Abstracts

The ketogenic diet is an effective form of treatment for patients with refractory epilepsy. An elevation in serum lipids and a decrease in serum carnitine are among the nutritional and metabolic consequences of the diet. It is unclear whether the lipid elevation associated with the ketogenic diet can result in adverse consequences as the typical duration of the ketogenic diet is relatively short (24 mos). It is clear that long-term hyperlipidemia increases the risk for cardiovascular disease. Preventing or minimizing lipid elevations may avoid potential adverse consequences associated with the diet. Triglycerides are often elevated during the ketogenic diet. Carnitine is involved in fat oxidation and its deficiency may result in lipid elevation. Carnitine supplementation has been reported to reduce triglycerides in selected patients with decreased serum carnitine levels. This study reports the effect of carnitine supplementation on triglycerides in adult patients who were treated with the ketogenic diet for refractory epilepsy.
Three patients were placed on the ketogenic diet with a ratio of 4 grams of fat to every 1 gram of combined carbohydrate and protein. Fasting lipid panels and carnitine levels (free, total and esters) were among the laboratory measurements collected for all patients. The ketogenic protocol at our institution calls for carnitine supplementation if triglycerides become elevated. All patients are supplemented with daily multivitamins.
One patient who began the diet without carnitine supplementation had an elevated triglyceride level of 310 mg/dl after 15 months on the diet. The addition of 990 mg/day of carnitine without dietary change reduced fasting triglycerides to 58 mg/dl (81% reduction). Two other patients who began the diet taking 990 mg/d of carnitine still experienced elevated triglycerides. Baseline triglyceride values of 383 mg/dl and 175 mg/dl rose to 659 mg/dl and 248 mg/dl, respectively. Increasing the carnitine to 1980 mg/day resulted in lowered triglycerides (271 mg/dl and 161 mg/dl). No adverse reactions to carnitine were seen.
The ketogenic diet raises triglyceride levels. This study suggests that elevated triglycerides may be successfully treated with carnitine. Long term follow-up is necessary to evaluate the possible consequences of elevated lipids during the course of the ketogenic diet in adults, as well as the long-term efficacy of carnitine.