Interesting Findings in Eating Disorders and Alzheimer's

First off, everyone take a couple of hours and hop on over to Robb Wolf's blog and listen to his podcast with Dr. Kurt Harris.  As usual, Kurt pulls it all together with fun and flair and a hefty serving of common sense.  He gives me and my blog a few mentions, which is very much appreciated, as always :)

I've been anticipating excitement hunting down a couple of papers that came out in the last couple of weeks - the first one:  An Update on Hospitalizations for Eating Disorders, 1999-2009.  As expected from a statistical brief, there is little there besides the numbers - so it is not all that exciting.  Overall, eating disorders as a primary or secondary diagnoses have increased 24% in that period, cost of hospitalizations have increased 29%, and hospitalizations for children under 12 have increased 72%, and for people 45-65 88%, and for men 53%.  Weirdly, hospitalizations for pica (compulsively eating non-food items, such as dirt or soap or whatever) have increased 93% but are still rather unusual.   If you look at eating disorders as a "principal" diagnosis only, the number has actually fallen 1.8%, and I've seen some funny headlines as a result - "eating disorder hospitalizations fall, but pica hospitalizations double."

An important caveat is that these numbers are generated from billing codes.  If someone comes to see me at the office, I am obligated (if I want to be paid by the insurance company) to generate a code based on a DSMIV diagnosis that I put on a billing form.  The same is true for inpatient hospitalizations.  And in the past 13 years, a number of states and the federal government have issued rules to prevent insurance companies from rejecting paying for psychiatric diagnoses that are so-called "biologic."  This change is a part of the mental health parity act.  "Biologic" diagnoses vary from state to state depending upon the laws, and even depending upon the insurance company, but generally include major depressive disorder, bipolar disorder, schizophrenia, etc.  Sometimes anxiety disorders are not included.  Addiction used to be not included, now it is I believe, and often autism and eating disorders are not included.  Therefore if I am a doctor who would like to get paid and not have patients stuck with bills when they pay their insurance premiums, and someone meets criteria for major depressive disorder (MDD) AND an eating disorder (which in the inpatient world will very often be the case), the MDD will always be the "principal" diagnosis to avoid issues down the line.  I know that anorexia is often more likely to be covered for inpatient care than bulimia, depending upon the medical status of the patient…  in short, the overall trend of primary and secondary diagnoses and increase in men and children and older people I find very interesting more than the drop in "principal" diagnosis.

It is actually rather difficult and getting more difficult all the time to be hospitalized for psychiatric disorders in general.  For the most part you must be an obvious imminent risk to self or others or completely unable to care for yourself in order to get a bed, which are in scarce supply.  In 1999 it was easier to get the slightly less ill hospitalized.  So with this background, I find it rather remarkable the eating disorder hospitalizations have increased to such a degree.  Binge eating rarely results in psychiatric hospitalization, and outpatient rates of binge eating and bulimia are rising also (though inpatient bulimia hospitalization dropped - the severe cases are often readily managed in intensive outpatient day programs nowadays, however.)  As obesity has also increased over the same period of time, I can't help but suspect the two trends are related, but I can't prove it.

The second article I was excited to hear about is probably a watershed paper in the treatment of Alzheimer's dementia:  Intranasal Insulin Therapy for Alzheimer Disease and Amnestic Mild Cognitive Impairment.  This paper discusses a pilot trial of 104 adults with amnestic mild cognitive impairment or Alzheimer's disease vs controls with a couple of doses of intranasal insulin.

Why intranasal?  None of the subjects had diabetes, and obviously systemic insulin could cause dangerous hypoglycemia.  The intranasal dose goes pretty much straight to the central nervous system via the olfactory and trigeminal nerve perivascular channels, and none of the subjects had hypoglycemia during the trial.

Why insulin?  Well, as I've discussed at great length (I really ought to repost some of those dementia articles up on Psychology Today…), there are very clear issues with the ability of a dementing brain to metabolize glucose (the example in that article is Parkinson's disease, but the principle is very similar for Alzheimer's).  This problem results in inefficient use of energy, free radical generation, and neuronal toxicity and death.    There are several ways to (theoretically) improve this issue - one of them is to use a therapeutic ketogenic diet.  The other way is to jack up insulin in the central nervous system to improve the ability of the cells to pull in and utilize glucose, theoretically.  In addition, insulin seems to have an effect on amyloid-beta peptides that may protect the neurons, and insulin and insulin activity are generally low in the CNS of folks with dementia (though hyperinsulinemia with insulin resistance seems to be a long-term risk factor for developing Alzheimer's dementia eventually).

My question is - and this is highly speculative - without improving the energetics, does jacking up the insulin help in the short term but hasten the problems in the long term?  No long term studies have been done.  In the absence of insulin resistance and with insulin in the CNS low already, perhaps not?  I'll have to think a little more on that one.