Nutrient Intake and Nutritional Status in Adult Patients with Inherited Metabolic Diseases Treated with Low-Protein Diets: A Review on Urea Cycle Disorders and Branched Chain Organic Acidemias

• Published in: Nutrients Vol. 12; no. 11; p. 3331
• Main Authors: Francini-Pesenti, Francesco, Gugelmo, Giorgia, Lenzini, Livia, Vitturi, Nicola
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 29-10-2020; MDPI
• Subjects: Adult; adult patients; Amino Acid Metabolism, Inborn Errors - diet therapy; Amino Acid Metabolism, Inborn Errors - physiopathology; Amino acids; Amino Acids, Branched-Chain - metabolism; Body Composition; Body mass; Chain branching; Chains; Children; Diet; Diet, Protein-Restricted - methods; Eating - physiology; Enteral nutrition; Enzymes; Fat body; Female; Food; Glycerol; Health services; Humans; inherited metabolic diseases; Lean body mass; Life expectancy; Life span; Low protein diet; Male; Metabolic disorders; Metabolites; Micronutrients - analysis; Nitrogen; Nutrient deficiency; Nutrient status; Nutrition; Nutritional Status; organic acidurias; Parenteral nutrition; Patients; Pediatrics; Proteins; Questionnaires; Review; Treatment Outcome; Urea; urea cycle; Urea Cycle Disorders, Inborn - diet therapy; Urea Cycle Disorders, Inborn - physiopathology; low protein diet; urea cycle; organic acidurias; adult patients; inherited metabolic diseases
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu12113331

Low-protein diets (LPDs) are the main treatment for urea cycle disorders (UCDs) and organic acidemias (OAs). In most cases, LPDs start in childhood and must be continued into adulthood. The improved life expectancy of patients with UCDs and OAs raises the question of their consequences on nutritional status in adult subjects. As this topic has so far received little attention, we conducted a review of scientific studies that investigated the nutrient intake and nutritional status in adult patients with UCDs and branched chain organic acidemias (BCOAs) on LPD.
The literature search was conducted in PubMed/MEDLINE, Scopus, EMBASE and Google Scholar from 1 January 2000 to 31 May 2020, focusing on nutrient intake and nutritional status in UCD and OA adult patients.
Despite protein restriction is recommended as the main treatment for UCDs and OAs, in these patients, protein intake ranges widely, with many patients who do not reach safety levels. When evaluated, micronutrient intake resulted below recommended values in some patients. Lean body mass resulted in most cases lower than normal range while fat body mass (FM) was often found normal or higher than the controls or reference values. Protein intake correlated inversely with FM both in adult and pediatric UCD patients.
The clinical management of adult patients with UCDs and BCOAs should include an accurate assessment of the nutritional status and body composition. However, as little data is still available on this topic, further studies are needed to better clarify the effects of LPDs on nutritional status in adult UCD and BCOA patients.