A three-year longitudinal study comparing bone mass, density, and geometry measured by dxa, pqct, and bone turnover markers in children with pku taking l-amino acid or glycomacropeptide protein substitutes

Anne Daly, Wolfgang Högler, Nicola Crabtree, Nick Shaw, Sharon Evans, Alex Pinto, Richard Jackson, Catherine Ashmore, Júlio C. Rocha, Boyd J. Strauss, Gisela Wilcox, William D. Fraser, Jonathan C.Y. Tang, Anita Macdonald

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

In patients with phenylketonuria (PKU), treated by diet therapy only, evidence suggests that areal bone mineral density (BMDa) is within the normal clinical reference range but is below the population norm. Aims: To study longitudinal bone density, mass, and geometry over 36 months in children with PKU taking either amino acid (L-AA) or casein glycomacropeptide substitutes (CGMP-AA) as their main protein source. Methodology: A total of 48 subjects completed the study, 19 subjects in the L-AA group (median age 11.1, range 5–6 years) and 29 subjects in the CGMP-AA group (median age 8.3, range 5–16years). The CGMP-AA was further divided into two groups, CGMP100 (median age 9.2, range 5–16years) (n = 13), children taking CGMP-AA only and CGMP50 (median age 7.3, range 5–15years) (n = 16), children taking a combination of CGMP-AA and L-AA. Dual X-ray absorptiometry (DXA) was measured at enrolment and 36 months, peripheral quantitative computer tomography (pQCT) at 36 months only, and serum blood and urine bone turnover markers (BTM) and blood bone biochemistry at enrolment, 6, 12, and 36 months. Results: No statistically significant differences were found between the three groups for DXA outcome parameters, i.e., BMDa (L2–L4 BMDa g/cm2 ), bone mineral apparent density (L2–L4 BMAD g/cm3 ) and total body less head BMDa (TBLH g/cm2 ). All blood biochemistry markers were within the reference ranges, and BTM showed active bone turnover with a trend for BTM to decrease with increasing age. Conclusions: Bone density was clinically normal, although the median z scores were below the population mean. BTM showed active bone turnover and blood biochemistry was within the reference ranges. There appeared to be no advantage to bone density, mass, or geometry from taking a macropeptide-based protein substitute as compared with L-AAs.

Original languageEnglish
Article number2075
JournalNutrients
Volume13
Issue number6
DOIs
Publication statusPublished - Jun 2021

Keywords

  • Amino acid protein substitute
  • Blood biochemistry
  • Bone mineral density
  • Bone turnover markers
  • Casein glycomacropeptide
  • Osteoporosis
  • PKU

Fingerprint

Dive into the research topics of 'A three-year longitudinal study comparing bone mass, density, and geometry measured by dxa, pqct, and bone turnover markers in children with pku taking l-amino acid or glycomacropeptide protein substitutes'. Together they form a unique fingerprint.

Cite this