The success of dietary protein restriction in alkaptonuria patients is age‐dependent

• Published in: Journal of inherited metabolic disease 1998-12, Vol.21 (8), p.791-798
• Main Authors: Haas, V., Carbasius Weber, E. C., Klerk, J. B. C., Bakker, H. D., Smit, G. P. A., Huijbers, W. A. R., Duran, M., Poll‐The, B. T.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aging; Alkaptonuria - complications; Alkaptonuria - diagnosis; Alkaptonuria - diet therapy; Aminoacid disorders; Behavior; Biological and medical sciences; Child; Child, Preschool; Diet, Protein-Restricted; Errors of metabolism; Female; Homogentisic Acid - urine; Humans; Male; Medical sciences; Metabolic diseases; Patient Compliance; Pigmentation Disorders - etiology; Social Behavior
• ISSN: 0141-8955; 1573-2665
• DOI: 10.1023/A:1005410416482

Alkaptonuria is characterized by an increased urinary excretion of homogentisic acid, pigmentation of cartilage and connective tissues, and ultimately the development of inflammatory arthropathy. Various diets low in protein have been designed to decrease homogentisic acid excretion and to prevent the ochronotic pigmentation and arthritic lesions. However, limited information is available on the long‐term beneficial effects of these diets. We reviewed the medical records of 16 patients aged 3–27 years (4>18 years) to ascertain the age of diagnosis, growth, development, social behaviour, signs of complications and longitudinal dietary compliance. The diagnosis of alkaptonuria was made at an average age of 1.4 years (2 months–4 years); following the diagnosis all patients were prescribed a diet with a protein content of 1.5 g/kg per day. All patients showed normal growth and development, and no major complications of the disease. Behavioural problems associated with poor dietary compliance emerged as the main problem. Dietary compliance decreased progressively with age. The effect of dietary protein restriction in homogentisic acid excretion was studied by fixing the amounts of protein in the diet at 1 g/kg per day and 3.5–5 g/kg per day during 8 days. Twelve patients, aged 4–27 years, participated in the investigation. Protein restriction resulted in a significantly lower excretion of homogentisic acid in the urine of children younger than 12 years (p