Yesterday I had the pleasure of speaking to a group of Japanese colleagues from the Sapporo Medical University on the Edmonton Obesity Staging System (EOSS) and the recently published Etiological Framework for Obesity Assessment. The evening was chaired by Professor Kazuaki Shimamoto, who I have had the pleasure of meeting on several previous visits to Japan.

In my discussions with the participants it became immediately obvious that our proposed clinical staging of obesity can also be applied to obese patients in Japan, albeit using the lower BMI cutoff of 25 used to define obesity in this population.

Given the large number of nephrologists and cardiologists in the audience, I also found that the edema analogy, which I now often use to describe the state of excess caloric balance (or caloric “retention”), very much resonates with clinicians and provides an immediately understandable framework for approaching patients presenting with excess weight gain.

This evening I also plan to meet with a number of colleagues from Tokyo, who have previously attended the International Cardiovascular Expert Fora that I had organised during my time at McMaster University. These fora, which brought together a select group of clinical researchers from across several European and Asian countries, continues to be an interesting network of friends around the world, who always provide a sounding board for some of the issues that are relevant to cardiovascular and metabolic risk management.

As obesity rates continue to grow around the world, it is becoming painfully obvious that much needs to be done to address this issue at a global level. While we hope and wait for preventive measures to kick in, there is no doubt that the access to proper evidence-based obesity management remains a dire challenge in virtually all medical systems.

I am certainly grateful for the opportunity to share and learn from colleagues around the world on how best to approach this issue.

AMS
Tokyo, Japan

Regular readers of these pages may recall an earlier post in which I emphasized the importance of not just describing behaviours (this patient eats too much) but rather actually attempting to determine the root causes of these behaviours (why does this patient eat too much?).

I also suggested that obesity can best be conceptualized as the physical manifestation of chronic energy excess.

In fact, using the analogy of oedema, the consequence of positive fluid balance or fluid retention, I explained that obesity can be seen as the consequence of positive energy balance or calorie ‘retention’.

I further recommended that just as the assessment of oedema requires a comprehensive assessment of factors related to fluid balance, the assessment of obesity requires a systematic assessment of factors potentially affecting energy intake, metabolism and expenditure.

The full paper describing this concept has now been published as an early release on OBESITY REVIEWS.

I believe that this paper provides an aetiological framework for the systematic assessment of the socio-cultural, biomedical, psychological and iatrogenic factors that influence energy input, metabolism and expenditure.

The full paper discusses factors that affect metabolism (age, sex, genetics, neuroendocrine factors, sarcopenia, metabolically active fat, medications, prior weight loss), energy intake (socio-cultural factors, mindless eating, physical hunger, emotional eating, mental health, medications) and activity (socio-cultural factors, physical and emotional barriers, medications).

Based on my own experience of using this framework in my practice, I anticipate that clinicians will find this approach helpful in systematically assessing, identifying and thereby addressing the aetiological determinants of positive energy balance.

I very much hope that application of this framework will ultimate result in more effective obesity prevention and management.

As always, comments are most welcome.

AMS
Toronto, Ontario

Most textbooks on obesity will tell you that assessing someone for obesity should start with a careful exploration of weight history, eating habits and lifestyle.

I disagree!

For reasons that I will outline below, I believe that the proper assessment of patients presenting with excess weight should first focus on the four “M”s or the mnemonic “M”, “M”, “M”, & “M”.

As I presented yesterday in a talk on obesity assessment at the American Heart Association Meeting in Orlando, obesity is not only a remarkably heterogeneous condition resulting from a wide range of environmental, psychosocial and biomedical causes, successful weight management is also remarkably difficult and tenuous even in the most motivated and determined of patients.

The primary goal of assessment therefore should first strive to identify the possible causes and circumstances leading to excess weight gain, determine to what extent that excess weight is affecting health and systematically look for barriers that will make weight management difficult, if not impossible.

Each of the four “M”s explores a domain that is potentially relevant to all of the above questions.

The first “M” stands for “Mental Health”. Not only can common mental health problems often lead to weight gain (e.g. depression, addictions, attention deficit, abuse, PTSD, sleep disorders, emotional eating, etc.), but when present (as is often the case), they can make weight management most challenging. In addition, excess weight can directly affect mental health by promoting poor self-esteem, depression and social anxiety disorder. Thus, devising a weight management plan always requires a good understanding of a patient’s mental health status, if only to determine that there are indeed no major mental health causes or consequences of weight gain nor significant mental health barriers that will make weight management difficult, if not impossible.

The second “M” is a reminder to look for the many “Mechanical” causes or complications of excess weight. These can present in the form of back pain or osteoarthritis, sleep apnea, reflux disease, urinary incontinence, and many other problems associated with excess weight. When present, these issues can not only promote or exacerbate weight gain but can also pose important barriers to weight management – clearly someone with plantar fasciitis is unlikely to walk the recommended 10,000 steps.

