Self-harm and glucose metabolism in women with EDs
Self-injury (such as cutting or burning oneself) is fairly common amongst people with eating disorders- approximately 25% to 45% of people with eating disorders self-injure, and approximately half of those who self-injure also have eating disorders (full article here). Many people report a sense of dissociation while self-harming, a desire to turn emotional pain into physical pain (ie, "real" pain), and also that this behavior reduces anxiety. Whether self-harm is from issues relating to impulse control, a more compulsive pattern of behavior, or something else entirely, the amount of overlap between self-injury and eating disorders is significant.
An interesting new paper from the journal Psychoneuroendocrinology looked at the relationship between self-injury and glucose metabolism in women with eating disorders, and what they found was significant. Women engaging in self-harm behaviors were given an oral glucose tolerance test, in which they were asked to drink a sweet solution to measure how the body handles sugar. The self-harming women who also had an eating disorder had higher levels of blood glucose after the test, but also higher levels of a hormone called glucagon.
Glucagon is essentially insulin's opposite: when the blood sugar is low, the pancreas secretes glucagon to prod cells into breaking down long chains of carbohydrates called glycogen into small sugars that can be released into the bloodstream and readily used by the body. When blood sugar rises after a meal, the pancreas secretes insulin, which stimulates cells to pull excess sugars out of the bloodstream and store them as glycogen for a rainy day*.
Besides low blood sugar, several other factors can stimulate the release of glucagon, including epinephrine (aka adrenaline), which is involved in the fight or flight response. Though I was unable to find any specific studies linking high levels of epinephrine and self-injury, it's certainly plausible to think that people who self-harm would have higher levels of epinephrine, especially right after an incident where such behavior occurs. Alternately, if high levels of glucagon also stem from high levels of epinephrine, the sufferer may be caught in a cycle of self-harm during episodes of low blood sugar.
For instance, a common pattern in those who binge and purge is binge-purge-self harm, where the self-harm typically occurs after the completion of the binge/purge cycle. After a binge, blood sugar goes up and glucagon levels go down. After a purge, blood sugar goes down, and glucagon and epinephrine levels go up.
No one knows at this point where the relationship between self-harm and glucose metabolism lies on the cause/effect scale. Certainly there is a feedback cycle between all of these systems. But one good point to keep in mind is the importance of helping sufferers regulate blood sugar levels by frequent meals and snacks that involve complex carbohydrates, proteins, AND fats. Food is medicine for the eating disorder, but it also might be true for self-injury.
*Aren't you glad I paid attention in my 8am biochem lecture 10 years ago?
(cross-posted at FEASTing on Research)
11 comments:
this is fascinating!! I love finding out the science behind-or related to- stigmatized behaviors.
Interesting post. I've always read about the serotonin factor for SIers, but this is a new avenue of research, probably one that is way past due actually.
Varying levels of blood sugar can affect us in many ways, so my guess is that those who are more pre-disposed to Deliberate Self-Harm, would be at risk.
In any case, this is just an example how important it is for our bodies to be nourished, and our blood/brain chemistries to remain stable. Bodies like homoestasis.
That's really interesting.
I haven't self injured in almost five years, but for it was definitely a substitute for puking. I wonder if puking sans bingeing raises your glucagon? I would imagine it does, because it seemed, for me at least, to have the adrenaline rush.
I have a naturally insanely fast metabolism, and while in refeeding often had post postprandial hypoglycemia. I wonder if puking/cutting wasn't a way of re-establishing a glucose of >40? I can't pull up the study now because I'm not on my school server, but there were some studies suggesting a role in stress/cortisol levels in refeeding postprandial hypoglycemia too.
Seems counter intuitive to me though-- the only way I could talk my way through it was to assume that anxiety caused a spike in glucose [cortisol/epinephrine] that resulted in the foodstuff being used up too quickly.
I wonder if that's responsible for the dazed spacey sort of relief puking/cutting afforded me.
Med physio made me REALLY appreciate how bodies work a whole hell of a lot more. And appreciate what extremes it takes to disrupt that homeostasis.
Lipstick,
Thanks for sharing that. I agree, the connection is likely much more complex than just self-harm and glucose levels, but I had never considered the importance of blood sugar in relation to cutting.
And hypoglycemia makes you feel anxious (well, it makes ME feel anxious), which would also interact with the self-harm/anxiety loop, too.
Great great post. A huge light bulb went off in my head. Having pcos has a huge relation to insulin resistance, so I'm very curious about all this!
Hi, Carrie
Wow! This is really interesting! It makes sense -- I do track my blood sugar (due to hypoglycemia issues) and I can see where my binge and self-injury behaviors could track with my blood sugar levels .. I'll have to check this out some more in my own situation! Thanks!
- Marie (Coming Out of the Trees)
http://mmaaggnnaa.wordpress.com/
thank you so much for writing this post, Reading this rung bells for me. My adult son diagnosed with with BPD many years ago self harmed regularly over a long period of time, After numerous interventions this has now ceased in the main. One of the avenues we pursued was a naturopath, who helped him see how what he ate had a major effect on his well being, he transformed his way of eating, he was addicted to toast and very sweet tea! All seems so obvious now after reading your article, thank you.
Sorry about the spam there...I try to keep a close eye on things, but occasionally stuff slips through.
Fascinating stuff which took me right back to the beginning of my daughter's problems with food and mood - 1 hour old and she was rigid and almost fitting - the cause, lack of sugar - hmmmmmmmmm
Marcella,
That's really interesting about your daughter. I am really sensitive to blood sugar changes (both Types 1 and 2 diabetes run in the family), and I think it's one of those things that is so important but so overlooked.
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