Special low protein foods (SLPF) are essential in the nutritional management of patients with phenylketonuria (PKU). The study objectives were to: 1) identify the number of SLPF available for use in eight European countries and Turkey and 2) analyse the nutritional composition of SLPF available in one of these countries. European Nutritionist Expert Panel on PKU (ENEP) members (Portugal, Spain, Belgium, Italy, Germany, Netherlands, UK, Denmark and Turkey) provided data on SPLF available in each country. The nutritional composition of Portuguese SLPF was compared with regular food products. The number of different SLPF available in each country varied widely with a median of 107 [ranging from 73 (Portugal) and 256 (Italy)]. Food analysis of SLPF available from a single country (Portugal) indicated that the mean phenylalanine content was higher in low protein baby cereals (mean 48 mg/100 g) and chocolate/energy bars/jelly (mean 41 mg/100 g). The energy content of different foods from a sub-group of SLPF (cookies) varied widely between 23 and 96 kcal/cookie. Low protein bread had a high fat content [mean 5.8 g/100 g (range 3.7 to 10)] compared with 1.6 g/100 g in regular bread. Seven of the 12 SLPF sub-groups (58 %) did not declare any vitamin content, and only 4 (33 %) identified a limited number of minerals. Whilst equal and free access to all SLPF is desirable, the widely variable nutritional composition requires careful nutritional knowledge of all products when prescribed for individual patients with PKU. There is a need for more specific nutritional standards for special low protein foods.

In phenylketonuria (PKU), synthetic protein derived from L-amino acids (AAs) is essential in a low-phenylalanine (Phe) diet. Glycomacropeptide (GMP), an intact protein, is very low in Phe in its native form. It has been modified and adapted for PKU to provide an alternative protein source through supplementation with rate-limiting amino acids (GMP-AAs), although it still contains residual Phe. This review aims to systematically evaluate published intervention studies on the use of GMP-AAs in PKU by considering its impact on blood Phe control (primary aim) and changes in tyrosine control, nutritional biomarkers, and patient acceptability or palatability (secondary aims). Four electronic databases were searched for articles published from 2007 to June 2018. Of the 274 studies identified, only eight were included. Bias risk was assessed and a quality appraisal of the body of evidence was completed. A meta-analysis was performed with two studies with adequate comparable methodology which showed no differences between GMP-AAs and AAs for any of the interventions analysed. This work underlines the scarcity and nature of studies with GMP-AAs interventions. All were short-term with small sample sizes. There is a need for better-designed studies to provide the best evidence-based recommendations.

Percutaneous endoscopic gastrostomy (PEG) is a standard procedure for feeding dysphagic amyotrophic lateral sclerosis (ALS) patients. Nevertheless, the effect of prognostic factors influencing survival after PEG remains unclear. We aimed to evaluate the prognostic value of several clinical features on survival after PEG placement. This study investigated 151 patients with ALS, in whom a PEG was inserted over the last 16 years in our centre. Survival curves were determined by Kaplan-Meier and the analysis of potential prognostic factors was performed by a Cox regression model. The overall median survival was 32 months, longer in spinal-onset disease patients − 42 vs. 29 months in bulbar-onset patients (p < 0.001). Median survival after PEG placement was 7.5 months, similar in both bulbar- and spinal-onset patients, 7.9 vs. 7.1 months, respectively. Thirteen percent of patients died within one month after PEG placement; this short-term survival was influenced by low forced vital capacity (FVC < 50%). In a multivariate analysis, only older age at disease onset was independently associated with poor outcome after PEG placement. In conclusion, survival after PEG placement was similar in bulbar- and spinal-onset patients, suggesting that the latter were in a more advanced stage at the time of PEG placement. Low FVC was associated with higher risk of short-term mortality. Older age at disease onset was associated with poorer outcome in bulbar-onset patients. Younger bulbar-onset patients are those who benefited most from PEG.