Nutrients, Vol. 18, Pages 488: Global Use of Casein Glycomacropeptide Protein Substitutes for Phenylketonuria (PKU): Health Professional Perspectives
Nutrients doi: 10.3390/nu18030488
Authors:
Sharon Evans
Rani Singh
Kirsten Ahring
Catherine Ashmore
Anne Daly
Suzanne Ford
Maria Ines Gama
Maria Giżewska
Melanie Hill
Fatma Ilgaz
Richard Jackson
Camille Newby
Alex Pinto
Martina Tosi
Ozlem Yilmaz Nas
Juri Zuvadelli
Anita MacDonald
Background/Objectives: Casein glycomacropeptide (cGMP) has been modified to enable its suitability as a low phenylalanine (Phe) protein substitute (PS) in phenylketonuria (PKU). No data is available about its global usage. Methods: A 60-item multiple choice and short answer/extended response questionnaire examining the use of modified cGMP in PKU was distributed globally to dietitians and physicians via web-based professional inherited metabolic disorder groups. Results: Respondents (n = 208) from 45 countries across 6 continents completed the questionnaire. Of these, 83.7% (n = 174) were dietitians/nutritionists, 14.9% (n = 31) medical doctors/physicians and 1.4% (n = 3) other health professionals, caring for both paediatric and adult patients (59.1%), paediatrics only (25.0%) or adults only (15.9%). cGMP PS were reported as not available in their centre/hospital by 19.7% (n = 41), mostly in Africa, South America, and southern and western Asia. The main reasons included lack of regulatory approval (65.8%), not promoted by manufacturers (41.5%), and cost (29.3%). An estimated 25% of represented patients globally were using cGMP PS; 78.4% (n = 163) following refusal/poor adherence with Phe-free amino acids and 54.8% (n = 114) for adult patients recommencing dietary treatment. There were concerns about the residual Phe in cGMP negatively impacting blood Phe levels in children <12y (66.3%), adolescents (48.0%), adults (34.6%), and the first trimester of pregnancy (53.1%). Sixty nine percent (n = 145) adjusted dietary Phe prescription according to the cGMP Phe content, particularly in regions with a higher percentage of severe PKU variants. Commonly perceived clinical advantages with cGMP were improved taste/palatability (93.2%, n = 194) and fewer gastrointestinal symptoms (55.8%, n = 116). Perceived clinical disadvantages were residual Phe (72.1%, n = 150), lack of data in children < 3 years (48.1%, n = 100), and the high energy content of some brands (45.2%, n = 94). There were concerns that cGMP PS were too high in sugar (34.1%, n = 71) and dissatisfaction or uncertainty about the adequacy of its Phe (66.3%) and amino acid (34.1%) content. Conclusions: There is global inconsistency in access to cGMP PS suitable for PKU, and in the interpretation of evidence-based research. Some professionals have significant concerns about its nutritional composition particularly residual Phe, limiting its estimated use to approximately 25% of PKU patients globally.
Background/Objectives: Casein glycomacropeptide (cGMP) has been modified to enable its suitability as a low phenylalanine (Phe) protein substitute (PS) in phenylketonuria (PKU). No data is available about its global usage. Methods: A 60-item multiple choice and short answer/extended response questionnaire examining the use of modified cGMP in PKU was distributed globally to dietitians and physicians via web-based professional inherited metabolic disorder groups. Results: Respondents (n = 208) from 45 countries across 6 continents completed the questionnaire. Of these, 83.7% (n = 174) were dietitians/nutritionists, 14.9% (n = 31) medical doctors/physicians and 1.4% (n = 3) other health professionals, caring for both paediatric and adult patients (59.1%), paediatrics only (25.0%) or adults only (15.9%). cGMP PS were reported as not available in their centre/hospital by 19.7% (n = 41), mostly in Africa, South America, and southern and western Asia. The main reasons included lack of regulatory approval (65.8%), not promoted by manufacturers (41.5%), and cost (29.3%). An estimated 25% of represented patients globally were using cGMP PS; 78.4% (n = 163) following refusal/poor adherence with Phe-free amino acids and 54.8% (n = 114) for adult patients recommencing dietary treatment. There were concerns about the residual Phe in cGMP negatively impacting blood Phe levels in children <12y (66.3%), adolescents (48.0%), adults (34.6%), and the first trimester of pregnancy (53.1%). Sixty nine percent (n = 145) adjusted dietary Phe prescription according to the cGMP Phe content, particularly in regions with a higher percentage of severe PKU variants. Commonly perceived clinical advantages with cGMP were improved taste/palatability (93.2%, n = 194) and fewer gastrointestinal symptoms (55.8%, n = 116). Perceived clinical disadvantages were residual Phe (72.1%, n = 150), lack of data in children < 3 years (48.1%, n = 100), and the high energy content of some brands (45.2%, n = 94). There were concerns that cGMP PS were too high in sugar (34.1%, n = 71) and dissatisfaction or uncertainty about the adequacy of its Phe (66.3%) and amino acid (34.1%) content. Conclusions: There is global inconsistency in access to cGMP PS suitable for PKU, and in the interpretation of evidence-based research. Some professionals have significant concerns about its nutritional composition particularly residual Phe, limiting its estimated use to approximately 25% of PKU patients globally. Read More