadians take medications for other chronic diseases (clearly a scalable approach), where are the medications for obesity?
Sadly, there are currently only two prescription medications available to Canadians (neither scalable, one due to cost the other due to unacceptable side effects).
So what would it take to find treatments for obesity that are scalable to the magnitude of the problem?
More on that in tomorrow’s post.
Now, a paper by Ari Schechter and colleagues from Columbia University, NY, published in Physiology and Behaviour, publish data from a small ‘pilot study’ suggesting that treating obesity with CPAP may reduce calorie intake, at least in some individuals.
The researchers examined ad libitum energy intake in four adult males with overweight or obesity, who had been diagnosed with sleep apnea but had not yet initiated CPAP.
After participants began using CPAP at their titrated setting (active) at home each night for 2 mo, they were invited to participate in this study for two days in an in patient setting.
On the first inpatient day, participants were fed a controlled weight maintenance diet with fixed meal times and participants were asked to use CPAP at their prescribed setting during the scheduled in-lab sleep episode (23:00–7:00).
Ad libitum energy intake was measured throughout the waking period on laboratory day 2, whereby all meals were presented in excess. Participants were instructed to eat until they felt comfortably full.
After a 1-mo washout, participants crossed over into the sham phase. Participants were provided with the sham CPAP devices, and instructed to use the CPAP at the titrated level for 2 mo. This was followed by the second laboratory period (repeat of first phase). After the second phase, participants were debriefed and instructed to return to active CPAP.
Mean total ad libitum EI including fixed meals and free snacks was 3744 ± 511 kcal in the active and 4030 ± 228 kcal in the sham CPAP setting. Three of the four participants increased their total daily EI during sham vs. active, whereas one participant showed a decrease.
While these findings are far from conclusive, they do point to the possibility that ongoing treatment of sleep apnea may influence appetite in a way that serves to reduce energy intake.
This is perhaps not all that surprising given that there is increasing recognition of the importance of restorative sleep on appetite and food intake.
I look forward to seeing more definitive studies exploring this interesting issue.
I would also be interested in hearing is anyone else has experience changes in appetite with starting CPAP treatment for sleep apnea.
Now, the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO), has published a new Position Statement on indications for surgery for obesity and weight-related diseases, published in Obesity Surgery.
Recommendations are graded based on the strength of the current evidence.
Recommendations with the highest strength of evidence include the following:
- Surgery for obesity and weight-related diseases is a codified discipline that has proven to be effective in the treatment of obesity resulting in long-term weight loss, improvement in or resolution of comorbidities, and the lengthening of life expectancy. (Level of evidence 1, grade of recommendation A)
- Surgery for obesity and weight-related diseases is a safe and effective therapeutic option for the management of T2DM in patients with obesity. Along with optimal medical treatment and lifestyle adjustment, it has been demon- strated that surgery for obesity and weight-related diseases can achieve a better glycemic control, lower glyco- sylated hemoglobin, and reduction of diabetes medications than optimal medical and lifestyle treatment alone. (Level of evidence 1, grade of recommendation A)
- Surgery for obesity and weight-related diseases demonstrated an excellent short- and midterm risk/benefit ratio in patients with class I obesity (BMI 30–35 kg/m2) suffering from T2DM and/or other comorbidities.
(Level of evidence 1, grade of recommendation A)
- Obesity, and visceral obesity in particular, is a major modifiable risk factor for cardiovascular diseases (CVD). Weight loss induced by surgery has been shown to reduce CVD risk, with the most relevant reductions in risk ob- served in the group of patients having the higher CVD risk before surgery. These patients obtain the most significant metabolic improvements thereafter. (Level of evidence 1, grade of recommendation A)
- Weight loss induced by surgery for obesity and weight- related diseases is associated to a reduction in the inci- dence of major cardiovascular events in patients with obesity, including myocardial infarction and stroke. Event reductions are more relevant in patients with a high cardiovascular risk before surgery. (Level of evidence 1, grade of recommendation A)
- Surgery for obesity and weight-related diseases may result in resolution/improvement of obstructive sleep apnea syndrome (OSAS). (Level of evidence 1, grade of recommendation A)
- In patients undergoing surgery for obesity and weight- related diseases, weight loss results in a substantial im- provement in pain and a reduction of disability derived from joint disease. (Level of evidence 1, grade of recommendation A)
- Surgery for obesity and weight-related diseases has proven to be effective in determining the overall improvement of the quality of life of patients suffering from obesity. (Level of evidence 1, grade of recommendation A)
- The improvement in the quality of life of the patient with obesity treated by surgery for obesity and weight-related diseases is independent from the type of performed procedure. (Level of evidence 1, grade of recommendation A)
- Surgery for obesity and weight-related diseases is effective in patients with class I obesity (BMI 30–35 kg/m2) and comorbidity. (Level of evidence 1, grade of recommendation A)
In addition, there are numerous recommendations, for which the evidence is perhaps less robust but nevertheless promising.
These recommendations cover a wide range of health issues including gastroesophageal reflux disease (GERD), hepatobiliary diseases, mental health, endocrinopathies and fertility, cancer and organ transplantation, pseudotumor cerebri, chronic inflammation, urinary tract and renal function, functional status, and quality of life.
I was particularly pleased to see the statement include recommendations regarding the limitations of BMI and an extensive discussion of the Edmonton Obesity Staging System as a potential guide to better defining indications for surgery.