Nutritional status in patients with protein metabolism disorders. Case-control study

Patients with protein metabolism disorders (PMDs) require a diet with strict protein control that can affect their growth and development. The aim of the study was to assess nutritional status and growth in patients with PMDs undergoing dietary treatment.

Prospective observational case-control study in 63 patients with PMDs and 63 healthy controls matched for age and sex. We collected data for anthropometric variables (weight, height, BMI, tricipital and subscapular skinfolds, arm and waist circumference) and calculated the corresponding z scores. We also estimated the body fat mass and classified patients into nutritional status categories.

The overall analysis found a lower height z score in patients with PMDs and an equal proportion of overweight and obesity with respect to controls (30.2%). When we divided patients with PMDs into 2 groups (phenylketonuria and other aminoacidopathies), we found that patients with phenylketonuria had a height that was similar to the height of controls and significantly higher compared to patients with other aminoacidopathies. When it came to nutritional status, the prevalence of overweight and obesity was greater in the phenylketonuria group (45.5%), while underweight and short stature were more frequent in the group with other aminoacidopathies.

Not all patients with PMDs follow the same growth pattern, and their body composition is variable. In our sample, the group of patients with phenylketonuria had an adequate height but also a higher prevalence of overweight and obesity. On the other hand, patients with other aminoacidopathies had a higher prevalence of underweight and lower z scores for height and arm circumference.