Wednesday, January 21, 2015

Activity Trumps Weight Loss For Health?

Despite the sharma-obesity-exercise2The fact that it is better to be fit and fat than skinny and unfit is not new – indeed, I would regard the evidence on this as pretty conclusive.

Nevertheless, for those, who still harbour any remaining doubts, the study by Ulf Ekelund on behalf of the EPIC Investigators, recently published in the American Journal of Clinical Nutrition should drive this message home.

This analysis looks at the relationship between physical activity and all-cause mortality in 334,161 European men and women followed for about 12.4 y (corresponding to 4,154,915 person-years).

No matter how the researchers looked at the data, activity levels appeared a better predictor of mortality than BMI or waist circumference.

Thus the authors calculated that while avoiding all inactivity would theoretcally reduce all-cause mortality by 7.35%, trying to maintain a “normal weight” (or rather a BMI less than 30) would reduce mortality by only 3.66% (although avoiding obesity AND inactivity did have the greatest effect).

Despite the limitations of these type of cross-sectional analyses, which as a rule, tend to overestimate the potential benefits of an actual intervention, the message is clear – it appears that even small increases in physical activity in inactive individuals can have substantially greater benefits to health than obsessing about losing a few pounds.

This is indeed useful information, as we have long known that increasing physical activity in most cases does surprisingly little in terms of weight loss but rather a lot in terms of increasing health and fitness.

So do not despair if the hours your patients are putting in at the gym are not changing those numbers on the scale – the health benefits are still worth the effort.

@DrSharma
Reykjavik, Iceland

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Friday, January 16, 2015

The Physiological Benefits Of Laughter

theater_masksAs regular readers are well aware, over the past year, I have been exploring the use of stand-up comedy in communicating about the science of obesity to anyone who cares to listen.

While preparing for this new venture included working with professional comedians, taking improv classes, and, yes, impromptu appearances at local “open-stages”, I have also delved into the (sometimes rather serious) literature on the science of comedy and laughter.

Indeed, as one may suspect, there is indeed a rather large and growing body of scientific literature on humor, comedy and laughter – including its physiological and psychological effects, its therapeutic use (in everything from depression and chronic pain to cancer and obesity), and as a communication tool for health professionals.

Anyone interested in this topic, may wish to refer to a recent article by Dexter Louie and colleagues from the University of California, Harvard Medical School and the Joslin Diabetes Centre on laughter as a tool for lifestyle medicine that recently appeared in the American Journal of Lifestyle Medicine (btw – a term that I really don’t like).

The article begins with a brief discussion of the three preeminent theories (out of over 100 competing ideas) of why we laugh, which are summarized as follows (the examples are mine):

1. Release theory, which argues that laughter is the physical manifestation of repressed desires and motivations (which explains potty jokes).

2. Superiority theory, which posits that laughter is a means of increasing one’s self-esteem at the expense of others (which is probably why most people laugh at fat jokes).

3. Incongruity theory, which states that humor is created by a sense of incongruity between two or more objects within a joke (e.g. an obesity doctor making jokes about obesity doctors).

The article then goes on to briefly review the physiological effects of laughter, whereby it makes a clear distinction between spontaneous and and self-induced laughter:

“The former refers to “genuine” or unforced laughter, often in response to a stimulus, whereas the latter describes laughter that is simulated de novo. Spontaneous laughter is often associated with positive mood, whereas simulated laughter is primarily physical and is not necessarily associated with positive emotions or feelings. Neuroimaging suggests that different neural pathways are used in these 2 forms of laughter.”

The researchers review a range of studies documenting the positive effects of spontaneous laughter on stress hormones, endorphins, immune response, pain tolerance, anxiety as well as studies showing that the cardiovascular response to a good laugh are virtually identical to those elicited by a bout of physical exercise (exercise physiologists take note!).

Despite these promising findings, the authors are also quick to point out that,

“There is great potential for future research in laughter. Randomized controlled large-scale trials are needed to further elucidate the physiologic effects of laughter.”

In the second part of the article, the authors discuss whether or not physicians should use humor as a tool to induce therapeutic laughter?

“Of course, health is a serious and often grave matter, and humor delivered at inappropriate times can be devastating, insensitive, and crass……Within the bounds of appropriateness, however, both humor and laughter can be beneficial. For one, laughter shared between the provider and patient conveys a measure of trust and light-heartedness. Furthermore, humor can improve communication, as a joke can signal a transition in the conversation from the serious to more benign topics.”

