Carnitine levels and the ketogenic diet.
OBJECTIVE
To determine the long-term effect of the ketogenic diet (KD) on carnitine levels and whether carnitine depletion is a significant cause of clinical complications during KD initiation or treatment.


METHODS
Carnitine levels at 0, 1, 6, 12, and 24 months of diet treatment, carnitine antiepileptic drug (AED) history, lowest blood glucose and time to achieve ketosis during diet initiation, and diet complications were analyzed for 38 consecutive patients who initiated the KD from May 1997 to March 2000. Carnitine levels at follow-up were analyzed for eight patients started on the diet before to May 1997.


RESULTS
Total carnitine (TC) at diet initiation correlated negatively with the number of AEDs at diet initiation but not with number of past AEDs, lowest blood glucose, or time to ketosis. TC decreased in the first months of diet treatment and then stabilized or increased slightly with long term treatment. Only 19% of patients were supplemented with carnitine for low TC. No patient showed clinical signs of carnitine deficiency.


CONCLUSIONS
Multiple AED exposure lowers TC, but actual TC deficiency in patients initiating the KD is not common, and TC levels do not appear to predict hypoglycemia or problems achieving ketosis. Mild carnitine depletion may occur early in KD treatment and occasionally TC decreases out of the normal range, without clinical symptoms. TC stabilizes or increases back toward baseline with long-term treatment, and most patients do not require carnitine supplementation.
Berry-Kravis
E
E
Department of Pediatrics, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois 60612, USA. Elizabeth_M_Berry-Kravis@rush.edu
Booth
G
G
Sanchez
A C
AC
Woodbury-Kolb
J
J
D000293:Adolescent; D000328:Adult; D002331:Carnitine / Q000097:blood* / Q000172:deficiency* / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000378:metabolism; D004041:Dietary Fats / Q000008:administration & dosage / Q000378:metabolism; D004827:Epilepsy / Q000097:blood / Q000178:diet therapy* / Q000378:metabolism; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007003:Hypoglycemia / Q000209:etiology / Q000378:metabolism; D007223:Infant; D007662:Ketosis / Q000209:etiology / Q000378:metabolism*; D008297:Male; D016896:Treatment Outcome
D004040:Dietary Carbohydrates; D004041:Dietary Fats; D002331:Carnitine