High prevalence of low bone mineral density in young adults with phenylketonuria

Although osteopenia, osteoporosis and low BMD have been reported in PKU, conflicting data also exist. Our study of a large adult cPKU cohort strongly supports previously published limited data that suggest male sex and low BMI confer a higher risk for low BMD in cPKU; and age, Phe levels and dietary adherence do not. In our study, although the patients were young, low BMD was quite common (25%). Bone health should be evaluated even in young adults with cPKU, especially in males and those with low BMI, regardless of treatment compliance and vitamin-mineral status. Prospective studies reporting on clinical outcomes such as bone pain or fractures will be valuable in the coming years.