Abstracts

RATIONALE: Ketogenic diet(KD)is an accepted treatment for children with intractable epilepsy. Previously we reported slowed linear growth after 6 months on KD. However, long-term nutritional impact of KD needs to be determined.
METHODS: 10 children were followed for 2 years after KD initiation, irrespective of length of time (LoT) on KD. To assess KD efficacy, parents completed seizure diaries. Nutritional status and growth were evaluated using: height, weight, skinfolds, % body fat and bone mineral density (BMD). Z scores were used to analyze growth. Biochemical indices included lipids, vitamin D and E, etc.
RESULTS: Mean time on KD was 14.5 months (4/10 on KD 9-12 months; 6/10 on KD 16-18 months). 7/10 (70%) patients had a greater than 50% reduction in seizures by 1 year. Z scores for weight for age, height for age, weight for height, mid-arm circumference (MAC)and tricep skinfold were not statistically different between baseline, 1 yr and 2 yrs. Percent body fat did not change significantly between baseline (mean 31.8%)and 1 yr (mean: 30.2%). However, body fat was significantly decreased by 2 yrs, when patients were off KD (mean: 24.3%; p [lt] 0.01). BMD decreased in 7/10 patients between baseline and 1 yr; this was not statistically significant. By 2 yrs 9/10 had an increase in BMD, indicating BMD begins to normalize once KD is discontinued. No clinically significant abnormalities were noted in laboratory indices, though 1 patient had a low bicarbonate at 1 yr and 2 had high alkaline phosphatase at 2 yrs. No indices were significantly different between baseline, 1 yr and 2 yrs with the exception of higher vitamin D and E levels. Patients did not experience a significant increase in lipids, despite mild individual increases in triglycerides and cholesterol. There was no statistically significant correlation between measured variables and LoT on KD. However, there is a trend toward correlation between LoT on KD and increase in MAC Z score and between LoT on KD and bone mineral content. No patient discontinued KD due to nutritional side effects. All discontinued KD in an effort to find a treatment that would result in seizure freedom with less parental and patient effort.
CONCLUSIONS: Despite early indications of slowed growth and decreased BMD while on KD, even strict adherence to classic KD results in adequate growth and good nutritional status. Recovery from mild negative nutritional impacts of KD, including BMD, occurs rapidly following KD discontinuation. The significant decrease in % body fat following KD discontinuation may be due to diet changes/restrictions or an increase in lean body mass. Although patients need to be monitored carefully for nutritional deficiencies and inadequate growth while on KD, KD does not adversely impact nutritional status and growth.
Support: Grant M01 RR00069.