Recommendations for protein and energy intakes by patients with phenylketonuria

Abstract

Recent reports describe poor growth in treated children with phenylketonuria (PKU). That poor growth is not a concomitant of the disorder and need not result from therapy is demonstrated by data from the U.S.A. PKU Collaborative Study and from recent data from the U.S.A. In these studies, sufficient protein equivalent was supplied by medical food containing either a low phenylalanine (Phe) casein hydrolysate or Phe-free L-amino acids. Protein and energy intakes of infants and children with PKU who grew well are compared to intakes of normal North American children. Factors that influence nitrogen (N) requirements include: state of health, energy intake, the form in which N is administered and the size of the dose. Failure to prevent poor growth in childhood may lead to a stunted adult [13] who is at risk for obesity. The use of actual body weight as a basis for calculating protein and energy requirements is appropriate only when the child is growing normally. Based on experience with PKU in the U.S.A., the following are recommended: (1) a protocol that prescribes a range for Phe, protein, and energy for infants and children should be developed; (2) adequate protein equivalent to cover N losses due to poor utilization of amino acids and protein hydrolysates should be prescribed; (3) medical food should be administered in several doses throughout the day; (4) a source of Phe should be fed with the medical food; (5) adequate energy should be prescribed to prevent excess use of amino acid for energy purposes; (6) nutrition support during illness should be appropriate to help prevent muscle protein catabolism with attendant elevated plasma Phe.

Chronic kidney disease in adolescent and adult patients with phenylketonuria

“…It has been reported before that obesity is a common problem in PKU patients (MacDonald et al 2011). Though, it is our experience and that of others that caloric intake in PKU patients is within normal limits (Acosta 1996). An increase in BMI in PKU patients may be due to inadequate energy expenditure (Acosta et al 2003;W h i t ee t al 1982).…”

The intake of total protein, natural protein and protein substitute and growth of height and head circumference in Dutch infants with phenylketonuria

“…The data from this study suggest that the composition of the protein substitutes used may be less than optimal in terms of the composition of natural protein. One reason may be that the metabolic use is less effective for the amino acids supplied by the protein substitute than for the protein derived from milk or egg (Acosta 1996;Fomon 1991). Especially when the daily intake of protein substitute is not adequately distributed over the day, plasma amino acid concentrations rise more rapidly (Gropper and Acosta 1991), and amino acids are used for oxidation rather than protein synthesis (Herrmann et al 1994).…”

“…The recommended protein intake of PKU infants is the subject of ongoing debate (Acosta 1996;Cockburn et al 1996;Przyrembel 1996). Most studies investigating the effects of the dietary treatment on growth in PKU have focused predominantly on the restriction in height growth (Acosta et al 1977;Kindt et al 1988;van Spronsen et al 1997).…”

Financial justification of investments into special diet for patients with phenylketonuria

“…Postepeno je ta granica pomerana ka starijem uzrastu, a danas je generalni stav da dijetu treba sprovoditi doživotno, s tim što je ona liberalnija nakon adolescencije. Izuzetak su pacijentkinje obolele od PKU u reproduktivnom periodu koje planiraju trudnoću jer je tada kao i tokom trudnoće dijeta ponovo veoma stroga [13,14].…”