GMDI/SERN VLCAD Nutrition Guidelines

Rohr F¹, van Calcar S², Sowa M³, Splett P⁴, Stembridge A⁵, Osara Y⁵, Singh RH⁵

¹Boston Children’s Hospital, Boston MA, ²Oregon Health Science University, Portland, OR, ³Children’s Hospital of Orange County, Orange, CA, ⁴Evaluation Consultant Splett & Associates, LLC,  Stanchfield, MN, ⁵Emory University School of Medicine, Atlanta GA

Background: Genetic Metabolic Dietitians International (GMDI) and the Southeast Regional Genetics Network (SERN) have partnered under a grant from HRSA (#UH7MC30772) to create web-based nutrition management guidelines for inherited metabolic disorders. The guidelines for very long chain acyl co-A dehydrogenase deficiency (VLCAD) are currently being updated from the current GMDI guidelines developed in 2009.

Objective: The purpose is to establish harmonization in treatment and monitoring, to guide the integration of nutrition therapy in the management of VLCAD, and to improve outcomes (nutritional, cognitive, and developmental) for individuals with VLCAD while reducing associated medical, educational, and social costs.

Methods: Six research questions about VLCAD nutrition management were formulated to support guideline development: Review, critical appraisal, and abstraction of 93 peer-reviewed studies and 26 gray literature (unpublished) documents, along with expert Delphi survey feedback, nominal group process, and external review from metabolic physicians and dietitians are utilized for development of recommendations relevant to each question. Recommendations will address diet composition based on disease severity, nutrition management during illness, supplementation, monitoring specific to life stages, exercise guidance and management during pregnancy and lactation. Recommendations are graded using a rigorous system derived from the Academy of Nutrition and Dietetics.

Results and Conclusions: There is a paucity of published data about individuals with VLCAD identified through newborn screening who are asymptomatic, therefore the nutrition guidelines are based heavily on gray literature and consensus for these individuals. For those presenting with cardiomyopathy and/or rhabdomyolysis more published literature exists. The updated guidelines will reflect new directions in practice: providing little or no nutrition intervention for asymptomatic newborns; restricting long chain fat to no less than 10% of energy for severe VLCAD; reconsidering the need for cornstarch and L-carnitine supplementation, encouraging exercise as tolerated and supporting activity with sufficient energy intake; routine monitoring of labs to assess disease status (but the lack of a single laboratory parameter to guide treatment); and careful monitoring during pregnancy and the post partum period. The final guidelines are to be published this fall and will be available at www.gmdi.org and https://southeastgenetics.org/ngp.