Month: March 2013

Eating Disorders in the Elderly

Tetyana 2 Comments

The first published case of a late-onset eating disorder (at the age of 40) was in 1930 by John M. Berkman. In 1936, John A. Ryle published a case study of an eating disorder in a 59-year-old woman. Just how common are eating disorders in late middle-age or elderly individuals?

One study of 475 community dwelling elderly women aged 60–70 years found that 3.8% met diagnostic criteria for eating disorders. A study of elderly Canadian women reported that symptoms of disordered eating were present in 2.6% of women aged 50–64 years, and in 1.8% of women aged 65 years or older (Gadalla, 2008). In an investigation of eating disorders in elderly outpatient males, a minority (11–19%) who were undernourished were found to have abnormal eating attitudes and body image, including inappropriate self-control around food (60%), unsuitable eating attitudes (26%), and distorted body image (3–52%) (Miller et al., 1991).

There aren’t … Continue reading →

Are There Any Meaningful Differences Between Subthreshold and Full Syndrome Anorexia Nervosa?

Tetyana 11 Comments

I see this on a daily basis: patients with subthreshold eating disorders feeling invalidated and “not sick enough.” They are struggling so much, but maybe they still have their periods, or maybe their weight isn’t quite low enough, and so they often (but not always, thankfully) get dismissed by doctors, other healthcare professionals, and insurance companies. Do you think you really need this treatment, maybe you can just focus on eating healthier? You know you are not fat, you are perfectly healthy! Just be happy! Or, Sorry, we can’t cover this psychological treatment because you don’t fit the full diagnostic criteria. 

Why do we draw a line between ‘threshold’ and ‘subthreshold’ at arbitrary numerical criteria?

No doubt numbers are important for medical treatment: someone with a very low BMI might have considerably more physical complications that need to be taken into account during treatment than someone with a not-so-low … Continue reading →

Your Body’s Response to Chewing and Spitting: The Role of Insulin

Shelly 19 Comments

In my previous post, I looked at two hormones released during the cephalic phase (gastric secretion that occurs before food is eaten), ghrelin and obestatin, and how they may contribute to runaway eating behavior. Today I’m going to be looking at insulin release during chew and spit (CHSP), a fairly common symptom in eating disorders where the food is tasted, chewed and spit out. Insulin is a small peptide hormone that acts as a key regulator of metabolism; deregulation of insulin signalling plays a role in illnesses such as diabetes and metabolic syndrome. Some people have theorized that CHSP behavior may influence insulin regulation. In fact, there are a number of individuals stating on internet forums that chronic CHSP could lead to insulin resistance, potentially promoting diabetes. As interesting as these theories are, recent data have shown that they are probably not true.

INSULIN RELEASE DURING THE CEPHALIC … Continue reading →

Demystifying the Genetics of Eating Disorders – Part II

Tetyana

In my last post I talked about some methods that scientists use to study the genetics of eating disorders. I focused on a subfield of genetics called behavioural genetics (which you can think of as a field that attempts to understand, in part, the interplay of genetics and environment in behaviour). In this post I’ll shift gears and focus on molecular genetics. I’ll be working of the same review paper by Drs. Zerwas and Bulik (2011). Molecular geneticists study the structure and function of genes on a molecular level. For example, they try to understand how different mutations or alterations in the genetic code can affect protein function and lead to disease states.

GENETIC ASSOCIATION STUDIES

Genetic association studies are hypothesis driven. This means that researchers make a list of genes that are known to be involved in biological mechanisms or behaviours that are affected in eating disorders, such … Continue reading →

Demystifying the Genetics of Eating Disorders – Part I

Tetyana 9 Comments

Today I thought I’d take the time to do an overview of what researchers know about the genetics of eating disorders and try to clear up some common misconceptions. The bulk of the content in this blog post comes from a very nice review paper published in 2011 by Drs. Stephanie Zerwas and Cynthia Bulik on the genetics and epigenetics of eating disorders. In an effort to keep blog posts short, this will be a multi-part mini-series.

