Tuesday, July 15, 2008

Sometimes it's what you CAN'T see that you should be paying attention to

I've been in this field for many years. Back when I started, and was learning about diabetes, I was taught that the best way to measure whether or not a diabetic had good blood glucose control, was to monitor blood glucose. When records looked good, we assumed all was good. Diabetics knew better. They often manipulated their diet and knew how to eat around the readings, and could straighten out a few days before a doctor's appointment with healthy readings.

These days, the glycosylated hemoglobin test is considered a more accurate assessment. It can give the practitioner an idea of what goes on, on average, all of the time. And people who are not compliant between doctor visits can't manipulate the science behind how the test does its job.

What I've learned from this, is that sometimes, even though things look good on the surface, there are problems underneath. And we should never assume that there are no problems just because we can't see them.

Enter epilepsy.

It has been known for quite awhile that certain antiepileptic medications can deplete the body of carnitine, a nutrient that is needed for healthy weight maintenance and to protect the brain against aging. In fact, older studies recommend supplementing carnitine in persons on medications such as valproic acid (Depakote) in order to minimize problems associated with carnitine deficiency.

Researchers recently compared carnitine levels in children on three other medications (vigabatrin or Sabril*, lamotrigine or Lamictal, and topiramate or Topamax). Clinically the only group with significantly lower carnitine levels were those on valproic acid.

If the conclusion of this study was that carnitine levels were not compromised by the other three medications, that would have been logical. However, the researchers also stated that because there were no apparent symptoms related to carnitine deficiency, that doing anything about it may not be necessary.

I happen to have spent the last few months going through several hundred pages of abstracts on carnitine, and with all due respect, I must disagree. I've got dozens of papers suggesting that carnitine is important to protect the brain against oxidation; in fact, it's been proposed by numerous researchers to be a potentially important agent in the fight against Alzheimer's disease.

With all the research I'm having to wade through, I cannot believe that it is not standard practice to recommend carnitine supplementation to anyone receiving valproic acid for any reason. My list of references is very, very long and I'm only up to the year 1992. If you happen to be reading this and would like me to spend another post detailing these references when I am finished, I would be happy to do so. Simply reply to this post so I know you'd like the information.

Just because we can't see everything happening in the brain...doesn't mean we shouldn't be doing anything about the things that we do know and can do something about.

Zelnik N, Isler N, Goez H, Shiffer M, David M, Shahar E. Vigabatrin, lamotrigine, topiramate and serum carnitine levels. Pediatr Neurol. 2008 Jul;39(1):18-21.

*Sabril is sold in Canada.

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