The authors even have suggestions on how to address the issue of laughter in clinical practice:

“Providers can ask, “What has made you laugh recently?” or “How often do you laugh?” Inquiring about laughter opens the door to light heartedness and also could lead to counseling on laughter and sharing the latest research with the patient. More important, it allows the provider to determine what the patient finds funny, thereby allowing the provider to tailor recommendations to better fit the patient’s needs and preferences. This also contains the potential to deepen the therapeutic relationship between patient and provider. Put together with a more structured approach, the health care provider could consider prescribing laughter to patients.”

And here is what a laughter prescription could look like (directly borrowed from exercise prescriptions):

(F) Frequency: once a week
(I) Intensity: belly laughing
(T) Time: 30 minutes

(T) Type: your favorite sit-com

While much remains to be studied in terms of the therapeutic use of laughter (e.g. spontaneous vs. self-induced, individual vs. group laughter, dose-response relationships, laughter yoga, etc.), as the authors point out, there is an increasing body of evidence pointing to potential benefits for health and well-being.

Or, as the authors put it,

“With no downsides, side-effects, or risks, perhaps it is time to consider laughter seriously.”

@DrSharma
Edmonton, AB

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Thursday, December 11, 2014

How Effective Is Obesity Management In Primary Care?

sharma-obesity-doctor-kidLosing weight with behavioural interventions in the context of a clinical trial, where you are often dealing with volunteers who are generally provided interventions that are far better structured and standardised than we can ever hope to deliver in a primary care settings, tells us little about the effectiveness of such interventions in real life.

Now a paper by Tom Wadden and colleagues from the University of Pennsylvania, published in JAMA, presents a systematic review of the behavioral treatment of obesity in patients encountered in primary care settings as delivered by primary care practitioners working alone or with trained interventionists (eg, medical assistants, registered dietitians), or by trained interventionists working independently..

A search of the literature yielded 12 trials, involving 3893 participants, that met inclusion-exclusion criteria and prespecified quality ratings.

At 6-months weight changes in the intervention groups ranged from a loss of 0.3 kg to 6.6 kg compared to a gain of 0.9 kg to a loss of 2.0 kg in the control group.

As one may expect, interventions that prescribed both reduced energy intake (eg, ≥ 500 kcal/d) and increased physical activity (eg, ≥150 minutes a week of walking), with traditional behavioral therapy, generally produced larger weight loss than interventions without all three specific components.

Also, more treatment sessions (in person or by telephone) were associated with greater mean weight loss and likelihood of patients losing 5% or more of baseline weight.

Unfortunately, overtime, weight loss in both groups declined with longer follow-up (12-24 months).

Thus, the authors conclude that,

“Intensive behavioral counseling can induce clinically meaningful weight loss, but there is little research on primary care practitioners providing such care. The present findings suggest that a range of trained interventionists, who deliver counseling in person or by telephone, could be considered for treating overweight or obesity in patients encountered in primary care settings.”

Whether any of this is worth the cost and effort was not discussed. My guess is that to see greater success in primary care we need better treatments that move well beyond the rather simplistic ‘eat-less move-more’ paradigm.

@DrSharma
Edmonton, AB

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Monday, December 8, 2014

Effectiveness Of Obesity Management For Osteoarthritis

sharma-obesity-knee-osteoarthritis1Osteoarthritis is one of the most common and disabling complications of obesity. Irrespective of whether or not the osteoarthritis is directly caused by excess weight, there is little doubt that the sheer mechanical forces acting on the affected joints will significantly impact mobility and quality of life.

Now the Canadian Agency for Drugs and Technologies in Health (CADTH) has released a report on the Clinical Effectiveness of Obesity Management Interventions Delivered in Primary Care for Patients with Osteoarthritis.

This systematic review of the literature leads to the following findings:

1) Dietary weight loss interventions, either alone or in combination with exercise produce greater reductions in the peak knee compressive force and plasma levels of interleukin-6 (IL-6) in knee OA patients compared with exercise-induced weight loss.

2) There is a significantly greater reduction in pain and improvements in functions in patients who received diet plus exercise interventions compared with either diet–only or exercise–only interventions.

3) Regardless of the type of weight-loss interventions, participants who lost 10% or more of baseline body weight had greater reductions in knee compressive force, systemic IL-6 concentrations, and pain, as well as gained greater improvement in function than those who lost less of their baseline weight.

4) Participants who lost the most weight also experienced greater loss of bone mass density at the femoral neck and hip, but not the spine, without a significant change of their baseline clinical classification with regards to osteoporosis or osteopenia.

