BackgroundIn Europe, dietary management of isovaleric acidemia (IVA) may vary widely. There is limited collective information about dietetic management.AimTo describe European practice regarding the dietary management of IVA, prior to the availability of the E-IMD IVA guidelines (E-IMD 2014).MethodsA cross-sectional questionnaire was sent to all European dietitians who were either members of the Society for the Study of Inborn Errors of Metabolism Dietitians Group (SSIEM-DG) or whom had responded to previous questionnaires on dietetic practice (n = 53). The questionnaire comprised 27 questions about the dietary management of IVA.ResultsInformation on 140 patients with IVA from 39 centres was reported. 133 patients (38 centres) were given a protein restricted diet. Leucine-free amino acid supplements (LFAA) were routinely used to supplement protein intake in 58% of centres. The median total protein intake prescribed achieved the WHO/FAO/UNU [2007] safe levels of protein intake in all age groups. Centres that prescribed LFAA had lower natural protein intakes in most age groups except 1 to 10 y. In contrast, when centres were not using LFAA, the median natural protein intake met WHO/FAO/UNU [2007] safe levels of protein intake in all age groups. Enteral tube feeding was rarely prescribed.ConclusionsThis survey demonstrates wide differences in dietary practice in the management of IVA across European centres. It provides unique dietary data collectively representing European practices in IVA which can be used as a foundation to compare dietary management changes as a consequence of the first E-IMD IVA guidelines availability.

Background: Adult phenylketonuria (PKU) patients often reduce their intake of amino acid mixture (AAM) to less than the prescribed amounts. Effects of reduced AAM intake on nutrient supply were evaluated. Methods: Nutrient intake was calculated in 20 adult PKU patients based on a structured food record and complemented by laboratory assessment of nutritional status. Patients were classified into 2 groups, (A) regular AAM intake, or (B) AAM intake below calculated requirements. Results: Group B consumed a higher proportion of natural protein (60 ± 23 vs. 33 ± 12%, p = 0.002); however, the total protein intake was below the recommended amounts in 60% of patients in group B versus 7% in group A (p = 0.03). Fat intake was higher in group B (39 ± 9% of energy vs. 31 ± 6%, p = 0.03), mainly from saturated fats. Selenium, folate, and vitamin B12 intake was below the recommended intake in group B. However, serum concentrations of these analytes remained within the normal range in both groups, although vitamin B12 levels were lower in group B. Plasma tyrosine correlated with AAM intake, and hydroxyproline correlated with the amount of natural protein consumed. Conclusion: Relaxed AAM intake resulted in insufficient nutrient supply, despite a compensatory increase in consumption of natural protein. Care needs to be taken to ensure adequate nutrition in adults with PKU.

BackgroundThe definitive dietary management of propionic acidaemia (PA) is unknown although natural protein restriction with adequate energy provision is of key importance.AimTo describe European dietary practices in the management of patients with PA prior to the publication of the European PA guidelines.MethodsThis was a cross-sectional survey consisting of 27 questions about the dietary practices in PA patients circulated to European IMD dietitians and health professionals in 2014.ResultsInformation on protein restricted diets of 186 PA patients from 47 centres, representing 14 European countries was collected. Total protein intake [PA precursor-free L-amino acid supplements (PFAA) and natural protein] met WHO/FAO/UNU (2007) safe protein requirements for age in 36 centres (77%). PFAA were used to supplement natural protein intake in 81% (n = 38) of centres, providing a median of 44% (14–83%) of total protein requirement. Seventy-four per cent of patients were prescribed natural protein intakes below WHO/FAO/UNU (2007) safe levels in one or more of the following age groups: 0–6 m, 7–12 m, 1–10 y, 11–16 y and > 16 y. Sixty-three per cent (n = 117) of patients were tube fed (74% gastrostomy), but only 22% received nocturnal feeds.ConclusionsThere was high use of PFAA with intakes of natural protein commonly below WHO/FAO/UNU (2007) safe levels. Optimal dietary management can only be determined by longitudinal, multi-centre, prospective case controlled studies. The metabolic instability of PA and small patient cohorts in each centre ensure that this is a challenging undertaking.

Dietary management of 418 adult patients with galactosaemia (from 39 centres/12 countries) was compared. All centres advised lactose restriction, 6 restricted galactose from galactosides ± fruits and vegetables and 12 offal. 38% (n=15) relaxed diet by: 1) allowing traces of lactose in manufactured foods (n=13) or 2) giving fruits, vegetables and galactosides (n=2). Only 15% (n=6) calculated dietary galactose. 32% of patients were lost to dietetic follow-up. In adult galactosaemia, there is limited diet relaxation.

BackgroundThe dietary management of methylmalonic acidaemia (MMA) is a low-protein diet providing sufficient energy to avoid catabolism and to limit production of methylmalonic acid. The goal is to achieve normal growth, good nutritional status and the maintenance of metabolic stability.AimTo describe the dietary management of patients with MMA across Europe.MethodsA cross-sectional questionnaire was sent to European colleagues managing inherited metabolic disorders (IMDs) (n=53) with 27 questions about the nutritional management of organic acidaemias. Data were analysed by different age ranges (0–6 months; 7–12 months; 1–10 years; 11–16 years; >16 years).ResultsQuestionnaires were returned from 53 centres. Twenty-five centres cared for 80 patients with MMA vitamin B12 responsive (MMAB12r) and 43 centres managed 215 patients with MMA vitamin B12 non-responsive (MMAB12nr). For MMAB12r patients, 44% of centres (n=11/25) prescribed natural protein below the World Health Organization/Food and Agriculture Organization/United Nations University (WHO/FAO/UNU) 2007 safe levels of protein intake in at least one age range. Precursor-free amino acids (PFAA) were prescribed by 40% of centres (10/25) caring for 36% (29/80) of all the patients. For MMAB12nr patients, 72% of centres (n=31/43) prescribed natural protein below the safe levels of protein intake (WHO/FAO/UNU 2007) in at least one age range. PFAA were prescribed by 77% of centres (n=33/43) managing 81% (n=174/215) of patients. In MMAB12nr patients, 90 (42%) required tube feeding: 25 via a nasogastric tube and 65 via a gastrostomy.ConclusionsA high percentage of centres used PFAA in MMA patients together with a protein prescription that provided less than the safe levels of natural protein intake. However, there was inconsistent practices across Europe. Long-term efficacy studies are needed to study patient outcome when using PFAA with different severities of natural protein restrictions in patients with MMA to guide future practice.