When it comes to the genetics of eating disorders, there are two main questions that research ask: What is the relative contribution of genetic factors to eating disorder behaviours? And what are those genetic factors? I’ll talk about research attempting to answer the first question in this post and the second question in my next post.

In order to understand the role that genetics plays in influencing eating disorder behaviours, researchers use family, … Continue reading →

Avoiding Refeeding Syndrome in Anorexia Nervosa

Tetyana 25 Comments

Refeeding syndrome (RS) is a rare but potentially fatal condition that can occur during refeeding of severely malnourished individuals (such as anorexia nervosa patients). After prolonged starvation, the body begins to use  fat and protein to produce energy because there are not enough carbohydrates. Upon refeeding, there’s a surge of insulin (because of the ingested carbohydrates) and a sudden shift from fat to carbohydrate metabolism. This sudden shift can lead to a whole set of problems that characterize the refeeding syndrome.

For example, one of the key features of RS is hypophosphotemia: abnormally low levels of phosphate in the blood. This occurs primarily because the insulin surge during food ingestion leads to a cellular uptake of phosphate. Phosphate is a very important molecule and its dysregulation affects almost every system in the body and can lead to “rhabdomyolysis, leucocyte dysfunction, respiratory failure, cardiac failure, hypotension, arrhythmias, seizures, coma, and … Continue reading →

Deep Brain Stimulation for Severe Anorexia Nervosa

Tetyana 15 Comments

This week, a team of researchers from the University of Toronto published a paper in The Lancet describing the results of a small study using deep brain stimulation (DBS) to treat severe/chronic anorexia nervosa. Major news outlets, including the BBC, reported on the findings. A few people emailed and messaged me asking me to do a post about it (which is cool! I love it!). So here it is.

DBS is a surgical procedure that involves implanting an electrode that delivers electrical signals to the brain. DBS is used to treat Parkinson’s disease and other movement disorders with good success, and has recently been implicated in the treatment of OCD and depression as well. (This is a pretty good video explaining how DBS works for movement disorders. There’s lots of information online about how DBS works, so I won’t go into detail here.)

This is not the first … Continue reading →

Your Body’s Response to Chewing & Spitting: The Role of Ghrelin and Obestatin

Shelly 3 Comments

Shelly’s follow-up post on chewing and spitting, an often overlooked symptom in eating disorders. In her first post, Shelly discussed the prevalence of chewing and spitting among eating disorder patients. In this post, Shelly discusses some of the physiological effects of chewing and spitting. Enjoy! – Tetyana

Your body responds to food long before it reaches your stomach. The taste, smell, even the mere sight of food all act to trigger a physiological response, “priming” the gut by stimulating various enzymes required for proper digestion and absorption of nutrients. This is called the “cephalic response”, and it is mediated by a part of the nervous system that’s generally not under conscious control (the autonomic nervous system). Keep in mind, the actual consumption of food is NOT necessary to trigger this reflex.

As you may have already guessed, the act of chewing and spitting (CHSP) out … Continue reading →

Living in a Large City: A Risk Factor for Bulimia Nervosa?

Tetyana 7 Comments

The link between urban living and mental disorders such as schizophrenia and depression has been known for quite some time (Sundquist et al., 2004). In one study, Sundquist et al found that individuals living in a densely populated area had a 68-77% higher risk of developing psychosis and 12-22% higher risk of developing depression.

The question then arises, do eating disorders follow a similar pattern? And if yes, what are some possible explanations? Certainly we know that both genetic and environmental factors are involved in the development of eating disorders, but what specific factors and to what extent remains unclear.

In this study, Gabrielle E. van Son and colleagues set out to explore whether increasing urbanization was an environmental risk factor for the development of eating disorders.

In order to answer this question, the researchers had a network general practitioners (GPs) record each newly diagnosed case of anorexia … Continue reading →