Thus, in summary, weight loss, particularly when achieved through a combination of both diet and exercise can result in significant improvement in physical function, mobility, and pain scores in individuals with osteoarthritis.

Unfortunately, this is by no means easy to achieve and even harder to sustain.

Although I may sound like a broken record – we desperately need better treatments for obesity.

@DrSharma
Edmonton, AB

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Monday, December 1, 2014

Are Sedentary Moms Promoting Childhood Obesity?

Edward Archer, PhD, University of Alabama Birmingham

Edward Archer, PhD, University of Alabama Birmingham

Last week, Edward Archer from the University of Alabama at Birmingham (UAB), published a paper in the Mayo Clinic Proceedings (to much media fanfare), suggesting that the primary driver of childhood obesity is the shifting of nutrient energy to fetal adipose tissue as a result of increased maternal energy availability paired with decreased maternal energy expenditure, resulting in fetal pancreatic b-cell and adipocyte hyperplasia – a theory, which Edwards labels the “maternal resource hypothesis”.

The primary process for these changes, as readers of these pages will have read before, is through epigenetic modification of DNA, which, together with other non-genetic modes of transmission including learned behaviours and environmental exposures (socioenvironmental evolution), leads to “phenotypic evolution”, which Edward describes as,

“…a unidirectional, progressive alteration in ontogeny that is propagated over multiple successive generations and may be quantified as the change over time in the population mean for the trait under examination (eg, height and obesity).”

Since the beginning of the 20th century, socioevironmental factors have significantly altered the energy balance equation for humans

“Socioenvironmental evolution has altered the evolution of human energy metabolism by inducing substantial decrements in EE imposed by daily life while improving both the quality and the quantity of nutrient-energy availability.”

“For example, as thermoneutral environments became ubiquitous, the energy cost of thermoregulation declined, and improved sanitation (eg, clean water and safer food) and vaccinations decreased the energy cost of supporting parasites (eg, fleas) and resisting pathogens (eg, communicable diseases and diarrheal infections).”

Over the past century, these developments have led to profound phenotypic changes including,

“progressive and cumulative increases in height, body stature and mass, birthweight, organ mass, head circumference, fat mass/adiposity as well as decreases in the age at which adolescents attain sexual maturity…”

Archer goes on to describe some of the many factors that may have changed in the past century, whereby, he singles out sedentariness as one of the key drivers of these developments (not surprising given Archer’s background in exercise science).

Thus, although one could perhaps make very similar arguments for any number of factor that may have changed in the past century to, in turn, affect insulin resistance and ultimately energy partitioning (change in diet, sleep deprivation, increasing maternal age, endocrine disruptors, antibiotic use, gut microbiota, medication use and many other factors I ca think of), Archer chooses to elevate sedentariness to being the main culprit.

While this may or may not be the full story, it does not change the thrust of the paper, which implies that we need to look for the key drivers of childhood obesity in the changes to the maternal-fetal (and early childhood) environment that have put us on this self-perpetuating unidirectional cycle of phenotypic evolution.

Ergo, the solution lies in focussing on the health behaviours (again, Archer emphasizes the role of physical activity) of moms.

While Archer largely focusses on maternal transmission, we should perhaps not forget that there is now some also evidence implicating a role for epigenetic modification and intergenerational transmission through paternal DNA – yes, dads are getting older and more sedentary too (not to mention fatter).

I do however agree with Edward, that this line of thinking may well have important implications for how we approach this epidemic.

For one,

“…the acknowledgment that obesity is the result of non-genetic evolutionary forces and not gluttony and sloth may help to alter the moralizing and demoralizing social and scientific discourse that pervades both public and clinical settings.”

Secondly,

“Future research may be most productive if funding is directed away from naive examinations of energy balance per se and redirected to investigations of interventions that alter the competitive strategies of various tissues.”

Thirdly,

“From the standpoint of the clinician, accurate patient phenotyping (inclusive of family obstetric history and metabolic profiling) may allow the targeting of women most likely to be a part of populations that have evolved beyond the metabolic tipping point and therefore require significant preconception intervention.”

While none of this may be easier or more feasible than other current efforts, they may well point us in a different direction than conventional theories about what is driving childhood obesity.

@DrSharma
Calgary, AB

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In The News

Diabetics in most need of bariatric surgery, university study finds

Oct. 18, 2013 – Ottawa Citizen: "Encouraging more men to consider bariatric surgery is also important, since it's the best treatment and can stop diabetic patients from needing insulin, said Dr. Arya Sharma, chair in obesity research and management at the University of Alberta." Read article

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