| First Author | Solverson P | Year | 2012 |
| Journal | PLoS One | Volume | 7 |
| Issue | 9 | Pages | e45165 |
| PubMed ID | 23028819 | Mgi Jnum | J:191864 |
| Mgi Id | MGI:5463502 | Doi | 10.1371/journal.pone.0045165 |
| Citation | Solverson P, et al. (2012) Low bone strength is a manifestation of phenylketonuria in mice and is attenuated by a glycomacropeptide diet. PLoS One 7(9):e45165 |
| abstractText | PURPOSE: Phenylketonuria (PKU), caused by phenylalanine (phe) hydroxylase loss of function mutations, requires a low-phe diet plus amino acid (AA) formula to prevent cognitive impairment. Glycomacropeptide (GMP), a low-phe whey protein, provides a palatable alternative to AA formula. Skeletal fragility is a poorly understood chronic complication of PKU. We sought to characterize the impact of the PKU genotype and dietary protein source on bone biomechanics. PROCEDURES: Wild type (WT; Pah(+/+)) and PKU (Pah(enu2/enu2)) mice on a C57BL/6J background were fed high-phe casein, low-phe AA, and low-phe GMP diets between 3 to 23 weeks of age. Following euthanasia, femur biomechanics were assessed by 3-point bending and femoral diaphyseal structure was determined. Femoral ex vivo bone mineral density (BMD) was assessed by dual-energy x-ray absorptiometry. Whole bone parameters were used in principal component analysis. Data were analyzed by 3-way ANCOVA with genotype, sex, and diet as the main factors. FINDINGS: Regardless of diet and sex, PKU femora were more brittle, as manifested by lower post-yield displacement, weaker, as manifested by lower energy and yield and maximal loads, and showed reduced BMD compared with WT femora. Four principal components accounted for 87% of the variance and all differed significantly by genotype. Regardless of genotype and sex, the AA diet reduced femoral cross-sectional area and consequent maximal load compared with the GMP diet. CONCLUSIONS: Skeletal fragility, as reflected in brittle and weak femora, is an inherent feature of PKU. This PKU bone phenotype is attenuated by a GMP diet compared with an AA diet. |
