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ORIGINAL RESEARCH article

Front. Endocrinol.
Sec. Translational and Clinical Endocrinology
Volume 16 - 2025 | doi: 10.3389/fendo.2025.1488215
This article is part of the Research Topic Endocrine Imbalances of Mineral Ions and Vitamins in Chronic Disease Pathogenesis View all 11 articles

Adults with Phenylketonuria have suboptimal bone mineral density apart from Vitamin D and calcium sufficiency

Provisionally accepted
Beatrice Hanusch Beatrice Hanusch 1Anne Schlegtendal Anne Schlegtendal 2Corinna Grasemann Corinna Grasemann 3Thomas Lücke Thomas Lücke 1,3,4Kathrin Sinningen Kathrin Sinningen 1*
  • 1 Research Department of Child Nutrition, University Children's Hospital of Ruhr-University Bochum, St. Josef-Hospital, Ruhr-University Bochum, Bochum, Germany
  • 2 Department of Paediatric Pulmonology, University Children's Hospital of Ruhr University Bochum, St. Josef-Hospital, Ruhr-University Bochum, Bochum, Germany
  • 3 Department of Rare Diseases, University Children's Hospital of Ruhr University Bochum, St. Josef-Hospital, Ruhr-University Bochum, Bochum, Germany
  • 4 Department of Neuropediatrics and Metabolism, University Children's Hospital of Ruhr University Bochum, St. Josef-Hospital, Ruhr-University Bochum, Bochum, Germany

The final, formatted version of the article will be published soon.

    Introduction: Improvement of early diagnosis and treatment in patients with Phenylketonuria (PKU) allowed for healthy survival into adulthood of these patients but non-neurological health impairments of unknown etiology emerged. One of these is impaired bone health which manifests in adolescence and adulthood, potentially depending on treatment-adherence but also on additional lifestyle factors and nutrition. Methods: 18 adults with PKU (18.3 – 51.6 years, ♀ n = 11) and 19 age- and gender-matched controls (18.3 – 54.9 years, ♀ n = 10) participated in the study. Bone metabolism-related parameters (BMRP) in plasma, serum and urine were analyzed. Dietary habits and lifestyle factors were obtained from questionnaires, a 6-minute walk test and a Dual X-ray Absorptiometry (DXA) measurement at two sites were performed. Phenylalanine (Phe) serum concentrations from the 5 years prior to study participation were collected from the patients’ charts. Results: Patients had reduced bone mineral density (BMD) T-Score in hips (-0.67 ± 1.05) and lumbar spine (-0.71 ± 1.11, both p = 0.018). Most BMRP in plasma, serum and urine, as well as markers of oxidative stress did not differ from healthy controls. While 89% of adults with PKU were Vitamin D sufficient, only 68% of controls reached Vitamin D sufficiency. 25-OH Vitamin D concentration was significantly higher in adults with PKU than in controls (33.1 ng/ml [26.2 – 40.3] vs. 23.4 ng/ml [17.2 – 24.9]; p < 0.001), whereas parathyroid hormone concentrations showed no difference (PKU: 27.6 pg/ml [19.6 – 42.8] vs. Co: 36.1 pg/ml [29.2 – 40.8]; p = 0.089). Neither Phe blood concentration nor dietary habits or lifestyle factors were associated with BMD in regression analysis. Conclusion: Neither dietary habits nor lifestyle factors showed an association with BMD in this group of adults with PKU, while BMD was reduced.

    Keywords: aromatic amino-acids, bone turnover, Dietary compliance, Calciotropic hormones, Oxidative Stress, dietary habits

    Received: 29 Aug 2024; Accepted: 14 Jan 2025.

    Copyright: © 2025 Hanusch, Schlegtendal, Grasemann, Lücke and Sinningen. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Kathrin Sinningen, Research Department of Child Nutrition, University Children's Hospital of Ruhr-University Bochum, St. Josef-Hospital, Ruhr-University Bochum, Bochum, Germany

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