The third “M” should prompt us to look for the wide range of “Metabolic” complications of excess weight. These not only include diabetes, dyslipidemia or gout, but also hypertension (a problem of sodium metabolism), fatty liver and gall-bladder disease, polycystic ovary syndrome, and some forms of cancer. Often the presence of these conditions or the treatments we use to control them can contribute to further weight gain rather than help solve the problem.

The fourth “M” stands for “Money”, a not unimportant factor that can affect weight gain (healthy eating is expensive) or pose an important barrier to weight management (weight management costs time and money).

Only after a complete understanding of the four “M”s can a clinician hope to fully appreciate the likely causes and consequences of obesity and the potential barriers to its treatment in a given patient.

Only after we have fully explored the four “M”s does it make sense to delve further into issues related to energy balance, i.e. ingestive behaviour, energy metabolism and physical activity in order to devise a sensible and effective management plan.

As I have argued before, simply assessing and describing a behaviour is not a diagnosis - understanding the root cause of that behaviour is.

AMS
Toronto, Ontario

Some readers may recall earlier studies on the increased risk for dementia associated with increased body weight.

A new study, by Cyrus Raji and colleagues from the Universities of California and Pittsburgh, just published in Human Brain Mapping, finds a significant decrease in brain volume in overweight and obese elderly individuals despite largely normal cognitive function.

The researchers used sophisticated morphometric methods to examine grey and white matter volume differences in MRI scans from 94 elderly subjects who remained cognitively normal for at least 5 years after their scan.

After correcting for various covariates including age, gender, race as well as fasting plasma insulin levels and and Type 2 Diabetes Mellitus increased BMI was associated with with atrophy in frontal, temporal, and subcortical brain regions.

Specifically, in individuals with a BMI >/= 30, atrophy was found in the frontal lobes, anterior cingulate gyrus, hippocampus, and thalamus compared with individuals with a normal BMI (18.5-25). These parts of the brain are particularly important for planning and for memory.

Whether or not subjects actually had clinically relevant defects in brain function was not examined in this study. Furthermore, this cross-sectional study does not provide any causal or mechanistic insights into this relationship.

Obviously, whether or not these findings of brain atrophy can be prevented by weight loss also remains to be seen.

Thus, while this paper is sure to get wide publicity in the media, the clinical relevance and implications of these findings remain obscure. Nevertheless, even subtle deficits in planning and memory, if present in elderly individuals with obesity, can potentially affect their ability to plan meals or follow complicated diet plans - something that may (if confirmed in other studies) have to be considered in counseling such patients.

AMS
Edmonton, Alberta

While I am taking a brief break from clinics and other obligations (including daily blog posts), I will be reposting past articles, which I still believe to be relevant but may have escaped the attention of the 100s of new readers who have signed up in the past months.

The following was first posted on 08/19/08

Many readers of this blog are familiar with the ongoing (endless?) discussion about whether or not obesity is a risk factor, a disease, a condition, or simply an extreme of the normal “bell curve” of body weights. Today, I want to throw in another term into this discussion. In fact, the more I think about it, the more I am convinced that we should look at obesity as a clinical sign - not unlike edema.

In the same manner that edema reflects the excess accumulation of fluid, obesity reflects the excess accumulation of body fat. As edema is a clinical sign of a perturbation of fluid homeostasis, excess fat accumulation is indicative of a perturbation in energy balance.

In a patient with edema, we can of course opt to simply provide symptomatic treatment by restricting salt and water intake, but my guess is that most experienced clinicians will likely make an effort to understand whether the fluid retention is a result of abnormal cardiac function, renal failure, venous or lymphatic stasis, vasodilatory drugs or a list of other possible causes of fluid retention.

Similarly, in a patient with excess body fat, we can simply prescribe “symptomatic treatment” by restricting food intake or increasing activity, or we can make an effort to truly understand the factors that are causing the patient to overeat or “undermove” (apologies for coining this term, but I kind of think it conveys the point). Obviously, whether or not the overeating is a result of peer pressure, hunger (meal skipping), depression, binge-eating, olanzapine, sugar-addiction, MC-4 receptor defect, or a craniopharyngeoma may well influence the choice of treatments.

Similarly, whether or not the “undermoving” results from lack of time, unsafe neighbourhoods, obstructive sleep apnea, anxiety disorders, depression, back pain, fibromyalgia, plantar fasciitis, vital exhaustion or quadroplegia will (hopefully) help determine the most appropriate and effective management strategy.

The idea that all people with excess body fat should simply eat less and move more is not unlike the notion that all people with edema should simply restrict their fluid intake and cut the salt.

If obesity is simply a “sign”, then “overeating” and “undermoving” are just symptoms!

The differential diagnosis of overeating and undermoving is complex and can involve sociocultural, psychological, medical and iatrogenic causes.

Let’s get more sophisticated in our diagnostics - hopefully our ability to address the underlying causes will follow.

AMS
Edmonton, Alberta