Nutrition management guideline for very-long chain acyl-CoA dehydrogenase deficiency (VLCAD): An evidence- and consensus-based approach.

The nutrition management guideline for very-long chain acyl-CoA dehydrogenase deficiency (VLCAD) is the fourth in a series of web-based guidelines focusing on the diet treatment for inherited metabolic disorders and follows previous publication of guidelines for maple syrup urine disease (2014), phenylketonuria (2016) and propionic acidemia (2019). The purpose of this guideline is to establish harmonization in the treatment and monitoring of individuals with VLCAD of all ages in order to improve clinical outcomes. Six research questions were identified to support guideline development on: nutrition recommendations for the healthy individual, illness management, supplementation, monitoring, physical activity and management during pregnancy. This report describes the methodology used in its development including review, critical appraisal and abstraction of peer-reviewed studies and unpublished practice literature; expert input through two Delphi surveys and a nominal group process; and external review from metabolic physicians and dietitians. It includes the summary statements of the nutrition management recommendations for each research question, followed by a standardized rating based on the strength of the evidence. Online, open access of the full published guideline allows utilization by health care providers, researchers and collaborators who advise, advocate and care for individuals with VLCAD and their families and can be accessed from the Genetic Metabolic Dietitians International (https://GMDI.org) and Southeast Regional Genetics Network (https://southeastgenetics.org/ngp) websites.

Nutritional management of PKU with glycomacropeptide from cheese whey.

Individuals with phenylketonuria (PKU) must follow a lifelong low-phenylalanine (Phe) diet to prevent neurological impairment. Compliance with the low-Phe diet is often poor owing to restriction in natural foods and the requirement for consumption of a Phe-free amino acid formula or medical food. Glycomacropeptide (GMP), a natural protein produced during cheese-making, is uniquely suited to a low-Phe diet because when isolated from cheese whey it contains minimal Phe (2.5-5 mg Phe/g protein). This paper reviews progress in evaluating the safety, acceptability and efficacy of GMP in the nutritional management of PKU. A variety of foods and beverages can be made with GMP to improve the taste, variety and convenience of the PKU diet. Sensory studies in individuals with PKU demonstrate that GMP foods are acceptable alternatives to amino acid medical foods. Studies in the PKU mouse model demonstrate that GMP supplemented with limiting indispensable amino acids provides a nutritionally adequate source of protein and improves the metabolic phenotype by reducing concentrations of Phe in plasma and brain. A case report in an adult with classical PKU who followed the GMP diet for 10 weeks at home indicates safety, acceptability of GMP food products, a 13-14% reduction in blood Phe levels (p<0.05) and improved distribution of dietary protein throughout the day compared with the amino acid diet. In summary, food products made with GMP that is supplemented with limiting indispensable amino acids provide a palatable alternative source of protein that may improve dietary compliance and metabolic control of PKU.

Renal transplantation in a patient with methylmalonic acidaemia.

Renal insufficiency is frequently reported in mutase-deficient methylmalonic acidaemia. We present a case report of a patient with mut- methylmalonic acidaemia who developed chronic tubulointerstitial nephropathy during adolescence. At 24 years of age, she developed end-stage renal failure and underwent renal transplantation. Both plasma and urine methylmalonic acid levels decreased significantly with improved renal function following transplantation. Complications included cyclosporin toxicity and development of diabetes. Renal, metabolic, and clinical status remained improved at 3 years after the kidney transplant.

Case reports of successful pregnancy in women with maple syrup urine disease and propionic acidemia.

We report on 2 women with organic acidemias, one with classical maple syrup urine disease and another with mild propionic acidemia in which protein restricted diets and carnitine supplementation were successfully employed to manage pregnancies. Healthy infants were delivered without maternal metabolic decompensation.

Dietary fiber and long-term large bowel response in enterally nourished nonambulatory profoundly retarded youth.

The objective of this year-long research was to determine the effects of three levels of a purified dietary fiber source, soy polysaccharide, on the long-term bowel function of 11 youth, aged 7 to 17 years, who were nonambulatory, profoundly disabled, constipated, and fed by gastrostomy. From day 1 to 60 the diet was a fiber-free enteral feeding; from day 61 to 300, 12 to 20 g/day total fiber was added to the diet; and from day 301 to 360, 18 to 25 g/day. Complete stool collections were made from day 51 to 60, day 111 to 120, day 291 to 300, day 321 to 330, and day 351 to 360. The second fiber addition significantly increased mean (+/- SD) daily stool frequency from 0.6 +/- 0.2 during the fiber-free diet to 1.1 +/- 0.5. The first addition of fiber compared to the fiber-free diet significantly increased stool moisture from 70 +/- 7% to 76 +/- 8% and wet stool weight from 30 +/- 13 g/day to 53 +/- 21; mean stool weight during days 351 to 360 was 87 +/- 45 g/day. Daily dry stool weight significantly increased with the second fiber addition. Soy polysaccharide fiber improved bowel function in this nonambulatory profoundly disabled population.

Long-term nutritional status of an enterally nourished institutionalized population.

Growth and nitrogen nutriture were evaluated during a yearlong study of 11 profoundly retarded nonambulatory institutionalized youth who were fed by gastrostomy and received anticonvulsants. The effects of dietary fiber and vitamin D were assessed by determining plasma levels and balances of zinc, magnesium, calcium, and phosphorus in a subset of six patients. Increase in body weight was 3.4 +/- 2.4 kg (means + SD), in height, 5.9 +/- 3.9 cm during the year. N balance remained positive throughout the study. Zn and Ca balances suggested that needs for this population may be greater than or equal to 150% of the Recommended Dietary Allowance. Vitamin D supplementation had no effect. Soy polysaccharide fiber intakes of 18-24 g/d compared with 0 or 12-20 g fiber/d significantly improved N and P retentions. Although the determination of nutrient needs of a severely disabled population is complex, our results suggest N and energy but not Zn and Ca allowances for a healthy population may be satisfactory guidelines.