CARNITINE DEFICIENCY IN CHILDREN WITH LON G-TERM TUBE-FEEDING VIA PERCUTANEOUS ENDOSCOPICALLY CONTROLLED GASTROSTOMY (PEG)

Background: L(-)-Carnitine is an essential factor for the energy metab olism of long chain fatty acids. Since about 20 years carnitine defici ency syndromes have been described with several clinical symptoms and marked muscular dystrophy. In infants the long term total parenteral ( carnitine-free) feeding is an important cause for the development of a secondary carnitine deficiency syndrome. Methods: We analysed the ser um carnitine levels of 16 children, mean age 6.2 years, with centrally caused neurogenous dysphagia. These children exclusively received a b alanced carnitine-free tube diet via PEG for some months. We estimated both free and total L(-)-carnitine in serum using a radiochemical enz ymatic method. Results: All 16 children showed a marked carnitine defi ciency in serum (mean +/- standard deviation for free carnitine 9.5 +/ - 3.2 mu mol/l, for total carnitine 10.2 +/- 3.6 mu mol/l) after carni tine-free diet. Those serum values are less than 20 % of the values in healthy children. 13 of the first examined 16 children then got each 1 g L(-)-carnitine (3.3 ml Biocarn) per day. After substitution for ab out two months the carnitine values in serum rose significantly and di d not differ from the normal values anymore (free carnitine 43.6 +/- 1 4.5 mu mol/l, total carnitine 47.8 +/- 13.5 mu mol/l). In two children the carnitine substitution was interrupted: After one or three months , respectively, the serum values decreased again to the low values tha t are characteristic for systemic carnitine deficiency. Conclusions: A long term carnitine-free tube feeding induces a secondary systemic ca rnitine deficiency, which is probably more frequent than the rare here ditary primary carnitine deficiencies. The endogenous carnitine biosyn thesis in children is not sufficient to maintain the carnitine homeost asis. Supplementation of L(-)-carnitine to tube diet is necessary for physiological serum carnitine levels.