Abstracts

Rationale: The ketogenic diet (KD) is a high-fat, low-carbohydrate (CHO) regimen used to treat pediatric epilepsy. Due to this shift in macronutrient distribution, hypoglycemia is a potential complication upon KD initiation. Methods: A retrospective chart review was conducted to study the effects of the KD on glucose metabolism in children with epilepsy who were admitted to MUSC for KD initiation (n=42; 60% male; 4.95.6y at KD initiation). Children consumed formula (KetoCal?(R)) either orally or via gastrostomy tube (n=30). Blood glucose and ketone production were monitored prior to and during the KD initiation period (mean monitoring time = 73.629.6h). There were no major differences between continuous and non-continuous feeders in demographic variables or unadjusted means, thus, children were analyzed by age (< or > 2y). Results: Children < 2y had longer BG/ketone monitoring times (81.431.5 h) compared to those >2y (63.123.8h, p=0.05). BG of younger children fell below 60 mg/dL more often (4.43.1 times, p=0.02) and tended to fall below 50 mg/dL more often over the monitoring period (1.51.7 times, p=0.06) compared to older children (2.12.8 times and 0.61.2, respectively). Accordingly, children < 2 y tended to reach their first hypoglycemic episode ( < 60 mg/dL) at a later time point (35.825.9h) compared to those >2y (24.823.5h, p=0.16). 82.6% of younger children reached hypoglycemia ( < 60 mg/dL), compared to 57.9% of older children (p=0.08). Percent of calories from protein (PRO%) was lower at baseline (p < 0.001) and upon KD initiation (p=0.004) for younger children (10.01.6 and 8.11.1%, respectively) compared to older children (15.34.7 and 9.62.1%, respectively). KD ratio, however, was not significantly different for older and younger children (mean KD ratio = 3.2 0.5). In the whole sample, KD ratio was significantly correlated with the number of times BG fell below 50 mg/dl (r=-32, p=0.04). Conclusions: Children younger than 2 years of age have frequent hypoglycemic episodes ( < 50 mg/dL), longer duration of ketogenic diet initiation period and high ratio of ketone bodies achieved compared to children older than 2 year of age. Difficult initiation of ketogenic diet therapy in younger children is likely due to poor adaptability and / or delayed maturation of enzyme systems involved in gluconeogenesis as well as utilization of ketone bodies as energy substrate by brain, liver and other peripheral tissues. This is reflected by higher incidence of hypoglycemia (< 50 mg/dL) and high ratio of ketone bodies achieved. Increasing protein content of KD may help reduce the frequent hypoglycemic episodes by improving substrate supply for gluconeogenesis. In addition initiating a slower transition to ketosis, and/or decreasing the goal ratio may also lower risk of hypoglycemia and improve tolerability of the transition to ketosis. Funding: No funding to disclose.