Friday, November 27, 2015
What Do Irregular Carnitine Levels Signal?
My 4 year old daughter has recently been diagnosed with Autistic Disorder. During her evaluation they ordered some labs. Everything came back normal except the carntine and TSH levels. The levels were as follows: TSH 7.870 normal range (.5-4.8) and Total Carnitine 21 norm (35-84UMOL/L) Free Carnitine 18 norm ( 24-63 UMOL/L) and Acylcarnitine 3 and norm (4-28 UMOL/L) Do these labs correlate with the diagnosis of Autism? Should we pursue treatment regarding the carntine level? Thanks
Where was she evaluated? A university medical center? If so, they should be able to make treatment recommendations based on any lab abnormalities. I'm surprised you would be writing to me for explanation, but here is some general background information.
A high TSH suggests a thyroid deficiency, which the pituitary is trying to make up for by producing more TSH to goad the thyroid gland into making more hormone. If the hormone levels (T3 and T4) are also high, it could be a generalized insensitivity to thyroid hormone, in which the thyroid receptors are sluggish and need extra thyroid hormone to be properly stimulated. If the T3 and T4 are low, it suggests that the thyroid gland is hypofunctioning. The doctor who ordered the tests should be able to advise you or refer you to a pediatric endocrinologist who could.
Regarding the carnitine, most of the carnitine in our system is ingested in animal protein (meat, fish, milk, eggs). We make some of what we need, but depend on ingesting the rest. Children with autism often have peculiar food preferences. If your daughter refuses animal protein, that could account for her low levels of carnitine. Again, the doctor who ordered the tests may recommend dietary correction or a small amount of carnitine supplement daily (it is available over the counter, like vitamins).
L Eugene Arnold, MD, MEd
Professor Emeritus of Psychiatry
College of Medicine
The Ohio State University