Body fat percentage in adolescents with phenylketonuria and associated factors

OBJECTIVE: To evaluate the percentage of body fat (% BF) in adolescents with PKU and to relate it to protein consumption, physical activity level, body mass index (BMI), sexual maturity and metabolic control. METHOD: This is a cross-sectional study conducted with 94 adolescents between 10 and 20 years of age, with early diagnosis and continuous treatment. Bioimpedance, weight measurements, height and BMI calculation were performed. Questionnaires were applied to quantify protein ingestion and establish the level of physical activity. Sexual maturity was assessed using the Tanner criteria. The annual mean of serum phenylalanine was used as a control parameter of the disease. A multivariate linear regression analysis was performed. RESULTS: Overweight, obesity, the female sex and the percentage of protein consumption explain 94.1% of the % BF of the patients (p < .05). The overweight prevalence was 19.1%. It was verified that 96.7% of the sample were sedentary. Only 50 (53.2%) of the adolescents had good treatment compliance, and no relationship was found between this variable and the % BF (p = .706). CONCLUSIONS: Being female and presenting high BMI values are important factors associated with % BF in phenylketonuric adolescents. Disease control and protein consumption do not seem to influence the body composition.